Goodman CAUF, CAPF, CAPT, CHPF, CSCF User Manual

Service Instructions

ComfortNet™

ASXC, DSXC, and GSXC Condensing Units,

ASZC, DSZC and GSZC

with R-410A Refrigerant

Blowers, Coils, & Accessories

Split System Heat Pumps

This manual is to be used by qualified, professionally trained HVAC technicians only. Goodman
does not assume any responsibility for property damage or personal injury due to improper
service procedures or services performed by an unqualified person.

Copyright © 2015-2017 Goodman Manufacturing Company, L.P.

is a registered trademark of Maytag Corporation or its related companies and is used under license to Goodman Company, L.P., Houston, TX. All rights reserved.

RS6200007r14

December 2017

IMPORTANT INFORMATION

Pride and workmanship go into every product to provide our customers with quality products. It is possible, however, that
during its lifetime a product may require service. Products should be serviced only by a qualified service technician who is
familiar with the safety procedures required in the repair and who is equipped with the proper tools, parts, testing instruments
and the appropriate service manual. REVIEW ALL SERVICE INFORMATION IN THE APPROPRIATE SERVICE MANUAL BEFORE

BEGINNING REPAIRS.

IMPORTANT NOTICES FOR CONSUMERS AND SERVICERS

RECOGNIZE SAFETY SYMBOLS, WORDS AND LABELS

WARNING

O

NLY PERSONNEL THAT HAVE BEEN TRAINED TO INSTALL, ADJUST, SERVICE OR

REPAIR (HEREINAFTER

MANUAL SHOULD SERVICE THE EQUIPMENT

BE RESPONSIBLE FOR ANY INJURY OR PROPERTY DAMAGE ARISING FROM

IMPROPER SERVICE OR SERVICE PROCEDURES

ASSUME RESPONSIBILITY FOR ANY INJURY OR PROPERTY DAMAGE WHICH MAY

RESULT

. IN

LICENSES TO SERVICE THE EQUIPMENT SPECIFIED IN THIS MANUAL, ONLY

LICENSED PERSONNEL SHOULD SERVICE THE EQUIPMENT

INSTALLATION, ADJUSTMENT, SERVICING OR REPAIR OF THE EQUIPMENT

SPECIFIED IN THIS MANUAL, OR ATTEMPTING TO INSTALL, ADJUST, SERVICE OR

REPAIR THE EQUIPMENT SPECIFIED IN THIS MANUAL WITHOUT PROPER

TRAINING MAY RESULT IN PRODUCT DAMAGE, PROPERTY DAMAGE, PERSONAL

INJURY OR DEATH

, “

SERVICE

”)

THE EQUIPMENT SPECIFIED IN THIS

. THE

MANUFACTURER WILL NOT

. IF

YOU SERVICE THIS UNIT, YOU

ADDITION, IN JURISDICTIONS THAT REQUIRE ONE OR MORE

. I

MPROPER

.

T

O PREVENT THE RISK OF PROPERTY DAMAGE, PERSONAL INJURY, OR DEATH,
DO NOT STORE COMBUSTIBLE MATER IALS OR USE GASOLINE OR OTHER
FLAMMABLE LIQUIDS OR VAPORS IN THE VICINITY OF THIS APPLIANC E.

To locate an authorized servicer, please consult your telephone book or the dealer from whom you purchased this product.
For further assistance, please contact:

CONSUMER INFORMA TION LINE

GOODMAN® BRAND PRODUCTS

TOLL FREE

1-877-254-4729 (U.S. only)

email us at: [e-mail]

fax us at: [phone]

(Not a technical assistance line for dealers.)

Outside the U.S., call 1-713-861-2500.

(Not a technical assistance line for dealers.) Your telephone company will bill you for the call.

is a registered trademark of Maytag Corporation or its related companies and is used under license to Goodman Company, L.P., Houston, TX. All rights reserved.

email us at: [e-mail]

AMANA® BRAND PRODUCTS

TOLL FREE

1-877-254-4729 (U.S. only)

fax us at: [phone]

(Not a technical assistance line for dealers.)

2

IMPORTANT INFORMATION

SAFE REFRIGERANT HANDLING

While these items will not cover every conceivable situation, they should serve as a useful guide.

WARNING

REFRIGERANTS ARE H EAVIER T HAN AIR. THEY CAN "PUS H OUT" THE

OXYGEN IN YOUR LUNGS OR IN ANY ENCLOSED SPACE.
POSSI BLE DIFFI CULTY IN BRE ATHIN G OR DEATH:

EVER PURGE REFRIGERANT INTO AN ENCLOSED ROOM OR SPACE. BY

•

N

LAW, ALL REFRIGERANTS MUST BE RECLAIMED.

IF AN INDOOR LEAK IS SUSPECTED, THOROUGHLY VENTIL ATE THE AREA

•
BEFORE BEGINNING WORK.

IQUID REFRIGERANT CAN BE VERY COLD. TO AVOID POSSIBLE FROST-

•

L

BITE OR BL INDNESS, AVOID CONTACT W ITH REFR IGERANT AND WEAR

I

GLOVES AND GOGGLES.
SKIN OR EYES, SEEK MEDICAL HELP IMMEDIATELY.

A

LWAYS FOLLOW

•
AS POIS ONOUS GA S WILL BE PRODUC ED.

F LIQUID REFRIGERANT DOES CONTACT YOUR

EPA

REGULATIONS. NEVER BURN REFRIGERANT,

O AVO ID

T

WARNING

HE UNITED STATES ENVIRONME NTAL PROTECTION AGENCY ( "

T

HAS ISSUED VARIOUS REGULATIONS REGARDING THE INTRODUCTION AN D
DISPOSA L OF REFRI GERANTS INTRODUC ED INTO T HIS UNIT .
FOLLOW T HESE REGU LATIONS MAY HARM TH E ENVIRON MENT AND CAN
LEAD TO THE H IMPOSI TION O F SUBSTAN TIAL FIN ES.
MAY VARY BY JURISDICTION.

EPA OFFICE.

LOCAL

SHOULD QUEST IONS ARI SE, CO NTACT YOUR

THESE REGULATIONS

EPA

AILURE TO

F

WARNING

TO AVOID POSSIBLE EXPLOSION:

EVER APPL Y FLAME O R STEA M TO A REFR IGERAN T CYLINDE R. IF YOU

•

N

MUST HEA T A CYLIND ER FOR FAS TER CHARG ING, PARTI ALLY IMME RSE
IT IN WARM WATER.

NEVER FILL A CYLINDER MORE THAN 80% FULL OF LIQUID REFRIG ERANT.

•

NEVER ADD ANYTHING OTHER T HAN R-22 TO AN R-22 CYLINDER OR

•

R-410A TO AN R-410A CYLINDER. THE SERVICE EQUIPMENT USED MUST

BE LISTED OR CERTIFIED FOR THE TYPE OF REFRIGERANT USED.

TORE CYLIN DERS IN A COOL, DRY PL ACE. NEVER US E A CYLIND ER

•

S

AS A PLATFORM OR A ROLLER.

WARNING

TO AVOID POSSIBLE EXPLOSION, USE ONLY RETURNABLE (NOT DISPOSABLE)

SERVICE CYLINDERS WHEN REMOVING REFRIGERANT FROM A SYSTEM.

•

ENSURE THE CYLINDER IS FREE OF DAMA GE WHICH COULD LEAD TO A

LEAK OR EX PLOS ION.

•

")

ENSURE THE HYDROST ATIC TEST DATE DOES NO T EXCEED 5 YEARS.

•

ENSURE THE PRESSURE RATING MEETS OR EXCEEDS 400 LBS.

WHEN IN DOUBT, DO NOT USE CYLINDER.

WARNING

WARNING

SYSTEM CONTAMINANTS, IMPROPER SERVICE PROCEDURE AND/OR PHYSICAL

ABUSE AFFECTING HERMETIC COMPRESSOR ELE CTRICAL TERMINALS MAY
CAUSE DANGEROUS SYSTEM VENTING.

The successful development of hermetically sealed refrigera­tion compressors has completely sealed the compressor's
moving parts and electric motor inside a common housing,
minimizing refrigerant leaks and the hazards sometimes
associated with moving belts, pulleys or couplings.

Fundamental to the design of hermetic compressors is a
method whereby electrical current is transmitted to the
compressor motor through terminal conductors which pass
through the compressor housing wall. These terminals are
sealed in a dielectric material which insulates them from the
housing and maintains the pressure tight integrity of the
hermetic compressor. The terminals and their dielectric
embedment are strongly constructed, but are vulnerable to
careless compressor installation or maintenance proce­dures and equally vulnerable to internal electrical short
circuits caused by excessive system contaminants.

T

O AVOID POSSIBLE INJURY, EX PLOSION OR DEATH, PRACTICE SAFE

HANDLING OF RE FRIGERANTS.

In either of these instances, an electrical short between the
terminal and the compressor housing may result in the loss
of integrity between the terminal and its dielectric embed­ment. This loss may cause the terminals to be expelled,
thereby venting the vaporous and liquid contents of the
compressor housing and system.

A venting compressor terminal normally presents no danger
to anyone, providing the terminal protective cover is properly
in place.

If, however, the terminal protective cover is not properly in
place, a venting terminal may discharge a combination of

(a ) hot lubricating oil and refrigerant
(b ) flammable mixture (if system is contaminated

with air)

in a stream of spray which may be dangerous to anyone in the
vicinity. Death or serious bodily injury could occur.

Under no circumstances is a hermetic compressor to be
electrically energized and/or operated without having the
terminal protective cover properly in place.

See Service Section S-17 for proper servicing.

3

PRODUCT IDENTIFICATION

s

ASXC 160241 AA

1 2 3 4,5 6 6 7 8,9

ComfortNet™

Brand

A - Ama na® bra nd Maj or/Mi nor Revi si on

D - Deluxe Goodman® brand

G - Goodman® brand

Type 1 - 208/230V Single-Phase 60 Hz

S 3 - 208/230V Three-Phase 60 Hz

Split Sys tem

4 - 460V Three-Phase 60 Hz

Type

C: Condenser R-22

H: Heat Pump R-22 024 - 2 Tons

X: Condenser R-410A 036 - 3 Tons

Z: Heat Pump R-410A 048 - 4 Tons

060 - 5 Tons

Communication Feature

C: 4-Wi re Communicati on Ready

SEER

16 - 16 SEER

18 - 18 SEER

Engineering

Voltage

Nominal Capacity

4

PRODUCT IDENTIFICATION

A

=

ComfortNet™

CAP F 1824 A 6 A

1 2 3 4 5,6,7,8 9 10 11,12

Brand Engineering*

C Indoor Coi l

Unit Application 2 = R-22

A Upflow/Downflow Coi l

H Horizontal A-Coil

Horizontal Slab Coil

S

Coated Coils

T

Nominal Width for Gas Furnace

A = Fits 14" Furna ce Cabinet

B = Fits 17-1/2" Furnace Cabi net

C =

Fits 21" Furnace Cabinet

D = Fits 24-1/2" Furnace Cabinet
N

Does Not Apply (Horizontal Slab Coils

Major/Minor Revisions

Refrigerant Charge

4 = R-410A

6 = R-410A or R-22

Cabinet Finish

U Unpainted

PPainted

N Unpai nted Ca se

Expansion Device

FFlowrator
T 4 - 5 Tons

Expansi on Valve 4 - 5 Tons

1824 =

3030 =

3131 =

3636 =

3642 =

3743 =

4860 = Factory-Installed Non-Adjustable

4961 =

Nominal Capacity @ 13 SEER

1-1/2 - 2 Tons

2-1/2 Tons

2-1/2 Tons

3 Tons

3 - 3-1/2 Tons

3 - 3-1/2 Tons

5

PRODUCT IDENTIFICATION

H

MB V C 12 00 A A 1

1,2 3 4 4 5,6 7 8 9

ComfortNet™

Brand

MB - Modular Blower 1: 208-230V/60Hz/1 P

Type A: First Seri es

Speed

V:

Communication Feature A: No Circui t Br eaker

C: 4-Wire Communication Ready

Airflow

12:

1200 CFM

16:

1600 CFM

20:

2000 CFM

B: Ci rcuit Breaker

Elect rical

Design Se ries

Circuit Breaker

Factory Heat

00 No Heat

6

PRODUCT IDENTIFICATION

A V P T C 1830 1 6 AA

1 2 3 4 5 6,7,8,9 11 12 13,14

ComfortNet™

Brand

A Airhandler

Unit Application

Vari a bl e Sp eed Motor

V

Cabinet Finish

U: Unpa inted

P: Painted 1 208/240V, 1 Phase, 60 Hz

N: Uncas ed

Expansion Device

F: Fl owrator

T: Expansion Valve

Communications

C: 4-Wire Communi cati on Ready

Multi-Position & Downflow Applications

Ceiling Mount & Wall Mount Applications

Maj or/Mi nor Revi si ons

1830 = 1-1/2 to 2-1/2 Tons

3137 = 3 Tons

4260 = 3-1/2 to 5 Tons

Engineering*

Refrigerant Charge

No Di git = R-22 Onl y

6 = R-410A or R-22

Electrical

Nominal Capacity

7

PRODUCT IDENTIFICATION

A

V

PTC18B1 4AA

1 2 3 4 5 6,7 8 9 10 11,12

ComfortNet™

Brand

A Si ngl e Piec e

Ai rhandl er

Unit Application

C Ceiling Mount PSC Motor 4 = R-410a

R Multi Position PSC Motor

S Multi Posi tion EEM Motor

W Wall Mount PSC/EEM Motor 1 208/240V, 1 Phase, 60 Hz

VMulti Position

Variable Speed Motor -

Communi cating

Cabinet Finish

U Unpainted

PPainted

NUncased

Expansion Device

FFlowrator 31 = 2 Tons

TExpansion Valve 33 = 1 1/2 - 2 Tons

Communications

ComfortNet

C

TM

Compatible

*Not used for inventory management

Nominal Capacity

Major/Minor Revisions

18 = 1-1/2 Tons

24 = 2 Tons

25 = 2 Tons

29 = 2 Tons

30 = 2-1/2 Tons

36 = 3 Tons

37 = 2 1/2 - 3 1/2 Tons

39 = 2 1/2 - 3 Tons

42 = 3-1/2 Tons

48 = 4 Tons

49 = 3 - 3 1/2 Tons

59 = 4 - 5 Tons

60 = 5 Tons

61 = 4 - 5 Tons

Engineering*

Refrige rant Charge

Electrical

Cabinet Width

B = 17-1/2"

C = 21"

D = 24-1/2"

All Airhandlers use DIRECT DRIVE MOTORS. Power supply is AC 208-230v, 60 hz, 1 phase.

8

PRODUCT IDENTIFICATION

ASXC16

MANA® BRAND SPLIT

A

Model/Rev Description

ASXC160 **1AA

AS XC160601BA Use ZPS49 compress or.

AS XC160481BA Smart Coi l® coil s

AS XC160(24/36)1BB Wi ring diagram updat ed wit h notes .

AS XC160(48-60)1BB Motor changed t o Nidec.

Introduces Amana® brand 2-stage 16 SEER condensing units with R-410A,
communicati ng m o dels.

OMMUNICATING CONDENSERS R-410A 16 SEER

X-C

ASXC160 (2 4/36)1BC
ASXC160 (4 8- 60) 1BC

ASXC160 (2 4/36)1BD
ASXC160 (4 8- 60) 1BD

AS XC160(241, 481)B E Refrigerant charge reduction

AS XC160(24,36,48,60)1CA 16 SE ER 2-Stage AC Developm ent with improved performance.

Ultrat ec h® 2.0 c ompressor change.

Replaced P CB HR103 Communicating Heat P um p Control B oard wit h PCBHR104
Communicating Heat P um p Control Board.

ASXC18

MANA® BRAND SPLIT

A

Model/Rev Description

ASXC18**1AA

AS XC180(36/48/ 60)1AB Wi ring di agram updated wit h not es .

ASXC180 (3 6/48-60)1AC

Initial release of Amana® brand 2-st age 18 SEER condensing units with R-410A ,
communicati ng m o dels.

Replaced compressors ZP S 20K4EPFV230 with ZPS20K5E P F V130 and compressor
ZPS30K4EPFV230 with ZPS30K5EPFV130.

OMMUNICATING CONDENSERS R-410A 18 SEER

X-C

ASXC180 (3 6/48/60)1AD

ASXC180 48 1BB

Replaced P CB HR103 Communicating Heat P um p Control B oard wit h PCBHR104
Communicating Heat P um p Control Board.

[Design Improvement]: Updating shared data for 18 SEER, 2-stage, 4 ton AC in
com m unicating installat i ons. Releasi ng m inor revision for affec ted models

9

PRODUCT IDENTIFICATION

GSXC16

OODMAN® BRAND SPLIT

G

Model / Re v Description

GSXC160( 24/36/48/60)1CA

OODMAN® BRAND SPLIT

G

Model / Rev Description

GSXC180( 24/36/48/60)1BA

GSXC180481BB

OMM UNICA T IN G CONDENSERS R-410A 16 SEER

X-C

16 SEER 2-Stage AC Development wi t h i m proved performan c e.

GSXC18

OMM UNICA T ING CONDEN SERS R-410A 18 SEER

X-C

18 SEER 2-Stage AC Development with improved performance.

[Design Improvement]: Updating shared data for 18 SEER, 2-stage, 4 ton AC in
communic a t i ng i nstall ations . Releasi n g m i no r revision for affect ed m odel s

10

PRODUCT IDENTIFICATION

DSXC16

ELUXE SPLIT

D

Model/Rev Description

DSXC160**1AA

DSXC160(24/36)1AB Wiring diagram updat ed with notes.

DSXC160(24/36)1AC
DSXC160(48-60)1BC

DSXC160481BA Sm artCoil ® coils.

DSXC160601BA ZPS49K compress or.

DSXC160(48-60)1BB Motor c hanged t o Nidec.

DSXC160241AF
DSXC160481BE

Initial release of Goodman® Deluxe brand 2-st age 16 S E ER condensing units with R­410A, communicating models.

Ult ratech® 2.0 compressor.

Refri gerant charge reduction

OMMUNICATING CONDENSERS R-410A 16 SEER

X-C

DSXC18

DELUXE SPLIT X-C

Model/Rev Description

DSXC18**1AA

DSXC180(36/48/60] 1AB W i ring di agram updat ed wit h not es.

DSXC18036AC

DSXC180(48-60)1AC Ult ratech® 2.0 compress or c hange.

Initial release of Goodm an® Deluxe brand 2-s tage 18 SEE R c ondens ing uni t s with R­410A, communic ating models .

Replaced c om pres sors ZPS20K4E P F V230 with ZPS20K5E P F V 130 and c om pres s or
ZPS30K4EPFV230 with ZPS30K5EPFV130.

OMMUN ICATING CONDENSERS R-410A 18 SEER

11

PRODUCT IDENTIFICATION

Model/Rev Description

ASZC160**1AA

MANA® BRAND SPLIT

A

Introduces A m ana ® brand 2-stage 16 SE ER heat pum p u ni ts with R-410A,
com municating m odel s.

OMMUNICATING HEAT PUMP R-410A 16 SEER

Z-C

ASZC16

ASZC160(24/36)1AB
ASZC160(48/60)1AB

ASZC160(24-48)1AC
ASZC160601BA

ASZC160(24-36])1AD
ASZC160601BB

ASZC160(24-36)1AE

AS ZC160481A E Ult rat e ch® 2. 0 compres sor change.

ASZC160[24/36/48/60]1C A

Sanhua ( RA NCO) reversing valves

Releas e of mod el s with accum ul ators and crankcase heaters.

Mot or changed t o Ni dec.

Replaced compres sors ZPS20K4EP F V 230 wit h ZPS20K 5E P F V 130 and com pres s or
ZPS30K4EPFV230 with ZPS30K5EPFV130.

Replac ed compres sors with Copeland's UltraTech™ 3 l i neup . Trans i tioned coils to 7mm.
Offers improved performance.

ASZC18

Model/Rev Description

ASZC180**1AA

MANA® BRAND SPLIT

A

Introduces A m ana ® brand 2-stage 18 SE ER heat pum p u ni ts with R-410A,
com municating m odel s.

OMMUNI CATING HEAT PUMPS R-410 A 18 SEER

Z-C

ASZC180601BC
ASZC180601BB

ASZC180(36/48/60)1A B Relea se of models with accum ul ators and crankcase heaters.

ASZC180(36-4)]1AC
ASZC180601BA
ASZC180361AD

ASZC180[24/36/48/60]1C A

Ult rat e ch® 2. 0 compres sor change.

Sanhua ( RA NCO) reversing valves

Replac ed compres sors with Copeland's UltraTech™ 3 l i neup . Trans i tioned c oils to 7mm.
Offers improved performance.

12

PRODUCT IDENTIFICATION

GSZC16

OODMAN® BRAND SPLIT

G

Model/Re v Description

GSZC160[24/36/48/60]

OODMAN® BRAND SPLIT

G

Model/Rev Descripti on

GSZC180[24/36/48/60]

OMMUN ICATING HEAT PUMP R-410A 16 SEER

Z-C

Replaced c om pres s ors with Copeland's UltraTech™ 3 l ineup. Transit i oned c oi ls
to 7mm . O ffers improved performance.

GSZC18

OMMUNICATING HEAT PUMP R-410A 16 SEER

Z-C

Replac ed c om pressors wi t h Copel and's Ul t raTech™ 3 li neup. Transiti oned coils
to 7m m. Offers i m proved performance.

13

PRODUCT IDENTIFICATION

DSZC16

ELUXE SPLIT

D

Model/Rev Description

DSZC16**1AA

DSZC160( 24 /36)1AB
DSZC160( 48 /60)1AB

DSZC160( 24 - 48) 1 AC
DSZC160601 BA

DSZC160( 24 - 48) ]1AD
DSZC160601 BB
DSZC160481 AE
DSZC160601 BC

DSZC160( 24 - 36) 1 AE

Initial release of Goodman® brand Deluxe 2-st age 16 S E ER heat pump units with R­410A, communicating models.

Sanh ua (RANCO) revers i ng valves .

Release of models wi t h ac cumulators and crankcase heaters.

Ultrat ec h® 2.0 com pres sor change.

Replaced c om pres sors ZPS20K4E P F V230 with ZPS20K5E P F V 130 and c om pres s or
ZPS30K4EPFV230 with ZPS30K5EPFV130.

OMMUN ICATING HEA T PUMP R-410A 16 SEER

Z-C

DSZC18

DELUXE SPLIT Z-C

Model/Rev Description

DSZC18**1AA

Initial release of Goodm an® brand Delux e 2-s t age 18 S E E R heat pum p unit s with R­410A, communic ating models .

OMMUN ICATING HEAT PUMP R-410A 18 SEER

DSZC180(36/ 48/ 60)1A B Sanhua (RANCO) reversing valves.

DSZC180361 AD

DSZC180( 36 - 48) 1 AC
DSZC180601 BA

DSZC160( 24 - 48) 1 AD
DSZC160601 BB

Replaced c om pres sors ZPS20K4E P F V230 with ZPS20K5E P F V 130 and c om pres s or
ZPS30K4EPFV230 with ZPS30K5EPFV130.

Release of models wi t h ac cumulators and crankcase heaters.

Ultrat ec h® 2.0 com pres sor change.

AVPTC****14

SINGLE PIECE AIR HANDLER MULTIPLE-POSITION VA RIA BLE SPEED

AINTED TXV WITH 4 -WIRE COMMUNICATING CON TROL

P

Model/Rev Description

AVPTC183014AA
AVPTC313714AA
AVPTC426014AA

AVPTC183014AB
AVPTC313714AB
AVPTC426014AB

Initial release of 13 SEER air handler with communicating control and serial
com m unicating indoor blower mot or.

Replaced P CBJA 10 c om m unicating air handler c ont rol board wit h P CB JA103.

14

PRODUCT IDENTIFICATION

AVPTC**14

SINGLE PIECE AIR HANDLER MULTIPLE-POSITION VARIABLE SPEED

AINTED TXV WITH 4-WIRE COMMUNICATING CONTROL

P

Model/Re v Description

AVPTC24B14AA
AVPTC(30/36)C14AA
AVPTC(42/48/60)D14AA

AVPTC48C14AA Updated S&R and travel labels.

Initial release of 13 SEER air handler with communicating control and serial
comm uni cating indoor blower motor. Redes ign of AV PTC models to new ai r handler
cabinetry. Incorporated 4-way, mult-position body utilized on ARTP/ASPt mdoels.

AVPTC(42/48/60)14AB

AVPTC60D14AC Serial plate update

AVPTC24B14AC
AVPTC30C14AB

AVPTC25B14AA
AVPTC29B14AA
AVPTC31C14AA
AVPTC37B14AA
AVPTC37C14AA
AVPTC37D14AA
AVPTC49D14AA
AVPTC59C14AA
AVPTC59D14AA
AVPTC61D14AA

AVPTC33C14AA
AVPTC39C14AA
AVPTC49C14AA

AVPTC35B14AA Introducing 2.5 and 3 Ton Air Handler product lines.

Redesign of AVPTC models to new air handler cabinetry. Incorporated 4-way, mul t ­position body utilized on ARTP/ASPt mdoels.

Heater Kit ai rflow update.

AV PTC Effi cienc y Upgrades
The new A V P TC redesign will i ncorporat e t he upgrade blower, c oil pan and coi l design
int e nded to inc rease effici en cy and standard i ze production.

Upgrade the current AVPTC C-49 cabinets to include 1. quality improvements captured in
Ready15 design. 2.include redesi gned drain pan, Morrison blower hous i ng and Em ers on
NXT Booster Charge Adjustable TXV.

AVPTC[31,37,39,49,59]C14AB
AVPTC[37,59,61]D14AB

AVPTC[25,29, 37]B14AB
AVPTC33C14AB
AVPTC[31, 37,39,49,59]C14AC
AVPTC49D14AB
AVPTC[37,59,61]D14AB

AVPTC35B14AA

Revis ions because of New Heater kit s released

Air handler revisions due to us i ng an upgraded (thic ker with higher R value)
Quietflex wrapper insulation.

The SR plate format i s chang i ng from SR075 to SR099 and in ord er to track t hi s chan ge
a minor revision is nec essary.

15

PRODUCT IDENTIFICATION

MBVC

ODULAR BLOWER AIR HAN DLER V-MULT I-POSITION VARIABL E-SPEED

M

OMMUNICAT ING REA D Y W/4-WIRES

C

Model/Rev Description

MBVC1200AA1-AA
MBVC1600AA1-AA
MBVC2000AA1-AA

MBVC1200AA1-AB
MBVC1600AA1-AB
MBVC2000AA1-AB

MBVC1200AA1-AC
MBVC1600AA1-AC
MBVC2000AA1-AC

MBVC1200AA1-AD
MBVC1600AA1-AD
MBVC2000AA1-AD

MBVC[1200,1600,2000]A A 1-A E Release of MBR/MBVC Models (M inor Revisions) for 11th St Plant. - Dayton to Houston

Introducti on of module blower with variabl e s peed blower motor wit h t he new
comm uni c at i ng c ont rol & s erial c om m unicating indoor blower motor.

Introducti on of a module blower with variable speed blower mot or wit h communic at ing
cont rol & s eri al c om m unicating indoor blower motor. Replac es exist ing E m ers on motors
(013M00111 & 013M00112).

Introducti on of a module blower with variable speed blower mot or wit h communic at ing
cont rol & s eri al c om m unicating indoor blower motor. Quali t y improvement t o us e 0.75"
Quiet Flex Insulation.

Introducti on of a module blower with variable speed blower mot or wit h communic at ing
cont rol & s eri al c om m unicating indoor blower motor. Introduc es a new Communic ating Air
Handler Control Board (PC).

MBVC[1200,1600,2000]AA1-AF

Add permanent s eali ng/ condensation-c ont rol upgrades t o all MB units and remove high­volt age knockout s

CAUF

INDOOR COIL A-UPFLOW/DOWNFLOW UNCASED FLOWRATOR

C-

Model/Rev Description

CAUF*****6AA Initial release of CAUF Dayton Upflow/ Downfl ow coil s .
CAUF*****6BA Burr Oak Louvered Fin released in place of the Wavy Fin.
CAUF****6*DA Replace d
CAUF*****6DB Drain pan material c hanged.

CAUF1824A6RDB
CAUF1824B6RDB

CAUF36***CA Redesign from 2 row to 3 row for performanc e im provement .
CAUF3030(A/B)6RDB

CAUF3030(C/D)6RDB
CAUF3131(B/C)6RDB

Manufact uring Loc at i on Change from Dayton t o Hous t on. Designated by "R".

Manufact uring Loc at i on Change from Dayton t o Hous t on. Designated by "R".

exi s ting copper coi ls and other ass ociated parts with aluminum components .

16

PRODUCT IDENTIFICATION

CHPF

-INDOOR COIL HORIZONTAL A-COIL PAINTED FLOWRATOR

C

Model/Rev Description

CHPF*****6AA Intial release of 13 S E E R CHPF horizont al A c oi l.

CHPF*****6BA

CHPF1824A6CA
CHPF2430B6CA
CHPF3636B6CA
CHPF3642C6CA
CHPF3642D6CA
CHPF3743C6BA
CHPF3743D6BA
CHPF4860D6DA

CHPF1824A6CB
CHPF2430B6CB
CHPF3636B6CB
CHPF3642C6CB
CHPF3642D6CB
CHPF3743C6BB
CHPF3743D6BB
CHPF4860D6DB

CHPF1824A6CC
CHPF2430B6CC
CHPF3636B6CC
CHPF3642C6CC
CHPF3642D6CC
CHPF3743C6BC
CHPF3743D6BC
CHPF4860D6DC

Released B urr Oak Louvered Fin in place of the Wavy F i n. The rows changed by one, (i. e.
4 row to 3 row; 3 row to 2 row) where appli cable.

Louvered fins. Replaced copper tube hairpins wi t h al umi num hairpins.

Drain pan material change to a Decabromodipheny l E t her free resin.

Change to prepainted wrappers

17

PRODUCT IDENTIFICATION

CAPF

INDOOR COIL A-UPFLOW/DOWNFLOW PAINTED FLOWRATOR

C-

Model/Rev Description

CAPF*****6A A Initial release of CAPF Dayt on Upflow/Downflow coils .
CAPF*****6B A Burr Oak Louvered Fin released in place of the Wavy F in.
CAPF36***CA Redesigned for performance improvement from 2 row t o 3 row.
CAPF* ****6DA Replaced exi sting c opper c oil s and other ass ociated parts with aluminum components .
CAPF*****6DB Drain pan mat erial c hanged.

CAPF182 4A6DC
CAPF182 4B6DC
CAPF182 4C 6D C
CAPF303 0A6DC
CAPF303 0B6DC
CAPF303 0C 6D C
CAPF303 0D 6D C
CAPF313 1B6DC
CAPF313 1C 6D C
CAPF313 7B6AB
CAPF363 6A6DC
CAPF363 6B6DC
CAPF363 6C 6D C
CAPF363 6D 6D C
CAPF364 2C 6D C
CAPF364 2D 6D C
CAPF374 3C 6D C
CAPF374 3D 6D C
CAPF486 0C 6D C
CAPF486 0D 6D C
CAPF496 1C 6D C
CAPF496 1D 6D C

Redesign t he wrapper for the CAPF t o provide increased eas e of ins tallati on.

C-

Model/Rev Description

CAPT3131B4BA
CAPT3131C4BA

CAPT3743C4AA
CAPT3743D4AA

CAPT4961C4AA
CAPT4961D4AA

CAPT3131B4AB
CAPT3131C4AB
CAPT3743C4AB
CAPT3743D4AB
CAPT4961C4AB
CAPT4961D4AB

18

INDOOR

CAPT

COIL

UPFLOW /DOWNFLOW PAINTED CASED FLOWRATOR W/TXV

A-

Initial release of coils with factory-installed, non-adjus table TXV . Single s t age A HRI ratings
for CAPT3131 NTC combinat i ons .

Initial release of single s t age A HRI ratings for CAPT3743 NTC c ombi nat i ons .

Initial release of single s t age A HRI ratings for CAPT4961C4 NTC com binations.

Redesign t he wrapper for the CAPT to provide inc reased ease of inst all at i on.

PRODUCT IDENTIFICATION

CSCF

INDOOR COIL S-HORIZONTAL SLAB COIL C-UNPAINTED FLOWRATOR

C-

Model/Rev Description

CSCF*****6AA Initial release of 13 SEER CSCF horizontal slab coils.
CSCF*****6BA

CSCF1824N6BB
CSCF3036N6BB
CSCF3642N6CB
CSCF4860N6CB

CSCF1824N6CA
CSCF3036N6CA
CSCF3642N6CA
CSCF4860N6CA

Burr Oak Louvered F in releas ed i n place of the Wavy Fin. Rows reduc ed by one where
applicable.

Drain pan material changed.

Replaced c opper c oil s and other ass oc i at ed part s with alumi num components .

19

ACCESSORIES

ComfortNet™

ASXC/DSXC 16
ASXC/DSXC/GSXC 18

Model Description

ABK-20 Anchor B racket Kit X X X X X X X X

ASXC16024
DSXC16024

ASXC16036
DSXC16036

ASXC16048
DSXC16048

ASXC16060
DSXC16060

ASXC18024
DSXC18024
GSXC18024

ASXC18036
DSXC18036
GSXC18036

ASXC18048
DSXC18048
GSXC18048

ASXC18060
DSXC18060
GSXC18060

TX2N4A TXV Kit

TX3N4 TXV Kit

TX5N4 TXV Kit

CSR-U-1 Hard-start Kit

CSR-U-2 Hard-start Kit
CSR-U-3 Hard-start Kit

1

FSK01A
LSK02*

B1141643

* Contains 20 brackets; four brackets needed to anchor unit to pad.
Installed on the indoor coil.
Available in 24V legacy mode only. This feature is integrated in the communicating mode.
This component is included in the CTK0*** communicating thermostat kit.

Freeze Prot ection Kit
Liquid Line Solenoid

Valve

3

24V Transformer

XX

XX

XX X X

XX

XX

XX X X

XXXXX X X X

XXXXX X X X

XXXXX X X X

ASZC/DSZ C 16
ASZC/DSZ C 18

Model Description

ASZC16024
DSZC16024

ABK-20Anchor Bracket KitXXXXXXX

1

TX2N4
TX3N4
TX5N4

TXV Kit X

1

TXV Kit X X

1

TXV Kit X X X X
CSR- U-1 Hard -star t Kit X X X
CSR- U-2 Hard -star t Kit X X X X X X
CSR- U-3 Hard -star t Kit X X X X

2

FSK01A

LSK02*

OT18-60A

B1141643

Freeze Protection KitXXXXXXX

Liquid Line Solenoid

Valve

Outdoor Thermostat/

3

Lockout Thermostat

4

24V TransformerXXXXXXX

XXXXXXX

XXXXXXX

ASZC16036
DSZC16036

ASZC16048
DSZC16048

ASZC16060
DSZC16060

ASZC18036
DSZC18036

ASZC18048
DSZC18048

ASZC18060
DSZC18060

20

* Conta ins 20 bracke t s; four brack et s needed to ancho r unit to pad

1

Field -installed, non-bleed, ex p ans i on valve k i t - Condensing unit s and heap pumps wi t h reciprocat i ng c o mp res sors require t he

use of s t art -assist com ponent s when used in conjunct i on with an indoor coil using a non-bleed the rmal expansion valve

refrigerant

2

Insta ll ed on t he i ndoor c oi l

3

Available in 24V l egacy mode onl y. This feature is integrat ed i n t he c om m uni c ating mode. Requi red for heat pum p appl ications

where ambient t em pe rat ure fall bel ow 0 °F with 50% or higher relat i ve humidit y.

4

This c om ponent i s incl uded in the CTK 0*** c omm unic at ing t hermost at kit.

ACCESSORIES

EXP ANSION VALVE KITS

1/4 FLARE CONNECTION

BULB TO BE LOCATED
AT 10 OR 2 O'CLOCK

For Applications requiring

a field installed access fitting

EVAPORATOR COIL

EVAPORATOR COIL

1/4' F L A RE
CONNECTION

SEAL SUPP L IE D W/ KIT

REMOVE BEFORE INSTALLI NG EXP ANS IO N VALVE

SUCTION LINE

BULB

EXPANSION VALVE

SUCTION LINE

EXPANSION VALVE

BULB

SEAL SUPPLIED W/ KIT

BULB TO BE LOCATED
AT 10 OR 2 O'CLOCK

DISTRIBUTOR
BODY

For Applications not requiring

a field installed access fitting

DISTRIBUTOR
BODY

7/8" NUT

PISTON

SEAL

PISTON

SEAL

TAILPIECE

3/8"­SWEAT

TAILPIECE

3/8"­SWEAT

SEAL SUPPLIED W/ KIT

REMO VE BEFORE
INSTALLING
EXPANSION VALVE

SEAL SUPPLIED W/ KIT

7/8" NUT

21

ACCESSORIES

Wire Nut

FSK01A

FREEZE THERMOSTAT

KIT

Y

k

c

a

l

B

k

c

a

l

B

Wire Nut

Y

Install Line

Thermostat

Here

Install Line
Thermostat

Here

B

l

a

c

B

l

Wire Nut

Wire Nut

Y

k

a

c

k

Y

22

ACCESSORIES

BLOWER

ELECTRIC HEAT KIT

NO HEAT

MBVC1200 AA-1* *
MBVC1600 AA-1* *
MBVC2000 AA-1* *

X = A llowable combinations

- = Restricted combinations

-XXXXXX- - -

-XXXXXX- - -

-XXXXX- X- -

ELECTRIC HEAT KIT APPLICATIONS - MBVC

HKR-03*

^ = Circuit 1: Single P hase for A ir Handler Motor
Circuit 2: 3-Phase for HKR3 Heater Kits

HKR05-(C)'

HKR-06*

HKR-08(C)*

HKR-10(C)*

HKA-15C*

HK* SERIES ELETRIC HEA T KITS -

HKA-20C*

^HKR3-15*

^HKR3-20A

23

ACCESSORIES

ELECTRIC HEAT KIT APPLICATIONS - A VPTC

MODELS HKR-03* HKR-05*/-05C* HKR-06* HKR-08*/-08C* HKR-10*/-10C* HKR-15C* HKR-20C* HKR-21C* HKA-15C* HKA-20C*

AVPTC183014A* X X X
AVPTC313714A* X X X

AVPTC426014A* X X X X X X X3 X3 X

* Revision level that may or may not be designated.
C Circuit breaker option.

NOTE:
When 8kW and 10kW heat kits are used with an AVPTC1830 and AVPTC3137, matched with 2- ton outdoor unit, see Note 1 below.

1

Set Heater Kit dip switches 9, 10 and 11 to 6kW setting (9-ON, 10-OFF,11-ON) to obtain 840 CFM.

2

This heater kit can only be used for ‘1000 CFM or higher’ applications.

3

This heater kit can only be used for ‘1200 CFM or higher’ applications.

1

X

1

X

1

X

1

X

--- --- --- --- ---

X 2 --- ---

2

X

X

3

X

24

ACCESSORIES

p

p

p

p

p

AVPTC**14**

Heat Kit Applications

Type / Model 24B14-A* 30C14-A* 36C14-A* 48C14-A* 42D14-A*

HKSX03XC X X X
HKSX05XC XXXXXXX
HKSX06XC XXXXXXX
HKSX08XC XXXXXXX

HKSX10XC XXXXXXX
HKSX15XF* XXXXX
HKSX20XF* XXXXX

HKSC05XC XXXXXXX

HKSC08XC XXXXXXX

HKSC10XC XXXXXXX

HKSC15XA XXXXX

HKSC15XB XXXXX
HKSC15XF* XXXXX
HKSC19CA* X X
HKSC19CB* X X

HKSC20DA XXX

HKSC20DB XXX

HKSCX20XF* XXXXX

HKSC25DC* XX

* Revision level that may or may not be designated.

Refer to the minimum airflow requirements for each of the heat kits.

AVPTC

†

48D14-A*

††

60D14-A*

†††

†For m atch u p wi th a 2 ton outdoo r uni t: Hea ter ki t ap pli caƟon shall not exceed 10 kW.

Airflow for 5 kW u

††For ma tch u

Airflo w for 5 kW u

†††For ma tch u

Airflo w for 5 kW u

** 3 kW heater kit is not applicable for this indoor application.

to 10 kW hea ter ki ts s hall be s et to 850 cfm speed tap of ON-ON-ON.

wi th a 3 ton ou tdoo r uni t: Hea ter ki t applicaƟon shall not exceed 15 kW.

to 15 kW hea ter ki ts s hall be s et to 1400 cfm speed tap of ON-ON-OFF.

wi th a 3.5 ton ou tdoo r uni t: Hea ter ki t applicaƟon shall not exceed 20 kW.

to 20 kW hea ter ki ts s hall be s et to 1620 cfm speed tap of ON-ON-OFF

25

ACCESSORIES

READY 15 AVPTC

Model AVPTC25B14 AVPTC29B14 AVPTC31C14 AVPTC33C14 AVPTC35B14 AVPTC39C14 AVPTC37B14 AVPTC37C14 AVPTC37D14 AVPTC49C14 AVPTC49D14 AVPTC59C14 AVPTC59D14 AVPTC61D14

HKSX03XC XX XX X

HKSX05XC XXXXXXXXXXXXXX

HKSX06XC XXXXXXXXXXXXXX

HKSX08XC XXXXXXXXXXXXXX

HKSX10XC XXXXXXXXXXXXXX

HKSC05XC XXXXXXXXXXXXXX

HKSC08XC XXXXXXXXXXXXXX

HKSC10XC XXXXXXXXXXXXXX

HKSC15XA XXXXXXXXXXX

HKSC15XB XXXXXXXXX XXXXX

HKSC15XF XXXXXXXX

HKSC19CA XXXX

HKSC19CB XXXXX

HKSC19CH X

HKSC20DA X

HKSC20DB XXX

HKSC20DH XX

HKSC20XF XXXX

HKSC25DA X

HKSC25DB X

26

PRODUCT DESIGN

This section gives a basic description of cooling unit opera­tion, its various components and their basic operation.
Ensure your system is properly sized for heat gain and loss
according to methods of the Air Conditioning Contractors
Association (ACCA) or equivalent.

CONDENSING UNIT

The condenser air is pulled through the condenser coil by a
direct drive propeller fan. This condenser air is then dis­charged out of the top of the cabinet. These units are
designed for free air discharge, so no additional resistance,
like duct work, shall be attached.

The suction and liquid line connections on present models
are of the sweat type for field piping with refrigerant type
copper. Front seating valves are factory installed to accept
the field run copper. The total refrigerant charge for a normal
installation is factory installed in the condensing unit.

ASXC, ASZC, DSXC, DSZC models are available in 2
through 5 ton sizes and use R-410A refrigerant. They are
designed for 208/230 volt single phase applications.

ASXC, ASZC, DSXC, DSZC R-410A model units use the
Copeland Scroll "Ultratech" Series compressors which are
specifically designed for R-410A refrigerant. These units also
have Copeland
ComfortAlert diagnostics are integrated into the unitary (UC)
control. These models are ComfortNetTM ready.

There are a number of design characteristics which are
different from the traditional reciprocating and/or scroll com­pressors.

"Ultractech" Series scroll compressors will not have a dis­charge thermostat. Some of the early model scroll compres­sors required discharge thermostat.

"Ultratech" Series scroll compressors use "POE" or
polyolester oil which is NOT compatible with mineral oil
based lubricants like 3GS. "POE" oil must be used if
additional oil is required.

The ASXC [16 & 18], ASZC [16 & 18], DSXC [16 & 18] and
DSZC [16 & 18] series split system units use a two-stage
scroll compressor. The two-step modulator has an internal
unloading mechanism that opens a bypass port in the first
compression pocket, effectively reducing the displacement
of the scroll. The opening and closing of the bypass port is
controlled by an internal electrically operated solenoid.

®

ComfortAlert diagnostics. The Copeland

The ZPS two-step modulated scroll uses a single step of
unloading to go from full capacity to approximately 67%
capacity. A single speed, high efficiency motor continues to
run while the scroll modulates between the two capacity
steps.

FIGURE A

A scroll is an involute spiral which, when matched with a
mating scroll form as shown, generates a series of crescent
shaped gas pockets between the two members.

During compression, one scroll remains stationary (fixed
scroll) while the other form (orbiting scroll) is allowed to orbit

®

(but not rotate) around the first form.

As this motion occurs, the pockets between the two forms
are slowly pushed to the center of the two scrolls while
simultaneously being reduced in volume. When the pocket
reaches the center of the scroll form, the gas, which is now
at a high pressure, is discharged out of a port located at the
center.

During compression, several pockets are being compressed
simultaneously, resulting in a very smooth process. Both the
suction process (outer portion of the scroll members) and the
discharge process (inner portion) are continuous.

Some design characteristics of the Compliant Scroll com­pressor are:

• Compliant Scroll compressors are more tolerant of liquid
refrigerant.

NOTE: Even though the compressor section of a Scroll
compressor is more tolerant of liquid refrigerant, contin­ued floodback or flooded start conditions may wash oil
from the bearing surfaces causing premature bearing
failure.

27

PRODUCT DESIGN

• Compliant scroll compressors perform "quiet" shutdowns
that allow the compressor to restart immediately without
the need for a time delay. This compressor will restart
even if the system has not equalized.

NOTE: Operating pressures and amp draws may differ
from standard reciprocating compressors. This informa­tion can be found in the unit's Technical Information
Manual.

CAPACITY CONTROL - COMFORTNET

TM

MODELS

During the compression process, there are several pockets
within the scroll that are compressing gas. Modulation is
achieved by venting a portion of the gas in the first suction
pocket back to the low side of the compressor thereby
reducing the effective displacement of the compressor. See
Figure A. Full capacity is achieved by blocking these vents,
increasing the displacement to 100%. A solenoid in the
compressor, controlled by an external 24-volt ac signal,
moves the slider ring that covers and uncovers these vents.
The vent covers are arranged in such a manner that the
compressor operates somewhere around 67% capacity
when the solenoid is not energized and 100% capacity when
the solenoid is energized. The loading and unloading of the
two step scroll is done “on the fly” without shutting off the
motor between steps. See Figure C below. The unloaded
mode default was chosen for two reasons:

Molded Plug*

Line

Run Capacitor

Line

Internal Unloader
Coil

24 vdc

*Rectifier is integrated on the UC PC B

FIGURE C

1. It is expected that the majority of run hours will be in the
low capacity, unloaded mode.

2. It allows a simple two-stage thermostat to control capac­ity through the second stage in both cooling and possibly
heating if desired.

18 to 28 volt ac. The coil power requirement is 20 VA. The
external electrical connection is made with a molded plug
assembly. This plug is connected to the Communicating
Unitary Control PCB (UC PCB) which contains a full wave
rectifier to supply direct current to the unloader coil.

COILS AND BLOWER COILS

MBVC blower cabinets are designed to be used as a two­piece blower and coil combination and can be utilized with the
CAUF, CAPF and CAPT coils for upflow and downflow
applications. The CACF and CHPF coils are designed for
horizontal applications. This two-piece arrangement allows
for a variety of mix-matching possibilities providing greater

flexibility.
The MBVC blower cabinets use a variable speed motor that

maintains a constant airflow with a higher duct static. MBVC
blower cabinets are approved for applications with cooling
coils of up to 0.8 inches W.C. external static pressure. The
MBVC models allow airflow trimming of +/-10%.

All units are constructed with R-4.2 insulation. In areas of
extreme humidity (greater than 80% consistently), insulate
the exterior of the blower with insulation having a vapor barrier
equivalent to ductwork insulation, providing local codes
permit.

AVPTC Multi-Position Air Handler

AVPTC is a multi-position, variable-speed air handler used
with R-410A and are available in 2 to 5 ton sizes with optional
3 kW to 25kW electric heat kits available for field installation.
The AVPTC unit’s blower design includes a variable-speed
ECM motor and is compatible with heat pumps and variable­capacity cooling applications.

This appliance can be installed in the vertical or left horizontal
position without modification. The horizontal right and downflow
positions require product modification. This product is de­signed for zero inches (0 inches) clearance; however, ad­equate access for service or replacement must be consid­ered without removing permanent structure. This unit can be
installed on a platform when deemed necessary.

In an attic installation a secondary drain pan must be provided
by the installer and placed under the entire unit with a
separate drain line properly sloped and terminated in an area
visible to the owner. This secondary drain pan is required in
the event that there is a leak or main drain blockage. Closed
cell insulation should be applied to the drain lines in uncon­ditioned spaces where sweating may occur.

UNLOADER SOLENOID

A nominal 24-volt direct current coil activates the internal
unloader solenoid. The input control circuit voltage must be

28

PRODUCT DESIGN

NOTE: AVPTC air handlers are factory-sealed to achieve a

2% or less leakage rate at 1.0" water gauge external duct
static pressure.

Communicating Unitary Control (UC) PCB

The Communicating System Unitary Control PCB is a micro­processor-based control for heat pump and air conditioning
condensing units with single-phase compressors up to 5 ton
capacity operating on standard residential or Delta and Wye
commercial power. The control incorporates the basic func­tionality of existing defrost controls, outdoor thermostats,
contactors, compressor staging controls, short cycle con­trols, line voltage monitors, Comfort Alert™ or CoreSense
Module (dependent upon which module you are using), two
speed condenser fan relays and the Active Protection com­ponent of enabled thermostats. The control is designed to
work as part of a fully communicating HVAC system with 4
wires. The control also supports legacy 24VAC thermostat
inputs for Y1, Y2, O and 24VAC outputs for RVS, W1, and L
for non-communicating systems. Outputs include compres­sor power, compressor stage select, and outdoor fan high
and outdoor fan low speed. System inputs include high/low
pressure switches, as well as thermistor inputs for outdoor
coil temperature and outdoor air temperature.

29

SYSTEM OPERA TION

COOLING

The refrigerant used in the system is R-410A. It is a clear,
colorless, non-toxic and non-irritating liquid. R-410A is a
50:50 blend of R-32 and R-125. The boiling point at atmo­spheric pressure is -62.9°F.

A few of the important principles that make the refrigeration
cycle possible are: heat always flows from a warmer to a
cooler body. Under lower pressure, a refrigerant will absorb
heat and vaporize at a low temperature. The vapors may be
drawn off and condensed at a higher pressure and tempera­ture to be used again.

The indoor evaporator coil functions to cool and dehumidify
the air conditioned spaces through the evaporative process
taking place within the coil tubes.

NOTE: The pressures and temperatures shown in the
refrigerant cycle illustrations on the following pages are for
demonstration purposes only. Actual temperatures and pres­sures are to be obtained from the "Expanded Performance
Chart".

Liquid refrigerant at condensing pressure and temperatures,
(270 psig and 122°F), leaves the outdoor condensing coil
through the drier and is metered into the indoor coil through
the metering device. As the cool, low pressure, saturated
refrigerant enters the tubes of the indoor coil, a portion of the
liquid immediately vaporizes. It continues to soak up heat and
vaporizes as it proceeds through the coil, cooling the indoor
coil down to about 48°F.

Heat is continually being transferred to the cool fins and tubes
of the indoor evaporator coil by the warm system air. This
warming process causes the refrigerant to boil. The heat
removed from the air is carried off by the vapor.

As the vapor passes through the last tubes of the coil, it
becomes superheated. That is, it absorbs more heat than is
necessary to vaporize it. This is assurance that only dry gas
will reach the compressor. Liquid reaching the compressor
can weaken or break compressor valves.

The compressor increases the pressure of the gas, thus
adding more heat, and discharges hot, high pressure super­heated gas into the outdoor condenser coil.

In the condenser coil, the hot refrigerant gas, being warmer
than the outdoor air, first loses its superheat by heat trans­ferred from the gas through the tubes and fins of the coil. The
refrigerant now becomes saturated, part liquid, part vapor and
then continues to give up heat until it condenses to a liquid
alone. Once the vapor is fully liquefied, it continues to give up
heat which subcools the liquid, and it is ready to repeat the
cycle.

HEATING

The heating portion of the refrigeration cycle is similar to the
cooling cycle. By energizing the reversing valve solenoid coil,
the flow of the refrigerant is reversed. The indoor coil now
becomes the condenser coil, and the outdoor coil becomes
the evaporator coil.

The check valve at the indoor coil will open by the flow of
refrigerant letting the now condensed liquid refrigerant by­pass the indoor expansion device. The check valve at the
outdoor coil will be forced closed by the refrigerant flow,
thereby utilizing the outdoor expansion device.

COOLING CYCLE

For communicating room thermostat: When the room ther­mostat calls for either low stage cool or high stage cool,
appropriate commands are sent via the data 1 and data 2 lines
to the outdoor unit's UC control. The UC control energizes the
on-board compressor relay and the on-board outdoor fan
relay. The compressor high stage solenoid is energized if it
is a high stage call.

The UC control sends a fan command to the indoor unit (air
handler or furnace). The indoor unit operates the indoor
blower at the appropriate airflow level. The system operates
at the cooling level demanded by the thermostat.

When the thermostat is satisfied, appropriate commands are
sent to the UC control. The compressor relay and outdoor
fan relay is de-energized. The compressor high stage
solenoid is de-energized if it was energized. The UC control
sends an appropriate command to the indoor unit to de­energize the indoor blower motor.

If room thermostat fan status is set to be “on”, then indoor
blower would run continuously rather than cycling with the
compressor.

For heat pumps, the reversing valve is energized during the
cooling cycle. The call for cooling from the communicating
thermostat indicates to the control that the reversing valve is
to be energized during cooling operation.

HEATING CYCLE

For communicating room thermostat: When the room ther­mostat calls for either low stage heat or high stage heat,
appropriate commands are sent via the data 1 and data 2 lines
to the outdoor unit's UC control. The UC control energizes the
on-board compressor relay and the on-board outdoor fan
relay. The compressor high stage solenoid is energized if it
is a high stage call. The UC control sends a fan command
to the indoor unit (air handler or furnace). The indoor unit
operates the indoor blower at the appropriate airflow level.
The system operates at the cooling level demanded by the
thermostat.

When the thermostat is satisfied, appropriate commands are
sent to the UC control. The compressor relay and outdoor
fan relay is de-energized. The compressor high stage
solenoid is de-energized if it was energized. The UC control
sends an appropriate command to the indoor unit to de­energize the indoor blower motor.

30

SYSTEM OPERA TION

DEFROST CYCLE - COMFORTNETTM MODELS

The defrosting of the outdoor coil is jointly controlled by the
UC PCB and the outdoor coil temperature (OCT) sensor.

The OCT sensor is clamped to a feeder tube entering the
outdoor coil. Defrost timing periods of 30, 60, 90 or 120
minutes may be selected via the dipswitch settings on the UC
PCB. In a communicating system, the defrost timing periods
can also be selected in the communicating thermostat user
menu. During operation, if the coil temperature is low enough
(approximately 31° F), the microprocessor will accumulate
the compressor run time. When the total compressor run
time reaches 30, 60, 90 or 120 minutes, and there is a call for
heat, the PCB will initiate a defrost cycle. When the
microprocessor detects the coil temperature to be high
enough (approximately 75 0F), or 10 minutes of maximum
defrost cycle time has elapsed, whichever occurs first, the
defrost cycle is terminated and the timing period is reset. The
field service personnel can also advance a heat pump to the
defrost cycle by simultaneously pressing the “TEST” button
and the “RECALL” button on the UC board.

Use the dipswitches to select defrost time interval (30, 60, 90
or 120 minutes) See chart below

31

SYSTEM OPERA TION

COOLING CYCLE

Reversing Va lve

(Energized)

Indoor

Coil

HEATING CYCLE

Outdoor

Coil

Accumulator

Thermostatic

Expansion

Valve

Bi-Flow

Filter Dryer

Check Valve

32

Indoor

Coil

Reversing Va lve

(De-Energized)

Outdoor

Coil

Accumulator

Thermostatic

Expansion

Valve

Bi-Flow

Filter Dryer

Check Valve

SYSTEM OPERA TION

EXPANSION VALVE/CHECK VALVE ASSEMBLY

IN COOLING OPERATION

Most expansion valves used in current Goodman/Amana

use an internally checked expansion valve.

This type of expansion valve does not require an external check valve as shown above.

However, the principle of operation is the same.

EXPANSION VALVE/CHECK VALVE ASSEMBLY

IN HEATING OPERATION

®

Brand Heat Pump products

33

TROUBLESHOOTING CHART

COOLING/HP ANALYSIS CHART

Com plaint

PO SSIBLE CAUS E

DOTS IN ANALYSIS

GUIDE INDICATE

"POS S I BLE CAUS E"

Pow er Failure
Blow n Fuse
Loose Connection
Shorted or Broken Wires
Open Fan Overload
Faulty Thermostat
Faulty Transf ormer
Shorted or Open Capacitor
Internal Compressor Overload Open
Shorted or Grounded Compressor
Compressor Stuck
Faulty Compressor Contactor
Faulty Fan Relay
Open Control Circuit
Low Voltage
Faulty Evap. Fan Motor
Shorted or Grounded Fan Motor
Improper Cooling Anticipator
Shortage of Refrigerant
Restric ted Liquid Line
Open Element or Limit on Elec. Heater
Dirt y Air Filter
Dirty Indoor Coil
Not enough air across Indoor Coil
Too much air across Indoor Coil
Overcharge of Refr igerant
Dirty Outdoor Coil
Noncondensibles
Recirculation of Condens ing Air
Infiltration of Outdoor Air
Improperly Located Thermostat
Air Flow Unbalanced
System Undersized
Broken Internal Parts
Broken Valves
Inefficient Compressor
Wrong Type Expans ion Valve
Expansion Device Restricted
Oversized Expansion Valve
Undersized Expansion Valve
Expansion Valve Bulb Loose
Inoperative Expansion Valve
Loose Hold-dow n Bolts
Faulty Reversing Valve
Faulty Defros t Control
Faulty Defros t Thermostat
Flow rator Not Seating Properly

No Coolin g

SYMPTOM

System will not start

Compressor will not start - fan runs

Comp. and Cond. Fan will not start

Eva porator fan will not start

Condenser fan will not start

Compressor runs - goes off on overload

Compressor cycles o n overload

Unsatisfactory

Cooling/Heating

System runs continuously - little cooling/htg

Too cool and then too warm

•

•••

•••

••••••

••

••• •

••

• ••••

•

••

•••

•••

•

•

•••

••

••

••

••

•• •• •

♦♦

••• •

••• •

••• •

•• •

•• •

••

•• •

•••

••

••

••

•• ••

•

••• • ••

••• • •• •

••

••• • •

•• •

•

•

• Cooling or Heat ing Cycle (Heat Pump)

•••

System

Ope rating

Pressures

Not cool enough on warm days

Certain areas too cool, others too warm

Compressor is no isy

System runs - blows cold air in heating

Unit will not terminate de frost

Unit will not defrost

Low suction pr essure

Low head pressure

High suction pressure

High head pressure

♦

♦

♦

♦

♦

♦

♦

•

♦

••

♦

♦

••

♦
♦
♦

•

••

•

•

♦

••

•

♦♦♦ ♦♦♦
♦♦♦♦♦ ♦
♦♦♦♦♦♦♦

Heating Cycle Only (He a t Pum p)

♦

Test Method

Rem edy

See Service Procedure Ref.

Test Voltage S-1
Inspect Fuse Size & Type S-1
Inspect Connection - Tighten S-2, S-3
Test Circuits W ith Ohmmeter S-2, S-3
Test Continuity of Overload S-17A
Test Continuity of Thermos tat & Wiring S-3
Check Control Cir cuit with Voltmeter S-4
Test Capacitor S-15
Test Continuity of Overload S-17A
Test Motor Windings S-17B
Use Tes t Co rd S-1 7D
Tes t Continuity of Coi l & Contacts S-7, S - 8
Test Continuity of Coil And Contacts S-7
Test Control Circuit w ith Voltmeter S-4
Test Voltage S-1
Repair or Replac e S-16
Test Motor Windings S-16
Check Resistance of Anticipator S-3B
Test For Leaks, A dd Refrigerant S-101,103
Remove Restriction, Replace Restricted Part S-112
Test Heater Element and Controls S-26,S-27
Inspect Filter-Clean or Replace
Inspect Coil - Clean
Check Blow er Speed, Duct Static Press, Filter S-200
Reduce Blow er Speed S-200
Recover Part of Charge S-113
Inspect Coil - Clean
Recover Charge, Evacuate, Recharge S-114
Remove Obstruction to Air Flow
Check Window s, Doors, Vent Fans, Etc.
Relo c ate Thermostat
Readjust A ir V olume Dampers
Refigure Cooling Load
Replace Compressor S-115
Test Compressor Eff iciency S-104
Test Compressor Eff iciency S-104
Replace Valve S-110
Remove Restriction or Replace Expansion Device S-110
Replace Valve
Replace Valve
Tighten Bulb Bracket S-105
Check V alv e Ope ration S-110
Tighten Bolts
Replace Valve or Solenoid S-21, 122
Test Contr ol S-24
Test Defrost Thermostat S-25
Check Flowrator & Seat or Replace Flow rator S-111

34

SERVICING TABLE OF CONTENTS

S-1 CHECKING VOLT AGE ................................................ 35

S-2 CHECKING WIRING ................................................... 35

S-3E CTK0*** COMFORTNETTM THERMOST A T..............35

S-4 CHECKING TRANSFORMER

AND CONTROL CIRCUIT ......................................48

S-6 CHECKING TIME DELAY RELA Y ...............................48

S-8A CHECKING UNITARY (UC) CONTROL

COMPRESSOR CONT ACTOR/RELA Y

CONTACTS .............................................................48

S-9 CHECKING HIGH AND LOW VOLT AGE

TO ECM MOTOR..........................................................49

S-10A COPELAND COMFORT ALER T™..............................49

S-12 CHECKING HIGH PRESSURE CONTROL...............63

S-13 CHECKING LOW PRESSURE CONTROL................63

S-14 CHECKING HIGH AND LOW PRESSURE SWITCH

VOLTAGE .................................................................63

S-15 CHECKING CAP ACITOR ...........................................63

S-15A RESISTANCE CHECK USING A DIGIT AL

MULTI-METER.........................................................63

S-15B CAPACITANCE CHECK USING A DIGIT AL

MUL TI-METER (IN CAP ACIT ANCE MODE).............64

S-16G CHECKING EMERSON ULTRATECH™

ECM MOTORS ........................................................64

S-16H ECM CFM ADJUSTMENTS A VPTC/MBVC .................67

S-17 CHECKING COMPRESSOR ..................................... 75

S-17A RESIST ANCE TEST...................................................75

S-17B GROUND TEST .........................................................75

S-17C UNLOADER TEST PROCEDURE ............................ 76

S-17D OPERA TION TEST.................................................... 77

S-18 TESTING CRANKCASE HEATER

(OPTIONAL ITEM) ...................................................77

S-21 CHECKING REVERSING V AL VE

AND SOLENOID .....................................................77

S-24 TESTING DEFROST CONTROL................................77

S-26 TESTING TEMPERA TURE SENSORS

(COMFORTNET READY MODELS ONL Y) .............78

S-40A AVPTC/MBVC ELECTRONIC

BLOWER/HEA TER CONTROL...............................78

S-60 ELECTRIC HEA TER (OPTIONAL ITEM) .................... 83

S-61A CHECKING HEATER LIMIT CONTROL(S) ................84

S-61BCHECKING HEATER FUSE LINK..............................84

(OPTIONAL ELECTRIC HEA TERS) ....................... 84

S-62 CHECKING HEA TER ELEMENTS ............................. 84

S-100 REFRIGERATION REP AIR PRACTICE..................... 84

S-101 LEAK TESTING

(NITROGEN OR NITROGEN-TRACED) ................ 85

S-102 EV

S-103 CHARGING.................................................................86

S-104 CHECKING COMPRESSOR EFFICIENCY................87

S-106 OVERFEEDING ..........................................................87

S-107 UNDERFEEDING ....................................................... 87

S-108 SUPERHEAT .............................................................. 87

S-109 CHECKING SUBCOOLING........................................87

S-1 10 CHECKING EXP ANSION V AL VE OPERA TION..........88

S-112 CHECKING RESTRICTED LIQUID LINE .................. 88

S-113 OVERCHARGE OF REFRIGERANT ..........................88

S-114 NON-CONDENSABLES ............................................. 88

S-115 COMPRESSOR BURNOUT .......................................91

S-120 REFRIGERANT PIPING .............................................91

S-203 SINGLE PIECE AIR HANDLER EXTERNAL

S-203A TWO PIECE AIR HANDLER EXTERNAL

ACUA TION .............................................................85

STATIC PRESSURE............................................92

STATIC PRESSURE............................................92

35

SERVICING

S-1 CHECKING VOLTAGE

1. Remove outer case, control panel cover, etc., from unit
being tested.

With power ON:

WARNING

Line Voltage now present.

2. Using a voltmeter, measure the voltage across terminals
L1 and L2 of the contactor for the condensing unit or at the
field connections for the air handler or heaters.

ComfortNetTM Ready Condensing Units: Measure the
voltage across the L1 and L2 lugs on the unitary (UC)
control.

3. No reading - indicates open wiring, open fuse(s) no power
or etc., from unit to fused disconnect service. Repair as
needed.

4. With ample voltage at line voltage connectors, energize
the unit.

5. Measure the voltage with the unit starting and operating,
and determine the unit Locked Rotor Voltage. NOTE: If
checking heaters, be sure all heating elements are
energized.

Locked Rotor Voltage is the actual voltage available at
the compressor during starting, locked rotor, or a stalled
condition. Measured voltage should be above minimum
listed in chart below.

To measure Locked Rotor Voltage attach a voltmeter to
the run "R" and common "C" terminals of the compressor,
or to the T1 and T2 terminals of the contactor. Start the unit
and allow the compressor to run for several seconds, then
shut down the unit. Immediately attempt to restart the
unit while measuring the Locked Rotor Voltage.

ComfortNet Ready Condensing Units: To measure the
Locked Rotor Voltage, attach a voltmeter to the run "R"
and common "C" terminals of the compressor or across
the "R" and "C" lugs on the unitary (UC) control. Start the
unit and allow the compressor to run for several seconds,
then shut down the unit. Immediately attempt to restart
the unit while measuring the Locked Rotor Voltage.

6. Locked rotor voltage should read within the voltage tabu­lation as shown. If the voltage falls below the minimum
voltage, check the line wire size. Long runs of undersized
wire can cause low voltage. If wire size is adequate, notify
the local power company in regard to either low or high
voltage.

Unit Supply Voltage

Voltage Min. Max

208/230 197 253

460 414 506

NOTE: When operating electric heaters on voltages other
than 240 volts, refer to the System Operation section on
electric heaters to calculate temperature rise and air flow.
Low voltage may cause insufficient heating.

S-2 CHECKING WIRING

HIGH VOLTAGE!
Disconnect ALL power before servicing
or installing. Multiple power sources
may be pr es ent. Fa ilur e to do s o ma y
cause pro pe rty dam age , pe rs onal in jury
or death.

1. Check wiring visually for signs of overheating, damaged
insulation and loose connections.

2. Use an ohmmeter to check continuity of any suspected
open wires.

3. If any wires must be replaced, replace with comparable
gauge and insulation thickness.

S-3E CTK0*** COMFORTNETTM THERMOSTAT

COMFORTNET™ SYSTEM

The ComfortNet system (or CT system) is a system that
includes a ComfortNet compatible air handler/furnace/modu­lar blower and air conditioner or heat pump with a CTK0*
thermostat. Any other system configurations are considered
invalid ComfortNet systems and must be connected as a
tradition (or legacy) system. The table below compares the
valid CT systems.

CT compatible Air Handler or

Modular Blo w er

CT compatible Air Handler or

Modular Blo w er

A ComfortNet heating/air conditioning system differs from a
legacy/traditional system in the manner in which the indoor
unit, outdoor unit and thermostat interact with one another. In
a traditional system, the thermostat sends commands to the
indoor and outdoor units via analog 24 VAC signals. It is a
one-way communication path in that the indoor and outdoor
units typically do not return information to the thermostat.

On the other hand, the indoor unit, outdoor unit, and thermo­stat comprising a ComfortNet system “communicate” digi­tally with one another. It is now a two-way communications
path. The thermostat still sends commands to the indoor and
outdoor units. However, the thermostat may also request and
receive information from both the indoor and outdoor units.
This information may be displayed on the CT thermostat. The
indoor and outdoor units also interact with one another. The
outdoor unit may send commands to or request information
from the indoor unit. This two-way digital communications

CT compatible

Air Conditioner

CT compatible

Heat Pump

Full CT system

benefits & features

Full CT system

benefits & features

36

SERVICING

between the thermostat and subsystems (indoor/outdoor
unit) and between subsystems is the key to unlocking the
benefits and features of the ComfortNet system.

Two-way digital communications is accomplished using
only two wires. The thermostat and subsystem controls are
powered with 24 VAC Thus, a maximum of 4 wires between
the equipment and thermostat is all that is required to operate
the system.

AIRFLOW CONSIDERATIONS

Airflow demands are managed differently in a fully communi­cating system than they are in a legacy wired system. The
system operating mode (as determined by the thermostat)
determines which unit calculates the system airflow demand.
If the indoor unit is responsible for determining the airflow
demand, it calculates the demand and sends it to the ECM
motor. If the outdoor unit or thermostat is responsible for
determining the demand, it calculates the demand and
transmits the demand along with a fan request to the indoor
unit. The indoor unit then sends the demand to the ECM
motor. The following table lists the various ComfortNet™
systems, the operating mode, and airflow demand source.

For example, assume the system is an air conditioner
matched with an air handler. With a call for low stage cooling,
the air conditioner will calculate the system’s low stage
cooling airflow demand. The air conditioner will then send a
fan request along with the low stage cooling airflow demand
to the air handler. Once received, the air handler will send the
low stage cooling airflow demand to the ECM motor. The
ECM motor then delivers the low stage cooling airflow. The
table below lists the nominal high and low stage airflow for the
ComfortNet air conditioners and heat pumps.

CONTROL WIRING
NOTE: Refer to section Electrical Connections - High

Voltage Connections for 208/230 volt line connections to
the air conditioner or heat pump.

NOTE: A removable plug connector is provided with the
control to make thermostat wire connections. This plug
may be removed, wire connections made to the plug, and
replaced. It is

strongly recommended that you do not
connect multiple wires into a single terminal. Wire nuts
are recommended to ensure one wire is used for each
terminal. Failure to do so may result in intermittent
operation.
Typical 18 AWG thermostat wire may be used to wire the
system components. 150 feet is the maximum length of wire
recommended between indoor unit and outdoor unit, or
between indoor unit and thermostat.

CTK04 STANDARD WIRING SCHEME:

Two wires may be utilized between the indoor and outdoor
units. For this wiring scheme, only the data lines, 1 and 2,
are required between the indoor and outdoor units. A 40VA,
208/230 VAC to 24 VAC transformer must be installed in the
outdoor unit to provide 24 VAC power to the outdoor unit’s
electronic control. The “C” 24v common of the outdoor
transformer should be grounded to the equipment (earth)
ground. The transformer is included with the CTK0* kit. See
kit instructions for mounting and wiring instructions. Four
wires are required between the indoor unit and thermostat.

12RC

Thermostat

Models

*SZC160241 800 600 800 600
*SZC160361 1200 800 1200 800
*SZC160481 1550 1100 1550 1100
*SZC160601 1800 1210 1800 1210
*SZC180241 850 550 850 550
*SZC180361 1250 850 1250 850
*SZC180481 1750 1210 1750 1210
*SZC180601 1750 1210 1750 1210

Cooling Heating

High Low High Low

40VA Transformer (included in
CTK04 kit)

208/230 VAC

24 VAC

12RC

12RC

Note

: Recommended (Field Provided)

System Wiring

Air Handler/Furnace/PCB

AC/HP/ PCB

(Ground Indicator)

37

SERVICING

g

(

1

2R

12RC

40VA Transformer
CTK0*** kit)

208/230 VAC

and Four Wires between Air Handler and Thermostat

included in

12

24 VAC

CTK04 System Wiring Using Three-Wires

between Air Handler and AC / HP

CTK 04 ALTERNATE WIRING SCHEME:

Three wires should be utilized between the indoor and outdoor
units. For this wiring scheme, two wires for the data lines, 1
and 2 are required and a wire connecting the common “C”
terminals between the indoor and outdoor units. This con­nects both commons to the same ground potential allowing
for better communication. A 40VA, 208/230 VAC to 24 VAC
transformer must be installed in the outdoor unit to provide
24 VAC power to the outdoor unit’s electronic control. The
transformer is included with the CTK0* kit. See kit instruc­tions for mounting and wiring instructions. Four wires are
required between the indoor unit and thermostat.

C

RC

Thermostat

Modular Blower
Inte

rated Control Module

AC/H P Integrate d
Control Module

COMFORTNET™ SYSTEM ADVANCED FEATURES

The ComfortNet™ system permits access to additional
system information, advanced setup features, and advanced
diagnostic/troubleshooting features. These advanced fea­tures are organized into a menu structure. Refer to the
Installation and Start-Up instructions shipped with your
particular CTKO*** thermostat.

Diagnostics

Accessing the air handler’s diagnostics menu provides ready
access to the last six faults detected by the air handler.
Faults are stored most recent to least recent. Any consecu­tively repeated fault is stored a maximum of three times.
Example: A clogged return air filter causes the air handler’s
motor to repeatedly enter a limiting condition. The control will
only store this fault the first three consecutive times the fault
occurs.

NOTE: It is highly recommended that the fault history be
cleared after performing maintenance or servicing the air
handler.

38

SERVICING

Network Troubleshooting

The ComfortNet™ system is a fully communicating system,
and thus, constitutes a network. Occasionally the need to
troubleshoot the network may arise. The integrated air
handler control has some on-board tools that may be used
to troubleshoot the network. These tools are: red communi­cations LED, green receive (Rx) LED, and learn button.
Refer to the Communications Troubleshooting Chart and Air
Handler Diagnostic Codes below for error codes, possible
causes and corrective actionS.

COMMUNICATIONS TROUBLESHOOTING CHART

LED LED

Status

Off

1 Flash

Red

Communications

LED

2 Flashes

Off

1 Steady

Flash

Green Receive

LED

Rapid

Flashing
On Solid

Indication Possible Causes Corrective Action(s) Notes & Cautions

x Normal condition x None x None x None
x Communications

Failure

x Out-of-box reset x Control power up

x No power
x Communications

error

x No network found x Broken/ disconnected

x Normal network

traffic

x Data 1/ Data 2

miss-wire

x Communications

Failure

x Learn button

depressed

x No power to air

handler

x Open fuse
x Communications error

data wire(s)

x Air handler is installed

as a non­communicating/
traditional system

x Control is “talking” on

network as expected

x Data 1 and data 2

wires reversed at air
handler, thermostat,
or ComfortNet™
compatible outdoor
AC/HP

x Short between data 1

and data 2 wires

x Short between data 1

or data 2 wires and R
(24VAC) or C (24VAC
common)

• Red communications LED – Indicates the status of the
network. The table below indicates the LED status and the
corresponding potential problem.

• Green receive communication LED – Indicates network
traffic. The table below indicates the LED status and the
corresponding potential problem.

• Learn button – Used to reset the network. Depress the
button for approximately 2 seconds to reset the network.

x Depress Learn Button
x Verify that bus BIAS

and TERM
dipswitches are in the
ON position.

x None x None

x Check fuses and

circuit breakers;
replace/reset

x Replace blown fuse
x Check for shorts in

low voltage wiring in
air handler/system

x Reset network by

depressing learn
button

x Check data 1/ data 2

voltages

x Check

communications
wiring (data 1/ data 2
wires)

x Check wire

connections at
terminal block

x Verify air handler

installation type (non­communicating/
traditional or
communicating)

x Check data 1/ data 2

voltages

x None x None

x Check

communications
wiring (data 1/ data 2
wires)

x Check wire

connections at
terminal block

x Check data 1/ data 2

voltages

x Depress once

quickly for a power­up reset

x Depress and hold

for 2 seconds for
an out-of-box reset

x Turn power OFF

prior to repair

x Turn power OFF

prior to repair

x Verify wires at

terminal blocks are
securely twisted
together prior to
inserting into
terminal block

x Verify data1 and

data voltages as
described above

x Turn power OFF

prior to repair

x Verify wires at

terminal blocks are
securely twisted
together prior to
inserting into
terminal block

x Verify data1 and

data voltages as
described above

39

SERVICING

7 S E GME NT LED

(characters will alternate)

( n o d i s p l a y) INTE R NAL CONTRO L FAULT / NO PO WER

On STANDBY, WAITING FOR INP UTS
Ec HEATER KIT TOO LARGE, TOO SMALL , OR NO MATCH

E5 FUSE O PE N

EF A UXIL IARY SWITCH OP EN

d0 DATA NOT ON NETWORK
d1 INVALID DATA ON N E TW O RK
d4 INVALID ME MORY CARD DATA
b0 BLOWER MOTOR NOT RUNNING
b1 BLOW E R MO TOR COMMUNICAT ION E R R O R
b2 BLOWER MOTOR HP MISMATCH

b3
b4 BLOWER MOTOR CURRE NT TRIP OR LOST ROTOR

b5 BLOWER MOTOR ROTOR LOCKED
b6 OVER/UNDER VOLTAGE TRIP OR OVER TEMPERATU RE TRI P
b7 INCOMPLETE PARAMETER SENT TO MOTOR

b9 LOW INDOOR AIRFLOW
C1 LOW STAGE COOL - LEGACY MODE ONLY
C2 HIGH STAGE COOL - LEGACY MODE ONLY

P1 L OW ST A GE HEAT PUMP HEAT - LEGACY MOD E ONLY

P2 HIGH STAGE HEAT PUMP HEAT - LEGACY MODE ONLY

h 1 EM ERG E NCY HEAT LOW - COM MUNIC A TING MODE ONL Y

h 2 EMERG E NC Y HEAT HIGH - CO M MUNICATING MOD E ONLY
F C FAN COOL - COMM UNICATING MO D E ONLY
F H FAN HEAT - COMMUNICATING MOD E ONLY

FFAN ONLY
H1 ELECTRIC HEAT LOW
H2 ELECTRIC HEAT HIGH

dF

BLOWER MOTOR OPERATING IN POWER, TEMP., OR SPEED
LIMIT

DEFROST - COMMUNICATING MODE ONLY
(Not e: d efro st is di s pla y e d as H1 in a lega c y setu p)

DES CRIPTION OF CONDITION

40

GREE N CFM LED - EA CH FLASH REP RES ENTS 100CFM (USE FOR AIRFLOW APPRO XIMATIO N

ONLY) - EXAMPLE: 8 FLASHES = 800CFM

0140A00070-A

SERVICING

Notes & Cautions

PCBJA101- PCBJA102 AIR HANDLER DIAGNOSTIC CODES

Corrective Actions

Possible Causes

ComfortNet ™

Thermostat Only

x Normal operation x None x Normal operation

None None

Message Code

model.

x Turn power OFF prior to repair.

x Use memory card for the specific

settings

x Verify electric heat dipswitch

x Verify the installed electric

dipswitches is too large for heater

kits in shared data set

x Heater kit selected via

Ec

LARGE

HTR TOO

turning power ON. Memory card

x Insert memory card BEFORE

heater is valid for the air handler.

Check nameplate or

model.

turning power ON. Memory card

may be removed after data is

loaded.

memory card.

may be removed after data is

loaded.

memory card.

data is loaded.

x Turn power OFF prior to repair.

x Use memory card for the specific

settings

x Verify electric heat dipswitch

x Verify the installed electric

dipswitches is too small for heater

kits in shared data set

x Heater kit selected via

Ec

SMALL

HTR TOO

x Insert memory card BEFORE

heater is valid for the air handler.

x Turn power OFF before removing

x Error code will be cleared once

Specification Sheet applicable to

your model* for allowable heater

kit(s).

for the specific model. Re-

populate data using correct

memory card if required.

x Verify shared data set is correct

x

Check nameplate or

Specification Sheet applicable to

your model* for allowable heater

kit(s).

x Turn power OFF before removing

x Verify shared data set is correct

for the specific model. Re-

populate data using correct

x Error code will be cleared once

data is loaded.

x Turn power OFF prior to repair.

memory card if required.

x Verify electric heat dipswitch

x Heater kit selected via

Ec

NO HTR

model.

x Use memory card for the specific

settings

x Verify the installed electric

dipswitches is doesn’t match

heater kits in shared data set

MATCH

turning power ON. Memory card

x Insert memory card BEFORE

heater is valid for the air handler.

Check nameplate or

may be removed after data is

loaded.

memory card.

data is loaded.

x Turn power OFF before removing

x Error code will be cleared once

Specification Sheet applicable to

your model* for allowable heater

kit(s).

for the specific model. Re-

populate data using correct

x Verify shared data set is correct

x Turn power OFF prior to repair.

x Replace fuse with 3-amp

voltage wiring

memory card if required.

x Short in low voltage wiring x Locate and correct short in low

Not

Displayed

Not

Displayed

automotive type

module fuse with 3A automotive

fuse.

x Turn power OFF prior to repair.

x Replace integrated control

power to air handler and

integrated control module.

x Assure 208/230 volt and 24 volt

x Check integrated control module

24 volt wire improperly

connected or loose

x Manual disconnect switch OFF or

x Blown fuse or circuit breaker

EE

FAULT

INTERNAL

x Replace integrated control

fuse (3A). Replace if necessary.

x Integrated control module has an

module with correct replacement

x Check for possible shorts in

internal fault

part

Discharge” section of manual.

x Read precautions in “Electrostatic

208/230 volt and 24 volt circuits.

Repair as necessary.

x Replace bad integrated control

module.

Fault Description

LED Codes

Diagnostic/Status

Symptoms of Abnormal Operation

(Communicating & Non-communicating

dipswitches is too large

for heater kits specified

x Normal operation

x Heater kit selected via

in shared data set

x Heater kit selected via

dipswitches is too small

for heater kits specified

in shared data set

x Heater kit selected via

dipswitches does not

heater kits specified in

shared data set

x Open Fuse

to air handler or no 24

volt power to integrated

control module

breaker

module has an internal

x No 208/230 volt power

x Blown fuse or circuit

fault.

x Integrated control

ON

1 Flash

1 Flash

1 Flash

5 Flashes

None

Thermostat)

W1 or Auxiliary/Emergency heat

provides the indicated error code.

icon illuminated

x LED display is ON continuously

x Electric heaters fail to energize on a call for

x Integrated control module LED display

x ComfortNet thermostat “Call for Service”

Handler” message

x ComfortNet thermostat scrolls “Check Air

x Electric heat airflow is higher than

expected on a call for W1 or

Auxiliary/Emergency heat

provides the indicated error code.

x Integrated control module LED display

x Electric heat airflow is higher than

expected on a call for W1 or

Auxiliary/Emergency heat

provides the indicated error code.

x Integrated control module LED display

provides the indicated error code.

Power”

provides no signal.

icon illuminated

x No air handler operation.

x Integrated control module LED display

x ComfortNet thermostat displays “Battery

x Air handler fails to operate

x Integrated control module LED display

x ComfortNet thermostat “Call for Service”

Handler” message

x ComfortNet thermostat scrolls “Check Air

41

SERVICING

PCBJA101- PCBJA102 AIR HANDLER DIAGNOSTIC CODES

Notes & Cautions

repair

specific model.

BEFORE turning power

ON. Memory card may be

removed after data is

loaded.

x Turn power OFF prior to

x Use memory card for the

x Insert memory card

x Turn power OFF before

removing memory card.

x Error code will be cleared

repair

specific model.

BEFORE turning power

ON. Memory card may be

removed after data is

loaded.

removing memory card.

once data is loaded.

x Turn power OFF prior to

x Use memory card for the

x Insert memory card

x Turn power OFF before

x Error code will be cleared

once data is loaded.

Corrective Actions

for the specific model. Re-

populate data using correct

x Populate shared data set using

memory card.

memory card if required.

x Verify shared data set is correct

Possible Causes

has been rejected by integrated

shared data.

x Air handler does not contain any

d0

x Shared data set on memory card

d4

control module

ComfortNet ™

Thermostat Only

Fault Description

LED Codes

Diagnostic/Status

NO NET

Message Code

x Data not yet on network.

9 Flashes

Thermostat)

DATA

INVALID

MC DATA

data.

x Invalid memory card

11 Flashes

Symptoms of Abnormal Operation

42

provides indicated error code.

icon illuminated.

(Communicating & Non-communicating

x Air handler fails to operate.

x Integrated control module LED display

x ComfortNet thermostat “Call for Service”

Handler” message.

x ComfortNet thermostat scrolls “Check Air

operation.

provides indicated error code.

icon illuminated.

x Operation different than expected or no

x Integrated control module LED display

x ComfortNet thermostat “Call for Service”

Handler” message.

x ComfortNet thermostat scrolls “Check Air

SERVICING

PCBJA101- PCBJA102 AIR HANDLER DIAGNOSTIC CODES

Notes & Cautions

repair

with correct replacement

x Replace circulator motor

part.

x Turn power OFF prior to

x Turn power OFF prior to

repair

with correct replacement

part.

x Replace circulator motor

x Replace integrated control

module with correct

replacement part.

x Turn power OFF prior to

repair

replacement part.

specific model

BEFORE turning power

ON. Memory card may be

removed after data is

loaded.

x Replace motor with correct

x Use memory card for the

x Insert memory card

x Turn power OFF before

removing memory card.

x Error code will be cleared

once shared data and

motor horse power match.

x Turn power OFF prior to

repair.

x Turn power OFF prior to

repair.

Corrective Actions

connection.

Replace if necessary.

connection.

x Tighten or correct wiring

Replace if necessary.

x Check circulator blower motor.

x Tighten or correct wiring

Replace if necessary.

x Check circulator blower motor.

x Check integrated control module.

x Verify circulator blower motor

horse power is the same

specified for the specific air

handler model. Replace is

necessary.

for the specific model. Re-

populate data using correct

memory card if required.

x Verify shared data set is correct

x Check filters for blockage.

Clean filters or remove

obstruction.

Remove obstruction. Verify all

registers are fully open.

sized for system. Resize/replace

ductwork if necessary.

installation requirements.

grills/registers, duct system, and

air handler/coil air inlet/outlet for

x Check ductwork for blockage.

x Verify ductwork is appropriately

x See "Installation Instructions" for

blockages.

x Check filters, filter

Possible Causes

circulator motor power leads or

circulator motor power leads

disconnected.

x Loose wiring connection at

b0

x Failed circulator blower motor.

x Loose wiring connection at

b1

circulator motor control leads.

x Failed circulator blower motor.

x Failed integrated control module.

b2

x Incorrect circulator blower motor

in air handler.

integrated control module.

x Incorrect shared data set in

x Blocked filters.

b3

change in speed or torque, sudden

blockage of air handler/coil air

inlet or outlet.

filters, very restrictive ductwork,

blockage of air handler/coil air

x Restrictive ductwork.

x Undersized ductwork.

x High ambient temperatures.

x Abnormal motor loading, sudden

b4

inlet or outlet.

x High loading conditions, blocked

ComfortNet ™

Thermostat Only

Fault Description

LED Codes

Diagnostic/Status

Message Code

Thermostat)

MOTOR

NOT RUN

is not running when it

should be running.

x Circulator blower motor

6 Flashes

COMM

MOTOR

module has lost

communications with

x Integrated control

6 Flashes

circulator blower motor.

MOTOR

MISMATCH

horse power in shared

data set does not match

x Circulator blower motor

6 Flashes

circulator blower motor

LIMITS

MOTOR

horse power.

x Circulator blower motor

6 Flashes

is operating in a power,

temperature, or speed

limiting condition.

TRIPS

MOTOR

senses a loss rotor

control.

x Circulator blower motor

6 Flashes

x Circulator blower motor

senses high current.

Symptoms of Abnormal Operation

provides indicated error code.

icon illuminated.

Handler” message.

provides indicated error code.

icon illuminated.

(Communicating & Non-communicating

x Air handler fails to operate.

x Integrated control module LED display

x ComfortNet thermostat “Call for Service”

x ComfortNet thermostat scrolls “Check Air

x Air handler fails to operate.

x Integrated control module LED display

x ComfortNet thermostat “Call for Service”

Handler” message.

x ComfortNet thermostat scrolls “Check Air

provides indicated error code.

icon illuminated.

x ComfortNet thermostat “Call for Service”

Handler” message.

x ComfortNet thermostat scrolls “Check Air

x Air handler fails to operate.

x Integrated control module LED display

performance.

x Air handler operates at reduced

provides b3 error code.

x Airflow delivered is less than expected.

x Integrated control module LED display

provides indicated error code.

icon illuminated.

x ComfortNet thermostat “Call for Service”

Handler” message.

x ComfortNet thermostat scrolls “Check Air

x Air handler fails to operate.

x Integrated control module LED display

43

SERVICING

PCBJA101- PCBJA102 AIR HANDLER DIAGNOSTIC CODES

Notes & Cautions

repair

replacement part.

x Turn power OFF prior to

x Replace motor with correct

x Replace wheel with correct

replacement part.

x Turn power OFF prior to

repair.

x Turn power OFF prior to

repair.

replacement part(s).

x Replace with correct

x Use memory card for the

repair.

specific model.

x Turn power OFF prior to

Corrective Actions

Verify line voltage to blower is

within the range specified on the

air handler rating plate.

obstructions. Remove and

repair/replace wheel/motor if

necessary.

shaft rotation and motor.

Replace motor if necessary.

x Check circulator blower for

x Check power to air handler.

x Check circulator blower motor

installation requirements.

Verify control is populated with

correct shared data set. See data

x See "Installation Instructions" for

errors above for details.

x Check integrated control module.

x Check for locked rotor condition

(see error code above for

details).

x Check filters for blockage.

Clean filters or remove

obstruction.

Remove obstruction. Verify all

registers are fully open.

sized for system. Resize/replace

x Check ductwork for blockage.

ductwork if necessary.

x Verify ductwork is appropriately

Possible Causes

handler.

housing.

bearings.

x Obstruction in circulator blower

x Seized circulator blower motor

x Failed circulator blower motor.

b5

x High AC line voltage to air

b6

handler.

x Low AC line voltage to air

x High ambient temperatures.

x Error with integrated control

b7

module.

condition.

x Motor has a locked rotor

b9

x Blocked filters.

x Restrictive ductwork.

x Undersized ductwork.

ComfortNet ™

Thermostat Only

Fault Description

LED Codes

Diagnostic/Status

Symptoms of Abnormal Operation

(Communicating & Non-communicating

ROTOR

Message Code

MTR LCKD

fails to start 10

x Circulator blower motor

6 Flashes

Thermostat)

x Air handler fails to operate.

x Integrated control module LED display

consecutive times.

provides indicated error code.

Service” icon illuminated.

x ComfortNet™ thermostat “Call for

x ComfortNet thermostat scrolls “Check Air

Handler” message.

VOLTS

MOTOR

shuts down for over or

under voltage condition.

x Circulator blower motor

6 Flashes

provides indicated error code.

x Air handler fails to operate.

x Integrated control module LED display

shuts down due to over

x Circulator blower motor

icon illuminated.

x ComfortNet thermostat “Call for Service”

temperature condition on

x ComfortNet thermostat scrolls “Check Air

power module.

Handler” message.

MOTOR

PARAMS

does not have enough

information to operate

x Circulator blower motor

6 Flashes

provides indicated error code.

x Air handler fails to operate.

x Integrated control module LED display

properly.

x Motor fails to start 40

icon illuminated.

x ComfortNet thermostat “Call for Service”

consecutive times.

x ComfortNet thermostat scrolls “Check Air

Handler” message.

LOW ID

x Airflow is lower than

6 Flashes

x Air handler operates at reduced

AIRFLOW

demanded.

performance or operates on low stage

when high stage is expected.

provides indicated error code.

x Integrated control module LED display

44

SERVICING

PCBJA104 AIR HANDLER DIAGNOSTIC CODES

Notes & Cautions

Corrective Actions

Possible Causes

repair.

the specific model.

BEFORE turning power

ON. Memory card may

be removed after data is

loaded.

removing memory card.

x Turn power OFF prior to

x Use memory card for

x Insert memory card

settings

heater is valid for the air

handler blower. Check

nameplate or Specification

Sheet applicable to your

x Verify electric heat dipswitch

x Verify the installed electric

dipswitches is too large for

heater kits in shared data set

x Heater kit selected via

x Normal operation x None x Normal operation

EC

model* for allowable heater

x Turn power off before

kit(s).

correct for the specific model.

Re-populate data using

x Verify shared data set is

repair.

the specific model.

BEFORE turning power

ON. Memory card may

be removed after data is

loaded.

x Turn power OFF prior to

x Use memory card for

x Insert memory card

correct memory card if

required.

settings

heater is valid for the air

handler blower. Check

nameplate or Specification

x Verify electric heat dipswitch

x Heater kit selected via

EC

x Verify the installed electric

dipswitches is too small for

heater kits in shared data set

Sheet applicable to your

removing memory card.

x Turn power off before

model* for allowable heater

kit(s).

correct for the specific model.

Re-populate data using

x Verify shared data set is

repair.

the specific model.

BEFORE turning power

ON. Memory card may

be removed after data is

loaded.

removing memory card.

x Turn power OFF prior to

x Use memory card for

x Insert memory card

correct memory card if

required.

settings

heater is valid for the air

handler blower. Check

nameplate or Specification

Sheet applicable to your

x Verify electric heat dipswitch

x Heater kit selected via

EC

dipswitches is doesn’t match

x Verify the installed electric

heater kits in shared data set

model* for allowable heater

x Turn power off before

kit(s).

correct for the specific model.

Re-populate data using

x Verify shared data set is

correct memory card if

required.

service.

x Turn power OFF prior to

service

x Check overflow pan and

evaporation coil.

x High water level in the

EF

ComfortNet™

Thermostat Only

Message Code

Fault Description

Codes

Characters

Will Alternate

7-Segment LED

None None

LARGE

HTR TOO

dipswitches is too

large for heater kits

specified in shared

x Normal operation

x Heater kit selected via

data set

EC

ON

SMALL

HTR TOO

dipswitches is too

small for heater kits

specified in shared

x Heater kit selected via

EC

MATCH

NO HTR

data set

x Heater kit selected via

EC

dipswitches does not

heater kits specified in

shared data set

Fault

Aux Alarm

x Aux switch open

EF

Symptoms of Abnormal Operation

(Legacy & ComfortNet™ Thermostat)

x LED display is ON continuously

x Electric heaters fail to energize on a

call for W1 or Auxiliary/Emergency heat

x Integrated control module LED display

provides the indicated error code.

Service” icon illuminated

x ComfortNet™ thermostat “Call for

“Check Air Handler” message

x ComfortNet™ thermostat scrolls

expected on a call for W1 or

Auxiliary/Emergency heat

x Electric heat airflow is higher than

provides the indicated error code.

x Integrated control module LED display

expected on a call for W1 or

Auxiliary/Emergency heat

x Electric heat airflow is higher than

provides the indicated error code.

x Integrated control module LED display

x Integrated control module LED display

EF error code.

x ComfortNet™ thermostat “Call for

Service”.

45

SERVICING

repair.

x Turn power OFF prior to

x Replace integrated

PCBJA104 AIR HANDLER DIAGNOSTIC CODES

repair

the specific model.

BEFORE turning power

ON. Memory card may

be removed after data is

loaded.

cleared once data is

loaded.

control module fuse with

3A automotive fuse.

control module with

correct replacement part

“Electrostatic Discharge”

section of manual.

x Turn power OFF prior to

x Use memory card for

x Replace integrated

x Read precautions in

x Insert memory card

x Error code will be

x Turn power off before

removing memory card

x Turn power OFF prior to

repair

x Use memory card for

the specific model.

BEFORE turning power

ON. Memory card may

be removed after data is

x Insert memory card

loaded.

x Error code will be

cleared once data is

loaded.

x Turn power OFF prior to

repair

x Use memory card for

the specific model.

BEFORE turning power

ON. Memory card may

be removed after data is

loaded.

cleared once data is

loaded.

x Insert memory card

x Error code will be

x Turn power off before

removing memory card

Possible Causes Corrective Actions Notes & Cautions

ComfortNet™

Thermostat Only

Fault Description

Message Code

volt power to air handler

blower and integrated control

x Assure 208/230 volt and 24

or 24 volt wire improperly

connected or loose

x Manual disconnect switch OFF

EE

FAULT

INTERNAL

to air handler blower

or no 24 volt power to

x No 208/230 volt power

module.

module fuse (3A). Replace if

x Check integrated control

an internal fault

x Blown fuse or circuit breaker

x Integrated control module has

integrated control

module

x Blown fuse or circuit

necessary.

208/230 volt and 24 volt

x Check for possible shorts in

breaker

module has an internal

x Integrated control

circuits. Repair as necessary.

x Replace bad integrated

fault.

using memory card.

control module.

x Populate shared data set

contain any shared data.

x Air handler blower does not

d0

DATA

NO NET

network.

x Data not yet on

set using memory card.

x Populate correct shared data

contain an appropriate shared

data set.

x Air handler blower does not

d1

DATA

INVALID

network.

x Invalid data on

x Verify shared data set is

x Shared data set on memory

d4

INVALID

x Invalid memory card

correct for the specific model.

card has been rejected by

MC DATA

data.

Re-populate data using

correct memory card if

required.

integrated control module

46

Codes

No Display

Characters

Will Alternate

7-Segment LED

Symptoms of Abnormal Operation

x Air handler blower fails to operate

x Integrated control module LED display

(Legacy & ComfortNet™ Thermostat)

provides no signal.

x ComfortNet™ thermostat “Call for

Service” icon illuminated

x ComfortNet™ thermostat scrolls

“Check Air Handler” message

d0

x Air handler blower fails to operate.

d1

provides indicated error code.

Service” icon illuminated.

x Integrated control module LED display

“Check Air Handler” message.

x ComfortNet™ thermostat “Call for

x ComfortNet™ thermostat scrolls

provides indicated error code.

Service” icon illuminated.

x Air handler blower fails to operate.

x Integrated control module LED display

“Check Air Handler” message.

x ComfortNet™ thermostat “Call for

x ComfortNet™ thermostat scrolls

d4

x Operation different than expected or no

operation.

provides indicated error code.

Service” icon illuminated.

x Integrated control module LED display

“Check Air Handler” message.

x ComfortNet™ thermostat “Call for

x ComfortNet™ thermostat scrolls

SERVICING

PCBJA104 AIR HANDLER DIAGNOSTIC CODES

Notes & Cautions

Corrective Actions

Possible Causes

x Turn power OFF prior to

x Tighten or correct wiring

x Loose wiring connection at

b0

repair

x Replace circulator motor

connection.

x Check circulator blower

circulator motor power leads

or circulator motor power

with correct

replacement part.

motor. Replace if necessary.

leads disconnected.

x Failed circulator blower motor.

x Turn power OFF prior to

x Tighten or correct wiring

x Loose wiring connection at

b1

repair

x Replace circulator motor

connection.

x Check circulator blower

circulator motor control leads.

x Failed circulator blower motor.

with correct

replacement part.

motor. Replace if necessary.

x Check integrated control

module.

x Failed integrated control

control module with

x Replace integrated

module. Replace if

necessary.

correct replacement

part.

x Turn power OFF prior to

x Verify circulator blower motor

x Incorrect circulator blower

b2

repair

x Replace motor with

horse power is the same

specified for the specific air

motor in air handler blower.

x Incorrect shared data set in

correct replacement

part.

x Use memory card for

handler blower model.

Replace is necessary.

x Verify shared data set is

integrated control module.

the specific model

x Insert memory card

correct for the specific model.

Re-populate data using

BEFORE turning power

correct memory card if

required.

ON. Memory card may

be removed after data is

loaded.

cleared once shared

x Error code will be

data and motor horse

power match.

x Turn power off before

removing memory card

x Turn power OFF prior to

x Check filters for blockage.

x Blocked filters.

b3

repair.

Clean filters or remove

obstruction.

x Restrictive ductwork.

x Undersized ductwork.

x Check ductwork for blockage.

x High ambient temperatures.

Remove obstruction. Verify

all registers are fully open.

x Verify ductwork is

appropriately sized for

system. Resize/replace

ductwork if necessary.

for installation requirements.

x See "Installation Instructions"

repair.

x Turn power OFF prior to

grills/registers, duct system,

x Check filters, filter

sudden change in speed or

x Abnormal motor loading,

b4

and air handler blower/coil air

inlet/outlet for blockages.

torque, sudden blockage of air

handler blower/coil air inlet or

outlet.

blocked filters, very restrictive

x High loading conditions,

ductwork, blockage of air

handler blower/coil air inlet or

outlet.

ComfortNet™

Thermostat Only

MOTOR

Message Code

NOT RUN

Fault Description

motor is not running

x Circulator blower

b0

Codes

Characters

Will Alternate

7-Segment LED

when it should be

running.

COMM

MOTOR

x Integrated control

b1

module has lost

MOTOR

MISMATCH

communications with

circulator blower

motor.

x Circulator blower

b2

motor horse power in

shared data set does

not match circulator

blower motor horse

power.

LIMITS

MOTOR

motor is operating in a

x Circulator blower

b3

power, temperature, or

speed limiting

condition.

TRIPS

MOTOR

x Circulator blower

b4

motor senses a loss

rotor control.

motor senses high

current.

x Circulator blower

Symptoms of Abnormal Operation

(Legacy & ComfortNet™ Thermostat)

provides indicated error code.

x Air handler blower fails to operate.

x Integrated control module LED display

Service” icon illuminated.

“Check Air Handler” message.

provides indicated error code.

Service” icon illuminated.

x ComfortNet™ thermostat “Call for

x ComfortNet™ thermostat scrolls

x Air handler blower fails to operate.

x Integrated control module LED display

“Check Air Handler” message.

x ComfortNet™ thermostat “Call for

x ComfortNet™ thermostat scrolls

provides indicated error code.

Service” icon illuminated.

x Air handler blower fails to operate.

x Integrated control module LED display

“Check Air Handler” message.

x ComfortNet™ thermostat “Call for

x ComfortNet™ thermostat scrolls

performance.

x Air handler blower operates at reduced

provides b3 error code.

x Airflow delivered is less than expected.

x Integrated control module LED display

provides indicated error code.

Service” icon illuminated.

x Air handler blower fails to operate.

x Integrated control module LED display

“Check Air Handler” message.

x ComfortNet™ thermostat “Call for

x ComfortNet™ thermostat scrolls

47

SERVICING

Notes & Cautions

Corrective Actions

repair

x Turn power OFF prior to

obstructions. Remove and

x Check circulator blower for

x Replace motor with

repair/replace wheel/motor if

correct replacement

part.

necessary.

x Check circulator blower motor

shaft rotation and motor.

x Replace wheel with

correct replacement

Replace motor if necessary.

part.

PCBJA104 AIR HANDLER DIAGNOSTIC CODES

repair.

x Turn power OFF prior to

blower. Verify line voltage to

blower is within the range

x Check power to air handler

specified on the air handler

blower rating plate.

for installation requirements.

x See "Installation Instructions"

x Turn power OFF prior to

x Check integrated control

repair.

x Replace with correct

module. Verify control is

populated with correct shared

replacement part(s).

x Use memory card for

data set. See data errors

above for details.

x Check for locked rotor

the specific model.

BEFORE turning power

ON.

removed after data is

loaded

removing memory card.

x Insert memory card

x Memory card may be

condition (see error code

above for details).

x Turn power off before

x Turn power OFF prior to

x Check filters for blockage.

repair.

Clean filters or remove

obstruction.

x Check ductwork for blockage.

Remove obstruction. Verify

all registers are fully open.

x Verify ductwork is

appropriately sized for

system. Resize/replace

ductwork if necessary.

Possible Causes

blower housing.

x Obstruction in circulator

b5

ComfortNet™

Thermostat Only

Message Code

MTR

LCKD

Fault Description

motor fails to start 10

x Circulator blower

b5

Codes

Characters

Will Alternate

7-Segment LED

bearings.

x Seized circulator blower motor

x Failed circulator blower motor.

ROTOR

consecutive times.

x High AC line voltage to air

b6

VOLTS

MOTOR

x Circulator blower

b6

handler blower.

motor shuts down for

hander blower.

x Low AC line voltage to air

over or under voltage

condition.

x High ambient temperatures.

x Circulator blower

motor shuts down due

to over temperature

condition on power

module.

module.

x Error with integrated control

b7

MOTOR

PARAMS

motor does not have

x Circulator blower

b7

condition.

x Motor has a locked rotor

enough information to

operate properly.

Motor fails to start 40

consecutive times.

x Blocked filters.

x Restrictive ductwork.

x Undersized ductwork.

b9

LOW ID

AIRFLOW

demanded.

x Airflow is lower than

b9

48

Symptoms of Abnormal Operation

(Legacy & ComfortNet™ Thermostat)

provides indicated error code.

x Air handler blower fails to operate.

x Integrated control module LED display

Service” icon illuminated.

“Check Air Handler” message.

x ComfortNet™ thermostat “Call for

x ComfortNet™ thermostat scrolls

provides indicated error code.

Service” icon illuminated.

x Air handler blower fails to operate.

x Integrated control module LED display

“Check Air Handler” message.

x ComfortNet™ thermostat “Call for

x ComfortNet™ thermostat scrolls

provides indicated error code.

Service” icon illuminated.

x Air handler blower fails to operate.

x Integrated control module LED display

“Check Air Handler” message.

x ComfortNet™ thermostat “Call for

x ComfortNet™ thermostat scrolls

x Air handler blower operates at reduced

performance or operates on low stage

when high stage is expected.

provides indicated error code.

x Integrated control module LED display

SERVICING

S-4 CHECKING TRANSFORMER AND CON-

TROL CIRCUIT

HIGH VOLT AGE!
Disconnect ALL power before servicing
or installing. Multiple power sources
may be present. Failure to do so may
cause property damage, personal injury
or death.

A step-down transformer (208/240 volt primary to 24 volt sec­ondary) is provided with each indoor unit. This allows ample
capacity for use with resistance heaters. The outdoor sec­tions do not contain a transformer (see note below).

TM

NOTE: ComfortNet
optional 240VAC to 24VAC transformer installed. This trans­former provides 24VAC power to the unitary (UC) control in
some communicating system installation scenarios.

ready condensing units may have an

WARNING

Disconnect ALL power before servicing.

1. Remove control panel cover, or etc., to gain access to
transformer.

With power ON:

3. Using an ohmmeter, check for continuity across termi­nals 3 and 1, and 4 and 5.

4. Apply 24 volts to terminals H1 and H2. Check for
continuity across other terminals - should test continu­ous. If not as above - replace.

NOTE: The time delay for the contacts to make will be
approximately 20 to 50 seconds and to open after the coil is
de-energized is approximately 40 to 90 seconds.

OHMMETER

TESTING COIL CIRCUIT

S-8A CHECKING UNITARY (UC) CONTROL

COMPRESSOR CONTACTOR/RELAY
CONTACTS

WARNING

Disconnect ALL power before servicing.

WARNING

Line Voltage now present.

2. Using a voltmeter, check voltage across secondary volt­age side of transformer (R to C).

3. No voltage indicates faulty transformer, bad wiring, or bad
splices.

4. Check transformer primary voltage at incoming line volt­age connections and/or splices.

5 If line voltage available at primary voltage side of trans-

former and wiring and splices good, transformer is inop­erative. Replace.

S-6 CHECKING TIME DELAY RELAY

Time delays are used in electric heaters to sequence in
multiple electric heaters.

WARNING

Disconnect ALL power before servicing.

1. Tag and disconnect all wires from male spade connec­tions of relay.

2. Using an ohmmeter, measure the resistance across
terminals H1 and H2. Should read approximately 150
ohms.

1. Connect voltmeter to lugs (L2) and (C).

2. With power ON, provide a call for cool or heat pump to
energize the on-board compressor contactor/relay.

WARNING

Line Voltage now present.

3. Measure voltage across on-board compressor contactor/
relay contacts.

A. No voltage indicates the contacts are closed and the
contactor/relay is functioning properly.

B. A reading of approximately half of the supply voltage
(example: 115VAC for 230VAC) indicates the relay is
open. Replace UC control if relay does not close.

NOTE: The unitary (UC) control has a built-in short cycle
delay. Ensure short cycle delay has elapsed before making
voltage measurements.

49

SERVICING

S-9 CHECKING HIGH AND LOW VOLTAGE TO

ECM MOTOR

HIGH VOLT AGE!
Disconnect ALL power before servicing
or installing. Multiple power sources
may be present. Failure to do so may
cause property damage, personal injury
or death.

1. Measure voltage between black and brown motor
leads. This should measure 208/230 volts depending
on your power supply.

2. If voltage is present proceed to check fan relay
contacts and voltage.

CHECKING FAN RELAY CONTACTS - ECM FAN MOTOR

1. Disconnect fan motor harness from plug on the UC
board.

2. Energize the system in low stage and check voltage:

• Pin 5(Blue wire) to Pin 3(Yellow wire) =
24VAC

3. Energize the system in high stage and check volt­age:

• Pin 5(Blue wire) to Pin 3(Yellow wire) =
24VAC

• Pin 5(Blue wire) to Pin 1(White wire) = 24
VAC.

CHECKING RELAY CONTACTS - PSC FAN MOTOR

HIGH VOLT AGE!
Disconnect ALL power before servicing
or installing. Multiple power sources
may be present. Failure to do so may
cause property damage, personal injury
or death.

1. Disconnect the motor leads from 6-circuit fan motor wire
harness.

2. Connect a voltmeter between circuit 3 and circuits 2 (low
speed) or 1 (high speed).

NOTE: Circuit 3 is connected directly to L2.

3. Energize the system at low or high stage.

WARNING

Line V oltage now present.

4. The measured voltage between circuit 3 and circuits 2 or
1 should be approximately 0VAC, which indicates the
relay contacts are closed. A voltage measurement of
approximately 115VAC indicates the relay is open. Re­place the control if the relay checks open when it should
be closed.

S-10A COPELAND COMFORT ALERTTM -
UNITARY (UC) CONTROL DIAGNOSTICS

Applies to ASXC, ASZC, and DSZC 2-stage models

4. If voltage is present at these pins plug harness into
plug on PC board and check voltages at motor to test
for broken wires.

5. If all voltages are present motor is defective and
needs to be replaced.

50

HIGH VOL TAGE!
Disconnect ALL power before servicing
or installing. Multiple power sources
may be present. Failure to do so may
cause pr ope rty dam age , pe rs onal inju ry
or death.

The Copeland Comfort AlertTM diagnostics are fully integrated
into the unitary (UC) control. The UC control and integraged
Comfort Alert™ diagnostics provide around-the-clock moni­toring for common electrical problems, compressor defects
and broad system faults. If a problem is detected, LED
indicators flash the proper alert codes to help you quickly
pinpoint the problem.

The diagnostic tables on following pages provide detailed
information regarding the system symptons, indicators (LED
and thermostat), potential problem(s), and corrective ac­tions. The diagnostic information applies to systems wired
as 24VAC traditional (legacy) systems and systems wired as
communicating systems with the CTK0* communicating
thermostat.

SERVICING

to repair .

consecutive normal

• Tu rn po w er OFF prior

• Fault will clear after 30

PCBHR101-103
PBBGR101-102

cycles.

cycling 24VAC to

control.

• Faul t may be cleared by

replacement part(s).

• Replace w ith correct

to repair .

replacement part(s).

• Tu rn po w er OFF prior

• Replace w ith correct

to repair .

cycling 24VAC to

control.

• Tu rn po w er OFF prior

• M u st cl ear fault by

replacement part(s).

• Replace w ith correct

C o rrective Actions Notes & Cautions

Poss ible Cause s

ComfortNet™

Th ermostat Only

Fault

D escription

charge; adjust as

needed.

li qui d li ne;

repair/repl ace as

needed.

motor; repair/replace

• Veri f y re frige ran t

• C heck for rest ricte d

failu re.

• Restri c tion in liquid lin e.

01 • Low refrigerant charge.

FAU LT

• Low Side Fault. LOW SIDE

presen t;

extremely low.

• Indoor blo wer m ot o r

• Indoor t hermos tat set

call

OFF if no

as needed.

• Check indoor blow er

charge; adjust as

needed.

li qui d li ne;

repair/repl ace as

needed.

motor; repair/replace

th e r mo stat settin g.

• Veri f y re frige ran t

• Check indoor

• C heck for rest ricte d

failu re.

• L ow refrig eran t charge.

• Restri c tion in liquid lin e.

LPS OPEN 01

CO Trip.

• Low Pressure

presen t;

extremely low.

• Indoor blo wer m ot o r

• Indoor t hermos tat set

call

OFF if no

as needed.

switc h; re pai r / rep lace

• Check indoor blow er

as needed.

• Chec k low pressure

charge; adjust as

needed.

li qui d li ne;

repair/repl ace as

needed.

motor; repair/replace

th e r mo stat settin g.

• Veri f y re frige ran t

• Check indoor

• C heck for rest ricte d

failu re.

• L ow refrig eran t charge.

• Restri c tion in liquid lin e.

01

LPS

LOCKOU T

(3 Trips).

• LPC O Lock o ut

presen t;

extremely low.

• Indoor blo wer m ot o r

• Indoor t hermos tat set

call

OFF if no

as needed.

switc h; re pai r / rep lace

as needed.

• Check indoor blow er

• Chec k low pressure

th e r mo stat settin g.

• Check indoor

Dia gnostic/ Status LED Codes

OFF 1 Fl ash OFF ON if call

Green Yellow Red Red Y1 Mes sage Code

Symp toms of A bno rma l Oper ation

(Legacy & Com fo r tNet™ Th er mo s t at)

trips with average run time betw een

trips greater th an 3 ho urs.

and outdoor fan operating at low speed

dia gno s t ic/s t at us LED’s di splay the

• V e r y lon g run ti me.

• Four consecutive com pressor protect or

• Comp res sor operating at h igh speed

in dicated code.

• Integrated control module

ON 1 Flash O FF O N if call

dia gno s t ic/s t at us LED’s di splay the

• Compress or and outdoor fan are off.

in dicated code.

• Therm o stat demand is present.

• Integrated control module

O N 1 Flash ON ON if call

same thermostat demand.

dia gno s t ic/s t at us LED’s di splay the

in dicated code.

S ervice” icon ill um inated.

“Check Air Conditioner” or “Check

• Compress or and outdoor fan are off.

• Low pressure switch trip 3 times within

• Therm o stat demand is present.

• Integrated control module

• ComfortNet™ t hermos tat “Call for

H eat P ump ” m es sage.

• Comfo rtNet™ thermo stat scrolls

51

SERVICING

to re pair .

cons e c ut ive nor m al

• Turn power OFF p ri or

cycles.

• Fault will clear after 4

PCBHR101-103
PBBGR101-102

cyc li ng 24 VAC to

control.

• Fault may be cleared by

r eplacement part(s).

• Replace with correct

to re pair .

r eplacement part(s).

• Turn power OFF p ri or

• Replace with correct

to re pair .

cyc li ng 24 VAC to

control.

• Turn power OFF p ri or

• Must clear fault by

r eplacement part(s).

• Replace with correct

to re pair .

cons e c ut ive nor m al

cycles.

cyc li ng 24 VAC to

control.

• Turn power OFF p ri or

• Fault will clear after 4

• Fault may be cleared by

r eplacement part(s).

• Replace with correct

Co rrective Act io ns Not es & Cautions

ComfortNet™

Fault

con denser coil.

m otor; repair/replace

as ne eded.

moto r wiring;

r epair/replace as

needed.

m otor capaci to r;

r eplace as neede d.

con denser coil.

m otor; repair/replace

as ne eded.

moto r wiring;

r epair/replace as

needed.

m otor capaci to r;

r eplace as neede d.

con denser coil.

m otor; repair/replace

as ne eded.

moto r wiring;

r epair/replace as

needed.

m otor capaci to r;

r eplace as neede d.

thermostat w irin g;

r epair/replace as

needed.

r elay operation;

r eplace control as

• Check and clean

• Check outdoor fan

• Check outdoor fan

Po ssible Causes

• O utdoor fan not running.

02 • Blocked condenser coil.

Thermostat Onl y

FAULT

Message Code

Description

• H igh Side Faul t HIGH SIDE

call

present;

OFF if no

• Check outdoor fan

• Check and clean

• Check outdoor fan

• Check outdoor fan

• Blo cked condenser coil.

• O utdoor fan not running.

HPS OP EN 02

CO Trip

• High Pressure

call

present;

OFF if no

• Check outdoor fan

• Check and clean

• Check outdoor fan

• Check outdoor fan

• O utdoor fan not running.

02 • Blocked condenser coil.

HPS

LOCKOUT

(3 Trips)

• HP CO Lo ckout

call

present;

OFF if no

• Check outdoor fan

• Check thermostat and

demand.

• Faulty compressor relay.

03 • Intermittent thermostat

CYCLE

• Short Cycling CMPR SHRT

call

present;

OFF if no

needed.

• Check compressor

52

OFF ON if call

Flashes

Diagnostic/Status LED Codes

OFF 2

Green Yellow Red Red Y1

Symptom s of Abnormal Operation

trips with average run time betw een

trips great er than 1 minute and less th an

15 minutes.

switc hes are closed.

diagnostic/ stat us LED’s display the

(Legacy & Comfort Net™ Thermostat)

• F ou r cons e c ut ive com pre s so r prot ec to r

• Lo w pressure and hi gh pressure

indicated co de.

• Integrated control module

OFF ON if call

Flashes

ON 2

diagnostic/ stat us LED’s display the

• Compressor and outdoor fan are off.

indicated co de.

• Thermostat d emand is present.

• Integrated control module

ON ON i f call

Flashes

ON 2

same thermostat demand.

diagnostic/ stat us LED’s display the

• Compressor and outdoor fan are off.

• Low pressure swi tch tri p 3 times within

indicated co de.

• Thermostat d emand is present.

• Integrated control module

OFF ON if call

Flashes

OFF 3

Service” icon il luminated.

“Check Air Co nditioner” or “Check

Heat Pump” message.

minut es each.

switc hes are closed.

diagnostic/ stat us LED’s display the

• ComfortNet™ thermostat “Call for

• C om f ort Net™ the r m os ta t sc r o lls

• Run ti me for last 4 cycles is less than 3

• Compressor pro tector has not tripped.

• Lo w pressure and hi gh pressure

indicated co de.

• Integrated control module

SERVICING

to re pai r.

cyc li ng 24 VAC to

• Turn pow er OFF prior

con trol.

• Must clear fault by

PCBHR101-103
PBBGR101-102

to re pai r.

cyc li ng 24 VAC to

con trol.

r eplacemen t part(s).

• Replace with correct

to re pai r.

normal cycle.

cyc li ng 24 VAC to

con trol.

• Turn pow er OFF prior

• Fault will clear after 1

• Fau lt may be cleared by

r eplacemen t part(s).

• Replace with correct

to re pai r.

normal cycle.

cyc li ng 24 VAC to

con trol.

r eplacemen t part(s).

• Turn pow er OFF prior

• Turn pow er OFF prior

• Fault will clear after 1

• Fau lt may be cleared by

• Replace with correct

• Must clear fault by

r eplacemen t part(s).

• Replace with correct

Co rrective Actions Not es & Cautions

Po s sible Causes

ComfortNet™

Thermostat Onl y

Fault

operation;

repair/replace as

needed.

r eplace as needed.

repair/replace as

needed.

w ithin ra nge on rating

pl ate; contact local

u tility i s out of ran ge.

and fuses.

repair/replace as

needed.

repair/replace as

needed.

• Check compressor

04 • Compressor bearings are

Message Code

Description

• Lo cked Rot or LOCKED

• Check run capacitor;

• Check wiring;

• Verify li ne voltage is

wiring.

capacitor.

seized.

• F a i le d com pr e ss or r un

ROTOR

present;

OFF i f no

• L ow li ne volt age .

• Faulty run capacitor

call

• Check circuit brea kers

• C he ck wir i ng to un it;

• Check compressor;

w ir e d to c ontrol.

protector.

• Compressor not properly

• Fa iled compressor

05 • Power is disconnected.

CIRCUIT

• Open Circuit OPEN

call

present;

OFF i f no

wiring; repair/replace

• Check compressor

repair/replace as

needed.

r eplace as needed.

repair/replace as

as ne eded.

• Check compressor;

• Check run capacitor;

capacitor.

is open.

• F a i le d com pr e ss or r un

O PEN S TAR T 06 • Compressor start windi ng

Circuit

• Open Start

call

present;

OFF i f no

needed.

• Check wiring;

w ir e d to c ontrol.

wiring.

• Faulty compressor wiring.

• Compressor not properly

• Faulty run capacitor

repair/replace as

needed.

r eplace as needed.

repair/replace as

• Check compressor;

• Check run capacitor;

capacitor.

is open.

• F a i le d com pr e ss or r un

06 • Compressor start winding

LOCK

O PEN S TAR T

Circui t L ockout

• Open Start

call

present;

OFF i f no

needed.

• Check wiring;

w ir e d to c ontrol.

wiring.

• Faulty compressor wiring.

• Compressor not properly

• Faulty run capacitor

ON ON if call

Flashes

Diagno stic/ Status LED Codes

OFF 4

Green Yellow Red Red Y1

Symptoms of Abnormal Operation

(Legacy & Comfort Net™ Thermos tat)

consec ut ive ti m es .

than 15 seconds.

diagnostic/stat us LED’s display the

indicat ed code.

• C om pre s so r and ou tdo o r fan are off.

• Co m pressor protec tor trips fo ur

• Average run time between trips is less

• Integrated control module

Service” icon illu minated.

• ComfortNet™ thermostat “Call for

OFF ON if call

Flashes

OFF 5

“C he ck Air Co nd it io ner ” or “Che c k

Heat Pump” message.

gre a ter tha n 4 hour s.

switches are c lo sed .

diagnostic/stat us LED’s display the

indicat ed code.

• ComfortNet™ thermostat scrolls

• C om pre s so r and ou tdo o r fan are off fo r

• Lo w pressure and high press ure

• Integrated control module

Service” icon illu minated.

• ComfortNet™ thermostat “Call for

OFF ON if call

Flashes

OFF 6

“C he ck Air Co nd it io ner ” or “Che c k

Heat Pump” message.

switches are c lo sed .

diagnostic/stat us LED’s display the

indicat ed code.

• ComfortNet™ thermostat scrolls

• C om pre s so r and ou tdo o r fan are off.

• Lo w pressure and high press ure

• Integrated control module

Service” icon illu minated.

• ComfortNet™ thermostat “Call for

ON ON if call

Flashes

OFF 6

“Check Air Conditioner” or “Check

Heat Pump” message.

switches are c lo sed .

t imes with 5 minute de lay between eac h

det ection.

diagnostic/stat us LED’s display the

indicat ed code.

Service” icon illu minated.

“C he ck Air Co nd it io ner ” or “Che c k

• ComfortNet™ thermostat scrolls

• C om pre s so r and ou tdo o r fan are off.

• Lo w pressure and high press ure

• Open start circuit h as been detected 4

• Integrated control module

• ComfortNet™ thermostat “Call for

Heat Pump” message.

• ComfortNet™ thermostat scrolls

53

SERVICING

to repair .

normal cy c le.

• Turn po wer OFF p rio r

• Fault will clear after 1

• Fault may be cleared by

PCBHR101-103
PBBGR101-102

to repair .

cycling 24V AC to

cont rol .

cycling 24V AC to

cont rol .

replacem ent part(s).

• Turn po wer OFF p rio r

• Replace with corr ect

• Mu st clear fault by

replacem ent part(s).

• Replace with corr ect

to repair .

voltage less than 185

• Turn po wer OFF p rio r

VAC.

• Control detects line

to repair .

voltage greater than 255

• Turn po wer OFF p rio r

VAC.

• Control detects line

Corrective Actions No tes & Cautions

Possible Causes

ComfortNet™

T hermo stat O n l y

Fault

repair/replace as

ne eded.

repair/replace as

• Check compressor;

open.

Messa ge Code

OPEN RUN 07 • Com pr ess or run w i ndi ng i s

Des cript ion

Circuit

• O pe n Run

present;

ne eded.

• Check wiring;

w i red t o cont rol.

• Com pr e s sor not pro pe r l y

• Faulty compress or wiring.

call

OFF if no

• Check compressor;

07 • Com pr ess or run w i ndi ng i s

OPEN RUN

• O pe n Run

repair/replace as

ne eded.

repair/replace as

ne eded.

• Check wiring;

open.

w i red t o cont rol.

• Com pr e s sor not pro pe r l y

• Faulty compress or wiring.

LOCK

Circuit Lockout

call

present;

OFF if no

and fuses.

conn e c ted to p ower

supply as specified on

rating plate.

volt age condition;

con ta c t loc a l ut ilit y if

ne eded.

volt age condition;

con ta c t loc a l ut ilit y if

ne eded.

conn e c ted to p ower

supply as specified on

rating plate.

volt age condition;

con ta c t loc a l ut ilit y if

• Verify unit is

08 • Low line voltage. • Check circuit breakers

VOLT

LOW LINE

Voltage

• Low Line

present;

OFF if no

• Correct lo w line

• Hig h line voltage. • C or r e c t hi gh line

08

HIGH LINE

• High Line

call

• Verify unit is

VOLT

Voltage

call

present;

OFF if no

ne eded.

• Correct lo w line

54

OFF ON if call

Fl ash es

Diagnostic/Status LED Codes

OFF 7

Green Yellow Red Red Y1

Symp tom s of Abnorm al Op era tion

(Legacy & ComfortNet™ Thermostat)

switches are closed.

diagnostic/status LED’s display the

indicated code.

• Compressor and outdoor fan are off.

• Low pressure and high pressure

• Integrated control module

Servic e ” i c o n il luminate d.

• ComfortNet™ therm ostat “Call for

ON ON if call

Fl ash es

OFF 7

“Check Air Con ditioner” or “Check

Heat Pump” message.

switches are closed.

times with 5 minute delay between each

detection.

diagnostic/status LED’s display the

indicated code.

• ComfortNet™ therm ostat scrolls

• Compressor and outdoor fan are off.

• Low pressure and high pressure

• Open run circuit has been detected 4

• Integrated control module

Servic e ” i c o n il luminate d.

• ComfortNet™ therm ostat “Call for

OFF ON if call

Fl ash es

OFF 8

“Check Air Con ditioner” or “Check

Heat Pump” message.

to be operating normally.

(c ompress or a nd ou tdo or fa n off).

diagnostic/status LED’s display the

• ComfortNet™ therm ostat scrolls

• Air cond itioner/heat pump may appear

• Compressor protector may be o pen

indicated code.

• Integrated control module

OFF ON if call

Fl ash es

ON 8

to be operating normally.

• Air cond itioner/heat pump may appear

• Compressor protector may be o pen

(compre ss or a nd outdoor fan off).

diagnostic/status LED’s display the

indicated code.

• Integrated control module

SERVICING

to rep air .

• Turn power O F F p rior

• Fault will clear if

PCBHR101-103
PBBGR101-102

second ary voltag e rises

above 2 1V AC .

rep la cement par t(s ).

to rep air .

normal cy cle.

cycling 24V AC t o

con tro l.

• Replace with co rrect

• Turn power O F F p rior

• Fault will clear af ter 1

• Fault may be cleared by

rep la cement par t(s ).

• Replace with co rrect

Corrective Actions Notes & Ca uti ons

Possible Causes

ComfortNet™

T herm o stat Only

Message Code

Fa ul t

D escription

voltage conditio n .

• Transformer o verloaded.

VOLT

OFF i f no

replace if nee ded.

• Check transformer;

• Low l ine voltage.

call

• Check f use.

• Corr ect low se condary

vo ltage less than 18 V AC.

09 • Control detects secondary

LO W

SECOND

Voltage

• Low Pi lot

present;

repair/ replace as

needed.

repair/ replace as

needed.

• Check compressor;

• Check wiring;

start win dings .

• No current through run or

Not

Not di splayed

• Comp Protector

is ope n.

• Compressor run w inding

• Compress or not pr ope rly

displ ayed

Open

call

present;

OFF i f no

replace as needed.

• Check run capacitor;

w ired t o control.

capacitor.

• Faulty compressor wiring.

• F ailed com p ressor run

wiring.

• Faulty run capacitor

OFF ON if call

Fl ashes

Diagnost ic/Status LED Codes

OFF 9

G reen Yell ow Red Red Y 1

Sym pto m s of Abn ormal O p eration

(Legacy & ComfortN et™ Thermostat)

to be opera ting normally.

diagnostic/status LED ’s dis play the

• Air conditioner/heat pum p m ay appear

i ndicated code.

• Integ rated control m odule

OFF ON ON ON if call

• Com pres so r i s off .

• Integ rated control m odule

diagnostic/status LED ’s dis play the

i ndicated code.

55

SERVICING

PCBHR104/PCBHR105

7 SEGMENT LED

(DS2)

0 n Standby
0 1 Low Pressure CO Trip
0 1 Low Side Fault
0 2 High Pressure CO Trip
0 2 High Side Fault
0 3 Short Cycling
0 4 Locked Rotor
0 5 Open Circuit
0 6 Open Start Circuit
0 7 Open Run Circuit
0 8 No Line Voltage
0 9 Low Pilot Voltage

88 Power Up
A 2 Outdoor Air Temp Sensor Fault
A 3 Outdoor Coil Tem p Sensor Fault *

b 0 No Indoor Airflow

b 9 Inadequate Airflow
C 3 Cool Mode Short Cycle Timer
C 1 Low Cool
C 2 High Cool

dF Defrost *

d t Max Defrost Time *

d E Forced Defrost *

d 0 Data not yet on N e twork

d 1 Invalid Data on Netw ork

d 2 System Mis-Match

d 3 Configuration Mis-Match

d 4 Invalid Memory Card Data

E E Board Misoperation

E 5 Open Fuse

F t Fiel d Test Mode
H 8 High Line Voltage

L 1 LPCO Lockout (3 Trips)

L 2 HPCO Lockout (3 Trips)

L 6 Open Start Circuit Lockout

L 7 Open Run Circuit Lockout

L 8 Low Line Voltage

P 3 Heat Mode Short Cycle Timer *

P 1 Low Heat *

P 2 High Heat *

P 0 Comp Protector Open

Pd Pump Down

7 S EGME NT LE D

(DS1)

DE SCRIPTION O F COND ITIO N

56

* CODE USED ON HEAT P UM P MODELS ONLY
NOTE 1: DS1, DS2 AND DS3 ARE LABELED ON THE CONTROL ABOVE EACH 7
SEGMENT LED DISPLAY
NOTE 2: 7 SEGMENT LED DISPLAY DS3 IS NOT USED

0140M00407-A

SERVICING

3YMPTOMSOF

!BNORMAL/PERATION

,EGACY#OMFORT.ET

4HERMOSTAT

sIntegrated control

module diagnostic/status
LED display shows the
indicated code.

s#OMFORT.ETTHERMOSTAT

displays ‘---‘ in the
temperature display area.

sHeat pump fails to operate

in heating mode.

sIntegrated control

module diagnostic/status
LED display shows the
indicated code.

s#OMFORT.ETTHERMOSTAT

displays error message.

sAir conditioner/heat pump

fails to operate.

sIntegrated control

module diagnostic/status
LED display shows the
indicated code.

sAir conditioner/heat pump

fails to operate.

sIntegrated control

module diagnostic/status
LED display shows the
indicated code.

sAir conditioner/heat pump

fails to operate.

sIntegrated control

module diagnostic/status
LED display shows the
indicated code.

s#OMFORT.ETTHERMOSTAT

displays error message.

s Air conditioner/heat

pump operates at reduced
performance.

sAir conditioner/heat pump

operating at low stage
when expected to operate
at high stage.

sIntegrated control

module diagnostic/status
LED display shows the
indicated code.

3934%-42/5",%3(//4).'

5.)4!29$)!'./34)##/$%3

$IAGNOSTIC3TATUS

,%$$ISPLAY#ODES

$IGIT $IGIT $IGIT -ESSAGE #ODE

",!.+ A 2 sOutdoor air

",!.+ A3s Outdoor coil

",!.+ E5s Open fuse ",/7.

",!.+ EEs Board mis-

",!.+ b0s Circulator

",!.+ b9s Airflow is

&AULT

$ESCRIPTION

temp sensor
fault

temp sensor
fault

operation

blower motor
is not running
when it
should be
running.

lower than
demanded

#OMFORT.ET

4HERMOSTAT/NLY

AIR

3%.3/2

FLT

COIL

3%.3/2

FLT

FUSE

).4%2.!,

FAULT

MOTOR

./425.

LOW ID

AIRFLOW

4-

A2 s Shorted sensor.

A3 sShorted sensor

E5 s Short in low

EE sCompressor

b0 sIndoor blower

b9 sIndoor blower



0OSSIBLE

#AUSES

sOpen sensor.
sSensor

disconnected.

sSensor out of

range.

sOpen sensor.
sSensor.

disconnected.

sSensor out of

range.

voltage wiring.

relay contacts
welded.

motor problem.

sCommunications

error between
indoor and
outdoor unit.

motor problem

s

Blocked filters.

sRestrictive/

undersized
ductwork

sIndoor/ outdoor

unit miss-match.

PCBHR104

#ORRECTIVE

!CTIONS

sCheck sensor

connection.

sReplace open/

shorted sensor.

sCheck sensor

connection.

sReplace open/

shorted sensor.

sLocate and

correct short
in low voltage
wiring.

sReplace control. sTurn power OFF prior

sCheck indoor

blower motor.

sCheck indoor

blower motor
wiring.

sCheck indoor unit

control.

sRepair/ replace

any faulty wiring.

sRepair/ replace

indoor blower
motor or control.

sCheck indoor

blower motor.

sCheck filters;

clean/replace as
needed.

sCheck ductwork;

resize as needed.

sVerify indoor and

outdoor units are
properly matched.

.OTES

#AUTIONS

sTurn power OFF prior

to repair.

sReplace with correct

replacement part.

sTurn power OFF prior

to repair.

sReplace with correct

replacement part.

sTurn power OFF prior

to repair.

sReplace fuse with

3-amp automotive type.

to repair

sReplace with correct

replacement part.

sTurn power OFF prior

to repair.

sApplies only to fully

communicating system

USING#OMFORT.ET

thermostat.

sReplace with correct

replacement part.

sTurn power OFF prior

to repair.

sApplies only to fully

communicating system

USING#OMFORT.ET

thermostat.

sReplace with correct

replacement part. See
specification sheet(s)
for airflow requirements
and maximum external
static pressure.

sSee specification

sheets for approved
system matches.

57

SERVICING

3YMPTOMSOF

!BNORMAL/PERATION

,EGACY#OMFORT.ET

4HERMOSTAT

sAir conditioner/heat pump

fails to operate.

sIntegrated control

module diagnostic/status
LED display shows the
indicated code.

s#OMFORT.ETTHERMOSTAT

displays error message.

sAir conditioner/heat pump

fails to operate.

sIntegrated control

module diagnostic/status
LED display shows the
indicated code.

s#OMFORT.ETTHERMOSTAT

displays error message.

sAir conditioner/heat pump

fails to operate.

sAir conditioner/heat pump

operating at reduced
performance.

sAir conditioner/heat pump

operating at low stage
when expected to operate
at high stage.

sIntegrated control

module diagnostic/status
LED display shows the
indicated code.

s#OMFORT.ETTHERMOSTAT

displays error message.

5.)4!29$)!'./34)##/$%3

$IAGNOSTIC3TATUS

,%$$ISPLAY#ODES &AULT

$IGIT $IGIT $IGIT -ESSAGE #ODE

",!.+ d0sData not yet

",!.+ d1sInvalid Data

",!.+ d2s System

$ESCRIPTION

ON.ETWORK

ON.ETWORK

Mis-Match

#OMFORT.ET4-

4HERMOSTAT/NLY 0OSSIBLE

./.%4

DATA

).6!,)$

DATA

).6!,)$

SYSTEM

d0 sAir conditioner/

d1 s Air conditioner/

d2 sAir conditioner/

#AUSES

heat pump is
wired as part of
a communicating
system and
integrated control
module does
not contain any
shared data.

heat pump is
wired as part of
a communicating
system and
integrated control
module contains
invalid shared
data or network
data is invalid for
the integrated
control module.

heat pump is
wired as part of
a communicating
system and
outdoor unit
requires airflow
greater than
indoor unit’s
airflow capability.

sShared data is

incompatible
with the system
or missing
parameters.

#ORRECTIVE

!CTIONS

sVerify

system type
(communicating
or legacy)

sPopulate shared

data using
memory card

sWire system as

legacy system

sVerify

system type
(communicating
or legacy).

sPopulate correct

shared data using
memory card.

sWire system as

legacy system.

sVerify system type

(communicating
or legacy).

sVerify shared

data is correct
for your specific
model; re­populate data if
required.

sWire system as

legacy system.

PCBHR104

.OTES

#AUTIONS

sTurn power OFF prior

to repair.

sUse memory card for

your specific model.

sInsert memory card

BEFORE turning power

/.-EMORYCARDMAY

be removed after data
is loaded. Turn power
OFF before removing
memory card.

sError code will

be cleared once
data is loaded.
Applies only to fully
communicating system

USING#OMFORT.ET

thermostat.

sTurn power OFF prior

to repair.

sUse memory card for

your specific model.

sInsert memory card

BEFORE turning power

/.-EMORYCARDMAY

be removed after data
is loaded. Turn power
OFF before removing
memory card.

sError code will

be cleared once
data is loaded.
Applies only to fully
communicating system

USING#OMFORT.ET

thermostat.

sTurn power OFF prior

to repair.

sUse memory card for

your specific model.

sInsert memory card

BEFORE turning power

/.-EMORYCARDMAY

be removed after data
is loaded. Turn power
OFF before removing
memory card.

sError code will

be cleared once
data is loaded.
Applies only to fully
communicating system

USING#OMFORT.ET

thermostat.

58

SERVICING

5.)4!29$)!'./34)##/$%3

3YMPTOMSOF

!BNORMAL/PERATION

,EGACY#OMFORT.ET

4HERMOSTAT

$IAGNOSTIC3TATUS

,%$$ISPLAY#ODES &AULT

$ESCRIPTION

#OMFORT.ET4-

4HERMOSTAT/NLY 0OSSIBLE

#AUSES

#ORRECTIVE

!CTIONS

.OTES

#AUTIONS

$IGIT $IGIT $IGIT -ESSAGE #ODE

s Air conditioner/heat pump

fails to operate.

sIntegrated control module

diagnostic/status LED
display shows the indicated
code.

s#OMFORT.ETTHERMOSTAT

displays error message.

",!.+ d3s Configuration

Mis-match

).6!,)$

#/.&)'

d3 sShared data sent

to integrated
control module
does not match
hardware
configuration.

sVerify

system type
(communicating
or legacy).

sVerify shared

data is correct
for your specific
model; re­populate data if
required.

sWire system as

legacy system.

sTurn power OFF prior

to repair.

sUse memory card for

your specific model.

sInsert memory card

BEFORE turning power

/.-EMORYCARDMAY

be removed after data
is loaded. Turn power
OFF before removing
memory card.

sError code will

be cleared once
data is loaded.
Applies only to fully
communicating system

USING#OMFORT.ET

thermostat.

sAir conditioner/heat pump

fails to operate.

sIntegrated control

module diagnostic/status
LED display shows the
indicated code.

s#OMFORT.ETTHERMOSTAT

displays error message.

",!.+ d4s Invalid

Memory
Card Data

).6!,)$

MC DATA

d4 sShared data on

memory card has
been rejected.

sVerify

system type
(communicating
or legacy).

sVerify shared

data is correct
for your specific
model; re­populate data if
required.

sWire system as

legacy system.

sTurn power OFF prior

to repair.

sUse memory card for

your specific model.

sInsert memory card

BEFORE turning power

/.-EMORYCARDMAY

be removed after data
is loaded. Turn power
OFF before removing
memory card.

sError code will be

cleared once data is
loaded.

s Very long run time.
sFour consecutive

compressor protector
trips with average run
time between trips greater
than 3 hours.

sCompressor operating at

high speed and outdoor fan
operating at low speed

sIntegrated control

module diagnostic/status
LED display shows the
indicated code.

",!.+ 01s Low Side

Fault

LOW SIDE

FAULT

01 s Low refrigerant

charge.

sRestriction in

liquid line.

sIndoor blower

motor failure.

sIndoor

thermostat set
extremely low.

sVerify refrigerant

charge; adjust as
needed.

sCheck for

restricted liquid
line; repair/
replace as
needed.

sCheck indoor

blower motor;
repair/replace as
needed.

sCheck indoor

thermostat setting.

sTurn power OFF prior

to repair.

sFault will clear after 30

consecutive normal
cycles.

sFault may be cleared

by cycling 24VAC to
control.

sReplace with correct

replacement part(s).

sCompressor and outdoor

fan are off.

sThermostat demand is

present.

sIntegrated control

module diagnostic/status
LED display shows the
indicated code.

",!.+ 01s Low Pressure

Cut Out Trip

,03/0%. 01 s Low refrigerant

charge.

sRestriction in

liquid line.

sIndoor blower

motor failure.

sIndoor

thermostat set
extremely low.

sVerify refrigerant

charge; adjust as
needed.

sCheck for

restricted liquid
line; repair/
replace as
needed.

sCheck indoor

blower motor;
repair/replace as
needed.

sCheck low

pressure switch;
repair/replace as
needed.

sCheck indoor

thermostat setting.

sTurn power OFF prior

to repair.

sReplace with correct

replacement part(s).

PCBHR104

59

SERVICING

Compressor and outdoor
f
Low pressure switch
trip 3 times within same
thermostat demand.
Thermostat demand is
present.
Integrated control
module diagnostic/status
LED display shows the
indicated code.

displays error message.

Four consecutive
compressor protector trips
with average run time
between trips greater than
1 minute and less than 15
minutes.
Low pressure and high
pressure switches are
closed.
Integrated control
module diagnostic/status
LED display shows the
indicated code.

Compressor and outdoor
f
Thermostat demand is
present.
Integrated control
module diagnostic/status
LED display shows the
indicated code.

Compressor and outdoor
f
Low pressure switch
trip 3 times within same
thermostat demand.
Thermostat demand is
present.
Integrated control
module diagnostic/status
LED display shows the
indicated code.

displays error message.

.

.

.

Digit 3 Digit 2 Digit 1

L1Low Pressure

02High Side

02High

L2High

Cut Out
Lockout
(3 T rips)

Fault

Pressure
Cut Out
Trip

Pressure
Cut Out
Lockout
(3 T rips)

LPS 01 Low refrigerant

HIGH SIDE

FAULT

HPS 02 Blocked

charge.
Restriction in
liquid line.
Indoor blower
motor failure.
Indoor
thermostat set
extremely low.

02 Blocked

condenser coil.
Outdoor fan not
running.

02 Blocked

condenser coil.
Outdoor fan not
running.

condenser coil.
Outdoor fan not
running.

Verify refrigerant
charge; adjust as
needed.
Check for
restricted liquid
line; repair/replace
as needed.
Check indoor
blower motor;
repair/replace as
needed.
Check low
pressure switch;
repair/replace as
needed.
Check indoor
thermostat setting.

Check and clean
condenser coil.
Check outdoor
fan motor; repair/
replace as
needed.
Check outdoor
fan motor wiring;
repair/replace as
needed.
Check outdoor
fan motor
capacitor; replace
as needed.

Check and clean
condenser coil.
Check outdoor
fan motor; repair/
replace as
needed.
Check outdoor
fan motor wiring;
repair/replace as
needed.
Check outdoor
fan motor
capacitor; replace
as needed.

Check and clean
condenser coil.
Check outdoor
fan motor; repair/
replace as
needed.
Check outdoor
fan motor wiring;
repair/replace as
needed.
Check outdoor
fan motor
capacitor; replace
as needed.

PCBHR104

Turn power OFF prior
to repair.
Must clear fault by
cycling 24VAC to
control.
Replace with correct
replacement part(s).

Turn power OFF prior
to repair.
Fault will clear after 4
consecutive normal
cycles.
Fault may be cleared
by cycling 24VAC to
control.
Replace with correct
replacement part(s).

Turn power OFF prior
to repair.
Replace with correct
replacement part(s).

Turn power OFF prior
to repair.
Must clear fault by
cycling 24VAC to
control.
Replace with correct
replacement part(s).

60

SERVICING

1

PCBHR104

Digit 3 Digit 1Digit 2

Run time for last 4 cycles
is less than 3 minutes
each.
Compressor protector has
not tripped.
Low pressure and high
pressure switches are
closed.
Integrated control
module diagnostic/status
LED display shows the
indicated code.

Compressor and outdoor
f
Compressor protector trips
four consecutive times.
Average run time between
trips is less than 15
seconds.
Integrated control
module diagnostic/status
LED display shows the
indicated code.

displays error message.

Compressor and outdoor
f
4 hours.
Low pressure and high
pressure switches are
closed.
Integrated control
module diagnostic/status
LED display shows the
indicated code.

displays error message.

Compressor and outdoor
f
Low pressure and high
pressure switches are
closed.
Integrated control
module diagnostic/status
LED display shows the
indicated code.

displays error message.

.

or greater than

.

03Short Cycling CMPR

04Locked Rotor

05Open Circuit

06Open Start

Circuit

SHRT

CYCLE

ROTOR

CIRCUIT

START

03 Intermittent

thermostat
demand.
Faulty
compressor
relay.

Compressor

04

bearings are
seized.
Failed
compressor run
capacitor.
Faulty run
capacitor wiring.
Low line voltage.

05

Power is
disconnected.
Failed
compressor
protector.
Compressor not
properly wired to
control.

06

Compressor start
winding is open.
Failed
compressor run
capacitor.
Faulty run
capacitor wiring.
Compressor not
properly wired to
control.
Faulty
compressor
wiring.

Check thermostat
and thermostat
wiring; repair/
replace as
needed.
Check
compressor
relay operation;
replace control as
needed.

Check
compressor
operation; repair/
replace as
needed.
Check run
capacitor; replace
as needed.
Check wiring;
repair/replace as
needed.
Verify line voltage
is within range
on rating plate;
contact local
utility is out of
range.

Check circuit
breakers and
fuses.
Check wiring
to unit; repair/
replace as
needed.
Check
compressor;
repair/replace as
needed
Check
compressor
wiring; repair/
replace as
needed.

Check
compressor;
repair/replace as
needed.
Check run
capacitor; replace
as needed.
Check wiring;
repair/replace as
needed.

Turn power OFF prior
to repair.
Fault will clear after 4
consecutive normal
cycles.
Fault may be cleared
by cycling 24VAC to
control.
Replace with correct
replacement part(s).
Minimum compressor
runt time is changed
from 30 seconds to 3
minutes.

Turn power OFF prior
to repair.
Must clear fault by
cycling 24VAC to
control.
Replace with correct
replacement part(s).

Turn power OFF prior
to repair.
Fault will clear after
normal cycle.
Fault may be cleared
by cycling 24VAC to
control.
Replace with correct
replacement part(s).

Turn power OFF prior
to repair.
Fault will clear after 1
normal cycle.
Fault may be cleared
by cycling 24VAC to
control.
Replace will correct
replacement part(s).

61

SERVICING

PCBHR104

Digit 3 Digit 2 Digit 1

Compressor and outdoor
f
Low pressure and high
pressure switches are
closed.
Open start circuit has been
detected 4 times with 5
minute delay between each
detection.
Integrated control
module diagnostic/status
LED display shows the
indicated code.

displays error message.
Compressor and outdoor

f
Low pressure and high
pressure switches are
closed.
Integrated control
module diagnostic/status
LED display shows the
indicated code.

displays error message.

.

.

Compressor and outdoor
f
Low pressure and high
pressure switches are
closed.
Open run circuit has been
detected 4 times with 5
minute delay between
each detection.
Integrated control
module diagnostic/status
LED display shows the
indicated code.

displays error message.
Air conditioner/heat

pump may appear to be
operating normally.
Compressor protector may
be open (compressor and
outdoor f
Integrated control
module diagnostic/status
LED display shows the
indicated code.

.

L6Open Start

Circuit
Lockout

07Open Run

Circuit

L7Open Run

Circuit
Lockout

L8Low Line

Voltage

START

VOLT

06 Compressor start

winding is open.
Failed
compressor run
capacitor.
Faulty run
capacitor wiring.
Compressor not
properly wired
to control.
Faulty
compressor
wiring.

07 Compressor run

winding is open.
Compressor not
properly wired
to control.
Faulty
compressor
wiring.

07 Compressor run

winding is open.
Compressor not
properly wired
to control.
Faulty
compressor
wiring.

Low line voltage. Check circuit

08

Check
compressor;
repair/replace as
needed.
Check run
capacitor; replace
as needed.
Check wiring
repair/replaced
as needed.

Check
compressor;
repair/replace as
needed.
Check wiring;
repair/replace as
needed.

Check compres­sor; repair/re­place as needed.
Check wiring;
repair/replace as
needed.

breakers and
fuses.
Verify unit is
connected to
power supply

rating plate.
Correct low line
voltage condition;
contact local
utility if needed.

Turn power OFF prior
to repair
Must clear fault by
cycling 24VAC to
control.
Replace with correct
replacement part(s).

Turn power OFF prior
to repair.
Fault will clear after 1
normal cycle.
Fault may be cycling
24VAC to control.
Replace with correct
replacement part(s).

Turn power OFF prior
to repair.
Must clear fault by cy­cling 24VAC to control.
Replace with correct
replacement part(s).

Turn power OFF prior
to repair.
Control detects line
voltage less than
185 VA C.
Fault will clear if line
voltage increases
above 185 VAC.

62

SERVICING

PCBHR104

Air conditioner/heat
pump may appear to be
operating normally.
Compressor protector
may be open (compressor
and outdoor f
Integrated control
module diagnostic/status
LED display shows the
indicated code.

Air conditioner/heat
pump may appear to be
operating normally.
Integrated control
module diagnostic/status
LED display shows the
indicated code.

Integrated control
module diagnostic/status
LED display shows the
indicated code.

Air conditioner/heat
pump may appear to be
operating normally.
Compressor protector
may be open (compressor
and outdoor f
Integrated control
module diagnostic/status
LED display shows the
indicated code.

.

Digit 3

Digit 1Digit 2

H8High Line

Voltage

09Low Pilot

Voltage

P0Comp

Protector
Open

08

08

VOLT

LOW

VOLT

displayed displayed through run or

VOLT AGE

High line
voltage

Control detects

09

secondary
voltage less
than 18 VAC.
Transformer
overloaded.
Low line voltage.

start windings.
Compressor
run winding is
open.
Compressor not
properly wired to
control.
Faulty
compressor
wiring.
Failed
compressor run
capacitor.
Faulty run
capacitor wiring.

08 Check circuit

Correct high line
voltage condition;
contact local utility
if needed.
Verify unit is
connected to power

on rating plate.

Check fuse.
Correct low second­ary voltage condition.
Check transformer;
replace if needed.

Check compressor;
repair/replace as
needed.
Check wiring; repair/
replace as needed.
Check run ca­pacitor; replace as
needed.

breaker and fuses.
Verify unit is con­nected to power

on rating plate.

Turn power OFF prior
to repair.
Control detects line
voltage greater than
255 VA C.
Fault will clear if line
voltage decreases
below 255 VAC.

T urn power OFF prior to
repair.
Fault will clear if
secondary voltage rises
above 21V AC.
Replace with correct
replacement part(s).

Turn power OFF prior
to repair.
Fault will clear after 1
normal cycle.
Fault may be cleared
by cycling 24VAC to
control.
Replace with correct
replacement part(s).

Turn power OFF prior
to repair.
Control detects line
voltage less than
185 VA C.
Fault will clear if line
voltage increases
above 185 VAC.

63

SERVICING

3YMPTOMSOF

!BNORMAL/PERATION

,EGACY#OMFORT.ET

4HERMOSTAT

sIntegrated control

module diagnostic/status
LED display shows the
indicated code.

s#OMFORT.ETTHERMOSTAT

displays ‘---‘ in the
temperature display area.

sHeat pump fails to operate

in heating mode.

sIntegrated control

module diagnostic/status
LED display shows the
indicated code.

s#OMFORT.ETTHERMOSTAT

displays error message.

sAir conditioner/heat pump

fails to operate.

sIntegrated control

module diagnostic/status
LED display shows the
indicated code.

sAir conditioner/heat pump

fails to operate.

sIntegrated control

module diagnostic/status
LED display shows the
indicated code.

sAir conditioner/heat pump

fails to operate.

sIntegrated control

module diagnostic/status
LED display shows the
indicated code.

s#OMFORT.ETTHERMOSTAT

displays error message.

s Air conditioner/heat

pump operates at reduced
performance.

sAir conditioner/heat pump

operating at low stage
when expected to operate
at high stage.

sIntegrated control

module diagnostic/status
LED display shows the
indicated code.

3934%-42/5",%3(//4).'

5.)4!29$)!'./34)##/$%3

$IAGNOSTIC3TATUS

,%$$ISPLAY#ODES

$IGIT $IGIT $IGIT -ESSAGE #ODE

",!.+ A 2 sOutdoor air

",!.+ A3s Outdoor coil

",!.+ E5s Open fuse ",/7.

",!.+ EEs Board mis-

",!.+ b0s Circulator

",!.+ b9s Airflow is

&AULT

$ESCRIPTION

temp sensor
fault

temp sensor
fault

operation

blower motor
is not running
when it
should be
running.

lower than
demanded

#OMFORT.ET

4HERMOSTAT/NLY

AIR

3%.3/2

FLT

COIL

3%.3/2

FLT

FUSE

).4%2.!,

FAULT

MOTOR

./425.

LOW ID

AIRFLOW

4-

A2 s Shorted sensor.

A3 s Shorted sensor

E5 s Short in low

EE sCompressor

b0 sIndoor blower

b9 sIndoor blower



0OSSIBLE

#AUSES

sOpen sensor.
sSensor

disconnected.

sSensor out of

range.

sOpen sensor.
sSensor.

disconnected.

sSensor out of

range.

voltage wiring.

relay contacts
welded.

motor problem.

sCommunications

error between
indoor and
outdoor unit.

motor problem

s

Blocked filters.

sRestrictive/

undersized
ductwork

sIndoor/ outdoor

unit miss-match.

PCBHR105

#ORRECTIVE

!CTIONS

sCheck sensor

connection.

sReplace open/

shorted sensor.

sCheck sensor

connection.

sReplace open/

shorted sensor.

sLocate and

correct short
in low voltage
wiring.

sReplace control. sTurn power OFF prior

sCheck indoor

blower motor.

sCheck indoor

blower motor
wiring.

sCheck indoor unit

control.

sRepair/ replace

any faulty wiring.

sRepair/ replace

indoor blower
motor or control.

sCheck indoor

blower motor.

sCheck filters;

clean/replace as
needed.

sCheck ductwork;

resize as needed.

sVerify indoor and

outdoor units are
properly matched.

.OTES

#AUTIONS

sTurn power OFF prior

to repair.

sReplace with correct

replacement part.

sTurn power OFF prior

to repair.

sReplace with correct

replacement part.

sTurn power OFF prior

to repair.

sReplace fuse with

3-amp automotive type.

to repair

sReplace with correct

replacement part.

sTurn power OFF prior

to repair.

sApplies only to fully

communicating system

USING#OMFORT.ET

thermostat.

sReplace with correct

replacement part.

sTurn power OFF prior

to repair.

sApplies only to fully

communicating system

USING#OMFORT.ET

thermostat.

sReplace with correct

replacement part. See
specification sheet(s)
for airflow requirements
and maximum external
static pressure.

sSee specification

sheets for approved
system matches.

64

SERVICING

5.)4!29$)!'./34)##/$%3

3YMPTOMSOF

!BNORMAL/PERATION

,EGACY#OMFORT.ET

4HERMOSTAT

$IAGNOSTIC3TATUS

,%$$ISPLAY#ODES &AULT

$ESCRIPTION

#OMFORT.ET4-

4HERMOSTAT/NLY 0OSSIBLE

#AUSES

#ORRECTIVE

!CTIONS

.OTES

#AUTIONS

$IGIT $IGIT $IGIT -ESSAGE #ODE

sAir conditioner/heat pump

fails to operate.

sIntegrated control

module diagnostic/status
LED display shows the
indicated code.

s#OMFORT.ETTHERMOSTAT

displays error message.

",!.+ d0sData not yet

ON.ETWORK

./.%4

DATA

d0 sAir conditioner/

heat pump is
wired as part of
a communicating
system and
integrated control
module does
not contain any
shared data.

sVerify

system type
(communicating
or legacy)

sPopulate shared

data using
memory card

sWire system as

legacy system

sTurn power OFF prior

to repair.

sUse memory card for

your specific model.

sInsert memory card

BEFORE turning power

/.-EMORYCARDMAY

be removed after data
is loaded. Turn power
OFF before removing
memory card.

sError code will

be cleared once
data is loaded.
Applies only to fully
communicating system

USING#OMFORT.ET

thermostat.

sAir conditioner/heat pump

fails to operate.

sIntegrated control

module diagnostic/status
LED display shows the
indicated code.

s#OMFORT.ETTHERMOSTAT

displays error message.

",!.+ d1sInvalid Data

ON.ETWORK

).6!,)$

DATA

d1 s Air conditioner/

heat pump is
wired as part of
a communicating
system and
integrated control
module contains
invalid shared
data or network
data is invalid for
the integrated
control module.

sVerify

system type
(communicating
or legacy).

sPopulate correct

shared data using
memory card.

sWire system as

legacy system.

sTurn power OFF prior

to repair.

sUse memory card for

your specific model.

sInsert memory card

BEFORE turning power

/.-EMORYCARDMAY

be removed after data
is loaded. Turn power
OFF before removing
memory card.

sError code will

be cleared once
data is loaded.
Applies only to fully
communicating system

USING#OMFORT.ET

thermostat.

sAir conditioner/heat pump

fails to operate.

sAir conditioner/heat pump

operating at reduced
performance.

sAir conditioner/heat pump

operating at low stage
when expected to operate
at high stage.

sIntegrated control

module diagnostic/status
LED display shows the
indicated code.

s#OMFORT.ETTHERMOSTAT

displays error message.

",!.+ d2s System

Mis-Match

).6!,)$

SYSTEM

d2 sAir conditioner/

heat pump is
wired as part of
a communicating
system and
outdoor unit
requires airflow
greater than
indoor unit’s
airflow capability.

sShared data is

incompatible
with the system
or missing
parameters.

sVerify system type

(communicating
or legacy).

sVerify shared

data is correct
for your specific
model; re­populate data if
required.

sWire system as

legacy system.

sTurn power OFF prior

to repair.

sUse memory card for

your specific model.

sInsert memory card

BEFORE turning power

/.-EMORYCARDMAY

be removed after data
is loaded. Turn power
OFF before removing
memory card.

sError code will

be cleared once
data is loaded.
Applies only to fully
communicating system

USING#OMFORT.ET

thermostat.

PCBHR105

65

SERVICING

3YMPTOMSOF

!BNORMAL/PERATION

,EGACY#OMFORT.ET

4HERMOSTAT

s Air conditioner/heat pump

fails to operate.

sIntegrated control module

diagnostic/status LED
display shows the indicated
code.

s#OMFORT.ETTHERMOSTAT

displays error message.

sAir conditioner/heat pump

fails to operate.

sIntegrated control

module diagnostic/status
LED display shows the
indicated code.

s#OMFORT.ETTHERMOSTAT

displays error message.

s Very long run time.
sFour consecutive

compressor protector
trips with average run
time between trips greater
than 3 hours.

sCompressor operating at

high speed and outdoor fan
operating at low speed

sIntegrated control

module diagnostic/status
LED display shows the
indicated code.

sCompressor and outdoor

fan are off.

sThermostat demand is

present.

sIntegrated control

module diagnostic/status
LED display shows the
indicated code.

5.)4!29$)!'./34)##/$%3

$IAGNOSTIC3TATUS

,%$$ISPLAY#ODES &AULT

$IGIT $IGIT $IGIT -ESSAGE #ODE

",!.+ d3s Configuration

",!.+ d4s Invalid

",!.+ 01s Low Side

",!.+ 01s Low Pressure

$ESCRIPTION

Mis-match

Memory
Card Data

Fault

Cut Out Trip

#OMFORT.ET4-

4HERMOSTAT/NLY 0OSSIBLE

).6!,)$

#/.&)'

).6!,)$

MC DATA

LOW SIDE

FAULT

,03/0%. 01 s Low refrigerant

d3 sShared data sent

d4 sShared data on

01 s Low refrigerant

#AUSES

to integrated
control module
does not match
hardware
configuration.

memory card has
been rejected.

charge.

sRestriction in

liquid line.

sIndoor blower

motor failure.

sIndoor

thermostat set
extremely low.

charge.

sRestriction in

liquid line.

sIndoor blower

motor failure.

sIndoor

thermostat set
extremely low.

#ORRECTIVE

!CTIONS

sVerify

system type
(communicating
or legacy).

sVerify shared

data is correct
for your specific
model; re­populate data if
required.

sWire system as

legacy system.

sVerify

system type
(communicating
or legacy).

sVerify shared

data is correct
for your specific
model; re­populate data if
required.

sWire system as

legacy system.

sVerify refrigerant

charge; adjust as
needed.

sCheck for

restricted liquid
line; repair/
replace as
needed.

sCheck indoor

blower motor;
repair/replace as
needed.

sCheck indoor

thermostat setting.

sVerify refrigerant

charge; adjust as
needed.

sCheck for

restricted liquid
line; repair/
replace as
needed.

sCheck indoor

blower motor;
repair/replace as
needed.

sCheck low

pressure switch;
repair/replace as
needed.

sCheck indoor

thermostat setting.

PCBHR105

.OTES

#AUTIONS

sTurn power OFF prior

to repair.

sUse memory card for

your specific model.

sInsert memory card

BEFORE turning power

/.-EMORYCARDMAY

be removed after data
is loaded. Turn power
OFF before removing
memory card.

sError code will

be cleared once
data is loaded.
Applies only to fully
communicating system

USING#OMFORT.ET

thermostat.

sTurn power OFF prior

to repair.

sUse memory card for

your specific model.

sInsert memory card

BEFORE turning power

/.-EMORYCARDMAY

be removed after data
is loaded. Turn power
OFF before removing
memory card.

sError code will be

cleared once data is
loaded.

sTurn power OFF prior

to repair.

sFault will clear after 30

consecutive normal
cycles.

sFault may be cleared

by cycling 24VAC to
control.

sReplace with correct

replacement part(s).

sTurn power OFF prior

to repair.

sReplace with correct

replacement part(s).

66

SERVICING

Compressor and outdoor
f
Low pressure switch
trip 3 times within same
thermostat demand.
Thermostat demand is
present.
Integrated control
module diagnostic/status
LED display shows the
indicated code.

displays error message.

Four consecutive
compressor protector trips
with average run time
between trips greater than
1 minute and less than 15
minutes.
Low pressure and high
pressure switches are
closed.
Integrated control
module diagnostic/status
LED display shows the
indicated code.

Compressor and outdoor
f
Thermostat demand is
present.
Integrated control
module diagnostic/status
LED display shows the
indicated code.

Compressor and outdoor
f
Low pressure switch
trip 3 times within same
thermostat demand.
Thermostat demand is
present.
Integrated control
module diagnostic/status
LED display shows the
indicated code.

displays error message.

.

.

.

Digit 3 Digit 2 Digit 1

L1Low Pressure

02High Side

02High

L2High

Cut Out
Lockout
(3 T rips)

Fault

Pressure
Cut Out
Trip

Pressure
Cut Out
Lockout
(3 T rips)

LPS 01 Low refrigerant

HIGH SIDE

FAULT

HPS

charge.
Restriction in
liquid line.
Indoor blower
motor failure.
Indoor
thermostat set
extremely low.

02 Blocked

condenser coil.
Outdoor fan not
running.

02 Blocked

condenser coil.
Outdoor fan not
running.

02 Blocked

condenser coil.
Outdoor fan not
running.

Verify refrigerant
charge; adjust as
needed.
Check for
restricted liquid
line; repair/replace
as needed.
Check indoor
blower motor;
repair/replace as
needed.
Check low
pressure switch;
repair/replace as
needed.
Check indoor
thermostat setting.

Check and clean
condenser coil.
Check outdoor
fan motor; repair/
replace as
needed.
Check outdoor
fan motor wiring;
repair/replace as
needed.
Check outdoor
fan motor
capacitor; replace
as needed.

Check and clean
condenser coil.
Check outdoor
fan motor; repair/
replace as
needed.
Check outdoor
fan motor wiring;
repair/replace as
needed.
Check outdoor
fan motor
capacitor; replace
as needed.

Check and clean
condenser coil.
Check outdoor
fan motor; repair/
replace as
needed.
Check outdoor
fan motor wiring;
repair/replace as
needed.
Check outdoor
fan motor
capacitor; replace
as needed.

PCBHR105

Turn power OFF prior
to repair.
Must clear fault by
cycling 24VAC to
control.
Replace with correct
replacement part(s).

Turn power OFF prior
to repair.
Fault will clear after 4
consecutive normal
cycles.
Fault may be cleared
by cycling 24VAC to
control.
Replace with correct
replacement part(s).

Turn power OFF prior
to repair.
Replace with correct
replacement part(s).

Turn power OFF prior
to repair.
Must clear fault by
cycling 24VAC to
control.
Replace with correct
replacement part(s).

67

SERVICING

1

PCBHR105

Digit 3 Digit 1Digit 2

Run time for last 4 cycles
is less than 3 minutes
each.
Compressor protector has
not tripped.
Low pressure and high
pressure switches are
closed.
Integrated control
module diagnostic/status
LED display shows the
indicated code.

Compressor and outdoor
f
Compressor protector trips
four consecutive times.
Average run time between
trips is less than 15
seconds.
Integrated control
module diagnostic/status
LED display shows the
indicated code.

displays error message.

Compressor and outdoor
f
4 hours.
Low pressure and high
pressure switches are
closed.
Integrated control
module diagnostic/status
LED display shows the
indicated code.

displays error message.

Compressor and outdoor
f
Low pressure and high
pressure switches are
closed.
Integrated control
module diagnostic/status
LED display shows the
indicated code.

displays error message.

.

or greater than

.

03Short Cycling CMPR

04Locked Rotor

05Open Circuit

06Open Start

Circuit

SHRT

CYCLE

ROTOR

CIRCUIT

START

03 Intermittent

thermostat
demand.
Faulty
compressor
relay.

Compressor

04

bearings are
seized.
Failed
compressor run
capacitor.
Faulty run
capacitor wiring.
Low line voltage.

05

Power is
disconnected.
Failed
compressor
protector.
Compressor not
properly wired to
control.

06

Compressor start
winding is open.
Failed
compressor run
capacitor.
Faulty run
capacitor wiring.
Compressor not
properly wired to
control.
Faulty
compressor
wiring.

Check thermostat
and thermostat
wiring; repair/
replace as
needed.
Check
compressor
relay operation;
replace control as
needed.

Check
compressor
operation; repair/
replace as
needed.
Check run
capacitor; replace
as needed.
Check wiring;
repair/replace as
needed.
Verify line voltage
is within range
on rating plate;
contact local
utility is out of
range.

Check circuit
breakers and
fuses.
Check wiring
to unit; repair/
replace as
needed.
Check
compressor;
repair/replace as
needed
Check
compressor
wiring; repair/
replace as
needed.

Check
compressor;
repair/replace as
needed.
Check run
capacitor; replace
as needed.
Check wiring;
repair/replace as
needed.

Turn power OFF prior
to repair.
Fault will clear after 4
consecutive normal
cycles.
Fault may be cleared
by cycling 24VAC to
control.
Replace with correct
replacement part(s).
Minimum compressor
runt time is changed
from 30 seconds to 3
minutes.

Turn power OFF prior
to repair.
Must clear fault by
cycling 24VAC to
control.
Replace with correct
replacement part(s).

Turn power OFF prior
to repair.
Fault will clear after
normal cycle.
Fault may be cleared
by cycling 24VAC to
control.
Replace with correct
replacement part(s).

Turn power OFF prior
to repair.
Fault will clear after 1
normal cycle.
Fault may be cleared
by cycling 24VAC to
control.
Replace will correct
replacement part(s).

68

SERVICING

PCBHR105

Digit 3 Digit 2 Digit 1

Compressor and outdoor
f
Low pressure and high
pressure switches are
closed.
Open start circuit has been
detected 4 times with 5
minute delay between each
detection.
Integrated control
module diagnostic/status
LED display shows the
indicated code.

displays error message.
Compressor and outdoor

f
Low pressure and high
pressure switches are
closed.
Integrated control
module diagnostic/status
LED display shows the
indicated code.

displays error message.

.

.

Compressor and outdoor
f .
Low pressure and high
pressure switches are
closed.
Open run circuit has been
detected 4 times with 5
minute delay between
each detection.
Integrated control
module diagnostic/status
LED display shows the
indicated code.

displays error message.
Air conditioner/heat

pump may appear to be
operating normally.
Compressor protector may
be open (compressor and
outdoor f
Integrated control
module diagnostic/status
LED display shows the
indicated code.

L6Open Start

Circuit
Lockout

07Open Run

Circuit

L7Open Run

Circuit
Lockout

L8Low Line

Voltage

START

VOLT

06 Compressor start

winding is open.
Failed
compressor run
capacitor.
Faulty run
capacitor wiring.
Compressor not
properly wired
to control.
Faulty
compressor
wiring.

07 Compressor run

winding is open.
Compressor not
properly wired
to control.
Faulty
compressor
wiring.

07 Compressor run

winding is open.
Compressor not
properly wired
to control.
Faulty
compressor
wiring.

Low line voltage. Check circuit

08

Check
compressor;
repair/replace as
needed.
Check run
capacitor; replace
as needed.
Check wiring
repair/replaced
as needed.

Check
compressor;
repair/replace as
needed.
Check wiring;
repair/replace as
needed.

Check compres­sor; repair/re­place as needed.
Check wiring;
repair/replace as
needed.

breakers and
fuses.
Verify unit is
connected to
power supply

rating plate.
Correct low line
voltage condition;
contact local
utility if needed.

Turn power OFF prior
to repair
Must clear fault by
cycling 24VAC to
control.
Replace with correct
replacement part(s).

Turn power OFF prior
to repair.
Fault will clear after 1
normal cycle.
Fault may be cycling
24VAC to control.
Replace with correct
replacement part(s).

Turn power OFF prior
to repair.
Must clear fault by cy­cling 24VAC to control.
Replace with correct
replacement part(s).

Turn power OFF prior
to repair.
Control detects line
voltage less than
185 VA C.
Fault will clear if line
voltage increases
above 185 VAC.

69

SERVICING

PCBHR105

Air conditioner/heat
pump may appear to be
operating normally.
Compressor protector
may be open (compressor
and outdoor f
Integrated control
module diagnostic/status
LED display shows the
indicated code.

Air conditioner/heat
pump may appear to be
operating normally.
Integrated control
module diagnostic/status
LED display shows the
indicated code.

Integrated control
module diagnostic/status
LED display shows the
indicated code.

Air conditioner/heat
pump may appear to be
operating normally.
Compressor protector
may be open (compressor
and outdoor f
Integrated control
module diagnostic/status
LED display shows the
indicated code.

.

Digit 3

Digit 1Digit 2

H8High Line

Voltage

09Low Pilot

Voltage

P0Comp

Protector
Open

08

08

09

08

High line
voltage

Control detects
secondary
voltage less
than 18 VAC.
Transformer
overloaded.
Low line voltage.

start windings.
Compressor
run winding is
open.
Compressor not
properly wired to
control.
Faulty
compressor
wiring.
Failed
compressor run
capacitor.
Faulty run
capacitor wiring.

VOLT

LOW

VOLT

displayed displayed through run or

VOLT AGE

Correct high line
voltage condition;
contact local utility
if needed.
Verify unit is
connected to power

on rating plate.

Check fuse.
Correct low second­ary voltage condition.
Check transformer;
replace if needed.

Check compressor;
repair/replace as
needed.
Check wiring; repair/
replace as needed.
Check run ca­pacitor; replace as
needed.

Check circuit
breaker and fuses.
Verify unit is con­nected to power

on rating plate.

Turn power OFF prior
to repair.
Control detects line
voltage greater than
255 VA C.
Fault will clear if line
voltage decreases
below 255 VAC.

T urn power OFF prior to
repair.
Fault will clear if
secondary voltage rises
above 21V AC.
Replace with correct
replacement part(s).

Turn power OFF prior
to repair.
Fault will clear after 1
normal cycle.
Fault may be cleared
by cycling 24VAC to
control.
Replace with correct
replacement part(s).

Turn power OFF prior
to repair.
Control detects line
voltage less than
185 VA C.
Fault will clear if line
voltage increases
above 185 VAC.

70

SERVICING

S-12 CHECKING HIGH PRESSURE CONTROL

HIGH VOL TAGE!
Disconnect ALL power before servicing
or installing. Multiple power sources
may be present. Failure to do so may
cause pr ope rty dam age , pe rs onal inju ry
or death.

The high pressure control capillary senses the pressure in
the compressor discharge line. If abnormally high condens­ing pressures develop, the contacts of the control open,
breaking the control circuit before the compressor motor
overloads. This control is automatically reset.

1. Using an ohmmeter, check across terminals of high
pressure control, with wire removed. If not continuous,
the contacts are open.

2. Attach a gauge to the dill valve port on the base valve.

With power ON:

WARNING

Line Voltage now present.

3. Start the system and place a piece of cardboard in front
of the condenser coil, raising the condensing pressure.

4. Check pressure at which the high pressure control cuts­out. If it cuts-out at 610 PSIG ± 10 PSIG, it is operating
normally (See causes for high head pressure in Service
Problem Analysis Guide). If it cuts out below this
pressure range, replace the control.

mately 50 PSIG for heat pumps and 95 PSIG for air condition­ers.

Test for continuity using a VOM and if not as above, replace
the control.

S-14 CHECKING HIGH AND LOW PRESSURE

SWITCH VOLTAGE

The HPC and LPC are wired in series so output at both
switches should be the same when switches are closed
voltage reading should be 6.5vdc or 8.0vac. NOTE: the
Discharge Thermostat is wired in series with the HPC if DT
is open you will read input voltage on the HPC and no voltage
on the output of HPC or LPC.

S-15 CHECKING CAPACITOR

CAPACITOR, RUN

A run capacitor is wired across the auxiliary and main
windings of a single phase permanent split capacitor motor.
The capacitors primary function is to reduce the line current
while greatly improving the torque characteristics of a motor.
This is accomplished by using the 90° phase relationship
between the capacitor current and voltage in conjunction with
the motor windings, so that the motor will give two phase
operation when connected to a single phase circuit. The
capacitor also reduces the line current to the motor by
improving the power factor.

The line side of this capacitor is marked with "COM" and is
wired to the line side of the circuit.

S-15A RESISTANCE CHECK USING A DIGITAL

MULTI-METER

S-13 CHECKING LOW PRESSURE CONTROL

The low pressure control senses the pressure in the suction
line and will open its contacts on a drop in pressure. The low
pressure control will automatically reset itself with a rise in
pressure.

The low pressure control is designed to cut-out (open) at
approximately 21 PSIG for heat pumps and 55 PSIG for air
conditioners. It will automatically cut-in (close) at approxi-

HIGH VOLTAGE!
Disconnect ALL power before servicing
or installing. Multiple power sources
may be present. Failure to do so may
cause property damage, personal injury
or death.

Check for Digital Test

1. Set the meter on Ohm range (Set it at lease 1000 Ohm
=1k).

WARNING

Discharge capacitor through a 20 to 30 OHM
resistor before han dling.

2. Connect the Meter leads to the Capacitor terminals.

3. Digital meter will show a reading momentarily (Figure 1).
Note the reading.

71

SERVICING

Figure 1 Figure 2

4. Reading will immediately return to the OL = (Open Line)
(Figure 2). Every attempt of Step 2 will show the same
result as was in step 4 and Step 5. This indicates that the
capacitor is good.

5. If there is no Change, then capacitor is dead and must be
replaced.

Check for Analog Meter

A. Good Condition - indicator swings to zero and slowly
returns to infinity. (Start capacitor with bleed resistor will
not return to infinity. It will still read the resistance of the
resistor).

B. Shorted - indicator swings to zero and stops there ­replace.

C. Open - no reading - replace. (Start capacitor would
read resistor resistance.)

S-15B CAPACITANCE CHECK USING A DIGI-

TAL MULTI-METER (IN CAPACITANCE
MODE)

WARNING

Discharge capacitor through a 20 to 30 OHM
resistor before handling.

NOTE: You can do this test with a multi-meter if you

have a Capacitance meter on your multi-meter.

4. If the reading is near to the actual value of the capacitor
(i.e. the printed value on the capacitor). The capacitor is
good. (Note that the reading may be less than the actual
printed value of the capacitor).

5. If you read a significantly lower capacitance or none at
all, then capacitor is dead and must be replaced.

S-16G CHECKING EMERSON ULTRATECH

TM

ECM MOTORS

DESCRIPTION

The AVPTC and MBVC models utilize an Emerson, 4-wire
variable speed ECM blower motor. The ECM blower motor
provides constant CFM.

The motor is a serially communicating variable speed motor.
Only four wires are required to control the motor: +Vdc,
Common, Receive, and Transmit.

The +Vdc and Common wires provide power to the motor's
low voltage control circuits.

GENERAL CHECKS/CONSIDERATIONS

1. Check power supply to the air handler or modular blower.
Ensure power supply is within the range specified on
rating plate. See section S-1.

2. Check motor power harness. Ensure wires are continu­ous and make good contact when seated in the connec­tors. Repair or replace as needed.

3. Check motor control harness. Ensure wires are continu­ous and make good contact when seated in the connec­tors. Repair or replace as needed.

4. Check thermostat and thermostat wiring. Ensure ther­mostat is providing proper cooling/heating/continuous
fan demands. Repair or replace as needed.

5. Check blower wheel. Confirm wheel is properly seated on
motor shaft. Set screw must be on shaft flat and torqued
to 165 in-lbs minimum. Confirm wheel has no broken or
loose blades. Repair or replace as needed.

6. Ensure motor and wheel turn freely. Check for interfer­ence between wheel and housing or wheel and motor.
Repair or replace as needed.

7. Check housing for cracks and/or corrosion. Repair or
replace as needed.

1. Remove the capacitor from the circuit.

2. Now Select "Capacitance" on your multi-meter.

3. Now connect the capacitor terminals to the multi-meter
leads.

72

SERVICING

8. Check motor mounting bracket. Ensure mouting bracket
is tightly secured to the housing. Ensure bracket is not
cracked or broken.

Emerson UltraCheck-EZTM Diagnostic Tool

The Emerson UltraCheck-EZTM diaganostic tool may be used
to diagnose the ECM motor.

HIGH VOLTAGE!
Disconnect ALL power before servicing
or installing. Multiple power sources
may be present. Failure to do so may
cause property damage, personal injury
or death.

To use the diagnostic tool, perform the following steps:

1. Disconnect power to the air handler.

2. Disconnect the 4-circuit control harness from the motor.

3. Plug the 4-circuit connector from the diagnostic tool into
the motor control connector.

4. Connect one alligator clip from the diagnostic tool to a
ground source.

5. Connect the other alligator clip to a 24VAC source.

NOTE: The alligator clips are NOT polarized.
NOTE: The UltraCheck-EZTM diagnostic tool is equipped

with a nonreplaceable fuse. Connecting the tool to a source
other than 24VAC could damage the tool and cause the fuse
to open. Doing so will render the diagnostic tool inoperable.

6. Turn on power to air handler or modular blower.

WARNING

Line Voltage now present.

Power
Button

OFF OFF

ON B linking Rotating

ON OFF Rotating

ON Blinking

ON OFF

Green

LED

Motor

Actio n

Not

Rotating

Not

Rotating

Not

Rotating

Indica tion(s)

Confirm 24VAC to
UltraCheck -EZ

If 24V A C is c onfirm e d,
diagnost ic tool is
inoperable.
M otor and cont rol/end
bell are func tioning
properly.
Replace motor
cont rol/end bell.
Check m otor (see
Motor Chec ks below).
Replace motor
cont rol/end bell; verify
motor (see Motor
Check s below).

TM

tool.

9. Depress the orange power button to turn off motor.

10. Disconnect power. Disconnect diagnostic tool.

11. Reconnect the 4-wire harness from control board to
motor.

Electrical Checks - High Voltage Power Circuits

HIGH VOLT AGE!
Disconnect ALL power before servicing
or installing. Multiple power sources
may be present. Failure to do so may
cause property damage, personal injury
or death.

7. Depress the orange power button on the diagnostic tool
to send a run signal to the motor. Allow up to 5 seconds
for the motor to start.

NOTE: If the orange power button does not illuminate when
depressed, the tool either has an open fuse or is not properly
connected to a 24VAC source.

8. The green LED on the diagnostic tool will blink indicating
communications between the tool and motor. See table
below for indications of tool indicators and motor actions.
Replace or repair as needed.

1. Disconnect power to air handler or modular blower.

2. Disconnect the 5-circuit power connector to the ECM
motor.

3. Turn on power to air handler or modular.

WARNING

Line Voltage now present.

4. Measure voltage between pins 4 and 5 on the 5-circuit
connector. Measured voltage should be the same as the
supply voltage to the air handler or modular.

73

SERVICING

1
2
3
4
5

5. Measure voltage between pins 4 and 3. Voltage should
be approximately half of the voltage measured in step 4.

6. Measure voltage between pins 5 and 3. Voltage should
be approximately half of the voltage measured in step 4.

7. If no voltage is present, check supply voltage to air handler
or modular blower. See section S-1.

8. Disconnect power to air handler or modular blower.
Reconnect the 5-circuit power harness disconnected in
step 2.

Electrical Checks - Low Voltage Control Circuits

1. Turn on power to air handler or modular.

Lines 1 and 2 will be connected
for 12OVAC Power Connector

}

applications only

Gnd
AC Line Connection

AC Line Connection

3. Remove the blower assembly from the air handler or
modular blower.

4. Remove the (3) screws securing the control/end bell to
the motor. Separate the control/end bell. Disconnect
the 3-circuit harness from the control/end bell to remove
the control/end bell from the motor.

5. Inspect the NTC thermistor inside the control/end bell
(see figure below). Replace control/end bell if thermistor
is cracked or broken.

WARNING

Line Voltage now present.

2. Check voltage between pins on the 4-wire motor control
harness between themotor and control board.

3. Voltage on pins should read:

Pins 1 to 4 = 3.3vdc
Pins 1 to 2 = 3.3vdc
Pins 3 to 4 = 15vdc

Motor Control/End Bell Checks

HIGH VOLTAGE!
Disconnect ALL power before servicing
or installing. Multiple power sources
may be present. Failure to do so may
cause property damage, personal injury
or death.

1. Disconnect power to air handler or modular blower.

NOTE: Motor contains capacitors that can hold a charge for
several minutes after disconnecting power. Wait 5 minutes
after removing power to allow capacitors to discharge.

2. Disconnect the motor control harness and motor power
harness.

6. Inspect the large capacitors inside the control/end bell
(see figure below). Replace the control/end bell if any of
the capacitors are bulging or swollen.

7. Locate the 3-circuit connector in the control/end bell.
Using an ohmmeter, check the resistance between each
terminal in the connector. If the resistance is 100 Ω or
greater, the control/end bell is functioning properly.
Replace the control/end bell if the resistance is lower
than 100 Ω.

8. Reassemble motor and control/end bell in reverse of
disassembly. Replace blower assembly into air handler
or modular blower.

74

SERVICING

Motor Checks

HIGH VOLTAGE!
Disconnect ALL power before servicing
or installing. Multiple power sources
may be present. Failure to do so may
cause property damage, personal injury
or death.

Tap A

OFF

ON
1
2

Cooling Airflow Speed Tap (* indicates factory setting)

1
2

Tap B

OFF

ON

1
2

Tap C

OFF

ON

Tap D*

OFF ON

1

2

1. Disconnect power to air handler or modular blower.
NOTE: Motor contains capacitors that can hold a charge for

several minutes after disconnecting power. Wait 5 minutes
after removing power to allow capacitors to discharge.

2. Disassemble motor as described in steps 2 through 4

above.

3. Locate the 3-circuit harness from the motor. Using an

ohmmeter, measure the resistance between each motor
phase winding. The resistance levels should be equal.
Replace the motor if the resistance levels are unequal,
open circuited or short circuited.

4. Measure the resistance between each motor phase

winding and the motor shell. Replace the motor if any
phase winding is short circuited to the motor shell.

5. Reassemble motor and control/end bell in reverse of

disassembly. Replace blower assembly into air handler
or modular blower.

S-16H ECM CFM ADJUSTMENTS AVPTC/MBVC

This section references the operation characteristics of the
AVPTC/MBVC models. The MBVC models utilize an
integrated air handler control. The air handler control
provides ECM blower motor control and includes all
dipswitches necessary to set up the cooling, heat pump and
electric airflow characteristics.

The control has three banks of dipswitches: a bank for
cooling airflow and trim adjustment, a bank for selecting one
of (4) enhancement profiles and enabling dehumidification,
and a bank for selecting the installed electric heater kit size.
Adjustments are made by selecting the appropriate ON/
OFF combinations of the dipswitches. The dipswitches
along with their functions are shown in the figures below.

Cooling Airflow Dipswitches - Used to set the desired
cooling airflow

Airflow Adjust Dipswitches - Used to adjust the airflow +/­10%

Normal*

OFF

ON

3

4

Airflow Adjust Taps (* indicates factory sett ing)

3

4

+10%

OFF

ON

3
4

-10%

OFF

ON

Normal

OFF ON

3

4

Ramping Profile Dipswitches - Used to select a comfort
profile for the cooling mode.

Tap A*

OFF ON

5
6

Cooling Airflow Ramping Profiles (* indicates factory

Tap B

OFF ON

5

6

5
6

setting)

Tap C

OFF ON

Tap D

OFF ON

5

6

Dehumidification Disable/Enable Dipswitch - Reduces cool­ing airflow by ~ 15% when enabled AND when used with a
humidistat (such as DEHUM1). Airflow is reduced when a
call for cooling is present and the humidistat is open.

OFF ON

7

8

DEHUM
Unused

Move to the ON position to
enable dehumidification

Electric Heater Airflow - Airflow for installed electric heaters
is set by adjusting the dipswitches to the appropriate heater
size.

75

SERVICING

10
11

21 kW*

OFF

9

ON

20 kW

OFF ON

9

10
11

15 kW

OFF ON

9

10
11

10 kW

OFF ON

9

10

11

Electric Heating Airflow (* indicates factory setting)

8 kW

OFF

ON

9

10
11

10
11

9

6 kW

OFF

ON

5 kW

OFF ON

9

10

11

10

11

3 kW

OFF

ON

9

Electric Heating Airflow (* indicates factory se tting)

The table on the following page indicates the airflow that
corresponds to the available dipswitch settings.

76

SERVICING

MBVC Airflow Table

Speed Selection Dip Switches

Cool Adjust Profile
Selection Selecti o n Selection
Switches Switch es Switches

TAP 1 2 3 4 5 6

A OFF OFF OFF OFF OFF OFF
B ON OFF ON OFF ON OFF
C OFF ON OFF ON OFF ON
D ON ON ON ON ON ON

Profiles Pre-Run Short-Run OFF Delay

A ------- -------- 60 sec/100%

B ------- 30 sec/5 0 % 60 sec/100%
C ------- 7.5 min/82% 60 sec/100%

D 30 s ec/50% 7.5 min/82% 30 sec/50%

To s et airflow:

(1) Select m o del and desired
high stage co o li ng airflow. Deter mine the coor espo nding tap
( A, B, C, or D ). Set dip switches 1 and 2 to the appropriate
ON / OFF positions. (2) Select model and inst alled elect r ic
heater size. Set switches 9, 10 , and 11 to the appropriate
ON/OFF positions. (3) Selec t the airflow adj ustm ent f actor tap
A and D are 0%; Tap B is +10%; Tap C -10%. Set dip switches 3
and 4 to the appropriat e ON / OFF positions .

Select desired Comf ort Mode prof ile

To set Comfo rt Mode:

(see prof il es abo ve). Set switc hes 5 and 6 to the approriat e
ON / O FF po sit i o n s .

0140A00045

Htr Kw 9 10 11 MBVC1200* MBVC16000* MBVC2000*

3 ON ON ON 600 800 800
5 ON ON OFF 600 800 800

6 ON OFF ON 635 800 800
8 ON OFF OFF 740 1000 1000
10 OFF ON ON 1000 1000 1200

15 OFF ON OFF 1400 1500 1500
20 OFF OFF ON NR NR 2000

Model Tap Low Stage High Stage
Cool Cool

A 40 0 600

MBVC12 0 0

*

B 540 800
C 670 1000
D 800 1200

A 670 100 0

MBVC16 0 0

*

B 800 1200
C 940 1400
D 10 70 1600

A 800 120 0

MBVC200 0

*

B 1070 1600
C 1200 1800
D 1340 2000

77

BLOWER PERFORMANCE DATA

MODEL

M B VC1200

M B VC1600

M B VC2000

^ Factory setting

HTR kW MBVC1200* MBVC1600* MBVC2000*

3 600 800 800
5 600 800 800
6 635 800 800

8 740 1000 1000
10 1000 1000 1200
15 1400 1500 1500
20 NR NR 2000
21

^ Factory setting

LOW STAGE

COOL

400 600 OFF
540 800 ON
670 1000 OFF
800 1200 ON
670 1000 OFF
800 1200 ON
940 1400 OFF

1070 1600 ON

800 1200 OFF
1070 1600 ON
1200 1800 OFF
1340 2000 ON

NR NR NR ON^ ON^ ON^

HIGH STAGE

COOL

COOL SELECTION

SWITCHES

1234 5 6

OFF
OFF

ON

ON
OFF
OFF

ON

ON
OFF
OFF

ON

ON

SWITCH9SWITCH10SWITCH

ON ON ON
ON ON OFF
ON OFF ON

ON OFF OFF
OFF ON ON
OFF ON OFF
OFF OFF ON

ADJUST SELECTION

SWITCHES

OFF

ON

OFF

ON

OFF

ON

OFF

ON

OFF

ON

OFF

ON

OFF
OFF

ON

ON
OFF
OFF

ON

ON
OFF
OFF

ON

ON

11

PRO FILE SELECTIO N

SWITCHES

OFF

ON

OFF

ON

OFF

ON

OFF

ON

OFF

ON

OFF

ON

OFF
OFF

ON

ON
OFF
OFF

ON

ON
OFF
OFF

ON

ON

Locate the blower speed selection DIP switches on the integrated control module. Select the desired “cooling”
speed tap by positioning switches 1 and 2 appropriately. Select the desired "adjust" tap by positioning switches
3 and 4 appropriatly. Refer to the following Dipswitches - Cooling Airflow and Airflow Adjust Taps figure for switch
positions and their corresponding taps. Verify CFM by counting the number of times the green CFM LED blinks.

Normal*

OFF OFF OFF OFFON ON ON ON

3
4

Air flow Adjust Taps (*indicates factory setting)

+10%

3
4

-10% N ormal

3
4

3
4

Dip Switches - Cooling Airflow and

Airflow Adjust Taps

Thermostat "Fan Only" Mode

During"Fan Only" operations, the CFM output is 30% of the maximum CFM capability.

CFM Trim Adjust

Minor adjustments can be made through the dipswitch combination of 3-4.

78

SERVICING

Speed Selection Dip Switches

Cool
Selec tion
Switches

Tap 1 2

AOFFOFF
BONOFF
COFFON
DONON

TO SET AIRFL OW :

1.Select appropriate m odel from Cooling/Heat P ump Airflow Table.
Based on desired Airflow for your ap plication select corresponding tap
(A,B,C or D). Set dip switches 1 & 2 to the appropriate ON/O FF
positions.

2. Select appropriate Airflow adjustment factor for application
(0%. +10%, -10%). Set dip switches 3 & 4 to the appropriate ON/OFF
positions.

3. If installed with Heater Kit:
Using El ectric H eat Airflow Table , set dip switches 9, 10 and 11 to the
appropriate O N/OFF positions based on H eater kit installed.
If installed without Heater Kit:
Ensure dip switches 9, 10 and 11 are set to a valid heater kit selection.
Example: The only valid heater k its for AVPTC183014* applications
are 3, 5, 6, 8 and 1 0 kW .
Failure to do so will result in a Heater Kit error code.

TO SET COMFORT MODE:

Select desired Comfort Mode profile (see profiles above). Set switches
5 and 6 to the approp riate ON/OF F positions.

Profiles 5 6

Pre-R un Sh ort-Run Off Delay

AOFFOFF

------- ------- 60 sec/100%

------- 30 sec/50% 60 sec/100%

BONOFF
COFFON

------- 7.5 mins/82% 60 sec/100%

30 sec/50% 7.5 mins/82% 30 sec/50%

DONON

TRIM

0%

+ 10%

- 10%
0%

AVPTC Airflow Table

Adj ust
Selection
Switches

34

OFF OFF

ON OF F

OFF ON

ON ON

Profile
Sel ection
Switches

Cooling/Heat Pump Airflow Tab le

Model

Tap

Low

Stage

Cool

High

Stage

Cool

A 420 630

AVPTC183014*

B 560 840
C 700 1040
A 410 610

AVPTC313714*

B 560 830
C 700 1040
D 830 1240
A 810 1210

AVPTC426014*

B 940 1410
C10501560
D12101800

NOTE: Airflow dat a shown applies to non-communicating mode operation only. For a fully
comm u nicatin g s ystem , plea se see the ou tdoor unit 's ins tall a tion instructions for coo ling and heat
pum p ai r flow d a ta.

See ComfortNet™ System - Airflow Consideration section for details.

Electric He at Airflow Table

Htr kW 9 10 11

AVPTC

183014*

AVPTC

313714*

AVPTC

426014*
3 ONONON630610600
5 ON ON OFF 730 710 680
6 ON OFF ON 840 840 790
8 ON OFF OFF 1080 1060 990

10 OFF ON ON 1270 1260 1190
15 O FF ON OFF NR 1470 1390
20 OFF OFF ON NR NR 1580
21 OFF OFF OFF NR NR 1580

NOTE: Airflow data shown appli es to t he emergency heat mode ( elec tric heat only) in ei ther non ­comm u nicatin g m od e operation or full y communicati ng mode oper ati on .

NOTE: When 8kW and 10kW heat kits are used with an
AVPTC1830 and AVPTC313, matched with 2-ton outdoor
unit, see Note 1below.

1 Set Heater Kit dip switches 9, 10 and 11 to 6kW setting

(9-ON, 10-OFF, 11-ON) to obtain 840 CFM.

79

SERVICING

Speed Selection Dip Switches

Cool Adjust Profile
Selection Selection Selection
Switches Switches Switches

TAP S1 S2 S3 S4 S5 S6

A OFF OFF OFF OFF OFF OFF
B ON OFF ON OFF ON OFF
C OFF ON OFF ON OFF ON
D ON ON ON ON ON ON

Profiles Pre-Run Short-Run OFF Delay

A ------- -------- 60 sec/100%

B ------- 30 sec/50% 60 sec/100%
C ------- 7.5 min/82% 60 sec/100%
D 30 sec/50% 7.5 min/82% 30 sec/50%

To set A irflow:

Airflow. Determ ine the corresponding tap (A, B, C, D). Set dip
switches S1 and S2 to the appropriate ON / OF F positions.
(2) Select mod el an d ins tal l ed e lec tr ic heater size. Set dip

switches S9, S10, and S11 to t he a ppropriate ON / OFF positions.

(3) If airflow adj ustment is required set Trim Enab l e Switch to

ON (OFF = 0% Trim) and set S3 and S4 to appropriate ON / OFF

positions. Tap A is +5%,Tap B is -5%, Tap C is +10%, Tap D is

-10%.

To Set Comfort mode:

profiles above). Set dip switches S5 and S6 to appropriate ON /
OFF positions.

Dehumidification:

airflow will be reduced to 85% of nomin al value during cool call
when Dehum command is presen t . To disable, set S7 to OFF.

Continuous Fan Speed:

one of 4 continuous fan speeds, Tap A is 25%. Tap B is 50%, Tap
C is 75%, Tap D is 100%.

Notes:

1. Airflow data shown applies to legacy mode o pe rat ion only.
For a fully communicating system, please see the outdoor
unit's installation instructions for c ooling and heat pump
airflow data. See

section for details.

2. Airflow blink codes are approxi mations of actual airflow.

(1) Select model and desired High Stag e Coolin g

Select desired Comfort Mode Profile (see

T o enable, set dip switch S7 to ON. Cooling

Use dip switches S12 and S13 to select

ComfortN et System-Airflow Consideration

Continuous

Fan

Speed

S12

OFF

ON

OFF

ON

S13

OFF

OFF

ON

ON

S8

Cooling/Hea t Pump Airflow Table

Model Spe ed tap

A

AVPTC24B14**

B

C

D

A

AVPTC30C14**

B

C

D

A

AVPTC36C14**

B

C

D

A

AVPTC48C14**

B

C

D

A

AVPTC42D14**

B

C

D

A

AVPTC48D14**

B

C

D

A

AVPTC60D14**

B

C

D

NOTE: Airflow blink codes are approximations of actual airflow. Airflows

provided are at 0.3 static.

Low stage

(CFM)

410 610
565 835
660 970
765 1125
440 610
605 835
740 1020
885 1225
500 725
700 1000
930 1330

1120 1600

500 725
700 1000
930 1330

1120 1600

560 800
763 1090
994 1420

1225 1750

900 1350
1035 1550
1140 1700
1200 1800
1210 1610
1365 1815
1450 1920
1525 2025

High stage

(CFM)

80

SERVICING

READY 15 AVPTC AIRFLOW TABLES

Speed Selection Dip Switches

Cool Adjust Profile
Selection Selection Selection
Switches Switches Switches

TAP S1 S2 S3 S4 S5 S6
A OFF OFF OFF OFF OFF OFF
B ON OFF ON OFF ON OFF

C OFF ON OFF ON OFF ON

D ON ON ON ON ON ON

Profiles Pre-Run Short-Run OFF Delay

A ------- -------- 60 sec/100%

B ------- 30 sec/50% 60 sec/100%
C ------- 7.5 min/82% 60 sec/100%
D 30 sec/50% 7.5 min/82% 30 sec/50%

To set A irflow:

Airflow. Determ ine the corresponding tap (A, B, C, D). Set dip
switches S1 and S2 to the appropriate ON / OFF positions.
(2) Select model and installed electric heater size. Set dip

switches S9, S10, and S11 to the appropriate ON / OFF positions.

(3) If airflow adjustment is required set Trim Enable Switch to

ON (OFF = 0% Trim) and set S3 and S4 to appropriate ON / OFF

positions. Tap A is +5%,Tap B is -5%, Tap C is +10%, Tap D is

-10%.

To Set Comfort mode:

profiles above). Set dip switches S5 and S6 to appropriate ON /
OFF positions.

Dehumidification:

airflow will be reduced to 85% of nominal value during cool call
when Dehum command is present. To disable, set S7 to OFF.

Continuous Fan Speed:

one of 4 continuous fan speeds,Ta p A is 25%. T ap B is 50%, Tap
C is 75%, Tap D is 100%.

Notes:

1. Airflow data shown applies to legacy mode operation only.
For a fully communicating sy stem, ple as e see the outdoor
unit's installation instructions for cooling and heat pump
airflow data. See

section for details.

2. Airflow blink codes are approximations of actual airflow.

(1) Select model and desired High Stage Cooling

Select desired Comfort Mode Profile (see

To enable, set dip switch S7 to ON. Cooling

Use dip switches S12 and S13 to select

ComfortNet System-Airflow Consideration

Continuous

Fan

Speed

S12

OFF

ON

OFF

ON

S13
OFF

OFF

ON

ON

S8

Cooling/Heat Pump Airflow Table

MODEL

AVPTC25B14

AV PTC29B14 AVPTC37B14

AV PTC31C14 A VP TC37C14

AVPTC33C14

AVPTC39C14

AVPTC49C14

AVPTC59C14

AVPTC37D14

AVPTC59D14

AVPTC49D14

AVPTC61D14

Tap Low Stage High Stage

A 445 650
B 600 855
C 690 980
D 745 1085
A 375 610
B 545 795
C 630 930
D 740 1085
A 590 880
B 705 1055
C 845 1265
D 910 1360
A 450 675
B 520 780
C 660 985
D 750 1115
A 665 990
B 770 1150
C 815 1215
D 910 1360
A 710 1060
B 745 1115
C 880 1315
D 975 1455
A 610 875
B 810 1225
C 940 1410
D10701595
A 605 900
B 725 1080
C 820 1225
D 940 1405
A10401445
B12601790
C13301890
D13951990
A 820 1195
B 895 1320
C 995 1460
D10561530
A10801630
B12101820
C12801925
D13502025

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SERVICING

ELECTRIC HEAT AIRF LOW TABLE

Htr kW 9 10 11 AVPTC24B14A* AVPTC30C14A* AVPTC 3 6C14A* AVPTC48C14*

3 ON ON ON
5 ON ON OFF
6 ON OFF ON

8 ON OFF OFF
10 OFF ON ON
15 OFF ON OFF NR NR

19* NR NR

OFF OFF ON

20 NR NR 1500 1500 1800

550 600

NR NR 850** NR NR
650 700 850 850 1250 1250 1250
700 750 900 900 1300 1300 1300
800 875 1000 1000 1500 1500 1500
850 950 1200 1200 1550 1550 1550

1440 1440 1720 1720 1780
1500 1500 NR

AVPTC42D14A*

21 or 25* OFFOFFOFFNRNRNRNRNR

NOTE: Airflow data shown applies to the electric heat only in either legacy mode or communicating mode operation.

* Within thermostat user menu, CTK0* communicating thermostat will display 20 kW for OFF-OFF-ON dip switch selection and
21 kW for OFF- OFF-OFF dip switch selection.
NR- Not rated

+

For match up with a 2 ton outdoor unit: Heater kit application shall not exceed 10 kW.

Airflow for 5 kW up to 10 kW heater kits shall be set to 850 cfm speed tap of ON-ON-ON.

++

For match up with a 3 ton outdoor unit: Heater kit application shall not exceed 15 kW.

Airflow for 5 kW up to 15 kW heater kits shall be set to 1300 cfm speed tap of ON-OFF-ON.

+++

For match up with a 3.5 ton outdoor unit: Heater kit application shall not exceed 20 kW.
Airflow for 5 kW up to 20 kW heater kits shall be set to 1500 cfm speed tap of ON-OFF-OFF
** 3 kW heater kit is not applicable for this indoor application.

+

AVPTC48D14A*++AVPTC60D14A*

+++

NR NR
1815 1850
1850 1850

DIP SWITCH SETTING & AIRFLOW TABLE FOR ELECTRIC HEAT

HTR KW S9 S10 S11

3 ON ON ON 550 550 600 550

5 ON ON OFF 650 650 700 650 850 850 1170 1170 1240 1240 1250 1250

6 ON OFF ON 700 700 750 700 900 900 1170 1170 1240 1240 1300 1300

8 ON OFF OFF 800 800 875 800 1000 1000 1170 1170 1240 1240 1500 1500

10 OFF ON ON 850 875 950 875 1170 1170 1170 1170 1240 1240 1550 1550

15 OFF ON OFF 875 875 950 1050 1345 1345 1345 1345 1520 1520 1720 1780

19* OFF OFF ON 1345 1345 1345 1345

20 OFF OFF ON 1520 1520 1850

21 OFF OFF OFF

25* OFF OFF OFF 1850
Note: Airflow data s hown a pplies to the el ectric heat only in either legacy mode or communicating mode operation
* Within thermostat user menu CTK0* communicati ng thermostat will displa y 20KW for OFF- OFF- ON dip switch s election,
21kW for OFF-OFF-OFF dip swi th selecti on.

NR - Not Rated
†† For match up wi th a 3 ton outdoor uni t:
Airflow for 5 kW up to 15 kW heater kits shall be set to 1300 cfm speed tap of ON-OFF-ON.

††† For matc h up wi th a 3.5 to n outdoor u nit: Hea ter ki t applica Ɵon s hal l no t exceed 2 0 kW.
Airflow for 5 kW up to 20 kW heater kits shall be set to 1500 cfm speed tap of ON-OFF-OFF.

AVPTC25B14 AVPTC29B14 AVPTC33C14 AVPTC37B14

AVPTC31C14
AVPTC37C14

AVPTC39C14 AVPTC49C14 AVPTC59C14 AVPTC37D14 AVPTC59D14 AVPTC49D14 ƚƚ AVPTC61D14 ƚƚƚ

82

SERVICING

S-17 CHECKING COMPRESSOR

WARNING

Hermetic compressor electrical terminal venting can
be dangerous. When insulating mat erial whic h
supports a hermeti c compresso r or electr ical t erminal
suddenly disintegrates due to physical abuse or as a
result of an electrical short between the terminal and
the compressor housing, the terminal may be
expelled, venting the vapor an d liquid contents of the
compres sor ho us ing an d sy stem .

If the compressor terminal PROTECTIVE COVER and
gasket (if required) are not properly in place and secured,
there is a remote possibility if a terminal vents, that the
vaporous and liquid discharge can be ignited, spouting
flames several feet, causing potentially severe or fatal
injury to anyone in its path.

This discharge can be ignited external to the compressor
if the terminal cover is not properly in place and if the
discharge impinges on a sufficient heat source.

Ignition of the discharge can also occur at the venting
terminal or inside the compressor, if there is sufficient
contaminant air present in the system and an electrical
arc occurs as the terminal vents.

Ignition cannot occur at the venting terminal without the
presence of contaminant air, and cannot occur externally
from the venting terminal without the presence of an
external ignition source.

Therefore, proper evacuation of a hermetic system is
essential at the time of manufacture and during servicing.

To reduce the possibility of external ignition, all open
flame, electrical power, and other heat sources should be
extinguished or turned off prior to servicing a system.

If the following test indicates shorted, grounded or open
windings, see procedures S-19 for the next steps to be
taken.

S-17A RESISTANCE TEST

Each compressor is equipped with an internal overload.
The line break internal overload senses both motor

amperage and winding temperature. High motor tem­perature or amperage heats the disc causing it to open,
breaking the common circuit within the compressor on
single phase units.

Heat generated within the compressor shell, usually due
to recycling of the motor, high amperage or insufficient
gas to cool the motor, is slow to dissipate. Allow at least
three to four hours for it to cool and reset, then retest.

Fuse, circuit breaker, ground fault protective device, etc.
has not tripped -

HIGH VOLTAGE!
Disconnect ALL power before servicing
or installing. Multiple power sources
may be present. Failure to do so may
cause property damage, personal injury
or death.

1. Remove the leads from the compressor terminals.

See warnings S-17 before removing compressor
terminal cover.

2. Using an ohmmeter, test continuity between terminals
S-R, C-R, and C-S, on single phase units.

C

OHMMETER

TESTING COMPRESSOR WINDINGS

If either winding does not test continuous, replace the
compressor.

NOTE: If an open compressor is indicated, allow ample time
for the internal overload to reset before replacing compres­sor.

S

COMP

R

S-17B GROUND TEST

If fuse, circuit breaker, ground fault protective device, etc.,
has tripped, this is a strong indication that an electrical
problem exists and must be found and corrected. The circuit
protective device rating must be checked, and its maximum
rating should coincide with that marked on the equipment
nameplate.

With the terminal protective cover in place, it is acceptable
to replace the fuse or reset the circuit breaker ONE TIME
ONLY to see if it was just a nuisance opening. If it opens
again, DO NOT continue to reset.

A Meghometer should not be used to determine good or bad
compressors. There is not an industry recognized specifica­tion for mega ohm values for small tonnage compressors.
Scroll compressors can have the motor winding end-turns in
the oil, which can produce a lower resistance reading to
ground. The insulation type is the same for scroll and
reciprocating compressors.

Disconnect all power to unit, making sure that all power
legs are open.

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SERVICING

1. DO NOT remove protective terminal cover. Disconnect
the three leads going to the compressor terminals at the
nearest point to the compressor.

2. Identify the leads and using an ohmmeter on the R x
10,000 scale or the highest resistance scale on your
ohmmeter check the resistance between each of the
three leads separately to ground (such as an unpainted
tube on the compressor).

3. If a ground is indicated, then carefully remove the
compressor terminal protective cover and inspect for
loose leads or insulation breaks in the lead wires.

4. If no visual problems indicated, carefully remove the
leads at the compressor terminals.

5. Carefully retest for ground, directly between compressor
terminals and ground.

6. If ground is indicated, replace the compressor. The
resistance reading should be infinity. If there is any
reading on meter, there is some continuity to ground and
compressor should be considered defective.

OHMMETER

WARNING

Damage can occur to the glass embedded terminals if
the leads are not pro perly removed. This can result in
terminal and hot oil discharging.

S-17C UNLOADER TEST PROCEDURE

Unloader Test Procedure with Comfort Alert™-Unitary
(UC) Control Diagnostics

If you suspected that the unloader is not working, the
following methods may be used to verify operation.

1. Operate the system and measure compressor amper­age. Cycle the unloader on and off at ten second
intervals by appling and removing Y2 voltage to the
module. Wait five seconds after power is applied to Y2
before taking a reading. An increase in compressor
amperage should be observed when switching from part­load to full-load and a reduction in compressor amperage
should be observed when changing from full-load to part­load. The percent change in current depends on the
operating conditions and voltage.

2. If Step 1 does not give the expected results remove the
solenoid plug from the compressor and with the unit
running and the thermostat calling for Y2 to be energized
test the voltage output at the plug with a dc voltmeter.
The reading should be 4 to 18 VDC for Comfort Alert. If
not, unplug the harness from the module and check
voltage at the "High" pins of the module. The module will
not power the unloader solenoid if the compressor is not
running.

3. If the correct DC voltage is at the control circuit molded
plug measure the unloader coil resistance. Shut off
power and remove the control circuit molded plug from
the compressor and measure te unloader solenoid coil
resistance. If the coil resistance is infinite, zero, or
grounded, the compressor must be replaced.

84

SERVICING

Y

S-17D OPERATION TEST

If the voltage, capacitor, overload and motor winding test fail
to show the cause for failure:

HIGH VOLTAGE!
Disconnect ALL power before servicing
or installing. Multiple power sources
may be present. Failure to do so may
cause property damage, personal injury
or death.

1. Remove unit wiring from disconnect switch and wire a
test cord to the disconnect switch.

NOTE: The wire size of the test cord must equal the line wire
size and the fuse must be of the proper size and type.

2. With the protective terminal cover in place, use the three
leads to the compressor terminals that were discon­nected at the nearest point to the compressor and
connect the common, start and run clips to the respec­tive leads.

3. Connect good capacitors of the right MFD and voltage
rating into the circuit as shown.

4. With power ON, close the switch.

WARNING

Line Voltage now present.

A.If the compressor starts and continues to run, the cause

for failure is somewhere else in the system.

B.If the compressor fails to start - replace.

COPELAND COMPRESSOR

03 A 12345 L

EAR

S-18 TESTING CRANKCASE HEATER (OP-

TIONAL ITEM)

The crankcase heater must be energized a minimum of four
(4) hours before the condensing unit is operated.

Crankcase heaters are used to prevent migration or accumu­lation of refrigerant in the compressor crankcase during the
off cycles and prevents liquid slugging or oil pumping on start
up.

A crankcase heater will not prevent compressor damage due
to a floodback or over charge condition.

MONTH

SERIAL

NUMBER

PLANT

WARNING

Disconnect ALL power before servicing.

1. Disconnect the heater lead in wires.

2. Using an ohmmeter, check heater continuity - should
test continuous. If not, replace.

NOTE: The positive temperature coefficient crankcase heater
is a 40 watt 265 voltage heater. The cool resistance of the
heater will be approximately 1800 ohms. The resistance will
become greater as the temperature of the compressor shell
increases.

S-21 CHECKING REVERSING VALVE AND

SOLENOID

Occasionally the reversing valve may stick in the heating or
cooling position or in the mid-position.

When stuck in the mid-position, part of the discharge gas
from the compressor is directed back to the suction side,
resulting in excessively high suction pressure. An increase
in the suction line temperature through the reversing valve
can also be measured. Check operation of the valve by
starting the system and switching the operation from COOL­ING to HEATING cycle.

If the valve fails to change its position, test the voltage (24V)
at the valve coil terminals, while the system is on the
COOLING cycle.

All heat pumps and ComfortNetTM heat pumps wired in
legacy - If no voltage is registered at the coil terminals,

check the operation of the thermostat and the continuity of
the connecting wiring from the "O" terminal of the thermostat
to the unit.

ComfortNet heat pumps only - Check voltage (24VAC) at
the non-insulated terminal E22 on the UC control board
(RVS on silkscreen) and "C" terminal on the 7-pin or 4-pin
connector on the UC control

If voltage is registered at the coil, tap the valve body lightly
while switching the system from HEATING to COOLING,
etc. If this fails to cause the valve to switch positions, remove
the coil connector cap and test the continuity of the reversing
valve solenoid coil. If the coil does not test continuous ­replace it.

If the coil test continuous and 24 volts is present at the coil
terminals, the valve is inoperative - replace it.

S-24 TESTING DEFROST CONTROL

LEGACY MODELS:
COMFORTNETTM UNITS:

To check the defrost control for proper sequencing, proceed
as follows: With power ON; unit not running.

1. Set thermostat to call for heating.

85

SERVICING

2. Press TEST and RECALL buttons simultaneously for
approximately 3 seconds, then release them. System
should go into defrost immediately.

3. Using VOM check for voltage across terminals "C & O".
Meter should read 24 volts (skip this step if system a fully
communicating system)

4. Visually inspect to see that the frost is gradually melting
on the coil and the compressor is running.

5. Using VOM check for voltage across "W2 & C" terminals
on the board. You should read 24 volts.

6. If not as above, replace control board.

7. Set thermostat to off position and disconnect power
before removing any jumpers or wires.

S-26 TESTING TEMPERATURE SENSORS

(COMFORTNET READY MODELS ONLY)

The ASXC and DSXC ComfortNet ready air conditioner
models are factory equipped with an outdoor air tempera­ture (OAT) sensor. The OAT sensor allows the outdoor air
temperature to be displayed on the CTK0* thermostat when
used with the ASXC and DSXC models.

The ASZC and DSZC ComfortNet ready heat pump models
are equipped with both an outdoor air temperature (OAT)
sensor and an outdoor coil temperature (OCT) sensor. The
OAT provides the balance point temperature in heat pump
systems (air handler w/electric heat + heat pump) and dual
fuel systems. The OCT sensor is provides the outdoor coil
temperature and is used in determining defrost cycles.

To check either the outdoor air or outdoor coil temperature
sensors:

HIGH VOLTAGE!
Disconnect ALL po wer before servicing
or installing. Multiple power sources
may be pre s ent. Fai lur e to do s o m ay
cause pro pe rt y da ma ge, pe r son al inj ur y
or death.

1. Disconnect power to the air conditioner or heat pump.

2. Disconnect the sensor from the unitary (UC) control.

3. Connect an ohmmeter across the sensor terminals. The
ohmmeter should read be 10kΩ, +/-10%, at 75°F.
Replace the sensor if the sensor is open, shorted, or
outside the valid resistance range.

Ohm Reading of Communicating Outdoor Unit Sensors

T, °F RW@ T T, °F RW@T T, °F RW @T T, °F RW@T T, °F RW@ T

-40 336,000 5 72,9 40 50 19,903 95 6,530 140 2,4 88

-31 242,700 14 55,3 19 59 15,714 104 5,327 149 2,0 83

-22 177,000 23 42,3 24 68 12,493 113 4,370 158 1,7 52

-13 130,400 32 32,6 54 77 10,000 122 3,603 167 1,4 80

-4 97,060 41 25,396 86 8,0 56 134 2,986 176 1,2 55

S-40A AVPTC/MBVC ELECTRONIC BLOWER/

HEATER CONTROL

Description

The AVPTC and MBVC models utilize an electronic control
that provides ECM blower motor control and control of up to
two electric heat sequencers. The control has thermostat
inputs for up to two stages of cooling, two stages of electric
heat, reversing valve, and dehumidification. Control input is
24VAC.

All dipswitches necessary to setup cooling, heat pump, and
electric heat airflow are fully integrated into the control.
Dehumidification is enabled/disabled via an on-board
dipswitch.

Features

The new air handler control includes advanced diagnostic
features with fault recall, estimated CFM display via on­board LED, and ComfortNetTM ready. Diagnostics includes
heater kit selection diagnostics, open fuse, internal control
fault, data errors, and blower motor faults. Data errors are
not included in the fault recall list. Diagnostic error codes are
displayed on a single red LED.

The estimated CFM is displayed as a flashing green LED.
The LED flashes once for each 100 CFM.

The AVPTC/MBVC air handlers may be used in a fully
communicating ComfortNet system when matched with a
compatiable outdoor unit and the CTK0* thermostat. A fully
communicating system offers advanced setup and diagnos­tic features.

Basic Operation

The air handler control receives thermostat inputs either from
a standard 24VAC thermostat or the CTK0* ComfortNet
thermostat. For cooling and heat pump operation, the
control operates the variable speed blower motor at the
demand as determined from the thermostat input(s). If a
demand for electric heat is received, the control will provide
a 24VAC output for up to two electric heat sequencers.

86

SERVICING

Troubleshooting

Motor Control Circuits

HIGH VOL TAGE!
Disconnect ALL power before servicing
or installing. Multiple power sources
may be pre sent. Fai lure to do s o may
cause property damage, personal injury
or death.

1. Turn on power to air handler or modular.

WARNING

Line Voltage now presen t.

2. Check voltage between pins 1 and 4 at the 4-wire motor
connector on the control board. See Electrical Checks -

Low Voltage Control Circuits section (S-16H).

Electric Heat Sequencer Outputs

Communications (Applies only to Systems with Compatible
ComfortNet

The integrated air handler control has some on-board tools
that may be used to troubleshoot the network. These tools
are: red communications LED, green receive (Rx) LED, and
learn button. These are described below

a. Red communications LED – Indicates the status of the

network. Refer to the Network Troubleshooting Chart for
the LED status and the corresponding potential problem.

b. Green receive LED – Indicates network traffic. Refer to the

Network Troubleshooting Chart for the LED status and the
corresponding potential problem.

c. Learn button – Used to reset the network. Depress the

button for approximately 2 seconds to reset the network.

Voltages between the two data lines and between each data
line and common may be used to determine if the network
is operating properly.

Do the following to measure the voltages on the communi­cations data lines.

TM

Outdoor Unit and CTK0*Thermostat)

WARNING

Line Voltage now present.

HIGH VOLT AGE!
Disconnect ALL power before servicing
or installing. Multiple power sources
may be pre sent . Fai lure to do s o m ay
cause pro per ty dam age , pe rs on al in ju ry
or deat h.

1. Turn on power to air handler or modular blower.

WARNING

Line Voltage now present.

2. Disconnect the 4-circuit harness connecting the control
to the electric heater kit.

3. Provide a thermostat demand for low stage auxiliary heat
(W1). Measure the voltage between circuits 1 and 3 at
the on-board electric heat connector. Voltage should
measure 24VAC. Replace control if no voltage is present.

NOTE: Allow for any built-in time delays before making
voltage measurements. Any electric heater faults that are
present may prevent the heater output from energizing.
Verify that no heater faults are present before making
voltage measurements.

4. Provide a thermostat demand for high stage auxiliary heat
(W1 + W2). Measure the voltage between circuits 1 and
3 at the on-board electric heat connector. Measure the
voltage between circuits 2 and 3 at the on-board electric
heat connector. Voltage should measure 24VAC. Re­place control if no voltage is present.

Data Line Voltage Troubleshooting and Bias
Switches

Proper data voltage is essential to robust and reliable com­munication on the ComfortNet™ system. Any wiring issues
must be corrected for good communication.

• Poor wiring connections at the terminal blocks

• Low voltage wires that are shorted, grounded or

broken.

• Communicating wires that are not connected to the
proper terminals at the connector.

• 24 volt common outside and inside are not at the
same ground potential

• Bias dip switch setting conflicts between indoor
board and outdoor board.

• It is STRONGLY recommended that you do not
connect multiple wires into a single terminal on the
wiring connector

• Wire nuts are recommended to connect multiple
wires to connector ensuring one wire is used for each
terminal.

• Failure to do so may result in intermittent operation.

• Typical 18 AWG thermostat wire may be used to wire

the system components. One hundred feet is the
maximum length of wire between indoor and outdoor
units or between indoor unit and thermostat.

• When outdoor transformer is used and there at least
three thermostat wires running to the outdoor unit

87

SERVICING

use one of the extra wires to connect the two 24 volt
commons together. This will ensure both 24 volt
commons are at the same ground potential.

• When outdoor transformer is used and there are only
two thermostat wires running to the outdoor unit
ground the 24 volt common “C” of the outdoor
transformer to a chassis ground (earth0 ground. This
is not as good as the third wire but it is better than
leaving the outdoor 24 volt common floating.

If this does not resolve communication issues Bias switch
issues will need to be checked.

Note: Only one unit should control bias on the system.

• Air Handler or Furnace should never have their bias
switches moved.

• Indoor bias switches are always in the

• A/C and Heat Pump bias switches can be moved.

• Thermostats do not have bias switches.

• It may be necessary to move bias switches on the

outdoor unit to achieve proper bias. If the switches
need to be moved both switches must be moved.

Checking Bias Voltage:
Remove communicating wires from outdoor board and

thermostat and check voltage at the indoor board.

1. DC voltage from C to data 1 should read approxi­mately 1.9vdc or 2.8vdc for some furnaces. (Figure 1)

2. DC voltage from C to data 2 should read approxi­mately 1.3vdc. or 2.2vdc for some furnaces . (Figure

2)

3. Difference in voltage should be .6vdc.

Figure 1

“ON” position

Figure 2

Reconnect communicating wires from outdoor
board check voltage again

1. Check voltage from C to data 1 and C to Data 2 if the
voltage is different than the original reading listed
above. The outdoor bias switches must be turned to
off.

2. Turn power off at outdoor unit and unplug the low
voltage connector.

3. Remove the plastic film covering the switches with
screwdriver or knife.

4. Turn both switches to “off” position.

5. Plug in connector and turn on power and check DC
voltage between C and data 1 and C and data 2.

Difference should be .6vdc.

SEQUENCE OF OPERATION

AVPTC/MBVC with ASXC/DSXC Condenser and CTK0*
Communicating Themostat

The AVPTC or MBVC air handle/modular blower matched
with an ASXC or DSXC condensing unit and CTK0* commu­nicating thermostat constitute a network. The three compo­nents, or subsystems, making up the system communicate
with one another with information passed between all three
components. This leads to a somewhat non-traditional
manner in which the system components receive commands
for system operation. All system commands are routed from
the component through the network to the appropriate desti­nation component.

NOTE: The individual subsystems will cease operation if the
request for operation is NOT refreshed after 5 minutes. This
is a built-in safe guard to prevent the possibility of runaway
operation.

1.0 Cooling Operation - Low and High Stage Cool

1.1 The CTK0* thermostat sends a request for low stage
cooling through the network to the unitary (UC) control in
the condenser. The UC control receives the command
and processes any compressor and fan delays.

1.2 The UC control sends a request for low stage fan speed

88

SERVICING

to the air handler/modular blower. The blower energizes
the ECM blower motor at the appropriate speed.

1.3 The condenser energizes the compressor and con­denser fan motor at the appropriate low stage speeds.

1.4 The system operates at low stage cooling.

1.5 If the thermostat demand cannot be met on low stage
cooling, the CTK0* thermostat sends a request for high
stage cooling to the condenser. The condenser in turn
sends a request for high stage fan speed to the air
handler/modular blower. The blower increases the blower
speed to the high stage cooling speed.

1.6 The condenser's unitary control energizes the high stage
compressor solenoid and switches the condenser fan
motor to high speed.

1.7 The system operates at high stage cooling.

1.8 Once the thermostat demand is satisfied, the CTK0*
thermostat commands the UC control to end cooling
operation. The condenser de-energizes the
compressorand condenser fan motor. The UC control
continues providing a fan request until any cooling blower
OFF delays have expired.

2.0 Heating Operation - Auxiliary/Emergency Heat

2.1 The CTK0* thermostat sends a request for emergency
heat to the air handler/modular blower.

2.2 The air handler control energizes the ECM blower motor
at the emergency heat speed. The electric heat se­quencer outputs are also energized, thus energizing the
electric heaters.

2.3 The system operates at emergency heat.

2.4 Once the thermostat demand is satisfied, the CTK0*
thermostat commands the air handler/modular blower to
end emergency heat operation. The air handler control
de-energizes the electric heat sequencer outputs. The
ECM blower motor remains energized until any blower
OFF delay timing has expired.

3.0 Continuous Fan Operation

3.1 With a demand for continuous fan operation, the CTK0*
thermostat sends a fan request to the integrated air
handler control along with a fan demand. The control
energizes the variavble speed ECM motor at fan demand
provided by the thermostat. The fan demand provided by
the thermostat will be 30%, 50%,or 70% of the air
handler's maximum airflow capability. The continuous
fan demand is set from the thermostat as low, medium,
or high.

3.2 If the thermostat demand for continuous fan is removed,
the CTK0* thermostat commands the integrated air
handler control to end continuous fan operation. The
integrated AH control immediately de-energizes the
ECM blower motor.

AVPTC/MBVC with ASZC/DSZC Heat Pump and CTK0*
Communicating Themostat

The AVPTC or MBVC air handle/modular blower matched
with an ASZC or DSZC condensing unit and CTK0* commu-

nicating thermostat constitute a network. The three compo­nents, or subsystems, making up the system communicate
with one another with information passed between all three
components. This leads to a somewhat non-traditional
manner in which the system components receive commands
for system operation. All system commands are routed from
the component through the network to the appropriate desti­nation component.

NOTE: Communicating heat pump systems are designed to
utilize a balance point temperature. The balance point
temperature in part controls heat pump operation. If the
outdoor temperature is below the balance point, the heat
pump is disable and only electric heat is available for heating.
The balance point temperature is set via the CTK0* thermo­stat in the advanced installer's configuration menu.

The CTK0* thermostat also allows the user to disable the
electric heaters in the air handler/modular blower depending
on the outdoor temperature. The electric heaters are disabled
If the outdoor temperature is above the set point. All heating
is supplied by the heat pump.

The outdoor air temperature is aquired from the outdoor air
temperature (OAT) sensor included with the ASZC/DSZC
heat pump models. Faults with the sensor will affect heating
operation.

NOTE: The individual subsystems will cease operation if the
request for operation is NOT refreshed after 5 minutes. This
is a built-in safe guard to prevent the possibility of runaway
operation.

1.0 Cooling Operation - Low and High Stage Cool

1.1 The CTK0* thermostat sends a request for low stage
cooling through the network to the unitary (UC) control in
the heat pump. The UC control receives the command
and processes any compressor and fan delays.

1.2 The UC control sends a request for low stage fan speed
to the air handler/modular blower. The blower energizes
the ECM blower motor at the appropriate speed.

1.3 The heat pump energizes the compressor and condenser
fan motor at the appropriate low stage speeds. The
reversing valve is also energized.

1.4 The system operates at low stage cooling.

1.5 If the thermostat demand cannot be met on low stage
cooling, the CTK0* thermostat sends a request for high
stage cooling to the heat pump. The heat pump in turn
sends a request for high stage fan speed to the air
handler/modular blower. The AH control increases the
blower speed to the high stage cooling speed.

1.6 The heat pump's unitary control energizes the high stage
compressor solenoid and switches the condenser fan
motor to high speed. The reversing valve remains
energized.

1.7 The system operates at high stage cooling.

1.8 Once the thermostat demand is satisfied, the CTK0*
thermostat commands the UC control to end cooling
operation. The heat pump de-energizes the compressor,
condenser fan motor, and reversing valve. The UC control

89

SERVICING

continues providing a fan request until any cooling blower
OFF delays have expired.

2.0 Heating Operation

Outdoor Temperature Above the Heat Pump Balance
Point

2.1 The CTK0* thermostat sends a request for the outdoor air
temperature to the heat pump. The heat pump returns an
outdoor air temperature that is above the balance point
temperature. Heat pump heating is enabled.

2.2 The CTK0* thermostat sends a request for low stage heat
pump heating to the unitary (UC) control in the heat
pump. The UC control receives the command and
processes any compressor and fan delays.

2.3 The UC control sends a request for low stage fan speed
to the air handler/modular blower. The blower energizes
the ECM blower motor at the appropriate speed.

2.4 The condenser energizes the compressor and con­denser fan motor at the appropriate low stage speeds.

2.5 The system operates at low stage heat pump heating.

2.6 If the thermostat demand cannot be met on low stage
heat pump heating, the CTK0* thermostat sends a
request for high stage heat pump heating to the heat
pump. The heat pump in turn sends a request for high
stage fan speed to the air handler/modular blower. The
AH control increases the blower speed to the high stage
heat pump heating speed.

2.7 The heat pump's unitary control energizes the high stage
compressor solenoid and switches the condenser fan
motor to high speed.

2.8 The system operates at high stage heat pump heating.

2.9 If the thermostat demand cannot be met on high stage
heat pump heating, the CTK0* thermostat sends a
request for auxiliary heat to the air handler/modular
blower.

2.10 Upon receiving a demand for auxiliary heat, the air
handler control determines the appropriate airflow for
high stage heat pump + auxiliary heat operation and
operates the ECM blower motor at that airflow demand.
The air handler control determines which airflow demand
is greatest and applies that demand when operating the
ECM blower motor.

2.11 The system operates at high stage heat pump heating
plus auxiliary heat.

2.12 Once the thermostat demand is satisfied, the CTK0*
thermostat commands the heat pump to end heat pump
heating operation. The compressor and outdoor fan
motor are de-energized.

The air handler/modular blower is commanded to end

auxiliary heat operation. The air handler control de­energizes the electric heat sequencer outputs. The ECM
blower motor remains energized until any blower OFF
delay timing has expired.

Outdoor Temperature Below the Heat Pump Balance
Point

2.1 The CTK0*** thermostat sends a request for the outdoor
air temperature to the heat pump. The heat pump returns
an outdoor air temperature that is below the balance point
temperature. Heat pump heating is disabled.

2.2 The CTK0*** thermostat sends a request for auxiliary
heat to the air handler/modular blower.

2.2 The air handler control energizes the ECM blower motor
at the auxiliary heat speed. The electric heat sequencer
outputs are also energized, thus energizing the electric
heaters.

2.3 The system operates at auxiliary heat.

2.4 Once the thermostat demand is satisfied, the CTK0*
thermostat commands the air handler/modular blower to
end auxiliary heat operation. The air handler control de­energizes the electric heat sequencer outputs. The ECM
blower motor remains energized until any blower OFF
delay timing has expired.

3.0 Continuous Fan Operation

3.1 With a demand for continuous fan operation, the CTK0*
thermostat sends a fan request to the integrated air
handler control along with a fan demand. The
controladjustable via the CTK0* thermostat. The com­pressor delay is intended to eliminate compressor noise
during the reversing valve shift.) The compressor will
energized (or re-energized) at high stage.

3.2 If the thermostat demand for continuous fan is removed,
the CTK0* thermostat commands the integrated air
handler control to end continuous fan operation. The
integrated AH control immediately de-energizes the
ECM blower motor.

4.0 Defrost Operation

4.1 While the system is operating in heat pump heating (see

2.0 Heating Operation), the control in the outdoor unit
may determines that a defrost cycle is needed. Upon
determing that a defrost cycle is needed, the UC control
de-energizes the condensor fan motor and energizes the
reversing valve.

4.2 The compressor may be de-energized for a short delay
during the reversing valve shift. (The delay period is
adjustable via the CTK0* thermostat. The compressor
delay is intended to eliminate compressor noise during
the reversing valve shift.) The compressor will energize
(or re-energize) at high stage.

4.3 The UC control sends a request for defrost operation to
the integrated air handler control. The air handler control
energizes the electric heat sequencer outputs and oper­ates the ECM blower model at the electric heat speed.

4.4 Once the defrost cycle is terminated, the heat pump
commands the air handler/modular blower to end defrost
operation.

4.5 The system returns to heat pump heating operation that
was in effect prior to the defrost cycle.

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SERVICING

5.0 Emergency Heat Operation

5.1 The CTK0* thermostat sends a request for emergency
heat to the air handler/modular blower.

5.2 The air handler control energizes the ECM blower motor
at the emergency heat speed. The electric heat se­quencer outputs are also energized, thus energizing the
electric heaters.

5.3 The system operates at emergency heat.

5.4 Once the thermostat demand is satisfied, the CTK0*
thermostat commands the air handler/modular blower to
end emergency heat operation. The air handler control
de-energizes the electric heat sequencer outputs. The
ECM blower motor remains energized until any blower
OFF delay timing has expired. energizes the variavble
speed ECM motor at fan demand provided by the thermo­stat. The fan demand provided by the thermostat will be
30%, 50%,or 70% of the air handler's maximum airflow
capability. The continuous fan demand is set from the
thermostat as low, medium, or high.

S-60 ELECTRIC HEATER (OPTIONAL ITEM)

Optional electric heaters may be added, in the quantities
shown in the specifications section, to provide electric
resistance heating. Under no condition shall more heaters
than the quantity shown be installed.

The low voltage circuit in the air handler is factory wired and
terminates at the location provided for the electric heater(s).
A minimum of field wiring is required to complete the instal­lation.

Other components such as a Heating/Cooling Thermostat
and Outdoor Thermostats are available to complete the
installation.

The system CFM can be determined by measuring the static
pressure external to the unit. The installation manual
supplied with the blower coil, or the blower performance table
in the service manual, shows the CFM for the static mea­sured.

Alternately, the system CFM can be determined by operating
the electric heaters and indoor blower WITHOUT having the
compressor in operation. Measure the temperature rise as
close to the blower inlet and outlet as possible.

If other than a 240V power supply is used, refer to the BTUH
CAPACITY CORRECTION FACTOR chart below.

BTUH CAPACITY CORRECTION FACTOR

SUPPLY VOLTAGE 250 230 220 208

MULTIPLICATION FACTOR 1.08 .92 .84 .75

EXAMPLE: Five (5) heaters provide 24.0 KW at the rated
240V. Our actual measured voltage is 220V, and our
measured temperature rise is 42°F. Find the actual CFM:

Answer: 24.0KW, 42°F Rise, 240 V = 1800 CFM from the
TEMPERATURE RISE chart on the right.

Heating output at 220 V = 24.0KW x 3.413 x .84 = 68.8
MBH.

Actual CFM = 1800 x .84 Corr. Factor = 1400 CFM.
NOTE: The temperature rise table is for sea level installa-

tions. The temperature rise at a particular KW and CFM will
be greater at high altitudes, while the external static pressure
at a particular CFM will be less.

TEMP ERATURE RISE (°F) @ 240V

CFM

60016253851---­70014223343---­800 12 19 29 38 57 - - -

900 11 17 26 34 51 - - ­1000 10 15 23 30 46 - - ­1100 9 14 21 27 41 55 - ­1200 8 13 19 25 38 50 - ­1300 7 12 18 23 35 46 - ­1400 7 11 16 22 32 43 54 65
1500 6 10 15 20 30 40 50 60
1600 6 9 14 19 28 38 47 57
1700 6 9 14 18 27 36 44 53
1800 5 8 13 17 25 34 42 50
1900 5 8 12 16 24 32 40 48
2000 5 8 12 15 23 30 38 45
2100 5 7 11 14 22 29 36 43
2200 4 7 11 14 21 27 34 41
2300 4 7 10 13 20 26 33 39

HTRKW3.0KW4.7KW6.0KW7.0KW9.5KW14.2KW19.5KW21.0

BTUH 10200 16200 20400 23800 32400 48600 66500 71600

3.0 kW4.8 kW7.2 kW9.6 kW14.4 kW19.2 kW24.0 kW28.8
kW

ELECTRIC HEATER CAPACITY BTUH

KW

FORMULAS:

Heating Output = KW x 3413 x Corr. Factor
Actual CFM = CFM (from table) x Corr. Factor
BTUH = KW x 3413
BTUH = CFM x 1.08 x Temperature Rise (T)
CFM = KW x 3413

1.08 x T

T = BTUH
CFM x 1.08

91

SERVICING

S-61A CHECKING HEATER LIMIT CONTROL(S)

Each individual heater element is protected with a limit
control device connected in series with each element to
prevent overheating of components in case of low airflow. This
limit control will open its circuit at approximately 150°F.

HIGH VOLT AGE!
Disconnect ALL power before servicing
or installing. Multiple power sources
may be present. Failure to do so may
cause property damage, personal injury
or death.

1. Remove the wiring from the control terminals.

2. Using an ohmmeter, test for continuity across the nor­mally closed contacts. No reading indicates the control
is open - replace if necessary.

IF FOUND OPEN - REPLACE - DO NOT WIRE AROUND.

S-61B CHECKING HEATER FUSE LINK

(OPTIONAL ELECTRIC HEATERS)

Each individual heater element is protected with a one time
fuse link which is connected in series with the element. The
fuse link will open at approximately 333°.

WARNING

Disconnect ALL power before servicing.

1. Remove heater element assembly so as to expose fuse
link.

2. Using an ohmmeter, test across the fuse link for continu­ity - no reading indicates the link is open. Replace as
necessary.

NOTE: The link is designed to open at approximately 333°F.
DO NOT WIRE AROUND - determine reason for failure.

S-62 CHECKING HEATER ELEMENTS

WARNING

Disconnect ALL power before servicing.

1. Disassemble and remove the heating element.

2. Visually inspect the heater assembly for any breaks in
the wire or broken insulators.

3. Using an ohmmeter, test the element for continuity - no
reading indicates the element is open. Replace as
necessary.

S-100 REFRIGERATION REPAIR PRACTICE

DANGER

Always remove the refrigerant charge in a proper
manner before applying heat to the system.

When repairing the refrigeration system:

HIGH VOLT AGE!
Disconnect ALL power before servicing
or installing. Multiple power sources
may be present. Failure to do so may
cause property damage, personal injury
or death.

1. Never open a system that is under vacuum. Air and
moisture will be drawn in.

2. Plug or cap all openings.

3. Remove all burrs and clean the brazing surfaces of the
tubing with sand cloth or paper. Brazing materials do not
flow well on oxidized or oily surfaces.

4. Clean the inside of all new tubing to remove oils and pipe
chips.

5. When brazing, sweep the tubing with dry nitrogen to
prevent the formation of oxides on the inside surfaces.

6. Complete any repair by replacing the liquid line drier in the
system, evacuate and charge.

BRAZING MATERIALS

IMPORTANT NOTE: Torch heat required to braze tubes of
various sizes is proportional to the size of the tube. Tubes of
smaller size require less heat to bring the tube to brazing
temperature before adding brazing alloy. Applying too much
heat to any tube can melt the tube. Service personnel must
use the appropriate heat level for the size of the tube being
brazed.

NOTE: The use of a heat shield when brazing is recommended
to avoid burning the serial plate or the finish on the unit. Heat
trap or wet rags should be used to protect heat sensitive
components such as service valves and TXV valves.
Copper to Copper Joints - Sil-Fos used without flux (alloy
of 15% silver, 80% copper, and 5% phosphorous). Recom­mended heat 1400°F.

Copper to Steel Joints - Silver Solder used without a flux
(alloy of 30% silver, 38% copper, 32% zinc). Recommended
heat - 1200°F.

92

SERVICING

S-101 LEAK TESTING (NITROGEN OR NITRO-

GEN-TRACED)

WARNING

To avoid the risk of fire or explosion, never use
oxygen, high pressure air or flammable gases for leak
testing of a refrigeration system.

WARNING

To avoid possible explosion, the line from the
nitrogen cylinder m ust include a pressure regulator
and a pressure relief valve. The pressure relief valve
must be set to open at no more than 150 psig.

Pressure test the system using dry nitrogen and soapy water
to locate leaks. If you wish to use a leak detector, charge the
system to 10 psi using the appropriate refrigerant then use
nitrogen to finish charging the system to working pressure,
then apply the detector to suspect areas. If leaks are found,
repair them. After repair, repeat the pressure test. If no leaks
exist, proceed to system evacuation.

S-102 EVACUATION

WARNING

REFRIGERA NT U NDER PR ESSUR E!
Failure to follow proper procedures may cause
property damage, pe rsonal injury or death.

a vacuum gauge to give a true reading of the vacuum in the
system.

NOTE: Never use the Scroll compressor as a vacuum pump
or run when under a high vacuum. Motor damage could occur.

Condensing unit liquid and suction valves are closed to
contain the charge within the unit. The unit is shipped with the
valve stems closed and caps installed. Do not open valves

until the system is evacuated.

1. Connect the vacuum pump with 250 micron capabil­ity to the service valves.

2. Evacuate the system to 250 microns or less using
suction and liquid service valves. Using both valves
is necessary as some compressors create a me­chanical seal separating the sides of the system.

3. Close pump valve and hold vacuum for 10 minutes.
Typically pressure will rise during this period.

4. If the pressure rises to 1000 microns or less and
remains steady the system is considered leak free;
proceed to startup.

5. If pressure rises above 1000 microns but holds
steady below 2000 microns, moisture and/or non­condensibles may be present or the system may
have a small leak.

6. Return to step 2: If the same result is encountered
check for leaks as previously indicated and repair
as necessary then repeat evacuation.

7. If pressure rises above 2000 microns, a leak is
present. Check for leaks as previously indicated and
repair as necessary then repeat evacuation.

WARNING

Do not front seat the service valve(s) with the
compressor open, with the suction line of the
comprssor closed or severely restricted.

IMPORTANT NOTE: Because of the potential damage to
compressors, do not allow suction pressure at service valve
to drop below 20 PSIG when pumping unit system down for
repair. Outdoor section, depending on line set length and
amount of charge in system, may not be able to hold the
entire system charge.

This is the most important part of the entire service procedure.
The life and efficiency of the equipment is dependent upon the
thoroughness exercised by the serviceman when evacuating
air (non-condensables) and moisture from the system. Air in
a system causes high condensing temperature and pres­sure, resulting in increased power input and reduced perfor­mance. Moisture chemically reacts with the refrigerant oil to
form corrosive acids. These acids attack motor windings and
parts, causing breakdown. The equipment required to thor­oughly evacuate the system is a high vacuum pump, capable
of producing a vacuum equivalent to 250 microns or less and

LOW SIDE

GAUGE

AND V ALVE

800 PSI

RATED

HOSES

UNIT SERVICE

VALVE PORTS

TO

HIGH SIDE

GAUGE

AND V ALVE

VACUUM PUMP

ADAPTER

VACUUM PUMP

EVACUATION

CHARGING

CYLINDER

AND SCALE

93

SERVICING

S-103 CHARGING

WARNING

REFRIGERANT UNDE R PRESSURE!
* Do not overcharge sy stem w ith refrigerant.
* Do not operate unit in a vacuum or at negative
pressure.
Failure to follow proper procedures may cause
property damage, personal injury or death.

CAUTION

Use refrigerant certified to AHRI standards. Used
refrigera nt may cause compressor da mage and is
not covered u nder the warranty. Most portable
machines cannot clean used refrigerant t o meet
AHRI standards.

Damage to the unit caused by operating the
compressor with the suction valve closed is
not covered under the warranty and may
cause serious compre ssor damage.

Charge the system with the exact amount of refrigerant. Refer
to the specification section or check the unit nameplates for
the correct refrigerant charge. An inaccurately charged sys­tem will cause future problems.

NOTE: R410A should be drawn out of the storage container
or drum in liquid form due to its fractionation properties, but
should be “Flashed” to its gas state before entering the
system. There is commercially available restriction devices
that fit into the system charging hose set to accomplish this.

DO NOT charge liquid R410A into the compressor.

NOTE: Power must be supplied to the 18 SEER outdoor units
containing ECM motors before the power is applied to the
indoor unit. Sending a low voltage signal without high voltage
power present at the outdoor unit can cause malfunction of
the control module on the ECM motor.

Adequate refrigerant charge for the matching evaporator coil
or air handler and 15 feet of line set is supplied with the
condensing unit. If using evaporator coils or air handlers other
than HSVTC coil it may be necessary to add or remove
refrigerant to attain proper charge. If line set exceeds 15 feet
in length, refrigerant should be added at .6 ounces per foot of
liquid line.

NOTE: The outdoor temperature should be 60°F or higher
when charging the unit.Charge should always be checked
using subcooling when using TXV equipped indoor coil to
verify proper charge. Open the suction service valve first!
If the liquid service valve is opened first, oil from the compres­sor may be drawn into the indoor coil TXV, restricting
refrigerant flow and affecting operation of the system.

When opening valves with retainers, open each valve only
until the top of the stem is 1/8" from the retainer. To avoid loss
of refrigerant, DO NOT apply pressure to the retainer. When
opening valves without a retainer remove service valve cap and
insert a hex wrench into the valve stem and back out the stem
by turning the hex wrench counterclockwise. Open the valve
until it contacts the rolled lip of the valve body.

NOTE: These are not back-seating valves. It is not necessary
to force the stem tightly against the rolled lip.

After the refrigerant charge has bled into the system, open the
liquid service valve. The service valve cap is the secondary
seal for the valve and must be properly tightened to prevent
leaks. Make sure cap is clean and apply refrigerant oil to
threads and sealing surface on inside of cap. Tighten cap
finger-tight and then tighten additional 1/6 of a turn (1 wrench
flat) to properly seat the sealing surfaces.

EXPANSION VALVE SYSTEM

NOTE: Units matched with indoor coils equipped with non-

adjustable TXV should be charged by subcooling only.
NOTE: The TXV should NOT be adjusted at light load

conditions 55º to 60ºF. Use the following guidelines and
methods to check unit operation and ensure that the refriger­ant charge is within limits. Charge the unit on low stage.

Units Equipped with Adjustable Expansion
Valves should be charged by Subcooling and
Superheat adjusted only if necessary.

1. Purge gauge lines. Connect service gauge manifold to
base-valve service ports. Run the system in low stage at least
10 minutes to allow pressure to stabilize.

2. Temporarily install a thermometer on the liquid line at the
liquid line service valve and 4-6" from the compressor on the
suction line. Ensure the thermometer makes adequate con­tact and is insulated for best possible readings. Use liquid line
temperature to determine subcooling and vapor temperature
to determine superheat.

3. Check subcooling and superheat. Systems with TXV
application should have a subcooling of 5 to 7°F and super­heat of 7 to 9 °F.

a. If subcooling and superheat are low, adjust TXV to 7 to

9 ºF superheat, and then check subcooling.

NOTE: To adjust superheat, turn the valve stem clockwise to
increase and counter clockwise to decrease.

b. If subcooling is low and superheat is high, add charge

to raise subcooling to 5 to 7 °F then check superheat.

c. If subcooling and superheat are high, adjust TXV valve

to 7 to 9 ºF superheat, then check subcooling.

d. If subcooling is high and superheat is low, adjust TXV

valve to 7 to 9 ºF superheat and remove charge to lower
the subcooling to 5 to 7 ºF.

94

SERVICING

NOTE: Do NOT adjust the charge based on suction

pressure unless there is a gross undercharge.

4. Disconnect manifold set, installation is complete.
SUBCOOLING FORMULA = SATURATED LIQUID

TEMP. - LIQUID LINE TEMP.
NOTE: Check the Schrader ports for leaks and

tighten valve cores if necessary. Install caps finger­tight.

HEAT PUMP - HEATING CYCLE

The proper method of charging a heat pump in the heat mode
is by weight with the additional charge adjustments for line
size, line length, and other system components. For best
results on outdoor units with TXVs, superheat should be 2­5°F at 4-6" from the compressor. Make final charge adjust­ments in the cooling cycle.

S-104 CHECKING COMPRESSOR EFFICIENCY

The reason for compressor inefficiency is broken or damaged
scroll flanks on Scroll compressors, reducing the ability of the
compressor to pump refrigerant vapor.

The condition of the scroll flanks is checked in the following
manner.

1. Attach gauges to the high and low side of the system.

2. Start the system and run a "Cooling Performance Test.
If the test shows:
a. Below normal high side pressure.
b. Above normal low side pressure.
c. Low temperature difference across coil.
d. Low amp draw at compressor.

And the charge is correct. The compressor is faulty - replace
the compressor.

S-106 OVERFEEDING

Overfeeding by the expansion valve results in high suction
pressure, cold suction line, and possible liquid slugging of the
compressor.

If these symptoms are observed:

1. Check for an overcharged unit by referring to the cooling
performance charts in the servicing section.

2. Check the operation of the power element in the valve as
explained in S-110 Checking Expansion Valve Operation.

3. Check for restricted or plugged equalizer tube.

S-107 UNDERFEEDING

Underfeeding by the expansion valve results in low system
capacity and low suction pressures.

If these symptoms are observed:

1. Check for a restricted liquid line or drier. A restriction will
be indicated by a temperature drop across the drier.

2. Check the operation of the power element of the valve as
described in S-110 Checking Expansion Valve Operation.

S-108 SUPERHEAT

The expansion valves are factory adjusted to maintain 7 to 9
degrees superheat of the suction gas. Before checking the
superheat or replacing the valve, perform all the procedures
outlined under Air Flow, Refrigerant Charge, Expansion Valve

- Overfeeding, Underfeeding. These are the most common
causes for evaporator malfunction.

CHECKING SUPERHEAT

Refrigerant gas is considered superheated when its tempera­ture is higher than the saturation temperature corresponding
to its pressure. The degree of superheat equals the degrees
of temperature increase above the saturation temperature at
existing pressure. See Temperature - Pressure Chart on
following pages.

CAUTION

To prevent personal injury, carefully connect and
disconnect manifold gauge hoses. Escaping liquid
refrigerant can cause burns. Do not vent refrigerant
to atmosp here. Recover during system repair
or final unit disposal.

1. Run system at least 10 minutes to allow pressure to
stabilize.

2. For best results, temporarily install a thermometer on the
liquid line at the liquid line service valve and 4-6" from the
compressor on the suction line. Ensure the thermometer
makes adequate contact and is insulated for best pos­sible readings. Use liquid line temperature to determine
sub-cooling and vapor temperature to determine super­heat.

NOTE: An optional method is to locate the thermometer
at the suction line service valve. Ensure the thermometer
makes adequate contact and is insulated for best
possible readings.

3. Refer to the superheat table provided for proper system
superheat. Add charge to lower superheat or recover
charge to raise superheat.

Superheat Formula = Suct. Line Temp. - Sat. Suct. Temp.

EXAMPLE:

a. Suction Pressure = 143
b. Corresponding Temp. °F. = 50
c. Thermometer on Suction Line = 61°F.

To obtain the degrees temperature of superheat, subtract

50.0 from 61.0°F.
The difference is 11° Superheat. The 11° Superheat would fall

in the ± range of allowable superheat.

S-109 CHECKING SUBCOOLING

Refrigerant liquid is considered subcooled when its temperature is
lower than the saturation temperature corresponding to its pressure.
The degree of subcooling equals the degrees of temperature
decrease below the saturation temperature at the existing pressure.

95

SERVICING

1. Attach an accurate thermometer or preferably a thermo­couple type temperature tester to the liquid line as it
leaves the condensing unit.

2. Install a high side pressure gauge on the high side (liquid)
service valve at the front of the unit.

3. Record the gauge pressure and the temperature of the
line.

4. Review the technical information manual or specification
sheet for the model being serviced to obtain the design
subcooling.

5. Compare the hi-pressure reading to the "Required Liquid
Line Temperature" chart (page 108). Find the hi-pressure
value on the left column. Follow that line right to the
column under the design subcooling value. Where the two
intersect is the required liquid line temperature.

Alternately you can convert the liquid line pressure gauge
reading to temperature by finding the gauge reading in
Temperature - Pressure Chart and reading to the left, find
the temperature in the °F. Column.

6. The difference between the thermometer reading and
pressure to temperature conversion is the amount of
subcooling.

Add charge to raise subcooling. Recover charge to lower
subcooling.

Subcooling Formula = Sat. Liquid Temp. - Liquid Line
Temp.

EXAMPLE:

a. Liquid Line Pressure = 417
b. Corresponding Temp. °F. = 120°
c. Thermometer on Liquid line = 109°F.

To obtain the amount of subcooling subtract 109°F from
120°F.

The difference is 11° subcooling. See the specification sheet
or technical information manual for the design subcooling
range for your unit.

S-110 CHECKING EXPANSION VALVE OPERA-

TION

1. Remove the remote bulb of the expansion valve from the
suction line.

2. Start the system and cool the bulb in a container of ice
water, closing the valve. As you cool the bulb, the suction
pressure should fall and the suction temperature will rise.

3. Next warm the bulb in your hand. As you warm the bulb,
the suction pressure should rise and the suction tempera­ture will fall.

4. If a temperature or pressure change is noticed, the
expansion valve is operating. If no change is noticed, the
valve is restricted, the power element is faulty, or the
equalizer tube is plugged.

5. Capture the charge, replace the valve and drier, evacuate
and recharge.

S-112 CHECKING RESTRICTED LIQUID LINE

When the system is operating, the liquid line is warm to the
touch. If the liquid line is restricted, a definite temperature
drop will be noticed at the point of restriction. In severe cases,
frost will form at the restriction and extend down the line in the
direction of the flow.

Discharge and suction pressures will be low, giving the
appearance of an undercharged unit. However, the unit will
have normal to high subcooling.

Locate the restriction, replace the restricted part, replace
drier, evacuate and recharge.

S-113 OVERCHARGE OF REFRIGERANT

An overcharge of refrigerant is normally indicated by an
excessively high head pressure.

An evaporator coil, using an expansion valve metering device,
will basically modulate and control a flooded evaporator and
prevent liquid return to the compressor.

An evaporator coil, using a capillary tube metering device,
could allow refrigerant to return to the compressor under
extreme overcharge conditions. Also with a capillary tube
metering device, extreme cases of insufficient indoor air can
cause icing of the indoor coil and liquid return to the compres­sor, but the head pressure would be lower.

There are other causes for high head pressure which may be
found in the "Service Problem Analysis Guide."

If other causes check out normal, an overcharge or a system
containing non-condensables would be indicated.

If this system is observed:

1. Start the system.

2. Remove and capture small quantities of gas from the
suction line dill valve until the head pressure is reduced to
normal.

3. Observe the system while running a cooling performance
test. If a shortage of refrigerant is indicated, then the
system contains non-condensables.

S-114 NON-CONDENSABLES

If non-condensables are suspected, shut down the system
and allow the pressures to equalize. Wait at least 15
minutes. Compare the pressure to the temperature of the
coldest coil since this is where most of the refrigerant will be.
If the pressure indicates a higher temperature than that of the
coil temperature, non-condensables are present.

Non-condensables are removed from the system by first
removing the refrigerant charge, replacing and/or installing
liquid line drier, evacuating and recharging.

96

SERVICING

12
14
16
18
20
22
24
26
28
30
32
34
36
38
40
42
44
46
48
50
52
54
56
58
60
62
64
66
68
70
72
74
76
78
80
82
84
86
88
90
92
94
96
98

°F

-37.7

-34.7

-32.0

-29.4

-36.9

-24.5

-22.2

-20.0

-17.9

-15.8

-13.8

-11.9

-10.1

-8.3

-6.5

-4.5

-3.2

-1.6

0.0

1.5

3.0

4.5

5.9

7.3

8.6

10.0

11.3

12.6

13.8

15.1

16.3

17.5

18.7

19.8

21.0

22.1

23.2

24.3

25.4

26.4

27.4

28.5

29.5

30.5

31.2

32.2

33.2

34.1

35.1

35.5

36.9

PSIG

100
102
104
106
108
110
112

PSIG

114.0

116.0

118.0

120.0

122.0

124.0

126.0

128.0

130.0

132.0

134.0

136.0

138.0

140.0

142.0

144.0

146.0

148.0

150.0

152.0

154.0

156.0

158.0

160.0

162.0

164.0

166.0

168.0

170.0

172.0

174.0

176.0

178.0

180.0

182.0

184.0

186.0

188.0

190.0

192.0

194.0

196.0

198.0

200.0

202.0

204.0

206.0

208.0

210.0

212.0

214.0

Pressure vs. Temperature Chart

R-410A

°F

37.8

38.7

39.5

40.5

41.3

42.2

43.0

43.8

44.7

45.5

46.3

47.1

47.9

48.7

49.5

50.3

51.1

51.8

52.5

53.3

54.0

54.8

55.5

56.2

57.0

57.7

58.4

59.0

59.8

60.5

61.1

61.8

62.5

63.1

63.8

64.5

65.1

65.8

66.4

67.0

67.7

68.3

68.9

69.5

70.1

70.7

71.4

72.0

72.6

73.2

73.8

PSIG

216.0

218.0

220.0

222.0

224.0

226.0

228.0

230.0

232.0

234.0

236.0

238.0

240.0

242.0

244.0

246.0

248.0

250.0

252.0

254.0

256.0

258.0

260.0

262.0

264.0

266.0

268.0

270.0

272.0

274.0

276.0

278.0

280.0

282.0

284.0

286.0

288.0

290.0

292.0

294.0

296.0

298.0

300.0

302.0

304.0

306.0

308.0

310.0

312.0

314.0

316.0

°F

74.3

74.9

75.5

76.1

76.7

77.2

77.8

78.4

78.9

79.5

80.0

80.6

81.1

81.6

82.2

82.7

83.3

83.8

84.3

84.8

85.4

85.9

86.4

86.9

87.4

87.9

88.4

88.9

89.4

89.9

90.4

90.9

91.4

91.9

92.4

92.8

93.3

93.8

94.3

94.8

95.2

95.7

96.2

96.6

97.1

97.5

98.0

98.4

98.9

99.3

99.7

PSIG

318.0

320.0

322.0

324.0

326.0

328.0

330.0

332.0

334.0

336.0

338.0

340.0

342.0

344.0

346.0

348.0

350.0

352.0

354.0

356.0

358.0

360.0

362.0

364.0

366.0

368.0

370.0

372.0

374.0

376.0

378.0

380.0

382.0

384.0

386.0

388.0

390.0

392.0

394.0

396.0

398.0

400.0

402.0

404.0

406.0

408.0

410.0

412.0

414.0

416.0

418.0

°F

100.2

100.7

101.1

101.6

102.0

102.4

102.9

103.3

103.7

104.2

104.6

105.1

105.4

105.8

106.3

106.6

107.1

107.5

107.9

108.3

108.8

109.2

109.6

110.0

110.4

110.8

111.2

111.6

112.0

112.4

112.6

113.1

113.5

113.9

114.3

114.7

115.0

115.5

115.8

116.2

116.6

117.0

117.3

117.7

118.1

118.5

118.8

119.2

119.6

119.9

120.3

PSIG

420.0

422.0

424.0

426.0

428.0

430.0

432.0

434.0

436.0

438.0

440.0

442.0

444.0

446.0

448.0

450.0

452.0

454.0

456.0

458.0

460.0

462.0

464.0

466.0

468.0

470.0

472.0

474.0

476.0

478.0

480.0

482.0

484.0

486.0

488.0

490.0

492.0

494.0

496.0

498.0

500.0

502.0

504.0

506.0

508.0

510.0

512.0

514.0

516.0

518.0

520.0

°F

120.7

121.0

121.4

121.7

122.1

122.5

122.8

123.2

123.5

123.9

124.2

124.6

124.9

125.3

125.6

126.0

126.3

126.6

127.0

127.3

127.7

128.0

128.3

128.7

129.0

129.3

129.7

130.0

130.3

130.7

131.0

131.3

131.6

132.0

132.3

132.6

132.9

133.3

133.6

133.9

134.0

134.5

134.8

135.2

135.5

135.8

136.1

136.4

136.7

137.0

137.3

PSIG

522.0

524.0

526.0

528.0

530.0

532.0

534.0

536.0

538.0

540.0

544.0

548.0

552.0

556.0

560.0

564.0

568.0

572.0

576.0

580.0

584.0

588.0

592.0

596.0

600.0

604.0

608.0

612.0

616.0

620.0

624.0

628.0

632.0

636.0

640.0

644.0

648.0

652.0

656.0

660.0

664.0

668.0

672.0

676.0

680.0

684.0

688.0

692.0

696.0

°F

137.6

137.9

138.3

138.6

138.9

139.2

139.5

139.8

140.1

140.4

141.0

141.6

142.1

142.7

143.3

143.9

144.5

145.0

145.6

146.2

146.7

147.3

147.9

148.4

149.0

149.5

150.1

150.6

151.2

151.7

152.3

152.8

153.4

153.9

154.5

155.0

155.5

156.1

156.6

157.1

157.7

158.2

158.7

159.2

159.8

160.3

160.8

161.3

161.8

*Based on ALLIED SIGNAL Data

97

SERVICING

REQUIRED LIQUID LINE TEMPERATURE

LIQUID PRESSURE

AT SERVICE VALVE (PSIG) 8 10 12 14 16 18

189 58 56 54 52 50 48
195 60 58 56 54 52 50
202 62 60 58 56 54 52
208 64 62 60 58 56 54
215 66 64 62 60 58 56
222 68 66 64 62 60 58
229 70 68 66 64 62 60
236 72 70 68 66 64 62
243 74 72 70 68 66 64
251 76 74 72 70 68 66
259 78 76 74 72 70 68
266 80 78 76 74 72 70
274 82 80 78 76 74 72
283 84 82 80 78 76 74
291 86 84 82 80 78 76
299 88 86 84 82 80 78
308 90 88 86 84 82 80
317 92 90 88 86 84 82
326 94 92 90 88 86 84
335 96 94 92 90 88 86
345 98 96 94 92 90 88
354 100 98 96 94 92 90
364 102 100 98 96 94 92
374 104 102 100 98 96 94
384 106 104 102 100 98 96
395 108 106 104 102 100 98
406 110 108 106 104 102 100
416 112 110 108 106 104 102
427 114 112 110 108 106 104
439 116 114 112 110 108 106
450 118 116 114 112 110 108
462 120 118 116 114 112 110
474 122 120 118 116 114 112
486 124 122 120 118 116 114
499 126 124 122 120 118 116
511 128 126 124 122 120 118

REQUIRED SUBCOOLING TEMPERATURE (°F)

98

SERVICING

CHECKING COMPRESSOR EFFICIENCY

The reason for compressor inefficiency is broken or damaged
scroll flanks on Scroll compressors, reducing the ability of the
compressor to pump refrigerant vapor. The condition of the
scroll flanks is checked in the following manner.

1. Attach gauges to the high and low side of the system.

2. Start the system and run a “Cooling Performance Test. If
the test shows:

a. Below normal high side pressure.
b. Above normal low side pressure.
c. Low temperature difference across coil.
d. Low amp draw at compressor.
And the charge is correct. The compressor is faulty

– replace the compressor.

S-115 COMPRESSOR BURNOUT

When a compressor burns out, high temperature develops
causing the refrigerant, oil and motor insulation to decom­pose forming acids and sludge.

If a compressor is suspected of being burned-out, attach a
refrigerant hose to the liquid line dill valve and properly remove
and dispose of the refrigerant.

NOTICE

Violation of EPA regulations may result in fines
or other penalties.

Now determine if a burn out has actually occurred. Confirm
by analyzing an oil sample using a Sporlan Acid Test Kit, AK­3 or its equivalent.

Remove the compressor and obtain an oil sample from the
suction stub. If the oil is not acidic, either a burnout has not
occurred or the burnout is so mild that a complete clean-up
is not necessary.

If acid level is unacceptable, the system must be cleaned by
using the clean-up drier method.

CAUTION

Do no t allow th e slud ge o r oil to co ntac t the skin .
Severe bu rns may result.

NOTE: The Flushing Method using R-11 refrigerant is no

longer approved by Amana® Brand Heating-Cooling.

Suction Line Drier Clean-Up Method

The POE oils used with R410A refrigerant is an excellent
solvent. In the case of a burnout, the POE oils will remove any
burnout residue left in the system. If not captured by the
refrigerant filter, they will collect in the compressor or other
system components, causing a failure of the replacement
compressor and/or spread contaminants throughout the
system, damaging additional components.

Install a field supplied suction line drier. This drier should be
installed as close to the compressor suction fitting as
possible. The filter must be accessible and be rechecked for
pressure drop after the system has operated for a time. It may
be necessary to use new tubing and form as required.

NOTE: At least twelve (12) inches of the suction line
immediately out of the compressor stub must be discarded
due to burned residue and contaminates.

1. Remove compressor discharge line strainer.

2. Remove the liquid line drier and expansion valve.
3 Purge all remaining components with dry nitrogen or

carbon dioxide until clean.

4. Install new components including liquid line drier.

5. Braze all joints, leak test, evacuate, and recharge sys­tem.

6. Start up the unit and record the pressure drop across the
drier.

7. Continue to run the system for a minimum of twelve (12)
hours and recheck the pressure drop across the drier.
Pressure drop should not exceed 6 PSIG.

8. Continue to run the system for several days, repeatedly
checking pressure drop across the suction line drier. If
the pressure drop never exceeds the 6 PSIG, the drier has
trapped the contaminants. Remove the suction line drier
from the system.

9. If the pressure drop becomes greater, then it must be
replaced and steps 5 through 9 repeated until it does not
exceed 6 PSIG.

NOTICE: Regardless, the cause for burnout must be deter­mined and corrected before the new compressor is started.

S-120 REFRIGERANT PIPING

The piping of a refrigeration system is very important in
relation to system capacity, proper oil return to compressor,
pumping rate of compressor and cooling performance of the
evaporator.

POE oils maintain a consistent viscosity over a large tem­perature range which aids in the oil return to the compressor;
however, there will be some installations which require oil
return traps. These installations should be avoided whenever
possible, as adding oil traps to the refrigerant lines also
increases the opportunity for debris and moisture to be
introduced into the system. Avoid long running traps in
horizontal suction line.

99

SERVICING

ALUMINUM INDOOR COIL CLEANING
(Qualified Servicer Only)

This unit is equipped with an aluminum tube evaporator coil.
The safest way to clean the evaporator coil is to simply flush
the coil with water. This cleaning practice remains as the
recommended cleaning method for both copper tube and
aluminum tube residential cooling coils.

An alternate cleaning method is to use one of the products
listed in the technical publication TP-109 (shipped in the
literature bag with the unit) to clean the coils. The cleaners
listed are the only agents deemed safe and approved for use
to clean round tube aluminum coils. TP-109 is available on the
web site in Partner Link > Service Toolkit.

NOTE: Ensure coils are rinsed well after use of any chemical
cleaners.

Air Handler Static Pressure Readings

S-203 SINGLE PIECE AIR HANDLER EXTERNAL

STATIC PRESSURE

To determine proper airflow, proceed as follows:

1. Using a Inclined Manometer or Magnehelic gauge ,
measure the static pressure of the return duct at the inlet of
the air handler, this will be a negative pressure ( for example

-.30"wc)

2. Measure the static pressure of the supply duct at the outlet
of the air handler, this should be a positive pressure (for
example .20"wc).

3. Add the two readings together (for example -.30"wc +
.20"wc = .50"wc total external static pressure.

NOTE: Both readings may be taken simultaneously and read
directly on the manometer if so desired.

4. Consult proper air handler airflow chart for quantity of air
(CFM) at the measured external static pressure.

S-203A TWO PIECE AIR HANDLER EXTERNAL

STATIC PRESSURE

To determine proper airflow, proceed as follows:

1. Using a Inclined Manometer or Magnehelic gauge, mea­sure the static pressure between the outlet of the evaporator
coil and the inlet of the air handler, this will be a negative
pressure ( for example -.30"wc)

2. Measure the static pressure of the supply duct at the outlet
of the unit, this should be a positive pressure (for example
.20"wc).

3. Add the two readings together (for example -.30"wc +
.20"wc = .50"wc total static pressure.

NOTE: Both readings may be taken simultaneously and read
directly on the manometer if so desired.

4. Consult proper air handler airflow chart for quantity of air
(CFM) at the measured external static pressure.

Supply Static
+.20”wc

100

Return Static

-.30”wc