York P*UR 140, P*UR 80, FG9-UP 40, FG9-UP 60, P*UR 60 Installation Instructions Manual

INSTALLATION
INSTRUCTION

CONTENTS

GENERAL INFORMATION . . . . . . . . . . . . . . . . . . . 3

SPECIFIC UNIT INFORMATION . . . . . . . . . . . . . . . 4

UPFLOW MODELS . . . . . . . . . . . . . . . . . . . . . . . . . 8

DOWNFLOW / HORIZONTAL MODELS -

HORIZONTAL APPLICATION . . . . . . . . . . . . . . . . 11

GAS PIPING . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12

ELECTRICAL POWER CONNECTION . . . . . . . . . 13

ELECTRICAL CONTROL CONNECTIONS . . . . . . 14

HIGH EFFICIENCY

GAS-FIRED FURNACES TUBULAR

HEAT EXCHANGER SERIES

UPFLOW MODELS: P*UR / FG9-UP / G9T-UP

40 - 140 MBH INPUT

DOWNFLOW/HORIZONTAL MODELS: P*DH / FG9-DH / G9T-DH

40 - 120 MBH INPUT

COMBUSTION AIR AND VENT SYSTEM . . . . . . . 15

HORIZONTAL VENT APPLICATIONS . . . . . . . . . 24

CONDENSATE PIPING . . . . . . . . . . . . . . . . . . . . . 24

SAFETY CONTROLS . . . . . . . . . . . . . . . . . . . . . . . 26

START-UP AND ADJUSTMENTS . . . . . . . . . . . . . 27

FURNACE ACCESSORIES . . . . . . . . . . . . . . . . . . 32

AIRFLOW DATA - UPFLOW . . . . . . . . . . . . . . . . . 33

AIRFLOW DATA - DOWNFLOW/HORIZONTAL . 33

OPERATION AND MAINTENANCE . . . . . . . . . . . 34

TROUBLESHOOTING . . . . . . . . . . . . . . . . . . . . . . 37

FURNACE CONTROL DIAGNOSTICS . . . . . . . . . 37

WIRING DIAGRAM - UPFLOW MODELS . . . . . . . 39

WIRING DIAGRAM - DOWNFLOW/HORIZONTAL 40

CAUTION: READ ALL SAFETY GUIDES BEFORE YOU

START TO INSTALL YOUR FURNACE.

SAVE THIS MANUAL

035-14370-000 REV A (899) Form 650.75-N4U

650.75-N4U 035-14370-000

TABLE OF CONTENTS

GENERAL INFORMATION . . . . . . . . . . . . . . . . . . . . . . . . . 3

DESCRIPTION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3

INSPECTION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3

NOTES, CAUTIONS & WARNINGS . . . . . . . . . . . . . . . . 3

VENT SAFETY CHECK PROCEDURE . . . . . . . . . . . . . 3

SPECIFIC UNIT INFORMATION . . . . . . . . . . . . . . . . . . . . . 4

LIMITATIONS & LOCATION . . . . . . . . . . . . . . . . . . . . . .4

CLEARANCES FOR ACCESS . . . . . . . . . . . . . . . . . . . .4

CLEARANCES TO COMBUSTIBLES . . . . . . . . . . . . . . .5

BELOW FREEZING LOCATIONS . . . . . . . . . . . . . . . . . .5

DUCTWORK . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .8

UPFLOW MODELS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8

SUPPLY PLENUM CONNECTION . . . . . . . . . . . . . . . . .8

RETURN DUCT CONNECTION . . . . . . . . . . . . . . . . . . . 9

UPFLOW FILTER INSTALLATION . . . . . . . . . . . . . . . . .9

I

NTERNAL INSTALLATION

S

IDE RETURN

B

OTTOM RETURN

- E

. . . . . . . . . . . . . . . . . . . . . . . . .9

XTERNAL FILTER

. . . . . . . . . . . . . . . . . 9

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10

DOWNFLOW/HORIZONTAL MODELS

DOWNFLOW APPLICATION . . . . . . . . . . . . . . . . . . . .10

DOWNFLOW FILTERS . . . . . . . . . . . . . . . . . . . . . . . . .10

SUPPLY AIR DUCTS . . . . . . . . . . . . . . . . . . . . . . . . . .11

DOWNFLOW / HORIZONTAL MODELS - HORIZONTAL

APPLICATION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11

HORIZONTAL FILTERS. . . . . . . . . . . . . . . . . . . . . . . . 11

ATTIC INSTALLATION . . . . . . . . . . . . . . . . . . . . . . . . .11

CRAWL SPACE INSTALLATION . . . . . . . . . . . . . . . . .12

GAS PIPING . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12

ELECTRICAL POWER CONNECTION . . . . . . . . . . . . . . .13

ELECTRICAL CONTROL CONNECTIONS . . . . . . . . . . .14

COMBUSTION AIR AND VENT SYSTEM . . . . . . . . . . . . 15

METHOD ONE: TWO PIPE SEALED COMBUSTION AIR

& VENT SYSTEM . . . . . . . . . . . . . . . . . . . . . . . . . . . . .15

COMBUSTION AIR INTAKE/VENT CONNECTIONS 15

COMBUSTION AIR/VENT PIPE SIZING . . . . . . . . . . 16

VENT TERMINATION (2-PIPE). . . . . . . . . . . . . . . . . 16

VENT CLEARANCES (2-PIPE) U.S. ONLY . . . . . . . 17

VENTING MULTIPLE UNITS. . . . . . . . . . . . . . . . . . . 17

PIPING ASSEMBLY . . . . . . . . . . . . . . . . . . . . . . . . . .18

METHOD TWO: ONE PIPE SYSTEM . . . . . . . . . . . . . . 19

COMBUSTION AIR . . . . . . . . . . . . . . . . . . . . . . . . . . .19

A

IR SOURCE FROM OUTDOORS

S

PECIAL COMBUSTION AND VENTILATION

C

ONSIDERATIONS

S

PECIALLY ENGINEERED INSTALLATIONS

C

OMBUSTION AIR QUALITY

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20

- . . . . . . . . . . . . . . . . . .20

. . . . . . . . . . . . 20

. . . . . . . . . . . . . . . . . . . . . . 20

VENT PIPE SIZING (1-PIPE SYSTEM) . . . . . . . . . . .21

VENT TERMINATION (1-PIPE SYSTEM) . . . . . . . . .21

VENT TERMINAL LOCATION CLEARANCES . . . . .21

PIPING ASSEMBLY . . . . . . . . . . . . . . . . . . . . . . . . . .23

METHOD THREE: TWO PIPE SYSTEM USING COM­BUSTION AIR FROM A VENTILATED ATTIC SPACE . 23

COMBUSTION AIR INTAKE . . . . . . . . . . . . . . . . . . . 23

COMBUSTION AIR TERMINATION . . . . . . . . . . . . . 23

COMBUSTION AIR REQUIREMENTS. . . . . . . . . . . . 23

VENT PIPE . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23

VENT TERMINATION. . . . . . . . . . . . . . . . . . . . . . . . . 24

HORIZONTAL VENT APPLICATIONS . . . . . . . . . . . . . . . 24

CONDENSATE PIPING 24

C

ONVERSION FOR HORIZONTAL APPLICATIONS

. . . . . . . 25

SAFETY CONTROLS . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26

L

IMIT CONTROL

A

UXILIARY LIMIT CONTROLS

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27

. . . . . . . . . . . . . . . . . . . . . 27

START-UP AND ADJUSTMENTS . . . . . . . . . . . . . . . . . . 27

IGNITION SYSTEM SEQUENCE . . . . . . . . . . . . . . . . . 27

GAS VALVE OPERATION . . . . . . . . . . . . . . . . . . . . . . 28

CHECKING GAS INPUT (NATURAL GAS) . . . . . . . . . 28

ADJUSTMENT OF MANIFOLD GAS PRESSURE . . . . 29

ADJUSTMENT OF TEMPERATURE RISE . . . . . . . . . . 30

ADJUSTMENT OF FAN-OFF CONTROL SETTINGS . 30

ACCESSORY CONNECTIONS . . . . . . . . . . . . . . . . . . 31

E

LECTRONIC AIR CLEANER CONNECTION

H

UMIDIFIER CONNECTION

. . . . . . . . . . . . . . . . . . . . . . . 31

. . . . . . . . . . . 31

FURNACE ACCESSORIES . . . . . . . . . . . . . . . . . . . . . . . 32

AIRFLOW DATA - UPFLOW . . . . . . . . . . . . . . . . . . . . . . 33

AIRFLOW DATA - DOWNFLOW/HORIZONTAL . . . . . . . 33

OPERATION AND MAINTENANCE . . . . . . . . . . . . . . . . . 34

SEQUENCE OF OPERATION. . . . . . . . . . . . . . . . . . . . 34

CONTINUOUS BLOWER . . . . . . . . . . . . . . . . . . . . . . . 34

INTERMITTENT BLOWER - COOLING . . . . . . . . . . . . 34

HEATING CYCLE . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 34

H

OT SURFACE IGNITION SYSTEM

. . . . . . . . . . . . . . . . . 34

MAINTENANCE . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 35

A

IR FILTERS

F

ILTER REMOVAL

F

ILTER REMOVAL

H

ORIZONTAL APPLICATIONS

L

UBRICATION

B

LOWER CARE

B

URNER REMOVAL/CLEANING

C

LEANING THE HEAT EXCHANGER

C

LEANING THE SECONDARY HEAT EXCHANGER

V

ENT/AIR INTAKE

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 35

- U

PFLOW MODELS

- D

OWNFLOW MODELS

. . . . . . . . . . . . . . 35

. . . . . . . . . . . . 35

. . . . . . . . . . . . . . . . . . . . . 36

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 36

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 36

. . . . . . . . . . . . . . . . . . . . 36

. . . . . . . . . . . . . . . . . 36

. . . . . . . 37

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . 37

TROUBLESHOOTING . . . . . . . . . . . . . . . . . . . . . . . . . . . 37

FURNACE CONTROL DIAGNOSTICS . . . . . . . . . . . . . . 37

WIRING DIAGRAM - UPFLOW MODELS. . . . . . . . . . . . . 39

WIRING DIAGRAM - DOWNFLOW/HORIZONTAL . . . . . 40

2 Unitary Products Group

035-14370-000 650.75-N4U

GENERAL INFORMATION

DESCRIPTION

IMPROPER INSTALLATION MAY CREATE A
CONDITION WHERE THE OPERATION OF THE
PRODUCT COULD CAUSE PERSONAL INJURY
OR PROPERTY DAMAGE.

IMPROPER INSTALLATION, ADJUSTMENT,
ALTERATION, SERVICE OR MAINTENANCE
CAN CAUSE INJURY OR PROPERTY DAMAGE.
REFER TO THIS MANUAL FOR ASSISTANCE
OR ADDITIONAL INFORMATION, CONSULT A
QUALIFIED INST ALLER, SER VICE AGENCY OR
THE GAS SUPPLIER.

THIS PRODUCT MUST BE INSTALLED IN
STRICT COMPLIANCE WITH THE ENCLOSED
INSTALLATION INSTRUCTIONS AND ANY
APPLICABLE LOCAL, STATE, AND NATIONAL
CODES INCLUDING BUT NOT LIMITED TO,
BUILDING, ELECTRICAL AND MECHANICAL
CODES.

This Category IV, dual certified, direct vent and 1-pipe vent
furnace is designed for residential or commercial installation
in a basement, closet, recreation room, garage or other loca­tion provided space temperature is 32°F or higher. For appli­cations in below freezing locations, refer to “BELOW
FREEZING LOCATIONS” section on page 5.

INSPECTION

As soon as a unit is received, it should be inspected for possi­ble damage during transit. If damage is evident, the extent of
the damage should be noted on the carrier's freight bill. A
separate request for inspection by the carrier's agent should
be made in writing. Also, before installation the unit should be
checked for screws or bolts which may have loosened in tran­sit. There are no shipping or spacer brackets which need to
be removed.

NOTES, CAUTIONS & WARNINGS

The installer should pay particular attention to the words:
NOTE, CAUTION and WARNING. NOTES are intended to

clarify or make the installation easier. CAUTIONS are given
to prevent equipment damage. WARNINGS are given to alert
the installer that personal injury and/or equipment or property
damage may occur if installation procedures are not handled
properly.

The furnace area must not be used as a broom
closet or for any other storage purposes, as a fire
hazard bay be created. Never store items such as

The cooling coil must be installed in the supply air
duct, downstream of the furnace. Cooled air may
not be passed over the heat exchanger.

the following on, near or in contact with the fur­nace.

VENT SAFETY CHECK PROCEDURE

1. Spray or aerosol cans, rags, brooms, dust mops,
vacuum cleaners or other cleaning tools.

2. Soap powders, bleaches, waxes or other cleaning
compounds; plastic items or containers; gasoline,
kerosene, cigarette lighter fluid, dry cleaning fluids
or other volatile fluid.

3. Paint thinners and other painting compounds.

This furnace may not be common vented with any
other appliance, since it requires separate, prop­erly-sized air intake and vent lines. The furnace
shall not be connected to any type of B, BW or L

4. Paper bags, boxes or other paper products

Never operate the furnace with the blower door

vent or vent connector, and not connected to any
portion of a factory-built or masonry chimney.

removed. To do so could result in serious personal
injury and/or equipment damage.

Unitary Products Group 3

If this furnace is replacing a common-vented furnace, it may
be necessary to resize the existing vent line and chimney to

650.75-N4U 035-14370-000

prevent oversizing problems for the new combination of units.
Refer to the National Gas Code (ANSI Z223.1) or CAN/CGA
B149.1 or.2 Installation Code (latest editions).

The following steps shall be followed with each appliance
connected to the venting system placed in operation, while
any other appliances connected to the venting system are not
in operation:

1. Seal any unused openings in the venting system.

2. Inspect the venting system for proper size and horizontal
pitch, as required in the National Fuel Gas Code, ANSI
Z223.1, or the CAN/CGA B149 Installation Codes and
these instructions. Determine that there is no blockage
or restriction, leakage, corrosion or other deficiencies
which could cause an unsafe condition.

3. Insofar as is practical, close all building doors and win­dows and all doors between the space in which the appli­ance(s) is located and other spaces of the building. Turn
on clothes dryers. Turn on any exhaust fans, such as
range hoods and bathroom exhausts, so they shall oper­ate at maximum speed. Do not operate a summer
exhaust fan. Close fireplace dampers.

4. Follow the lighting instructions. Place the appliance
being inspected in operation. Adjust thermostat so the
appliance shall operate continuously.

5. Test for draft hood equipped appliance spillage at the
draft hood relief opening after 5 minutes of main burner
operation. Use the flame of a match or candle.

Downflow/horizontal models are AGA/CGA listed for down­flow application into a manufactured (mobile) home.

Upflow models or horizontal applications are not approved for
mobile homes.

A manufactured (mobile) home installation must conform with
the Manufactured Home Construction and Safety Standard,
Title 24 CFR, Part 3280, or when this standard is not applica­ble, the Standard for Manufactured Home Installations (Man­ufactured Home Sites, Communities and Set-Ups), ANSI
A225.1, and/or CAN/CSA-Z240 MH Series, Mobile Homes.

CLEARANCES FOR ACCESS

Ample clearances should be provided to permit easy access
to the unit. The following minimum clearances are recom­mended:

1. Twenty-four (24) inches between the front of the furnace
and an adjacent wall or another appliance, when access
is required for servicing and cleaning.

2. Eighteen (18) inches at the side where access is
required for passage to the front when servicing or for
inspection or replacement of flue/vent connections.

:

NOTE

In all cases, accessibility clearances shall take prece­dence over clearances for combustible materials where
accessibility clearances are greater.

6. After it has been determined that each appliance con­nected to the venting system properly vents when tested
as outlined above, return doors, windows, exhaust fans,
fireplace dampers and any other gas burning appliance
to their previous conditions of use.

7. If improper venting is observed during any of the above
tests, the venting system must be corrected.

8. Any corrections to the common venting system must be
in accordance with the National Fuel Gas Code Z223.1
or CAN/CGA B149.1 or.2 Installation Code (latest edi­tions). If the common vent system must be resized, it
should be resized to approach the minimum size as
determined using the appropriate tables in Appendix G
of the above codes.

SPECIFIC UNIT INFORMATION

LIMITATIONS & LOCATION

This furnace should be installed in accordance with all
national and local building/safety codes and requirements, or
in the absence of local codes, with the National Fuel Gas
Code ANSI Z223.1 or CAN/CGA B149.1 or.2 Installation
Code (latest editions), local plumbing or waste water codes,
and other applicable codes.

Do not install the furnace in an unconditioned
space or garage that could experience ambient
temperatures of 32F (0C) or lower. For application
in below freezing locations, See “BELOW FREEZ­ING LOCATIONS” on page 5

The furnace is not to be used for temporary heat­ing of buildings or structures under construction.

This unit must be installed in a level (1/4”) position
side-to-side and front-to-back to provide proper
condensate drainage.

Do not allow return air temperature to be below
55°F for extended periods. To do so may cause
condensation to occur in the main fired heat
exchanger.

4 Unitary Products Group

035-14370-000 650.75-N4U

vent chilled air from entering the furnace, and if manually
operated, must be equipped with means to prevent operation
of either unit unless the damper is in the full heat or cool posi­tion.

Furnaces shall not be installed directly on carpet­ing, tile or other combustible material other than

The furnace shall be located:

wood flooring. An accessory combustible floor
base is available to allow direct installation of
downflow models on combustible flooring.

1. Where a minimum amount of air intake/vent pipin
elbows will be required.

g and

Furnace shall be installed so the electrical compo­nents are protected from water.

The size of the unit should be based on an acceptable heat
loss calculation for the structure.

Check the rating plate to make certain the unit is equipped for
the type of gas supplied, and proper electrical characteristics
are available.

For installations above 2,000 feet, reduce input 4% for each
1,000 feet above sea level. Refer to Form 650.75-N2.1V for
correct pressure switch/orifice or other required conversion
information.

A furnace installed in a residential
that all burners and burner ignition devices are located not
less that 18" above the garage floor, and located or protected
to prevent damage by vehicles.

Allow clearances from combustible materials as listed under
Clearances to Combustibles, ensuring that service access is
allowed for both the burners and blower.

When the furnace is used in conjunction with a cooling coil,
the furnace must be installed parallel with or on the upstream
side of the cooling unit to avoid condensation in the primary
heat exchanger.

When a parallel flow arrangement is used, the dampers or
other means used to control air flow shall be adequate to pre-

garage shall be located so

2. As centralized with the air distribution as possible.

3. In an area where ventilation facilities provide for safe lim­its of ambient temperature under normal operating con­ditions. Ambient temperatures must not fall below 32°F
(0°C).

4. Where it will not interfere with proper air circulation in the
confined space.

5. Where the outdoor combustion air/vent terminal will not
be blocked or restricted.

6. Where it will not interfere with the cleanin
removal of other appliances.

g, servicing or

CLEARANCES TO COMBUSTIBLES

Minimum clearances from combustible construction are
shown in Table 3, “UNIT CLEARANCES TO COMBUSTI­BLES,” on page 8.

BELOW FREEZING LOCATIONS

If this furnace is installed in any area where the ambient tem­perature may drop below 32° F, a UL listed self regulated
heat tape must be installed. It is recommended that self regu­lating heat tape rated at 3 watts per foot be used. This must
be installed around the condensate drain lines in the uncondi­tioned space. Always install the heat tape per the manufac­turer's instructions. Cover the self-regulating heat tape with
fiberglass or other heat resistant, insulating material.

Unitary Products Group 5

650.75-N4U 035-14370-000

4

Models P*XU &

G9D—UH

60 / 55 / 1200 / “B”

80 / 75 / 1200 / “B”

1.

C

4

C

12-3/4

16-1/4

16-1/4

19-3/4

19-3/4

19-3/4

23-1/4

2 (3)

23-1/4

2 (3)

1

DIMENSIONS - UPFLOW MODELS: P*UR/FG9-UP/G9T-UP

B

B

45

3/4

3/4

G A S O U T L E T
1-1/4" X 2-1/2"
(A ll gas pipe
connections 1/2" N P T)

45

B

A

A

20

FRO N T LEFT SIDE

FRO N T LEFT SIDE

A

C

(W IT H K .O .
REM OVED )

BO TTO M IM AG E

(F R O N T )

20

D

In ta k e

onnection

B

FRO N T

TO P IM AG E

D

In ta k e

onnection

E

Vent C onnection
(v e n t s iz e )

FRONT

28-1/2

TO P IM AG E

23

ALL DIMENSIONS ARE IN INCHES, AND ARE
APPROXIMATE.

20

20

G A S O U T L E T
1-1/4" X 2-1/2"
(A ll gas pipe
connections 1/2" N P T)

OPTIONAL SIDE

OPTIONAL SIDE

RETURN CUT-OUT

RETURN CUT-OUT

(EITHER SIDE)

(EITHER SIDE)

28-1/2

28-1/2

28-1/2

7-5/8

E

Vent C onnection
(v e n t s iz e )

3/4"
FLANG E

7-5/8

3-1/4

3-1/4

7/8" H O LE
POW ER W IRING

POW ER W IRING

1-3/4

1-3/4

T'STAT W IR ING

T'STAT W IR ING

7/8" K .O .

7/8" K.O .

A

C

9-7/8

6-7/8

6-7/8

(W IT H K .O .

23

DRAIN

CONDENSATE

REM O VED)

Models P*UR/

FG9-UP/G9T—UP

40 / 37 / 800 / A 14-1/2

BO TTO M IM A G E

(F R O N T )

60 / 55 / 1000 / B 17-1/2
80 / 75 / 1200 / B 17-1/2

80 / 75 / 1600 / C 21
100 / 95 / 1400 / C 21
100 / 95 / 2000 / C 21

120 / 112 / 2000 / D 24-1/2

140 / 130 / 2000 / D 24-1/2

1.

Vent pipe must be increased to 3” on this model.

4-1/8

4-1/8

7/8" H O LE

9-7/8

CONDENSATE
DRAIN

7-5/8

7-5/8

1-1/4

1-1/4

1-3/4

1-3/4

14-1/2

14-1/2

22-3/4

22-3/4

RIGHT SIDE

RIGHT SIDE

3/4"

ABCDE

FLANG E

10-1/8 2 2
13-1/8 2 2
13-1/8 2 2

80 / 75 / 1600 / “C” 21 19

16-5/8 2 2

100 / 95 / 1400 / “C” 21 19

16-5/8 2 2

100 / 95 /2000 / “C” 21 19

16-5/8 2 2
20-1/8 3

120 / 112 / 2000 / “D” 24-1/2 23

20-1/8 3

Vent pipe must be increased

1

1

3/

3/

A

17-1/2 16
17-1/2 16

1

FIGURE 1 :

TABLE 1: RATINGS & PHYSICAL / ELECTRICAL DATA - UPFLOW MODELS (P*UR/FG9-UP/G9T-UP)

MODELS P*UR/FG9-UP/

G9T—UP

INPUT

MBH

OUTPUT

MBH

NOM

CFM

.

CABINET

WIDTH

IR

MEAN AIR

CFM

TEMP

RISE

1

A

TEMP

RISE °F

AFUE

@

OUTLET

TEMP

MAX

AIR

.

F

. °

DIA (IN

BLOWER

WIDTH

)

IN

(

MAX

OVER

CURRENT

PROTECT

TOTAL

HP

UNIT

AMPS

.)

40 37 800 14-1/2 92.4 35 - 65 685 165 9 6 1/4 9.0 20 14
60 55 1000 17-1/2 92.2 45 - 75 850 175 10 6 1/3 9.0 20 14
80 74 1200 17-1/2 92.0 35 - 65 1160 165 11 8 1/2 9.0 20 14

80 76 1600 21 94.3 30 - 60 1540 160 11 8 3/4 12.0 20 14
100 93 1400 21 92.2 45 - 75 1465 175 10 10 1/2 9.0 20 14
100 94 2000 21 93.0 30 - 60 1955 160 11 10 1 12.0 20 14
120 112 2000 24-1/2 92.0 45 - 75 1730 175 11 10 1 12.0 20 14
140 130 2000 24-1/2 92.0 45 - 75 2005 175 11 10 1 12.0 20 14

1.

AFUE numbers are determined in accordance with DOE test procedures

2.

Wire size and overcurrent protection must comply with the National Electrical Code (NFPA-70-latest edition).
For altitudes above 2,000 ft., reduce capacity 4% for each 1,000 ft. above sea level. Refer to Form 650.74-N1.1V.
Wire size based on copper conductors, 60°C, 3% voltage drop.
Continuous return air temperature must not be below 55°F.

-

2

MIN

SIZE (AWG

@ 75

ONE WAY

WIRE

)

FT

.

2

6 Unitary Products Group

035-14370-000 650.75-N4U

T

B

3/4

C ondensate

D rain A ccess

3-1/4 X 3

45

Air Intake

3-5/8 x 3-5/8

C onn. S ize/

(

G

Pipe S ize)

A

FRO N T LEFT SIDE

B

Power

20

Wiring

7/8" K .O .

1-7/8

E

OP IMAGE/RETURN END

D

FRO N T

Vent C onnection

(v e n t s iz e )

5-3/8

F

1-3/8

3 7/8

BOTTOM IM AG E/SU PPLY END

ALL DIMENSIONS ARE IN INCHES, AND ARE APPROXIMATE.

H

19-1/4

G A S IN L E T

A

C

FRO N T

1-3/8

8

D

20

T'STAT W IR ING

7/8" K .O .

1 -3 /4

5-1/4

3-3/4

G A S IN L E T
1-1/4" X 2-1/2"

2 -3 /4

(V ent C onnection)

35

18-1/2

16-3/4

1-1/4

7 -1 /2

6 -1 /4

4 -1 /8

3-3/4

C ondensate
D rain A ccess
3-1/4 X 3

6-1/2

Air Intake

3-5/8 x 3-5/8

C onn. S ize/

(

G

Pipe Size)

1-1/4

ALT. G AS IN LET

1-1/4" X 2-1/2"

2 8 -1 /2

RIGHT SIDE

MODELS P*DH/
FG9-DH/G9TDH

40 /37 / 800 / A 14-1/2 13-1/4 11-3/4 2 5-1/8 2-1/2 2
60 /55 / 1200 / B 17-1/2 16-1/4 14-3/4 2 6-5/8 2-1/4 2
80 /75 / 1200 / B 17-1/2 16-1/4 14-3/4 2 6-5/8 2-1/4 2

80 /75 / 1600 / C 21 19-3/4 18-1/4 2 8-3/8 2-1/4 2

100 /95 / 2000 / C 21 19-3/4 18-1/4 2 8-3/8 2-1/4 2

120 /112 / 2000 / D 24-1/2 23-1/4 21-3/4

1.

Vent pipe must be increased to 3” on this model.

ABCDEFG

1

2 (3)

10-1/8 2-1/4 3

FIGURE 2 : DIMENSIONS - DOWNFLOW/HORIZONTAL MODELS: P*DH/FG9-DH/G9T-DH

TABLE 2: RATINGS & PHYSICAL / ELECTRICAL DATA - UPFLOW MODELS (P*DH/FG9-DH/G9T-DH)

MODELS P*DH/FG9-DH/

1

A

TEMP

RISE °F

INPUT

MBH

G9T—DH

OUTPUT

MBH

CABINET

NOM

CFM

WIDTH

.

AFUE

40 37 800 14-1/2 91.0 25 - 55 856 155 10 6 1/4 9.0 20 14
60 55 1200 17-1/2 91.0 35 - 65 1018 165 11 8 1/2 9.0 20 14
80 75 1200 17-1/2 91.0 35 - 65 1370 165 11 8 1/2 9.0 20 14

80 75 1600 21 91.0 30 - 60 1563 160 11 8 3/4 12.0 20 14
100 95 2000 21 91.0 40 - 70 1582 170 11 10 1 12.0 20 14
120 112 2000 24-1/2 91.0 40 - 70 1885 170 11 10 1 12.0 20 14

1.

AFUE numbers are determined in accordance with DOE test procedures

2.

Wire size and overcurrent protection must comply with the National Electrical Code (NFPA-70-latest edition).
For altitudes above 2,000 ft., reduce capacity 4% for each 1,000 ft. above sea level. Refer to Form 650.74-N1.1V.
Wire size based on copper conductors, 60°C, 3% voltage drop.
Continuous return air temperature must not be below 55°F.

IR

MEAN AIR

CFM

TEMP

RISE

@

OUTLET

TEMP

MAX

AIR

.

BLOWER

DIA

F

. °

(IN)

WIDTH

IN

.)

(

HP

TOTAL

UNIT

AMPS

MAX

OVER

CURRENT

PROTECT

-

2

WIRE

MIN

SIZE (AWG

FT

@ 75

ONE WAY

)

.

2

Unitary Products Group 7

650.75-N4U 035-14370-000

TABLE 3: UNIT CLEARANCES TO COMBUSTIBLES

APPLICATION TOP FRONT REAR

UPFLOW 1 3 0 0 0 0 COMBUSTIBLE YES YES YES NO

DOWNFLOW / HORIZONTAL MODELS (P*DH / FG9-DH / G9T-DH)

DOWNFLOW130000

HORIZONTAL 0 3 0 1 1 0

1.

Special floor base or air conditioning coil required for use on combustible floor.

2.

Minimum of 8” clearance required to install condensate removal system.

3.

Line contact only permitted between lines formed by the intersection of the rear panel and side panel (top in horizontal position) of the
furnace jacket and building joists, studs or framing.

LEFT
SIDE

UPFLOW MODELS (P*UR / FG9-UP / G9T-UP)

RIGHT

SIDE

FLUE

FLOOR/

BOTTOM

1

1"

COMBUSTIBLE

CLOSET ALCOVE ATTIC

YES YES YES NO

2

NO YES YES

When the furnace is used in conjunction with a cooling coil,
the furnace must be installed parallel with, or on the upstream
side of the cooling unit to avoid condensation in the primary
heat exchanger.

If this unit is installed in an unconditioned space
and an extended power failure occurs, there will
be potential damage to the condensate trap, drain
lines and internal unit components. Following a
power failure situation,

Do Not Operate the Unit

Until Inspection and Repair Are Performed.

When a parallel flow arrangement is used, the dampers or
other means used to control air flow must be adequate to pre­vent chilled air from entering the furnace, and if manually
operated, must be equipped with means to prevent operating
of either unit unless the damper is in the full heat or cool posi­tion.

LINE
CON­TACT

YES

3

DUCTWORK

The duct system's design and installation must:

1. Handle an air volume appropriate for the served space
and within the operating parameters of the furnace spec­ifications.

2. Be installed in accordance with standards of NFPA
(National Fire Protection Association) as outlined in
NFPA pamphlets 90A and 90B (latest editions) or appli­cable national, provincial, local fire and safety codes.

3. Create a closed duct system. The supply duct system
must be connected to the furnace outlet and the return
duct system must be connected to the furnace inlet. Both
supply and return duct systems must terminate outside
the space containing the furnace.

4. Generally complete a path for heated or cooled air to cir­culate through the air conditioning and heating equip­ment and to and from the conditioned space.

UPFLOW MODELS

SUPPLY PLENUM CONNECTION

Attach the supply plenum to the fur­nace outlet duct connection flanges.
This is typically through the use of S
cleat material when a metal plenum is
used. The use of an approved flexible
duct connector is recommended on all
installations. This connection should be
sealed to prevent air leakage.

If a matching cooling coil is used, it
may be placed directly on the furnace
outlet and sealed to prevent leakage.
Follow the coil instructions for installing
the supply plenum.

On all installations without a coil, a removable access panel
is recommended in the outlet duct such that smoke or
reflected light would be observable inside the casing to indi­cate the presence of leaks in the heat exchanger. This
access cover shall be attached in such a manner as to pre­vent leaks.

The cooling coil must be installed in the supply air
duct downstream of the furnace.

8 Unitary Products Group

035-14370-000 650.75-N4U

g

g

g

g

g

g

g

g

g

g

F

RETURN DUCT CONNECTION

Return air may enter the furnace through the side(s) or bot­tom depending on the type of application.

not be connected into the rear panel of the unit.

Return air may

See the
specific type application installation for details. Be sure to see
the Filters section of this instruction.

CLIPS

POSITION WIRE RETAINER
(PROVIDED) UNDER FLANGE

FILTER

(PROVIDED

UPFLOW FILTER INSTALLATION

All applications require the use of a filter. A high velocity filter
and retainer are provided for field installation.

Internal Installation

1. Select desired filter position (left/ri

Remove the correspondin

cabinet cut-outs per instruc-

ht side, or bottom).

tions provided.

2. Install snap-in retainer clips into the correspondin

from the outside rear of the cabinet (Refer to Fi
To prevent cabinet air leaks, install snap-in plu

slots

ure 3.)

s (pro­vided) into the unused slots at the outside rear of the
cabinet.

FURNACE

(REAR CABINET)

LEFT

RIGHT
SIDE
SLOTS

BOTTOM SLOTS
CABINET
SLOT

FILTER SUPPORT
CLIPS (PROVIDED)

SIDE
SLOTS

PLUG UNUSED
CABINET SLOTS
WITH PLUGS
(PROVIDED)

RIGHT SIDE
INSTALLATION
SHOWN

FURNACE

FRONT

FIGURE 4 : SIDE FILTER RETAINER PLACEMENT

5. Position the filter between the wire retainer and the cabi­net wall (or floor) so it completely covers the cabinet air
opening and secure the filter in place at the front of the
cabinet by fastening the closed (looped) end of the
retainer wire under the flanged edge of the cabinet.
When properly installed the filter should fit flush with all
four sides of the cabinet wall.

NOTE:

Air velocity through throw-away type filters may not
exceed 300 feet per minute. All velocities over this require the
use of high velocity filters.

Side Return - External Filter

Locate and knock out the square corner locators. These indi­cate the size of the cutout to be made in the furnace side
panel (Refer to Figure 5).

FIGURE 3 : FURNACE FILTER SLOT LOCATIONS

3. Install the wire retainer inside the cabinet. Insert the
open ends of the wire retainer into the clip loops at the
rear of the blower compartment. The retainer wire should
pivot freely like a hin
cabinet. (Refer to Fi

4. Install the filter(s) provided. Cut filter if necessary to
match air openin
beyond openin
from bypassin
from inside the filter. Shorten the rods, if necessary, to
match final filter size.

Unitary Products Group 9

e, on the clips at the rear of the

ure 4.)

in cabinet. Filter should extend

edge as much as possible to prevent air

the filter. DO NOT remove stiffening rods

FR O N T O
FU RN A CE

CORNER
MARKINGS

FIGURE 5 : SIDE RETURN CUTOUT MARKINGS

Install the side filter rack following the instructions provided
with that accessory. If a filter(s) is provided at another loca­tion in the return air system, the ductwork may be directly
attached to the furnace side panel.

650.75-N4U 035-14370-000

NOTE:

Some accessories such as electronic air cleaners and

pleated media may require a larger side opening.

DOWNFLOW/HORIZONTAL MODELS­DOWNFLOW APPLICATION

DOWNFLOW FILTERS

A top return filter rack is supplied with

All installations must have a filter installed.

The return duct may be attached to the furnace by S-cleat,
bend tabs or other approved methods. Be sure to seal the
duct to the furnace to prevent air leakage.

Those applications over 1800 CFM require either return from
two sides, one side and the bottom, or bottom only. For bot­tom only application, see data and notes on blower perfor­mance data tables in this manual.

Where the return duct system is not complete, the return con­nection must run full size to a location outside the utility room
or basement. For further details, consult Section 5.3 (Air for
Combustion and Ventilation) of the National Fuel Gas Code,
ANSI Z223.1, or CAN/CGA B149.1 or.2, Installation Code ­latest editions.

Bottom Return

Bottom return applications normally pull return air throu

gh a
base platform or return air plenum. Be sure the return plat­form structure is suitable to support the weight of the furnace.
Be sure to seal the furnace to plenum connection to prevent
air leakage. (Refer to Figure 3 on page 9) and (Refer to
Table 1 on page 6).

The bottom panel is equipped with a perforated opening for
easy removal. Tabs must be cut with sheet metal snips to
allow removing knock-out. Scribe marks are included for
forming flanges for attachment of the return air ductwork.

NOTE:

If an external mounted filter rack is being used, see
the instructions provided with that accessory for proper hole
cut size.

Upflow attic installations must meet all minimum clearances
to combustibles and have floor support with required service
accessibility.

A

DUCTW ORK

FIGURE 6 : DOWNFLOW FILTERS

the furnace. Two 14" x 20" permanent
washable filters are supplied with each
unit.

Downflow furnaces typically are
installed with the filters located above
the furnace, extending into the return
air duct.

Any branch duct must attach to the ver­tical ductwork above the filter height
(FH) and for proper installation refer to
Figure 6.

F IL T E R R A C K
(FACTO RY SU PPLIED )

R A C K A N D F IL T E R S S E C U R E D

A

NOTE: FILTER ACCESS THRU DUCT­W O RK M UST BE PRO VIDED FOR
REMOVAL AND CLEANING

C R O S S S E C T IO N A -A
(W ITH PLENU M AND FILTERS)

IN SIDE BLO W ER SECTIO N
FO R S HIPM EN T

C A S IN G S IZ E D IM E N S IO N F H
1 4 -1 /2 " 1 3 -1 /4 "
1 7 -1 /2 " 1 2 -1 /2 "
2 1 " 1 1 - 1 /2 "
2 4 -1 /2 " 9 -3 /4 "

FILTER S

FILTER
RACK

BRANCH
DUCTS

FH

10 Unitary Products Group

The filter rack (provided) should be secured to the center of
the front and rear flanges at the furnace top. Drill a hole
through the front and rear duct flange into the filter rack and
secure it with a sheet metal screw.

Refer to the unit rating plate for furnace model then see the
dimensions page of this instruction for return air plenum
dimensions. Install the plenum following instructions under
Ductwork in this instruction.

035-14370-000 650.75-N4U

VENT (MAINTAIN
REQUIRED CLEARANCES
TO COMBUSTIBLES)

GAS PIPING

SEDIMENT TRAP

12"

30" MIN
WORK AREA

SHEET METAL
IN FRONT OF FURNACE
COMBUSTION
AIR OPENINGS IS
RECOMMENDED

RETURN AIR

SUPPLY AIR

LINE CONTACT ONLY PERMISSIBLE
BETWEEN LINES FORMED BY THE
INTERSECTION OF FURNACE TOP
AND TWO SIDES AND BUILDING
JOISTS, STUDS OR FRAMING

DOWNFLOW / HORIZONTAL MODELS ­HORIZONTAL APPLICATION

DOWNFLOW
FURNACE

WARM AIR PLENUM
WITH 1" FLANGES

FIBERGLASS
INSULATION

FIBERGLASS TAPE
UNDER FLANGE

COMBUSTIBLE FLOOR
BASE ACCESSORY

FIGURE 7 : COMBUSTIBLE FLOOR BASE

ACCESS’Y

SUPPLY AIR DUCTS

Installations on combustible material or floors must use a
combustible floor base (shown in Figure 7 - 1CB0314, 17, 21
& 24) as specified on the rating plate or a matching cooling
coil. Follow the instructions supplied with the combustible
floor base accessory.

This base can be replaced with a matching cooling coil, prop­erly sealed to prevent leaks. Follow the cooling coil instruc­tions for installing the plenum.

Downflow furnaces may be installed horizontally with the sup­ply airflow toward the left or right by laying the unit on the left
or right side panel.

Do not install the unit on the rear panel.

After determining the best orientation, lay the unit on top of
the shipping carton to protect the finish. The appropriate elec­trical knock-outs for power wiring, control wiring and gas pip­ing should be removed at this time.

For horizontal application, return air may enter through the
end only.

Return air may not be connected into the rear

panel of the unit.

HORIZONTAL FILTERS

All filters and mounting provision must be field supplied. Fil­ters(s) may be located in the duct system external to the fur­nace or in a return filter grille(s).

ATTIC INSTALLATION

All downflow application supply duct systems must be
designed and installed in accordance with the standards of
NFPA 90A and 90B, and/or all local codes.

Unitary Products Group 11

FIGURE 8 : TYPICAL ATTIC INSTALLATION

650.75-N4U 035-14370-000

g

This appliance is design certified for line contact for furnaces
installed horizontally. The intersection of the furnace top and
sides form a line. This line may be in contact with combustible
material. Refer to “Where it will not interfere with the cleanin
servicing or removal of other appliances." Section on page 5
in this manual for additional information.

Secure a platform constructed of plywood or other building
material to the floor joists. Sheet metal, 12" in front of the fur­nace combustion air openings is recommended. (Refer to
Figure 9.)

Note:

The unit must be elevated to allow clearnace fo the

condensate trap and drain pipe

. .

If this furnace is installed over a finished space, a
condensate safety pan must be installed.

adequate height to ensure the unit will not be subject to water
damage.

,

When suspending the furnace from rafters or floor joists
using rod, pipe or straps, refer to Physical Data and,Table 3,
“UNIT CLEARANCES TO COMBUSTIBLES,” on page 8, for
furnace weights to determine suitable means of suspension.

Angle supports should be placed at the supply aire end and
near the blower deck. (Refer to Figure 9.)

Do not support

at return air end of unit.

Units may also be suspended by using straps or other mate­rial at the same location. All four suspension points must be
level to ensure quiet furnace operation.

In any application where temperatures below
freezing are possible, See “BELOW FREEZING
LOCATIONS” on page 5

GAS PIPING

When a furnace is installed in an attic or other
insulated space, keep all insulating materials at
least 12" away from furnace and burner combus­tion air openings.

NOTE:

See crawl space installation for suspending the fur­nace in attic installations.

ANGLE IRON
BRACKET

1" MAX BETWEEN
ROD & FURNACE

6" MIN BETWEEN
ROD & FURNACE

SUPPORT
ROD

1" MAX BETWEEN
ROD & FURNACE

FIGURE 9 : TYPICAL FURNACE INSTALLATION

USING SUSPENSION MATERIALS

CRAWL SPACE INSTALLATION

The furnace can be hung from floor hoists or installed on suit­able blocks or pad. Blocks or pad installations shall provide

The gas supply must be installed in accordance with the cur­rent National Fuel Gas Code, ANSI Z223.1 (in the U.S.) or
CAN-B149.1 or.2 (in Canada) installation codes and all appli­cable local and utility requirements. All pipe and fitting mate­rial, pipe size and installation procedures must comply with
the appropriate code. Some utilities may require larger pipe
sizes than shown in the code. Gas piping may be connected
from either side of the furnace. Each side of the unit has two
gas pipe entry knockouts.

For downflow/horizontal models,

piping before determining the correct gas pipe entry

plan your combustion air

. Use 90
degree service elbow(s), or short nipples and conventional 90
degree elbow(s) to enter through the cabinet access holes..

An overpressure protection device, such as a
pressure regulator, which conforms to the National
Fuel Gas Code, ANSI Z223.1 (U.S.) or CAN­B149.1 or.2 (Canada) and acts to limit the down­stream pressure to a value that does not exceed

0.5 PSI (14" w.c.), must be installed in the gas pip­ing system upstream of the furnace. Failure to do
so may result in a fire or explosion or cause dam­age to the furnace or some of its components.

12 Unitary Products Group

035-14370-000 650.75-N4U

g

G

NOTE

An accessible manual shutoff valve must be installed

:

upstream of the furnace gas controls and within 6 feet of the
furnace.

The installation of a ground joint union and drip leg are
required. (Refer to Figure 10.) Maximum and minimum sup­ply gas pressures are shown below.

INLET GAS PRESSURE RANGE

Natural Gas Propane (LP)

Minimum 4.5 In. W.C. 11 In. W.C.

Maximum 13.8 In. W. C. 13.8 In. W.C.

EXTERNAL M ANUAL

SH U TOFF VALVE

TO G AS
SUPPLY

DROP LEG

GROUND JOINT UNION

M AY BE IN S TALLE D

IN S ID E O R O U T S ID E U N IT

GAS VALVE

TO G AS
SUPPLY

DROP LE

FIGURE 10 : GAS PIPING

NOTE

A 1/8” NPT plug is included in the inlet side of the gas

:

valve for measuring incoming gas pressure.

The furnace must be isolated from the gas supply piping sys­tem by closing its individual external manual shutoff valve
during any pressure testing of the gas supply piping system
at pressures equal to or less than 1/2 psig (3.48 kPa).

Compounds used on threaded joints of gas piping
must be resistant to the action of liquefied petro­leum gases. After connections are made, leak-test
all pipe connections.

After all gas piping connections are completed,
leak test all joints, fittings and furnace connections
with rich soap and water solution, commercially
available bubble type leak detection fluid, or other
approved means.

Do not use an open flame or other source of igni­tion for leak testing.

ELECTRICAL POWER CONNECTION

Field wiring to the unit must conform to and be grounded in
accordance with the provisions of the National Electrical
Code ANSI/NFPA No. 70-latest edition, Canadian Electric
Code C22.1 Part 1 - (latest edition) and/or local codes. Elec­tric wires which are field installed shall conform with the tem­perature limitation for 63°F/35°C rise wire when installed in
accordance with instructions. Specific electrical data is given
for the furnace on its rating plate and in Refer to Table 1 on
page 6.

Provide a power supply separate from all other circuits. Install
overcurrent protection and disconnect switch per local/
national electrical codes. The switch should be close to the
unit for convenience in servicing. With the disconnect switch
in the OFF position, check all wiring against the unit wiring
label. Also, see the wiring diagram in this instruction.

NOTE

The furnace’s control system depends on correct

:

polarity of the power supply and a proper ground connection.
“FURNACE CONTROL DIAGNOSTICS" Section on pa
for symptoms of reversed power supply polarity.

e37

The furnace and its individual shutoff valve must be discon­nected from the gas supply piping system during any pres­sure testing of that system at test pressures in excess of 1/2
psig (3.48 kPa).

Never apply a pipe wrench to the body of the com­bination automatic gas valve. A wrench must be
placed on the projection or wrench boss of the
valve when installing piping to it.

Unitary Products Group 13

Use copper conductors only.

Connect the power supply as shown on the unit wiring label
on the inside of the blower compartment door and Figures 11
& 12. The black furnace lead must be connected to the L1
(hot) wire from the power supply. The white furnace lead
must be connected to neutral. Also, the green equipment
ground wire must be connected to the power supply ground.

Remove the screws retaining the wiring box cover. Route the
power wiring through the unit top panel with a conduit con-

650.75-N4U 035-14370-000

nector or other proper connection. Make wiring connections,
(Refer to Figure 11.) Replace the wiring box cover and
screws.

L1

(HOT)

N

BLK

GRD

WHI

GRN

WIRING INSIDE
JUNCTION BOX

: BLK/BLK

WHI/WHI

GRN/GRN

JUNCTION
BOX

BURNER COMPARTMENT

DOOR SWITCH

TRANSFORMER

IGNITION MODULE

G

R

W

C

Y

Y

HUM

EAC

XFMR

LINE

CIR

HUM

EAC

XFMR

LINE

PARK

PARK

HEAT

COOL

CLASS 2 SYSTEM
CONTROL WIRING
TO THERMOSTAT

L1

(HOT)

JUNCTION
BOX

N

GRD

WHI

BLK

GRN

WIRING INSIDE
JUNCTION BOX

: BLK/BLK

WHI/WHI

GRN/GRN

BLOWER COMPARTMENT

VENT PIPE

C

O

O

L

H

E

A

T

P

A

R

K

P

A

R

K

L

I

N

E

X

F

M

IGNITION MODULE

R

E

A

C

H

U

M

C

I

R

L

I

N

E

X

F

M

R

E

A

C

H

U

M

Y

Y

C

R

W

G

CLASS 2 SYSTEM
CONTROL WIRING
TO THERMOSTAT

FLUE CHASE

TRANSFORMER

DOOR
SWITCH

BURNER COMPARTMENT

FIGURE 12 : DOWNFLOW / HORIZONTAL MODELS

(P*DH / FG9-DH / G9T-DH) ELECTRI­CAL WIRING

BLOWER COMPARTMENT

FIGURE 11 : UPFLOW MODELS (P*UR / FG9-UP /

G9T-UP) ELECTRICAL WIRING

An alternate wiring method is to use a field provided 2 x 4 box
and cover on the outside of the furnace. Route the furnace
leads into the box using a protective bushing where the wires
pass through the furnace panel.

NOTE:

The power connection leads and wiring box on upflow
units may be relocated to the left side of the furnace. Remove
the screws and cut wire tie holding excess wiring. Reposition
on the left side of the furnace and fasten using holes pro­vided.

ELECTRICAL CONTROL CONNECTIONS

Install the field-supplied thermostat. The thermostat instruc­tions for wiring are packed with the thermostat. With the ther­mostat set in the OFF position and the main electrical source
disconnected, complete the low-voltage wiring from the ther­mostat to the terminal board on the ignition module. Connect
Class 2 control wiring as shown in Figures 13 & 14. Electronic
thermostats may require a common connection as shown
dashed in Figure 14.

Set the heat anticipator in the room thermostat to
.45 amps. Setting it lower will cause short cycles.
Setting it higher will cause the room temperature to
exceed the setpoints

FIGURE 13 : POWER WIRING CONNECTIONS

ROOM
THERMOSTAT

R
W

G

Y

C

FURNACE
CONTROL

R

W
G

Y

C

CONDENSING
UNIT

TO AIR CONDITIONER

CONTROLS

FIGURE 14 : TYPICAL HEATING AND COOLING

14 Unitary Products Group

035-14370-000 650.75-N4U

g

g

g

g

R

NOTE.

Some electronic thermostats do not have adjustable

heat anticipators. They may have other type cycle rate

vent connection (top right of unit) back to the outdoors. Refer
to Figure 15 and Figure 16.

adjustments. Follow the thermostat manufacturer's instruc­tions.

The 24-volt, 40 VA transformer is sized for the furnace com­ponents only , and should not be connected to power auxiliary
devices such as humidifiers, air cleaners, etc. The trans­former may provide power for an air conditioning unit contac­tor.

COMBUSTION AIR AND VENT SYSTEM

This furnace is certified to be installed with one of
three possible intake/vent configurations.

1. Two-pipe with a sealed combustion intake/vent system
outdoor combustion air.

usin

2. Sin

3. Two-pipe intake/vent system usin

Be sure to follow the appropriate venting section details,
related information and limitations for your type of installation.

le pipe vent system using combustion air from the

area surroundin

the furnace.

combustion air from a

ventilated attic space and a vent pipe to the outside.

Furnace Intake / Vent Connection Size (All Models)

40 - 100 MBH 120 - 140 MBH

Intake 2” 3"

Vent 2”

1

2"

C O M B U S T IO N A IR P IP E

PASSES THRO UG H TO P PANEL

CONNECTS TO COLLAR
O N T O P O F B U R N E R B O X

VENT PIPE

IN T O S O C K E T J U S T
UND ER TO P PAN EL

O FF

O N

M

P

C

132

CEMENTS

FIGURE 15 : UPFLOW A IR INTAKE/VENT LOCATIONS

(MODELS P*UR / FG9-UP /G9T-UP)

VENT PIPE PASSES
THRO UG H TOP PANEL

COOL
HEAT
PARK
PARK
LINE
XFMR
EAC
HUM

CIR
LINE
XFMR
EAC
HUM

YWRG

C

1.

Vent must be increased to 3" on this model.

Note 1: Any vent pipe size change must be made out-

side furnace casing in a vertical pipe section
to allow proper drainage of condensate.

Note 2: An offset using two 45 degree elbows will be

required for plenum clearance when the vent
is increased to 3”.

METHOD ONE: TWO PIPE SEALED COMBUSTION
AIR & VENT SYSTEM

COMBUSTION AIR INTAKE/VENT CONNECTIONS

This type installation requires outdoor combustion air. Two
separate, properly-sized pipes must be used. One bringing
air from the outdoors to the furnace combustion air intake col­lar on the burner box, and a second pipe from the furnace

OPTIONAL
L E F T S ID E
COM BUSTION AIR
PIPE RO UTING

COM BUSTION AIR PIPE
CONNECTS TO CO LLAR
ON BOTTOM OF BURNE
BOX

FIGURE 16 : DOWNFLOW / HORIZONTAL AIR

INTAKE/VENT LOCATIONS (MODELS
P*DH / FG9-DH /G9T-DH)

The intake/vent should be located either through the wall
(horizontal or side vent) or through the roof (vertical vent).
Care should be taken to locate side vented systems where
trees or shrubs will not block or restrict supply air from enter­ing or combustion products from leaving the terminal.

Also, the terminal assembly should be located as far as pos­sible from a swimming pool or a location where swimming
pool chemicals might be stored. Be sure the terminal assem­bly follows the outdoor clearances listed in Table 3 for U.S.
installations: In Canada, refer to CAN/CGA-B149.1 or.2

Unitary Products Group 15

650.75-N4U 035-14370-000

Installation Code (latest edition-Venting Systems and Air
Supply).

COMBUSTION AIR/VENT PIPE SIZING

To select the proper size piping for combustion air intake and
venting, refer to Table 4 or Table 5. The size will be deter­mined by a combination of furnace model, total length of run,
and the number of elbows required. The following rules must
also be observed.Long radius elbows are required for all
units.

1. Long radius elbows are required for all units.

2. Elbows are assumed to be 90 degrees. Two 45 degree
elbows count as one 90 degree elbow.

3. Elbow count refers to combustion air piping and vent pip­ing separately. For example, if the table allows for 5
elbows, this will allow a maximum of 5 elbows in the
combustion air piping and a maximum of 5 elbows in the
vent piping.

4. Three vent terminal elbows (two for vent pipe and one for
air intake pipe) are already accounted for and should not
be counted in the allowable total indicated in the table
(see vent termination section). These parts are shown
shaded.

For downflow/horizontal models only two additional
elbows are also accounted for and also should not be
counted. These parts are shown shaded.

5. Combustion air and vent piping must be of the same
diameter.

6. All combustion air/vent pipe and fittings must conform to
American National Standards Institute (ANSI) standards
and American Society for Testing and Materials (ASTM)
standards D1785 (Schedule 40 PVC), D2665 (PVC­DWV), F891 (PVC-DWV Cellular Core). D2241 (SDR-21
and SDR-26 PVC), D2261 (ABS-DWV), or F628 (Sched­ule 40 ABS. Pipe cement and primer must conform to
ASTM Standards D2564 (PVC) or D2235 (ABS).

7. The use of flexible connectors or no hub connectors in
the vent system is not allowed. This type connection is
allowed in the combustion air pipe near the furnace for
air conditioning coil accessibility.

TABLE 4: INTAKE/VENT PIPING - 2 PIPE SYSTEM

Models P*UR/

FG9-UP/G9T-UP

40 / 37 / 800 / A
60 / 55 / 1000 / B
80 / 75 / 1200 / C
80 / 75 / 1600 / C

100 / 95 / 1400 / C
100 / 95 / 2000 / C

40 / 37 / 800 / A
60 / 55 / 1000 / B
80 / 75 / 1200 / C
80 / 75 / 1600 / C

100 / 95 / 1400 / C
100 / 95 / 2000 / C

120 / 112 / 2000 / D

140 / 130 / 2000 / D

1.

Elbow count does not include the elbows required for
the termination. See Step 4 under Combustion Air/Vent
Pipe Sizing

Pipe
Size

3" Only 6 5 4 N/A

Max. Elbows vs. One Way Vent

Length (Ft.)

5 - 40 45 50 75

2”654N/A

3”8765

1

TABLE 5: INT AKE/VENT PIPING 2-PIPE SYSTEM

Models P*DH/

FG9-DH/G9T-DH

40 /37 / 800 / A
60 /55 / 1200 / B
80 /75 / 1200 / B
80 /75 / 1600 / C

100 /95 / 2000 / C

40 /37 / 800 / A
60 /55 / 1200 / B
80 /75 / 1200 / B
80 /75 / 1600 / C

100 /95 / 2000 / C

120 /112 / 2000 / D 3" Only 6 5 4 N/A

1.

Elbow count does not include (2) 90 ° elbows required
to pipe intake into burner box or those required for the
termination. See Step 4 under Combustion Air/Vent
Pipe Sizing

Pipe Size

2” 6 5 4 N/A

3” 8 7 6 5

Max. Elbows vs. One Way

Vent Length (Ft.)

5-30 35 40 60

1

16 Unitary Products Group

VENT TERMINATION (2-PIPE)

Side wall horizontal vent terminals and roof mounted vertical
terminals may be field fabricated. Standard PVC/SRD fittin

gs
may be used. Terminal configuration must comply as detailed
in this section.

035-14370-000 650.75-N4U

g

g

g

g

VENT

OVERHANG

COMBUSTION AIR

12" SEPARATION BETWEEN
BOTTOM OF COMBUSTION AIR
AND BOTTOM OF VENT

MAINTAIN 12" CLEARANCE ABOVE
HIGHEST ANTICIPATED SNOW LEVEL
OR GRADE, WHICHEVER IS GREATER

12" MINIMUM

90°

VENT

OVERHANG

COMBUSTION AIR
(ELBOW PARALLEL TO WALL)

12" SEPARATION BETWEEN
BOTTOM OF COMBUSTION AIR
AND BOTTOM OF VENT

MAINTAIN 12" CLEARANCE ABOVE
HIGHEST ANTICIPATED SNOW LEVEL
OR GRADE, WHICHEVER IS GREATER

12" MINIMUM

90°

NOTE

Combustion air and vent pipes must terminate

:

together in the same atmospheric zone, either through a roof
or sidewall.

NOTE

Accessory concentric intake/vent terminations,

:

models 1CT0302 and 1CT0303 are available and
approved for use with these furnaces. Refer to Form

650.75-N2.4V for installation details.

When selecting the location for combustion air/vent termina­tion the following should be considered:

1. Comply with all clearance requirements as listed below.

2. Termination should be positioned where vent vapors will
not dama

e plants or shrubs or air conditioning equip-

ment.

3. Termination should be located where it will not be
affected by wind
allow recirculation of flue

usts, light snow, airborne leaves or

ases.

4. Termination should be located where it will not be dam-

ed or exposed to flying stones, balls, etc.

a

5. Termination should be positioned where vent vapors are
not objectionable.

17 to Figure 22. Sidewall termination may require sealing or
shielding of building surfaces with a corrosive resistance
material to protect against combustion product corrosion.

FIGURE 17 : HORIZONTAL TERMINATION CON-

FIGURATION WITH 12” MINIMUM
CLEARANCE

VENT CLEARANCES (2-PIPE) U.S. ONLY

Dryer Vent. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3 ft.

Plumbing Vent Stack. . . . . . . . . . . . . . . . . . . . . . . . . . . 3 ft.

Gas Appliance Vent Terminal . . . . . . . . . . . . . . . . . . . 3 ft.*

From any mechanical fresh air intake. . . . . . . . . . . . . . 1 ft.

From any door, window or non-mechanical fresh air or

combustion air intake . . . . . . . . . . . . . . . . . . . . . . . . . . 1 ft.

Above grade and anticipated snow depth. . . . . . . . . . . 1 ft.

Above grade when adjacent to public walkway. . . . . . . 7 ft.

From electric, gas meters, regulators and relief equipment -

min. horizontal distance . . . . . . . . . . . . . . . . . . . . . . . . 4 ft.

* Does not apply to multiple installations of this furnace

model. Refer to “VENTING MULTIPLE
UNITS" Section on page 17 .

FIGURE 18 : HORIZONTAL TERMINATION RAISED

CONFIGURATION FOR ADDITIONAL
CLEARANCE

VENTING MULTIPLE UNITS

In Canada, refer to CAN/CGA-B149.1 or.2 Installation
Code (latest edition - Venting Systems and Air Supply)

NOTE

Consideration must be given for degradation of build-

:

Each unit must have its own intake/vent piping and termina­tion. Do not use common pipes for combustion air or venting.
The vent terminals must be located as shown in Figure 21
and FIGURE 22.

ing materials by flue gases.

NOTE

Shaded components of the combustion air/vent sys-

:

tem shown in the following figures are considered to be part
of the vent terminal. These components should not be
counted when determining piping limitations. Refer to Figure

Unitary Products Group 17

650.75-N4U 035-14370-000

R

OVERHANG

12" MINIMUM

VENT

90°

COMBUSTION AIR

18" MAXIMUM

12" SEPARATION BETWEEN
BOTTOM OF COMBUSTION AIR
AND BOTTOM OF VENT

MAINTAIN 12" CLEARANCE ABOVE
HIGHEST ANTICIPATED SNOW LEVEL
OR GRADE, WHICHEVER IS GREATE

FIGURE 19 : HORIZONTAL TERMINATION CON-

FIGURATION WITH HORIZONTAL
EXTENSION

12" VERTICAL SEPARATION
BETWEEN COMBUSTION
AIR AND VENT

VENT

COMBUSTION AIR

6"

FIGURE 22 : DOUBLE ROOFTOP TERMINATION

PIPING ASSEMBLY

The final assembly procedure for the vent/combustion air pip­ing is as follows:

1. Cut piping to the proper length, beginning at the furnace.

2. Deburr the piping inside and outside.

3. Chamfer the outer edges of the piping.

4. Dry-fit the entire vent/combustion air piping assembly.

MAINTAIN 12" MINIMUM
CLEARANCE ABOVE HIGHEST
ANTICIPATED SNOW LEVEL.
MAXIMUM OF 24" ABOVE ROOF

FIGURE 20 : VERTICAL TERMINATION

VENT

COMBUSTION AIR

2"

FIGURE 21 : DOUBLE SIDEWALL TERMINATION

5. Disassemble the piping and apply cement primer and
cement per the cement manufacturer's instructions.
Primer and cement must conform to ASTM D2564 for
PVC, or ASTM D2235 for ABS piping.

Solvent cements are flammable and must be used
in well-ventilated areas only . Keep them away from
heat, sparks and open flames (including pilots). Do
not breathe vapors and avoid contact with skin and
eyes.

6. All joints must be made to provide a permanent, air-tight,
water-tight seal.

7. Support the combustion air and vent piping such that it is
angled 1/4” per linear foot so that condensate will flow
back toward the furnace. Piping should be supported
with pipe hangers to prevent sagging. Maximum spacing
between hangers is five (5) feet, except SDR-PVC pip­ing, where maximum spacing is three (3) feet.

8. Seal around the openings where the combustion air and
vent piping pass through the roof of side wall.

18 Unitary Products Group

035-14370-000 650.75-N4U

S

VENT PIPE PASSES
THRO UG H TOP PANEL

COOL
HEAT

Vent piping must be insulated with 1/2” Armaflex
insulation if it will be subjected to freezing temper­atures such as routing through unheated areas or
through an unused chimney.

PARK
PARK
LINE
XFMR
EAC
HUM

CIR
LINE
XFMR
EAC
HUM

YWRG

C

When combustion air pipe is installed above a sus­pended ceiling, the pipe must be insulated with 1/
2” Armaflex type insulation. The combustion air
pipe should also be insulated when it passes
through a warm, humid space.

Note

Vent pipe must be sloped 1/4” per foot to allow conden-

:

G AS PIPIN G
KNO CKO U TS

sate to flow back to the furnace.

METHOD TWO: ONE PIPE SYSTEM

This type installation will use combustion air from within the
space surrounding the furnace. This may be from within the
space in a non-confined location or it may be brought into the
furnace area from outdoors. It is not directly ducted into the
furnace. A single, properly sized pipe from the furnace vent
connector to the outdoors must be provided.

For upflow models combustion air is brought into the furnace
through the unit top panel opening. It is not necessary to
install a pipe into the intake collar on top of the burner box.
Refer to Figure 23 .

COMBUSTION AIR

VENT PIPE

INTO SOCKET JUST
UNDER TOP PANEL

OFF

ON

M
P

C

132

CEMENT

C O M B U S T IO N A IR

FIGURE 24 : DOWNFLOW / HORIZONTAL VENT

PIPE CONNECTION (P*DH/ FG9-DH /
G9T-DH)

For downflow/horizontal models, remove a minimum of two
gas piping knockouts for combustion air access. It is not nec­essary to install a pipe into the intake collar on bottom of the
burner box. For details, refer to Figure 24.

COMBUSTION AIR

All installations must comply with Section 5.3, Air for Com­bustion and Ventilation of the National Fuel Gas Code, ANSI
Z223.1 or Sections 7.2, 7.3 or 7.4 of CAN/CGA B149.1 or.2
Installation Code - latest editions.

An unconfined space

Btu/hr input rating for all appliances installed in that area.
Rooms communicating directly with the space containing the

appliances are considered part of the unconfined space, if
openings are not furnished with doors.

A confined space

1000 Btu/hr input rating for all appliances installed in that
area.

is not less than 50 cubic feet per 1000

is an area with less than 50 cubic feet per

FIGURE 23 : UPFLOW VENT PIPE CONNECTION

(P*UR / FG9-UP / G9T-UP)

For downflow/horizontal models combustion air is brought
into the furnace through the unit side panel openings.

Unitary Products Group 19

The following must be considered to obtain proper air for
combustion and ventilation in confined spaces.

Air Source from Inside the Building -

Two permanent
openings, one within 12 inches of the top of the confined
space and one within 12 inches of the bottom, shall each
have a free area of not less than one square inch per 1,000

650.75-N4U 035-14370-000

g

Btuh of total input rating of all appliances located in the
space. The openings shall communicate freely with interior
areas having adequate infiltration from the outside.

NOTE

At least 100 square inches free area shall be used for

:

each opening.

Air Source from Outdoors -

1. Two permanent openings, one within 12 inches of the
top of the confined space and one within 12 inches of the
bottom, shall communicate directly, or by means of
ducts, with the outdoors or to such crawl or attic spaces
that freely communicate with the outdoors.

Vertical Ducts -

a.

Each opening must have a free
area of not less than one square inch per 4,000 Btuh
of total input of all appliances located in the space.

EXAMPLE:

Total Input of All Appliances

4000

Horizontal Ducts -

b.

= Square Inches Free Area

Each openin

must have a free
area of not less than one square inch per 2,000 Btuh
of total input of all appliances located in the space.

NOTE

Ducts must have the same cross-sectional area as

:

the free area in the opening to which they are connected. The
minimum dimension of rectangular ducts shall be three
inches.

TABLE 6: ESTIMATED FREE AREA

Wood or Metal

Louvers or Grilles

2

Screens

1.

Do not use less than 1/4 in. mesh

2.

Free area or louvers an grilles varies widely; installer
should follow louver or grille manufacturer’s instruc­tions.

Wood 20-25%
Metal 60-70%

1/4 in. mesh or larger 100%

Special Combustion and Ventilation Considerations

Operation of a mechanical exhaust, such as an exhaust fan,
kitchen ventilation system, clothes dryer or fireplace may cre­ate conditions requiring special attention to avoid unsatisfac­tory operation of gas appliances.

Specially Engineered Installations

The above requirements shall be permitted to be waived
where special engineering, approved by the authority having
jurisdiction, provides an adequate supply of air for combus­tion, ventilation and dilution of flue gases.

Combustion Air Quality

The recommended source of combustion air is to use the out­door air supply. Excessive exposure to contaminated com­bustion air will result in safety and performance related
problems. However, the use of indoor air in most applications
is acceptable, except as follows:

1
1

2. One permanent opening, commencing within 12 inches
of the top of the enclosure shall be permitted where the
equipment has clearances of at least 1 inch from the
sides and back and 6 inches from the front of the appli­ance. The opening shall communicate through a vertical
or horizontal duct to the outdoors, or spaces (crawl or
attic) that freely communicate with the outdoors and shall
have a minimum free area of:

a. 1 sq. in. per 3000 Btu per hr of the total input rating

of all equipment located in the enclosure.

b. Not less than the sum of the areas of all vent con-

nectors in the confined space.

3. Louvers, Grilles and Screens
a. In calculating free area, consideration must be given

to the blocking effects of louvers, grilles and
screens.

b. If the free area of a specific louver or grille is not

known, refer to Table 6, to estimate free area.

NOTE

If mechanically operated louvers are used, a means

:

to prevent main burner ignition and operation must be pro­vided should louvers close during startup or operation.

1. If the furnace is installed in a confined space it is recom­mended that the necessary combustion air come from
the outdoors by way of attic, crawl space, air duct or
direct openin

g.

2. If indoor combustion air is used, there must be no expo­sure to the installations or substances listed in 3 below.

3. The following types of installations may require OUT­DOOR AIR for combustion, due to chemical exposure.

a. Commercial buildings
b. Buildings with indoor pools
c. Furnaces installed in laundry rooms
d. Furnaces installed in hobby or craft rooms
e. Furnaces installed near chemical storage areas

Exposure to the following substances in the combustion air
supply may also require OUTDOOR AIR for combustion.

f. Permanent wave solutions
g. Chlorinated waxes and cleaners
h. Chlorine based swimming pool chemicals
i. Water softening chemicals

20 Unitary Products Group

035-14370-000 650.75-N4U

g

g

g

g

g

j. De-icing salts or chemicals
k. Carbon tetrachloride
l. Halogen type refrigerants
m. Cleaning solvents (such as perchloroethylene)
n. Printing inks, paint removers, varnishes, etc.
o. Hydrochloric acids
p. Cements and glues
q. Antistatic fabric softeners for clothes dryers
r. Masonry acid washing chemicals

VENT PIPE SIZING (1-PIPE SYSTEM)

Refer to Table 7 to select the proper size piping for venting.
The size will be determined by a combination of furnace
model, total length of run, and the number of elbows required.
The following rules must also be observed.

NOTE

Furnace vent pipe connections are sized for 2-in. pipe.

:

Any pipe size change must be made outside the furnace cas­ing in a vertical pipe section to allow proper drainage of vent
connections.

NOTE

An offset using two 45 degree elbows may be required

:

for plenum clearance when the vent is increased to 3".

1. Long radius elbows are required for all units.

2. Elbows are assumed to be 90 de
elbows count as one 90 de

rees. Two 45 degree

ree elbow.

3. One Vent terminal elbow is already accounted for and
should not be counted in the allowable total indicated in
the table. See “VENT TERMINAL LOCATION
CLEARANCES" Section on pa

e 21 . This part is shown

shaded.

4. All vent pipe and fittin

s must conform to American
National Standards Institute (ANSI) standards and Amer­ican Society for Testin

and Materials (ASTM) standards
D1785 (Schedule 40 PVC), D2665 (PVC-DWV), F891
(PVC-DWV Cellular Core), D2241 (SDR-21 and SDR-26
PVC), D2261 (ABS-DWV), or F628 (Schedule 40 ABS.
Pipe cement and primer must conform to ASTM Stan­dards D2564 (PVC) or D2235 (ABS).

5. The use of flexible connectors or no hub connectors in
the vent system is not allowed.:

TABLE 7: VENT PIPING / 1-PIPE SYSTEM (ALL

MODELS)

Max. Elbows vs. One Way V ent

Model Pipe Size

5-40 45 50 75

All Models Except:

120 / 112 / 2000 / D

140 / 130 / 2000 / D

All Models Except:
120 / 112 / 2000 / D
140 / 130 / 2000 / D

120 / 112 / 2000 / D
140 / 130 / 2000 / D

2” 6 5 4 N/A

3” 8 7 6 5

3” Only 6 5 4 N/A

VENT TERMINATION (1-PIPE SYSTEM)

Side wall horizontal vent terminals and roof mounted vertical
terminals may be field fabricated. Standard PVC/SRD fittings
may be used. Terminal configuration must comply as detailed
in this section.

When selecting the locations for vent termination, the follow­ing should be considered:

1. Comply with all clearance requirements. (Refer to Figure
25 on page 22)

2. Termination should be positioned where vent vapors will

not damage plants or shrubs or air conditioning equip­ment.

3. Termination should be located where it will not be

affected by wind gusts, light snow, airborne leaves or
allow recirculation of flue gases.

4. Termination should be located where it will not be dam-

aged or exposed to flying stones, balls, etc.

5. Termination should be positioned where vent vapors are

not objectionable.

In Canada, refer to CAN/CGA-B149.1 or.2 Installation
Code (latest edition - Venting Systems and Air Supply)

VENT TERMINAL LOCATION CLEARANCES

The vent must be installed with the following minimum clear­ances(Refer to Figure 25 on page 22), and complying with
local codes or utility requirements or other authority having
jurisdiction.

Length (Ft.)

Unitary Products Group 21

1. 1 foot above grade and above normal snow levels.

2. Not above any walkway.

3. 4 feet below, 4 feet horizontally from, or 1 foot above any

door/window or gravity air inlet to the building, or from
gas or electric meters.

650.75-N4U 035-14370-000

R

R

SOFFIT
VENTS

6'
10' RECOMMENDED

ELECTRIC
METER

FURNACE VENT

INSIDE
CORNER

4' 4'

4'

4'

4'

4'

FRESH AIR

3'

1' PLUS
SNOW CLEARANCE

INTAKE

10'

12"

MAINTAIN 12" CLEARANCE ABOVE
HIGHEST ANTICIPATED SNOW LEVEL
OR GRADE, WHICHEVER IS GREATE

VENT ELBOW

FIGURE 25 : VENT TERMINAL CLEARANCES

(1-PIPE SYSTEM) - U.S. ONLY

4. 6 feet from any inside corner formed by two exterior
walls. 10 feet is recommended where possible.

5. At least 4 feet horizontally from any soffit or undereave
vent.

6. 10 feet from any forced air inlet to the building. Any fresh
air or make up inlet as for a dryer or furnace area is con­sidered to be a forced air inlet.

7. Avoid areas where condensate drippage may cause
problems such as above planters, patios, or adjacent to
windows where steam may cause fogging.

NOTE

Consideration must be given for degradation of build-

:

ing materials by flue gases.

NOTE

Shaded components of the vent system shown in Fig-

:

ure 25 through Figure 28 are considered to be termination.
These components should not be counted when determining
pipe diameter. Sidewall termination may require sealing or
shielding of building surfaces with a corrosive resistant mate­rial due to vent system corrosive combustion products.

FIGURE 26 : HORIZONTAL TERMINATION CON-

FIGURATION WITH 12” MINIMUM
CLEARANCE

12" MINIMUM

90°

VENT

MAINTAIN 12" CLEARANCE ABOVE
HIGHEST ANTICIPATED SNOW LEVEL
OR GRADE, WHICHEVER IS GREATE

FIGURE 27 : HORIZONTAL TERMINATION RAISED

CONFIGURATION FOR ADDITIONAL
CLEARANCE

22 Unitary Products Group

VENT

MAINTAIN 12" MINIMUM
CLEARANCE ABOVE HIGHEST
ANTICIPATED SNOW LEVEL.
MAXIMUM OF 24" ABOVE ROOF

FIGURE 28 : ROOFTOP TERMINATION

035-14370-000 650.75-N4U

g

g

g

g

g

g

g

g

g

g

gging

g

g

g

g

12" M IN IM UM BETW EEN
BO TTOM O F ELBOW AN D
ANY M ATERIAL

12"

MINIMUM

PIPING ASSEMBLY

The final assembly procedure for the vent piping is as follows:

1. Cut pipin

2. Deburr the pipin

3. Chamfer the outer ed

4. Dry-fit the entire vent pipin

5. Disassemble the pipin

to the proper length, beginning at the furnace.

inside and outside.

es of the piping.

system.

and apply cement primer and
cement per the cement manufacturer's instructions.
Primer and cement must conform to ASTM D2564 for
PVC, or ASTM D2235 for ABS pipin

.

Solvent cements are flammable and must be used
in well-ventilated areas only . Keep them away from
heat, sparks and open flames (including pilots). Do
not breathe vapors and avoid contact with skin and
eyes.

6. All joints must be made to provide a permanent, air ti
water ti

ht seal.

ht.

In Canada, refer to CAN/CGA-B149.1 or.2 Installation
Code (latest edition - Venting Systems and Air Supply)

COMBUSTION AIR INTAKE

Refer to Table 4 on page 16, for intake pipe sizing, allowable
length and elbow usage. Follow all notes, procedures and
required materials in the Two-Pipe Sealed Combustion sec­tion (Method 1) when installing the combustion air pipe within
the unit and into the ventilated attic space.

COMBUSTION AIR TERMINATION

Refer to Figure 29 for required termination method and con­figuration for the intake pipe. For attic termination, use two 90
elbows with the open end in a downward position. Be sure to
maintain 12" clearance above any insulation, flooring or other
material.

Be sure to instruct the owner not to block this
intake pipe.

7. Support the vent pipin
ear foot so that condensate will flow back towards the
furnace. Pipin
prevent sa
5 feet, except SDR-PVC pipin
in

8. Seal around the openin
throu

Vent piping must be insulated with 1/2” Armaflex
insulation if it will be subjected to freezing temper­atures such as routing through unheated areas or
through an unused chimney.

NOTE:

densate to flow back to the furnace.

METHOD THREE: TWO PIPE SYSTEM USING COM­BUSTION AIR FROM A VENTILATED ATTIC SPACE

This type installation requires two properly sized pipes. One
brings combustion air from a properly ventilated attic space
and a second pipe from the furnace vent connection (top right
of unit) exits to the outdoors.

such that it is angled 1/4” per lin-

should be supported with pipe hangers to

. Maximum spacing between hangers is

, where maximum spac-

is 3 feet.

s where the vent piping passes

h the roof or side wall.

Vent pipe must be sloped 1/4” per foot to allow con-

FIGURE 29 : ATTIC COMBUSTION AIR TERMINA-

TION

COMBUSTION AIR REQUIREMENTS

The ventilated attic space from which the combustion air is
taken must comply with the requirements shown on page 11
in this instruction or in Section 5.3, Air for Combustion and
Ventilation of the National Fuel Gas Code, ANSI Z223.1 (lat­est edition).

VENT PIPE

For vent pipe sizing, allowable length and elbow usage, see
Refer to Table 7 on page 21. Follow all notes, installation pro­cedures and required materials in the “METHOD TWO ONE
PIPE SYSTEM, on page 19” to install the vent pipe from the
unit to the outdoors.

Unitary Products Group 23

650.75-N4U 035-14370-000

VENT TERMINATION

The vent pipe termination must be installed within the allow­able locations shown in Figure 24 and Section 7.8 in the
National Fuel Gas Code, ANSI Z223.1 (current edition). Fol­low all local agency and utility requirements if more restrictive
than those shown. Vent termination must be as shown in Fig­ure 27through Figure 28.

In Canada, refer to CAN/CGA-B149.1 or .2 Installation Code (lat­est edition - Venting Systems and Air Supply)

HORIZONTAL VENT APPLICATIONS

If installing a horizontal venting system through any uncondi­tioned space such as an attic or crawl space, it is recom­mended, but not required, that a vent drain be added to the
vent pipe to prevent the accumulation of excess condensate
in the inducer motor during operational cycles. (Refer to Fig­ures 30 and 31).

FIGURE 30 : HORIZONTAL VENT DRAIN -

UPFLOW MODELS P*UR/FG9-UP/
G9T-UP

To install the vent drain, complete the following steps:

1. Place a tee of the proper diameter for the vent system
being installed (2" or 3") in the horizontal run closest to
the furnace.

FIGURE 31 : HORIZONTAL VENT DRAIN -

DOWNFLOW/HORIZONTAL MODELS
P*DH/FG9-DH/G9T-DH

2. Place a reducer bushing of proper diameter in the stem
portion of the tee. The recommended size for the
reducer is 5/8”.

3. Place a piece of 5/8” diameter or other selected size pipe
a minimum of 3" long into the reducer to serve as a nip­ple.

NOTE

Tee, reducer and nipple must be properly cemented

:

together using the appropriate method and materials speci­fied in the Combustion Air Intake/Vent Connections section of
these instructions.

4. Connect a piece of flexible drain tubing such as EPDM
rubber, Vinyl or PVC to the nipple.

5. Loop the drain tubing to provide a trap.

6. Connect the discharge end of the drain tube to the con­densate disposal system externally to the furnace.

CONDENSATE PIPING

The condensate drain connection is packed in the furnace for
field installation. It consists of a formed hose with a 1/2” NPT
male connection. A 1/2” FM x 3/4” PVC slip coupling is pro­vided.

24 Unitary Products Group

035-14370-000 650.75-N4U

This drain hose may be installed to allow left or right side con­densate drain connection. (Refer to Figure 32.) Cut the hose
to allow for proper fit for left or right exit.

LH DRAIN

RH DRAIN

FIGURE 32 : UPFLOW MODELS P*UR/FG9-UP/

G9T-UP

For horizontal left airflow (inducer and vent low) or horizontal
right airflow (inducer and vent high), install condensate drain
hoses as follows:

RIGHT AIRLOW (Inducer High) - Three hoses are required.
Hoses are supplied with furnace. Refer to Figure 34 and
Table 8 for application.

LEFT AIRFLOW (Inducer Low) - Two hoses are required.
Inducer outlet to trap is supplied. Condensate pan to trap
must be field supplied using 5/8” I.D. hose material. Refer to
Figure 34 and Table 8, for hose placement and sizing.

TABLE 8: HORIZONTAL CONDENSATE DRAIN HOSE

SIZES - MODELS P*DH / FG9-DH / G9T-DH

CABINET SIZE (IN.)

DIMEN.

A 4-1/2 4-3/4 3-1/2 5-1/4
B 7-1/2 10-1/2 14 17-1/2

C 13-1/2 16-1/2 20 23-1/2

D 3-3/8 3-1/4 3-1/4 3-1/4

RIGHT AIRFLOW (INDUCER HIGH)

14-1/2 17-1/2 21 24-1/2

LEFT AIRFLOW (INDUCER LOW)

CONDENSATE
T R A P T U B IN G

FIGURE 33 : DOWNFLOW/HORIZONTAL MODELS

P*DH/FG9-DH/G9T-DH

To install the drain hose assembly, remove the 7/8” knockout
in the side panel. Remove the conduit nut from the 1/2” male
fitting. Push the male fitting through the hole and reinstall the
nut. The use of the 3/4” PVC coupling is optional.

Conversion for Horizontal Applications

Remove the condensate trap and its mounting bracket from
the unit side panel. Remove all drain hoses.

Reinstall the trap/bracket on the side panel which will be on
the bottom when the unit is located horizontally. Use the orig­inal mounting screws.

Refer to Figure 34 for hose locations and Table8 for hose
cut lengths. All hoses are identified as shown in Figure 34.

Plug all unused condensate trap, condensate pan
and inducer drain connection points using plugs
provided.

Drain Connection:

The following steps apply to all models.
For horizontal application, also follow the procedure for relo­cating the trap assembly and installing drain hoses.

1. It is recommended that either 1/2” or 3/4” PVC or equiva-

lent pipe be field installed as drain pipe. The condensate
piping may be tied together with the air conditioning con­densate drain if the air conditioning condensate drain
line is trapped upstream of the tie-in and the combined
drains are constructed of the same material.

2. All pipe joints must be cleaned, de-burred and cemented

using PVC primer and cement.

3. The furnace contains an internal trap. Therefore, no

external trap should be used.

4. If a condensate pump is used, it must be suitable for use

with acidic water.

5. Where required, a field-supplied neutralizer can be

installed in the drain line, external to the furnace.

NOTE

The condensate drain from the furnace may be con-

:

nected in common with the drain from an air conditioning coil

Unitary Products Group 25

650.75-N4U 035-14370-000

RIGHT AIRFLO W
(INDUCER HIGH)

HOSE
ID E N T .
NUMBERS

1 - C ON DENSATE PAN TO TRAP
"A " D IM E N S IO N

2 - INDUCER BOTTOM TO TRAP
"B " D IM E N S IO N

3 - INDUCER O UTLET TO TRAP
"C " D IM E N S IO N

LEFT A IR FLOW
(INDUCER LOW )

HOSE
ID E N T .
NUMBERS

4 - INDUCER OUTLET TO TRAP
U S E A S P R O V ID E D

5 - CO ND ENSATE PAN TO TRAP
"D " D IM E N S IO N

A

1

23

D

5

C

B

4

FIGURE 34 : HORIZONTAL APPLICATION CONDENSATE DRAIN CONNECTION (MODELS P*DH / FG9-DH /

G9T-DH)

if allowed by local code. Follow the instructions with the coil
for trapping the drain.

SAFETY CONTROLS

Control Circuit Fuse:

the 24 volt transformer from overload caused by control cir­cuit wiring errors. This is an ATO 3, automotive type fuse and
is located in the unit wiring harness between the control
transformer and the furnace control.

Blower Door Safety Switch:

Electrical Interlock Switch mounted in the blower compart­ment. This switch interrupts all power at the unit when the
panel covering the blower compartment is removed.

Blower and burner must never be operated without
the blower panel in place.

A 3 amp. fuse is provided to protect

This unit is equipped with an

Electrical supply to this unit is dependent upon the panel that
covers the blower compartment being in place and properly
positioned.

Main power to the unit must still be interrupted at
the main power disconnect switch before any ser­vice or repair work is to be done to the unit. Do not
rely upon the interlock switch as a main power dis­connect.

Rollout Switch Controls:

This control is mounted on the
burner box assembly. If the temperature in the burner com­partment exceeds its set point, the igniter control and the gas
valve are de-energized. The operation of this control indi­cates a malfunction in the combustion air blower, heat
exchanger or a blocked vent pipe connection. Corrective
action is required. This is a manual reset control and must be
reset before operation can continue.

Pressure Switches:

This furnace is supplied with pressure
switches which monitor the flow through the combustion air/
vent piping system. These switches de-energize the ignition

26 Unitary Products Group

035-14370-000 650.75-N4U

g

g

g

control module and the gas valve if any of the following condi­tions are present. Refer to Figure 35 for tubing connections.

1LP

UPFLOW

1LP2LP

Auxiliary Limit Controls

Downflow/horizontal units have a single limit switch munted
on the blower assembly. This is a manual reset control and
gives high temperature protection in the event of a blower
motor failure.

START-UP AND ADJUSTMENTS

The initial start-up of the furnace requires the following addi­tional procedures:

1. When the gas supply is initially connected to the furnace,
the gas piping may be full of air. In order to purge this air,
it is recommended that the ground union be loosened
until the odor of gas is detected. When gas is detected,
immediately retighten the union and check for leaks.
Allow five minutes for any gas to dissipate before con­tinuing with the start-up procedure.

Be sure proper ventilation is available to dilute and
carry away any vented gas.

DOWNFLOW / HORIZONTAL

FIGURE 35 : PRESSURE SWITCH TUBING ROUTING

1. Blocka

2. Blocka

3. Failure of combustion air blower motor (1LP).

4. Blocka

• Upflow units (1LP)

• Downflow/Horizontal Units

Limit Control

There are high temperature limit control(s) located on the fur­nace vestibule panel near the gas valve. These are automatic
reset control and provides over temperature protection due to
reduced airflow, such as a dirty filter.

e of combustion air piping or terminal. (1LP)
e of vent piping or terminal (1LP).

e of condensate drain piping:

• Downflow (1LP)

• Horizontal Left (1LP)

• Horizontal Right (2LP)

Perform the following procedures only after the
condensate trap has been properly piped to a
drain connection using the procedure in this
instruction.

2. The condensate trap must be filled with water before put­ting the furnace into operation. The recommended pro­cedure is as follows:

a. Disconnect the condensate drain hose from the

induced draft blower discharge.
b. Elevate this hose and fill with water using a funnel.
c. Replace the condensate drain hose and clamps.

NOTE

If this procedure is not followed, the unit may not prop-

:

erly drain on initial start up.

3. All electrical connections made in the field and in the fac­tory should be checked for proper tightness.

IGNITION SYSTEM SEQUENCE

1. Turn the gas supply ON at external valve and main gas
valve.

2. Set the thermostat above room temperature to call for
heat.

Unitary Products Group 27

650.75-N4U 035-14370-000

3. System start-up will occur as follows:
a. The induced draft blower motor will start and oper-

ate on low speed. Shortly after venter start-up, the
hot surface igniter will glow for about 17 seconds.

Wrench
Boss

Wiring
Terminals

Outlet

b. The ignition module will energize (open) the main

gas valve on low fire for seven seconds.

c. After flame is established, the supply air blower will

start in about 30 seconds.

NOTE

Burner ignition may not be satisfactory on first start-up

:

due to residual air in line.

4. With furnace in operation, paint the pipe joints and valve
gasket lines with a rich soap and water solution, Bubbles
indicate a gas leak. Take appropriate steps to stop the
leak. If the leak persists, replace the component.

DO NOT omit this test! Never use a flame to check
for gas leaks.

GAS VALVE OPERATION

The manual valve knob is a two-position (ON-OFF) type. To
turn the valve ON, rotate knob clockwise or counterclockwise
to line up the word ON on the knob with the indicator on the
cover casting (Refer to Figure 36).

CHECKING GAS INPUT (NATURAL GAS)

NOTE

Front door of burner box must be secured when

:

checking gas input.

1. Turn off all other gas appliances connected to the gas
meter.

2. With the furnace turned on, measure the time needed for
one revolution of the hand on the smallest dial on the
meter. A typical domestic gas meter usually has a 1/2 or
1 cubic foot test dial.

3. Using the number of seconds for each revolution and the
size of the test dial increment, find the cubic feet of gas
consumed per hour, (Refer to Table 9 on page 29).

To find the BTUH input use the following formula:

Inlet

ON - OFF Switch

Main
Regulator
Adjust

Outlet
Pressure
Tap

FIGURE 36 : GAS VALVES -

(TOP ) W HITE - R ODG E R S 36E 2 4
(BOTTOM) HONEYWELL VR8205

(approved for field replacement)

lated. Higher temperatures (over 60° F) will speed up the
meter and make it read high.

Temperatures under 60° F will slow it and make it read low.
The barometric pressure above 30.0" will slow the meter and
below 30.0" speed up the meter. At some conditions the
meter may be off significantly. an error of
mon. The gas meter correction factor is calculated as follows:

(Barometric Pressure) x 520

= Meter Correction Factor

(Temperature F + 460) x 30

+

5% is not uncom-

Cu. Ft. Gas x meter correction factor x Gas BTU Content =
BTU Per Hour Input

The gas meter is affected by both the temperature and also
the barometric pressure. The meter should be correct at 60°
F, and 30.0" barometric pressure. At all other conditions it will
be inaccurate, although the correction factor is easily calcu-

28 Unitary Products Group

Example 1: 28.9" Barometric Pressure, 80° F

(28.9) x 520 = 15028

= .928 Correction Factor

(80 + 460) x 30 = 16200

Contact your gas supplier for actual BTU content of the gas.

035-14370-000 650.75-N4U

g

g

g

g

g

EXAMPLE - CHECKING GAS INPUT

It is found by measurement that it takes 26 seconds for the
hand on the 1 cubic foot dial to make a revolution with only a
120,000 Btuh furnace running. Using this information, locate
26 seconds in the first column of Table 9, “

as rate (cubic feet

per hour),” on page 29. Read across to the column headed

cubic foot

where you will see that 138 cubic feet of gas per

hour are consumed by the furnace at that rate.
With the barometer at 28.9" and a 70° F temperature, the cor-

rection factor will be.945. If the local gas heating value is 935
BTU per cubic foot the calculations will be as follows:

138 cu. ft/hrx.945 correction factor x 935 BTU/cu. ft. =
121,933 BTU/Hr.

The calculated firing rate of 121,933 BTU per hour is within

+

2% tolerance of our nominal 120,000 furnace..

the

+

If the actual input is not within

2% of the furnace rating, with
allowance being made for the permissible range of the regu­lator setting (0.3 inches W.C.), replace the orifice spuds with
spud of the proper size.

Be sure to relight any gas appliance that were
turned off at the start of this input check.

ADJUSTMENT OF MANIFOLD GAS PRESSURE

Manifold gas pressure may be measured by two different pro­cedures. It may be measured with the burner box cover in
place or it may be measured with the burner box cover
removed. Follow the appropriate section, 2a or 2b in the
instructions below.

1. Turn

2. Read the inlet

as off at main gas valve. Revove 1/8” Allen socket

head pipe plu

from the manifold end of the main gas
valve. Install the proper manometer tube adapter into
this openin

.

as pressure using either of the two meth-

ods below.

Reading the gas pressure with the burner box

a.

cover in place

- Disconnect the pressure reference
hose from the right side of the burner box. Using a
tee fitting and a short piece of hose, connect the
negative side of the manometer to the burner box
pressure reference port. Connect the positive side
of the manometer to the adapter previously installed
in the gas valve Refer to Figures 39 and 40 on
page 31.

TABLE 9 : GAS RATE (CUBIC FEET PER HOUR)

TEST DIAL

SIZE

SECONDS FOR ONE

REVOLUTION

1

10 180 360
12 150 300
14 129 257
16 113 225
18 100 200
20 90 180
22 82 164
24 75 150
26 69 138
28 64 129
30 60 120
32 56 113
34 53 106
36 50 100
38 47 95
40 45 90
42 43 86
44 41 82
46 39 78
48 37 75
50 36 72
52 35 69
54 34 67
56 32 64
58 31 62
60 30 60

Reading the gas pressure with the burner box

b.

cover removed

CUBIC FOOT

1/2

- Remove the screws securing the
burner box front cover plate. Remove the cover. It is
gasketed and may stick in place. Connect the posi­tive side of the manometer to the adapter previously
installed in the gas valve as shown in Refer to Fig­ures 39 and 40 on page 31. There will be no second
connection to the manometer as it will reference
atmospheric pressure.

NOTE:

The screw-off cap for the pressure regulator must be
removed entirely to gain access to the adjustment screw.
Loosening or tightening the cap does not adjust the flow of
gas.

OF

CUBIC FOOT

1

Unitary Products Group 29

650.75-N4U 035-14370-000

3. Refer to Figure 36 on page 28, for location of pressure
regulator adjustment cap and screw on main gas valve.

4. Turn gas and electrical supplies ON. Start furnace and
observe manifold pressure on manometer.

5. Adjust manifold pressure by adjusting gas valve regula­tor screw for the appropriate gas per the following:.

Natural Gas ..............................................................3.5” W.C.

Propane (LP) Gas ....................................................10.0” W.C.

If gas valve regulator is turned in, or clockwise, manifold
pressure is increased. If screw is turned out, or counterclock­wise, manifold pressure will decrease.

If manifold pressure is too high, an over-fire condi­tion exists which could cause heat exchanger fail­ure. If the manifold pressure is too low, sooting
and eventual clogging of the heat exchanger could
occur.

All direct-drive blowers have multi-speed motors. The blower
motor speed taps are located in the control box in the blower
compartment. Refer to Figure 37, and the unit wiring label to
change the blower speed.

You may select a heating speed and a cooling speed. They
may be the same speed or a different speed.To use the same
speed tap for heating and cooling, the heat terminal and cool
terminal must be connected using a jumper wire and con­nected to the desired motor lead. Place all unused motor
leads on Park terminals. Two Park terminals are provided. .

Do not energize more than one motor speed at a
time or damage to the motor will result.

ADJUSTMENT OF FAN-OFF CONTROL SETTINGS

This furnace is equipped with a time-on/time-off heating fan
control. The fan on is fixed at 30 seconds. The fan off is field
adjustable from 60 to 180 seconds. The fan off is factory set
to 60 seconds. Adjust the off time by repositioning the fan off
switches. (Refer to Figure 37.)

Once the correct gas pressure to the burners has
been established, turn the gas valve knob to OFF
and turn the electrical supply switch to OFF; then
remove the pressure tap at the gas valve and re­install the plug, using a compound (on the threads)
resistant to the action of LP gases. Replace the
burner box front cover or the pressure reference
hose.

Be sure that gas valve regulator cap and burner
box to gas valve pressure reference hose is recon­nected.

Turn the electrical and gas supplies back on, and with the
burners in operation, check for gas leakage around the plug
with a soap and water solution.

ADJUSTMENT OF TEMPERATURE RISE

The temperature rise, or temperature difference between the
return air and the heated air from the furnace, must be within
the range shown on the furnace rating plate. Application limi­tations are shown in Table 1 or 2. After the temperature rise
has been determined, the cfm can be calculated.

After about 20 minutes of operation, determine the furnace
temperature rise. Take readings of both the return air and the
heated air in the ducts, about six feet from the furnace where
they will not be affected by radiant heat.

Increase the blower speed to decrease the temperature rise;
decrease the blower speed to increase the rise.

FIGURE 37 : TYPICAL HEAT/COOL SPEED TAP

CONNECTIONS

The fan-off setting must be long enough to adequately cool
the furnace, but not so long that cold air is blown into the
heated space. The fan-off timing may be adjusted by setting
the option switches located (Refer to Figure 37) on the con­trol board as follows:

To Delay Fan-Off

By:

60 Sec. ON ON

90 Sec. OFF ON
120 Sec. ON OFF
180 Sec. OFF OFF

Set Switch

1 2

30 Unitary Products Group

035-14370-000 650.75-N4U

HUM

EAC

EAC

HUM

115 VOLT
ELECTRONIC
AIR CLEANER

EAC HOT

HUM HOT

BLK

BLK

WHI

WHI

115 VOLT
HUMIDIFIER

SWITCHED
CIRCUITS

NEUTRALS

W

N

For units using a Texas Instruments control, connect the
jumper at the desired off timing. Refer to Figure 37 on
page 30, 60 second off timing shown.

ACCESSORY CONNECTIONS

Do not exceed 1.0 amp loading.

The furnace control will allow power switching control of vari­ous accessories. Refer to Figure 38

Electronic Air Cleaner Connection

Two 1/4” spade terminals (EAC and EAC N) for electronic air
cleaner connections are located on the control board. The
terminals provide 120 VAC (1.0 amp maximum) durin
lating blower operation.

OUTLET

PRESSURE

TAP

BURNER BOX

PRESSURE

REFERENCE HOSE

.

g circu-

GAS

VALVE

Humidifier Connection

Two 1/4” spade terminals (HUM and HUM N) for humidifier

connections are located on the control board. The terminals

provide 120 VAC (1.0 amp maximum) during heat speed

operation of the circulating blower..

FIGURE 38 : ACCESSORY CONNECTIONS

GAS

VALVE

BURNER BOX

OUTLET

PRESSURE

TAP

PRESSURE
REFERENCE HOSE
(NOT USED)

BURNER BOX

ITH COVER

U-TUBE

MANOMETER

FIGURE 39 : UPFLOW MODELS (P*UR/ FG9-UP / G9T-UP) - READING GAS PRESSURE

WITH BURNER BOX COVER IN PLACE WITH BURNER BOX COVER REMOVED

BURN ER BO X

BURN ER BO X
PRESSUR E
REFERENCE HO SE

TEE FITTIN G

FIGURE 40 : DOWNFLOW/HORIZONTAL MODELS (P*DH/ FG9-DH / G9T-DH) - READING GAS PRESSURE

WITH BURNER BOX COVER IN PLACE WITH BURNER BOX COVER REMOVED

Unitary Products Group 31

W ITH CO VER

OUTLET
PRESSUR E
TAP

GAS

VALVE

6
5
4
3
2
1
0
1
2
3
4
5
6

6
5
4
3
2
1
0
1
2
3
4
5
6

TEE

FITTING

3.5 IN.

WATER COLUMN

GAS PRESSURE

SHOWN

3.5 IN.

W ATER COLUMN

GAS PR ESSURE

SHO W N

U-TUBE

MANOMETER

BURNER BOX
WITH COVER REMOVED

BURN ER BO X
PRESSUR E
REFERENCE HO SE
(NO T USED)

BURN ER BO X
W ITH CO VER REM OVED

OUTLET
PRESSUR E
TAP

GAS
VALVE

6
5
4
3
2
1
0
1
2
3
4
5
6

6
5
4
3
2
1
0
1
2
3
4
5
6

WATER COLUM

GAS PRESSURE

SHOWN

U-TUBE

MANOMETER

3.5 IN .
W ATER COLUMN
GAS PR ESSURE

SHO W N

U-TUBE

MANOMETER

3.5 IN.

650.75-N4U 035-14370-000

FURNACE ACCESSORIES

ELECTRICAL

2TH07700124 Single Stage Thermostat, One-Stage Heat/One-Stage Cool
2TH13700424 Deluxe 24V Thermostat - with heat only subbase (must be used w/subbase 2TB17700424)
2TB17700424 Subbase (24V) One-Stage Heat/One-Stage Cool
2ET07700224 Programmable, Electronic Thermostat, One-Stage Heat/One-Stage Cool
2TC03700124 Twinning Control

NON-ELECTRICAL

1NP0347 Propane (LP) Conversion Kit
1NP0349 Propane (LP) Conversion Kit
1PS0306
1PS0307
1PS0308
1PS0309
1PS0310
1SR0302 External Side Filter Rack (6-Pack)
1BR0314 External Bottom Filter Rack - Cabinet “A”
1BR0317 External Bottom Filter Rack - Cabinet “B”
1BR0321 External Bottom Filter Rack - Cabinet “C”
1BR0324 External Bottom Filter Rack - Cabinet “D”
1CT0302 Concentric Vent Termination - 2” V ent Pipe
1CT0303 Concentric Vent Termination - 3” V ent Pipe
1CB0314 Combustible Floor Base - Cabinet “A”
1CB0317 Combustible Floor Base - Cabinet “B”
1CB0321 Combustible Floor Base - Cabinet “C”
1CB0324 Combustible Floor Base - Cabinet “D”

High Altitude Pressure Switch (See Form 650.75-N2.1V for proper application)

32 Unitary Products Group

035-14370-000 650.75-N4U

AIRFLOW DATA - UPFLOW MODELS: P*UR/FG9-UP/G9T-UP

MODELS

Input/Output/Airflow/

cabinet

40 / 37 / 800 / A

60 / 55 / 1000 / B

80 / 75 / 1200 / B

100 / 75 / 1600 / C

100 / 95 / 1400 / C

100 / 95 / 2000 / C

120 / 112 / 2000 / D

140 / 130 / 2000 / D

Airflow expressed in standard cubic feet per minute.
Notes: 1. Return air is through side opposite motor (left side).

2. Air flows above 1800 CFM require either return from two sides or one side plus bottom.

3. Air filter installed. All filters must be high velocity, cleanable type.

4. Motor voltage at 115 V.

SPEED TAP

HI 1051 1005 977 985 835 757 665 450 — —
MED 900 887 851 810 752 693 609 403 — —
LOW — 581 577 569 542 468 — — — —

HI 1220 1200 1190 1152 1115 1065 1012 950 872 771
MED — — 920 915 900 880 842 803 740 650
LOW — — 725 729 715 700 681 653 600 525

HI 1431 1395 1355 1317 1263 1226 1165 1101 1029 937
MED 1188 1076 1065 1046 1023 994 955 906 842 752
LOW 832 823 811 805 794 766 742 672 624 561

HI 1879 1837 1794 1740 1688 1627 1559 1485 1406 1314
MED — 1379 1374 1348 1340 1313 1271 1232 1158 1978
LOW — — — 1196 1181 1141 1095 1053 1001 936

HI 1742 1672 1602 1519 1433 1348 1232 1098 934 766
MED — 1390 1360 1320 1265 1176 1082 965 810 656
LOW — — 1097 1061 1035 1000 927 830 708 574

HI 2300 2229 2168 2100 2026 1939 1855 1758 1661 1546
MED 1937 1897 1855 1808 1737 1673 1597 1511 1425 1305
LOW 1579 1564 1533 1481 1461 1415 1350 1291 1205 1093

HI 2366 2298 2226 2153 2065 1988 1890 1808 1712 1600
MED 2000 1961 1920 1874 1821 1757 1685 1606 1510 1430
LOW 1588 1578 1545 1525 1492 1455 1399 1340 1260 1163

HI 2343 2275 2204 2132 2047 1968 1871 1791 1695 1585
MED 1981 1942 1901 1856 1803 1740 1669 1591 1490 1416
LOW 1575 1562 1530 1510 1477 1440 1386 1327 1248 1152

0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 1.0

EXTERNAL STATIC PRESSURE, INCHES WC

AIRFLOW DATA - DOWNFLOW/HORIZONTAL MODELS: P*DH/FG9-DH/G9T-DH

MODELS

Input/Output/Airflow/

cabinet

40 / 37 / 800 / A

60 / 55 / 1200 / B

80 / 75 / 1200 / B

80 / 75 / 1600 / C

100 / 95 / 2000 / C

120 / 112 / 2000 / D

Airflow expressed in standard cubic feet per minute.
Notes: 1. Air filter installed. All filters must be high velocity, cleanable type.

2. Motor voltage at 115 V.

SPEED TAP

HI 1182 1164 1136 1101 1063 1018 967 904 824 724

MED 954 938 919 899 876 838 798 744 686 588

LOW 650 643 634 620 602 577 542 494 440 335

HI 1567 1552 1532 1517 1484 1441 1384 1315 1243 1166

MED 1175 1173 1169 1159 1144 1126 1089 1039 985 910

LOW 881 879 871 861 842 826 795 756 724 664

HI 1603 1579 1558 1522 1485 1433 1380 1311 1233 1139

MED 1250 1230 1210 1190 1160 1125 1083 1029 955 889

LOW 925 904 891 873 845 829 793 761 685 618

HI 2024 1960 1911 1855 1780 1698 1627 1540 1458 1387

MED 1479 1471 1465 1452 1429 1393 1359 1300 1238 1163

LOW — — 1210 1208 1198 1175 1149 1110 1052 982

HI 2272 2200 2128 2061 1984 1890 1810 1710 1627 1519

MED 1980 1933 1887 1838 1769 1701 1626 1535 1426 1328

LOW 1573 1546 1526 1498 1464 1417 1359 1290 1222 1132

HI 2281 2215 2144 2065 2002 1903 1820 1720 1618 1505

MED 1945 1902 1849 1794 1738 1675 1604 1535 1426 1343

LOW 1507 1485 1463 1433 1398 1358 1305 1249 1172 1095

0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 1.0

EXTERNAL STATIC PRESSURE, INCHES WC

Unitary Products Group 33

650.75-N4U 035-14370-000

OPERATION AND MAINTENANCE

SEQUENCE OF OPERATION

The following describes the sequence of operation of the fur­nace. Refer to the schematic wiring diagrams in the back of
this manual for component location.

CONTINUOUS BLOWER

On cooling/heating thermostats with fan switch, when the fan
switch is set in the ON position, a circuit is completed
between terminals R and G of the thermostat. The blower
motor is energized through the low heat terminal and runs on
the selected speed. This allows constant air circulation at
lower flow rate.

INTERMITTENT BLOWER - COOLING

On cooling/heating thermostats with fan switch, when the fan
switch is set in the auto position and the thermostat calls for
cooling, a circuit is completed between the R, Y and G termi­nals.

The motor is energized through the cool fan terminal and
runs on the selected speed. The fan off setting is fixed at 60
seconds for SEER enhancement.

HEATING CYCLE

When the system switch is set on HEAT and the fan is set on
AUTO, and the room thermostat calls for heat, a circuit is
completed between terminals R and W of the thermostat.
When the proper amount of combustion air is being provided,
a pressure switch activates the ignition control

If flame is not detected within the seven second sensing
period, the gas valve is de-energized. The control is
equipped with a re-try option. This provides a 60 second wait
following an unsuccessful ignition attempt (flame not
detected).

After the 60 second wait, the ignition sequence is restarted
with an additional 10 seconds of igniter warm-up time. If this
ignition attempt is unsuccessful, one more re-try will be made
before lockout.

A momentary loss of gas supply, flame blowout, or a shorted
or open condition in the flame probe circuit will be sensed
within 0.8 seconds.

The gas valve will deenergize and the control will restart the
ignition sequence immediately. Recycles will begin and the
burner will operate normally if the gas supply returns, or the
fault condition is corrected prior to the last ignition attempt.
Otherwise, the control will lockout.

The control will repeat the ignition sequence for a total of two
recycles if flame is lost within the first 10 seconds of estab­lishment.

If flame is established for more than 10 seconds after ignition,
the control will clear the ignition attempt (retry) counter. If
flame is lost after 10 seconds, it will restart the ignition
sequence. This can occur a maximum of five times.

During burner operation, a momentary loss of power of 50
milliseconds or longer will drop out the main gas valve. When
the power is restored, the gas valve will remain de-energize
and a restart of the ignition sequence will begin immediately

Hot Surface Ignition System

The ignition control provides a 17-second warm-up period.
The gas valve then opens for seven seconds.

As gas starts to flow and ignition occurs, the flame sensor
begins its sensing function. If a flame is detected within seven
seconds after ignition, normal furnace operation continues
until the thermostat circuit between R and W is opened. After
flame is present for 30 seconds, the circulating blower is
energized.

Do not attempt to light this furnace by hand (with a
match or any other means). There may be a
potential shock hazard from the components of the
hot surface ignition system. The furnace can only
be lit automatically by its hot surface ignition sys­tem.

When the thermostat circuit opens, the ignition control is de­energized. With the ignition control de-energized, the gas
flow stops and the burner flames are extinguished. The ven­ter continues to operate for 15 seconds after the gas flow
stops.

The blower motor continues to operate for the amount of time
set by the fan-off delay switches located on the control board.
The heating cycle is then complete, and the unit is ready for
the start of the next heating cycle.

34 Unitary Products Group

.

035-14370-000 650.75-N4U

FIGURE 41 : FURNACE CONTROL EVENT SCHEDULE

MAINTENANCE

Air Filters

The filters must be checked periodically for dirt accumulation.
Dirty filters greatly restrict the flow of air and may cause dam­age to the system.

Clean the filters at least every three months. On new con­struction, check the filters every week for the first four weeks.
Inspect the filters every three weeks after that, especially if
the system is running constantly .

All filters used with the furnace are the high-velocity, clean­able type. Clean these filters by washing in warm water.
Make sure to shake all the water out of the filter and have it
reasonably dry before installing it in the furnace. When
replacing filters, be sure to use the same size and type as
originally supplied.

Filter Removal - Upflow Models

The ends of the retainer are attached to the rear panel in two
metal loops. Refer to Table 42 on page 35. The ends must be
squeezed together to free them from the loops. The retainer
may then be moved to the new location and the ends inserted
in the loops on the rear panel at the new location. Loops are
provided for retainer location to accommodate filter applica­tion on the bottom or either side of the furnace.

Swing the retainer toward the center of the furnace. This will
expose the filter to allow removal. To reinstall the filter, simply
reverse this procedure.

FIGURE 42 : UPFLOW FILTER RETAINER

Filter Removal - Downflow Models

1. Turn off electrical power supply to the furnace at discon­nect switch. Remove access doors.

To remove a filter from the bottom location, push the closed
end of the filter retainer to the left until it clears the lip on the
front of the furnace base, which acts as a catch for the
retainer. When the retainer is clear of the flange, it will pivot in
the loops.

Unitary Products Group 35

2. Filters are installed in the plenum area above the blower
assembly . Filters rest against the side of the plenum wall
and are supported in the middle by a frame. Lift filter
slightly to dislodge and remove for service.

3. Remove the filter and follow the cleaning instructions
above. DO NOT remove the filter stiffener rods, if pro-

650.75-N4U 035-14370-000

vided. When reinstalling the filter(s) be sure it completely
covers the plenum opening.

To reinstall the filters, simply reverse this procedure.

Horizontal Applications

In most horizontal applications the filter is located in the
return air duct near the furnace or in a filter grille.

When replacing filters, DO NOT use a type with
excessively high pressure drop. Some high effi­ciency filters available will cause the furnace to
operate improperly and could result in a safety
hazard.

Lubrication

Blower motors in these furnaces are permanently lubricated
and do not require periodic oiling.

Blower Care

Even with good filters properly in place, blower wheels and
motors will become dust laden after long months of opera­tion. The entire blower assembly should be inspected annu­ally. If the motor and wheel are heavily coated with dust, they
can be brushed and cleaned with a vacuum cleaner.

6. To reassemble, reverse the procedure, restore power to
the furnace and verify operation.

Burner Removal/Cleaning

The main burners should be checked periodically for dirt
accumulation.

If cleaning is required, follow this procedure:

1. Turn off the electrical power to the unit.

2. Turn off the gas supply at the external manual shutoff
valve and loosen the ground union joint.

3. Remove the upper access panel and remove the burner
box cover.

4. Remove the screws that hold the burner box assembly to
the vest panel and remove the assembly.

5. Remove burners from the burner assembly.

6. Burners may be cleaned by rinsin

7. Reassemble the burners in the reverse order.

Cleaning the Heat Exchanger

1. Turn off the main manual gas valve external to the fur­nace.

2. Turn off electrical power to the furnace.

3. Remove the upper access panel and remove the burner
box cover.

g in hot water.

The procedure for removing the direct drive blower assembly
for cleaning is as follows:

1. Disconnect the electrical supply to the furnace and
remove remove the access doors.

2. On downflow/horizontal models only, remove the two
wires leading to the auxiliary limit mounted on the side
opposite the blower motor.

3. On downflow/horizontal models only, remove four top
panel screws and lift the top panel enough to disengage
and remove the flue chase assembly.

4. Remove blower assembly mounting screws and slide the
blower assembly out of the slots in the deck. If the two
shipping screws were not previously removed, also
remove and discard these two screws located on each
front corner of the blower assembly.

5. On downflow models only, note the wire/terminal location
and then remove the blower wiring from the furnace con­trol. Remove the protective boot and disconnect run
capacitor wires. Remove the screws securing the electri­cal panel to the blower housing. Pull blower assembly
out of the unit. When cleaning or servicing the blower
assembly, DO NOT remove or change the balance clips
on the blower wheel.

4. Disconnect wires from flame sensor, rollout switch and
HSI igniter. Remove igniter carefully, as it is easily bro­ken.

Label all wires prior to disconnection when servic­ing controls. Wiring errors can cause improper and
dangerous operation. Verify proper operation after
servicing.

5. Remove the screws that hold the burner box assembly to
the vestibule panel and remove the assembly . The upper
portion of the heat exchanger will now be exposed.

6. Remove the upper cover plate at the top of the furnace.
Remove the internal baffle.

7. The upper portion of the heat exchanger is now
exposed.

8. With a long flexible wire brush, clean inside each tube at
both the top and bottom. The brush must pass around
the rear heat exchanger tubes. Vacuum loose scale and
dirt from each tube.

36 Unitary Products Group

035-14370-000 650.75-N4U

g

g

g

g

g

g

g

g

g

g

g

g

g

50A50-241 IGNITION CONTROL (P/N 031-01266-000)

Normal flame sense current is approximately

2.0 microamps DC (

µ

a)

Low flame signal control lockout point is

0.15 microamps (DC (

µ

a)

9. Clean - vacuum all burners.

10. Replace all components in reverse order. Reconnect all
wirin

.

11. Restore electrical power and

12. Check furnace operation.

Cleaning the Secondary Heat Exchanger

1. Follow steps 1 thru 10 under Cleanin
Exchan

2. Remove the vent pipin
nect the drain lines from the venter and from the conden­sate drain pan. Remove the venter blower and the
condensate pan. The turbulators can then be
removed from the secondary heat exchan

3. With a stiff wire brush, brush out loose scale or soot.

4. Vacuum the secondary heat exchan

5. Finish the cleanin
12 under Cleanin

Vent/Air Intake

Should it be necessary to service the vent/air intake system,
the manufacturer recommends this service be conducted by
a qualified service agency.

The operation of this appliance requires the reassembly and
resealing of the vent/air intake system as specified on Page

11.

er.

procedure by following steps 10 thru

the Primary Heat Exchanger.

as supply to the furnace.

the Primary Heat

from the venter housing. Discon-

ently

er.

er.

TROUBLESHOOTING

The following visual checks should be made before trouble­shooting:

1. Check to see that the power to the furnace and the i
tion control module is ON.

ni-

troubleshooting section in this manual to check the system's
operation..

POWER SUPPLY POLARITY - 50A50-241 Control
Only

lowing unit operation will occur. On a call for heat, the
inducer will run, the HSI will glow and the gas valve will
energize and the burners will ignite. The burners will
immediately extinguish and the unit will recycle. This will
occur 3 times and then the unit will lockout. A “7” flash
code will be displayed. This code means the flame could
not be established. This occurs because the control can­not sense flame with the power supply polarity reversed.

If the power supply polarity is reversed, the fol-

FURNACE CONTROL DIAGNOSTICS

The furnace has built-in, self diagnostic capability. If a system
problem occurs, a fault code is shown by a blinking LED. It is
located behind a clear view port in the blower compartment
door. DO NOT remove the furnace blower compartment
panel OR turn off furnace power as either action will clear the
control's memory of the fault.

The control continuously monitors its own operation and the
operation of the system. If a failure occurs, the LED will indi­cate the failure code. If the failure is internal to the control, the
light will stay on continuously. In this case, the entire control
should be replaced as the control is not field repairable.

If the sensed failure is in the system (external to the control),
the LED will flash in the following flash-pause sequences to
indicate failure status.

Flash sequence codes 2 thru 9 are as follows. LED will turn
on for 1/4 second and off for 1/4 second. This pattern will be
repeated the number of times equal to the code. For exam­ple, six on flashes equals a number 6 fault code.

All flash code sequences are broken by a 2 second off period

2. The manual shutoff valves in the
must be open.

3. Make sure all wirin

4. Review the sequence of operation.

Start the system by setting the thermostat above the room
temperature. Observe the system's response. Then use the

connections are secure.

Unitary Products Group 37

as line to the furnace

.

CONTINUOUS FLASHING (1 sec on - 1 sec off):

cates that flame was sensed when there was not a call for
heat. With this fault code the control will also turn on both the
inducer motor and supply air blower. This fault would typically

This indi-

650.75-N4U 035-14370-000

be caused by a gas valve that leaks through or is slow clos­ing.

2 FLASH:

switch contacts are stuck in the closed position. The control
confirms these contacts are open at the beginning of each
heat cycle. This would indicate a faulty pressure switch or
mis-wiring.

3 FLASH:

contact did not close at the beginning of the heat cycle. This
could be caused by a number of problems; faulty inducer,
blocked vent pipe, high winds at vent terminal, broken pres­sure switch hose or faulty pressure switch.

4 FLASH:

its normally closed contacts. With this fault code the control
will operate the supply air blower and inducer. This condition
may be caused by: dirty filter, improperly sized duct system,
incorrect blower speed setting, incorrect firing rate or faulty
blower motor.

5 FLASH:

tacts in the rollout switch opens. The rollout control is manu­ally reset. If it has opened, check for proper combustion air,
proper inducer operation, primary heat exchanger failure or
burner problem. Be sure to reset the switch after correcting
the failure condition.

This indicates that the normally open pressure

This indicates the normally open pressure switch

This indicates the auxiliary limit switch has opened

This fault is indicated if the normally closed con-

NOTE:

The control will blink one time when initially powered.

This is normal and not an indication of any malfunction.

RESET FROM LOCKOUT:

out condition break the line voltage supply or 24 volt signal
from the thermostat for 30 seconds.

To reset the control from any lock-

Do not try to repair controls. Replace defective
controls with Source 1 Parts.

Never adjust pressure switch to allow furnace
operation.

Never jump pressure switch or rewire in an
attempt to allow furnace operation. To do so will
allow furnace to operate under potentially hazard­ous conditions.

6 FLASH:

pressure switch opened 5 times during the call for heat. This
could be caused by a number of problems; blocked vent or
combustion air intake, high winds at vent terminal, faulty
inducer, cracked pressure switch hose, or a blockage in the
condensate drainage system.

7 FLASH:

established. This no-light condition occurred 3 times during
the call for heat before locking out. This may be caused by
low gas pressure, faulty gas valve, faulty hot surface igniter
or burner problem.

8 FLASH:

during the heating cycle. This could be caused by low gas
pressure or faulty gas valve.

LED ON CONSTANTLY:

furnace control discovered during its self-check procedure.
Replace the control.

60 MINUTE AUTOMATIC RESET FROM LOCKOUT:

control includes a watchdog type circuit that will reset from a
lockout condition after 60 minutes. Operational faults 6, 7 & 8
will be reset. This provides protection to an unoccupied struc­ture if a temporary conditions exists causing a unit malfunc­tion. An example would be a low incoming gas supply
pressure condition preventing unit operation. When the gas
pressure was restored, at some point the watchdog would
restart the unit and provide heat for the house.

This indicates that after the unit was operating, the

This fault code indicates that flame could not be

This fault is indicated if the flame is lost 5 times

This indicated an internal fault in the

This

38 Unitary Products Group

035-14370-000 650.75-N4U

WIRING DIAGRAM - UPFLOW MODELS: P*UR / FG9-UP / G9T-UP

NOTE:

THE FURNACE’S CONTROL SYSTEM DEPENDS ON CORRECT POLARITY OF THE POWER SUPPLY

.

Unitary Products Group 39

WIRING DIAGRAM - DOWNFLOW/HORIZONTAL MODELS: P*DF / FG9-DH / G9T-DH

NOTE:

THE FURNACE’S CONTROL SYSTEM DEPENDS ON CORRECT POLARITY OF THE POWER SUPPLY

.

Subject to change without notice. Printed in U.S.A.
Copyright © by Unitary Products Group 1999. All rights reserved. Supersedes: 650.75-N4U (599) 650.75-N1U (899)

Unitary 5005 York Norman
Product Drive OK

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