International comfort products N9MSE0601410A, N9MSE1002120A, N9MSE1002114A, N9MSE0401712A, N9MSB0401410B Service And Technical Support Manual

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Printed in U.S.A. 440 04 4401 01 July 2012

SERVICE AND TECHNICAL

SUPPORT MANUAL

Single Stage, PSC Blower Motor

35” Tall, High Efficiency Condensing Gas Furnace

N9MSE (A Series)

Save this manual for future reference.

Safety Labeling and Signal Words

DANGER, WARNING, CAUTION, and NOTE

The signal words DANGER, WARNING, CAUTION, and NOTE are used to identify levels of

hazard seriousness. The signal word DANGER is only used on product labels to signify an immediate hazard. The signal words WARNING, CAUTION, and NOTE will be used on product labels and throughout this manual and other manual that may apply to the product.

DANGER − Immediate hazards which will result in severe personal injury or death.

WARNING − Hazards or unsafe practices which could result in severe personal injury or death.

CAUTION − Hazards or unsafe practices which may result in minor personal injury or product or property damage.

NOTE − Used to highlight suggestions which will result in enhanced installation, reliability, or operation.

WARNING

Signal Words in Manuals

The signal word CAUTION is used throughout this manual in the following manner:

CAUTION

Signal Words on Product Labeling

Signal words are used in combination with colors and/or pictures or product labels.

The signal word WARNING is used throughout this manual in the following manner:

Safety−alert symbol

When you see this symbol on the unit and in instructions or manuals, be alert to the potential for personal injury.

TABLE OF CONTENTS

START−UP, ADJUSTMENT, AND SAFETY CHECK 4...........

PRIME CONDENSATE TRAP WITH WATER 4.................

PURGE GAS LINES 4......................................

ADJUST TEMPERATURE RISE 10............................

ADJUST BLOWER OFF DELAY (HEAT MODE) 11..............

ADJUST COOLING AIRFLOW 11.............................

ADJUST THERMOSTAT HEAT ANTICIPATOR 11...............

CHECK SAFETY CONTROLS 11.............................

CHECKLIST 12.............................................

SERVICE AND MAINTENANCE PROCEDURES 13.............

RETRIEVING STORED FAULT CODES 14.....................

COMPONENT SELF−TEST 14...............................

CARE AND MAINTENANCE 15...............................

CLEANING AND/OR REPLACING AIR FILTER 15..............

BLOWER MOTOR AND WHEEL MAINTENANCE 15............

CLEANING BURNERS AND FLAME SENSOR 17...............

SERVICING HOT SURFACE IGNITER 18......................

FLUSHING COLLECTOR BOX AND DRAINAGE SYSTEM 18....

CLEANING CONDENSATE DRAIN AND TRAP 19..............

CLEANING HEAT EXCHANGERS 19..........................

WINTERIZATION 20........................................

SERVICE LABEL 21.........................................

WIRING DIAGRAM 22.......................................

TROUBLESHOOTING − FLOW CHART 23....................

SEQUENCE OF OPERATION 25.............................

PARTS REPLACEMENT INFORMATION GUIDE 26............

PRODUCT NOMENCLATURE 27.............................

MODELS

N9MSE0401410A N9MSE0601410A N9MSE0601714A N9MSE0801716A N9MSE0802120A N9MSE1002114A N9MSE1002120A N9MSE1202420A N9MSE1402420A

Use of the AHRI Certified TM Mark indicates a manufacturer’s participation in the program. For verification of certification for individual products, go to www.ahridirectory.org .

440 04 4401 01

Specifications are subject to change without notice.

SAFETY CONSIDERATIONS

Improper installation, adjustment, alteration, service, maintenance, or use can cause explosion, fire, electrical shock, or other conditions which may cause death, personal injury, or property damage. Consult a qualified installer, service agency, or your distributor or branch for information or assistance. The qualified installer or agency must use factory−authorized kits or accessories when modifying this product. Refer to the individual instructions packaged with the kits or accessories when installing.

Follow all safety codes. Wear safety glasses, protective clothing, and work gloves. Use quenching cloth for brazing operations. Have fire extinguisher available. Read these instructions thoroughly and follow all warnings or cautions included in literature and attached to the unit. Consult local building codes, the current editions of the National Fuel Gas Code (NFCG) NFPA 54/ANSI Z223.1, and the National Electrical Code (NEC) NFPA 70.

In Canada refer to the current editions of the National standards of Canada CAN/CSA−B149.1 and .2 Natural Gas and Propane Installation Codes, and Canadian Electrical Code CSA C22.1.

Recognize safety information. This is the safety−alert symbol

. When you see this symbol on the unit and in instructions or manuals, be alert to the potential for personal injury. Understand these signal words; DANGER, WARNING, and CAUTION. These words are used with the safety−alert symbol. DANGER identifies the most serious hazards which will result in severe personal injury or death. WARNING signifies hazards which could result in personal injury or death. CAUTION is used to identify unsafe practices which may result in minor personal injury or product and property damage. NOTE is used to highlight suggestions which will result in enhanced installation, reliability, or operation.

WARNING

PERSONAL INJURY, AND/OR PROPERTY DAMAGE HAZARD

Failure to carefully read and follow this warning could result in equipment malfunction, property damage, personal injury and/or death. Installation or repairs made by unqualified persons could result in equipment malfunction, property damage, personal injury and/or death. The information contained in this manual is intended for use by a qualified service technician familiar with safety procedures and equipped with proper tools and test instruments. Installation must conform with local building codes and with the Natural Fuel Gas Code (NFCG) NFPA 54/ANSI Z223.1, and National standards of Canada CAN/CSA−B149.1 and .2 Natural Gas and Propane Installation Codes.

WARNING

ELECTRICAL SHOCK HAZARD

Failure to follow this warning could cause personal injury or death.

Before performing service or maintenance operations on unit, always turn off main power switch to unit and install lockout tag. Unit may have more than one power switch.

WARNING

CARBON MONOXIDE POISONING AND FIRE HAZARD

Failure to follow safety warnings could result in personal injury, death, and/or property damage.

This furnace is not designed for use in mobile homes, trailers or recreational vehicles.

CAUTION

CUT HAZARD

Failure to follow this caution may result in damage personal injury.

Sheet metal parts may have sharp edges or burrs. Use care and wear appropriate protective clothing, safety glasses and gloves when handling parts and servicing furnaces.

SERVICE AND TECHNICAL MANUAL Gas Furnace: N9MSE

440 04 4401 01 3

Specifications subject to change without notice.

START−UP CHECK SHEET

For PSC Models N9MSE

(This sheet is optional. Keep for future reference.)

Date of Start−Up:

Dealer Name:

Address:

City, State(Province), Zip or Postal Code:

Phone:

Owner Name:

Address:

City, State(Province), Zip or Postal Code:

Model Number:

Serial Number:

Setup Checks

Check the box when task is complete.

All Electrical Connections Tight?

Have hoses been relocated for furnace U/D/H application?

Condensate Drain Connected?

Condensate Drain Trapped?

Manual Gas Shut−off Upstream of Furnace/Drip Leg

Gas Valve turned ON?

Type of Gas: Natural: Propane:

Filter Type and Size:

Check in box the Blower OFF Delay Jumper Heating Position for Fan “Time OFF” Setting:

1 and 2 2 and 3 3 and 4 5 and 6

90 120 150 180

Calculated Input (BTU) Rate: (See Checks and Adjustments

Section).

Heating Check

Measured Line Pressure During Heat:

Measured Manifold Pressure: Heat

Temperature of Supply Air: Heat

Temperature of Return Air:

Temperature Rise (Supply − Return): Heat

In Rise Range (see furnace rating plate)?

Static Pressure (Ducts) High Heat: Supply

Return

The Blower Speed Tap used for: Heat

Optional Check: CO?

CO2?

Cooling Check

Temperature of Supply Air:

Temperature of Return Air:

Temperature Difference:

Static Pressure (Ducts) Cooling: Supply

Return

The Blower Speed Tap used for: Cooling

Dealer Comments:

SERVICE AND TECHNICAL SUPPORT MANUAL Gas Furnace: N9MSE

START−UP, ADJUSTMENT, AND SAFETY CHECK

General

1. Furnace must have a 115-v power supply properly connected and grounded.

NOTE: Proper polarity must be maintained for 115-v wiring. Control status indicator light flashes rapidly and furnace does not operate if polarity is incorrect or if the furnace is not grounded.

2. Thermostat wire connections at terminals R, W, G, and Y must be made at 24-v terminal block on furnace control.

3. Natural gas service pressure must not exceed 0.5 psig (14- in. w.c., 1125 Pa), but must be no less than 0.16 psig (4.5-in. w.c., 350 Pa).

4. Blower door must be in place to complete 115-v electrical circuit and supply power to the furnace components.

CAUTION

UNIT OPERATION HAZARD

Failure to follow this caution may result in intermittent unit operation or performance satisfaction.

These furnaces are equipped with a manual reset limit switch in burner assembly. This switch opens and shuts off power to the gas valve if an overheat condition (flame rollout) occurs in the burner assembly/enclosure. Correct inadequate combustion−air supply, improper gas pressure setting, improper burner or gas orifice positioning, or improper venting condition before resetting switch. DO NOT jumper this switch.

Before operating furnace, check flame rollout manual reset switch for continuity. If necessary, press button to reset switch.

EAC (115vac) terminal is energized whenever blower operates. HUM (24vac) terminal is only energized the draft inducer is energized in heating.

Prime Condensate Trap with Water

WARNING

CARBON MONOXIDE POISONING HAZARD

Failure to follow these warnings could result in personal injury or death.

Failure to use a properly configured trap or NOT water-priming trap before operating furnace may allow positive pressure vent gases to enter the structure through drain tube. Vent gases contain carbon monoxide which is tasteless and odorless.

1. Remove upper and middle collector box drain plugs opposite of the condensate trap. (See Figure 1)

2. Connect field-supplied 5/8-in. (16 mm) ID tube with attached funnel (see Figure 1) to upper collector box drain connection.

3. Pour one quart (liter) of water into funnel/tube. Water should run through collector box, overfill condensate trap, and flow into open field drain.

4. Remove funnel; replace collector box drain plug.

5. Connect field-supplied 5/8-in. (16 mm) ID tube to middle collector box drain port.

6. Pour one quart (liter) of water into funnel/tube. Water should run through collector box, overfill condensate trap, and flow into open field drain.

7. Remove funnel and tube from collector box and replace collector box drain plug.

Figure 1 Priming Condensate Drain

Representative drawing only, some models may vary in appearance.

L11F065

Purge Gas Lines

If not previously done, purge the lines after all connections have been made and check for leaks.

FIRE OR EXPLOSION HAZARD

Failure to follow this warning could result in personal injury, death, and/or property damage.

Never purge a gas line into a combustion chamber. Never test for gas leaks with an open flame. Use a commercially available soap solution made specifically for the detection of leaks to check all connections. A fire or explosion may result causing property damage, personal injury or loss of life.

WARNING

Adjustments

FIRE HAZARD

Failure to follow this warning could result in personal injury, death and/or property damage.

DO NOT bottom out gas valve regulator adjusting screw. This can result in unregulated manifold pressure and result in excess overfire and heat exchanger failures.

FURNACE DAMAGE HAZARD

Failure to follow this caution may result in reduced furnace life.

DO NOT redrill orifices. Improper drilling (burrs, out−of−round holes, etc.) can cause excessive burner noise and misdirection of burner flames. This can result in flame impingement of heat exchangers, causing failures. (See Figure 2)

WARNING

CAUTION

4 440 04 4401 01

Specifications subject to change without notice.

SERVICE AND TECHNICAL SUPPORT MANUAL Gas Furnace: N9MSE

Figure 2 Orifice Hole

BURNER

ORIFICE

A93059

For proper operation and long term reliability the furnace input rate must be within +/−2 percent of input rate on furnace rating plate, or as adjusted for altitude.

The gas input rate on rating plate is for installation at altitudes up to 2000 ft. (610 M).

NOTICE

The NATURAL GAS manifold pressure adjustments in Table 3 compensate for BOTH altitude AND gas heating value. DO NOT apply an additional de−rate factor to the pressures shown in Table 3. The values in this Table and NOT referenced to sea level; they are AS−MEASURED AT ALTITUDE.

The heating content of natural gas at altitude may already provide for a reduction in capacity or altitude. Refer to Table 3. No adjustments to the furnace may be necessary at altitude for certain gas heating values.

Refer to the instructions provided in the factory-specified LP/Propane conversion kit for instructions for setting gas manifold pressures for LP/Propane applications.

In the USA, the input rating for altitudes above 2000 ft. (610 M) must be reduced by 2 percent for each 1000 ft. (305 M) above sea level refer to Table 1. The natural gas manifold pressures in Table 3 adjust for BOTH altitude and natural gas heating value.

In Canada, the input rating must be reduced by 5 percent for altitudes of 2000 ft. to 4500 ft. (610 to 1372 M) above sea level. The natural gas manifold pressures in Table 3 adjust for BOTH altitude and natural gas heating value.

NOTE: For Canadian altitudes of 2000 to 4500 ft. (610 to 1372 M), use USA altitudes of 2001 to 3000 ft. (611 to 914 M) in

Table 3.

To adjust manifold pressure to obtain the proper input rate, first, determine if the furnace has the correct orifice installed. At higher altitudes or different gas heat contents, it may be necessary to change the factory orifice to a different orifice. Tables have been provided in the furnace Service and Technical Manual to match the required orifice to the manifold pressure to the heat content and specific gravity of the gas. To do this:

1. Obtain average yearly gas heat value (at installed altitude) from local gas supplier.

2. Obtain average yearly gas specific gravity from local gas supplier.

3. Find installation altitude range for your installation in the manifold pressure tables in Table 3.

4. Find closest natural gas heat value and specific gravity in Table 3. Follow heat value and specific gravity lines to point of intersection to find orifice size and low-and high-heat manifold pressure settings for proper operation.

5. Check and verify burner orifice size in furnace. NEVER ASSUME ORIFICE SIZE. ALWAYS CHECK AND VERIFY.

NOTICE

If orifice hole appears damaged or it is suspected to have been redrilled, check orifice hole with a numbered drill bit of correct size. Never redrill an orifice. A burr−free and squarely aligned orifice hole is essential for proper flame characteristics.

6. Replace orifice with correct size, if required by Table 3. Use only factory−supplied orifices. See EXAMPLE 1.

EXAMPLE 1:

0 - 2000 ft. (0 - 609.6M) altitude Heating value = 1050 Btu/cu ft. Specific gravity = 0.62

Therefore: Orifice No. 44 (Furnace is shipped with No. 44 orifices. In this example, all main burner orifices are the correct size and do not need to be changed to obtain proper input rate.) Manifold pressure: 3.4-in. w.c. (847 Pa).

NOTE: To convert gas manifold Table pressures to Pascals, multiply the in.w.c. value by 249.1 Pa/in. w.c. (1 in. wc. = 249.1 Pa).

Table 1 Altitude Derate Multiplier for USA

ALTITUDE

FT. (M)

0–2000

(0−610)

2001–3000

(610−914) 3001–4000 (914−1219) 4001–5000

(1219−1524)

5001–6000

(1524−1829)

6001–7000

(1829−2134)

7001–8000

(2134−2438)

8001–9000

(2438−2743)

9001–10,000

(2743−3048)

* Derate multiplier factors are based on midpoint altitude for altitude range.

NOTE: For Canadian altitudes of 2000 to 4500 ft. (610 to 1372 M), use USA altitudes of 2001 to 3000 ft. (610 to 914 M)

Check Inlet Gas Pressure

The inlet gas pressure must be checked with the furnace operating in maximum heat. This is necessary to make sure the inlet gas pressure does not fall below the minimum pressure of

4.5 in. w.c.

1. Make sure the gas supply is turned off to the furnace and at the electric switch on the gas valve.

2. Remove the 1/8 in. NPT plug from the inlet pressure tap on the gas valve.

3. Connect a manometer to the inlet pressure tap on gas valve.

4. Turn on furnace power supply.

PERCENT

OF DERATE

0 1.00

4−6 0.95

6−8 0.93

8−10 0.91

10−12 0.89

12−14 0.87

14−16 0.85

16−18 0.83

18−20 0.81

DERATE MULTIPLIER

FACTOR*

440 04 4401 01 5

Specifications subject to change without notice.

SERVICE AND TECHNICAL SUPPORT MANUAL Gas Furnace: N9MSE

5. Turn gas supply manual shutoff valve to ON position.

6. Turn furnace gas valve switch to ON position.

7. Jumper R and W thermostat connections at the furnace control board.

8. When main burners ignite, confirm inlet gas pressure is between 4.5 in. w.c. (1125 Pa) and 13.6 in. w.c. (3388 Pa).

9. Remove jumper across thermostat connections to terminate call for heat. Wait until the blower off delay is completed.

10. Turn furnace gas valve electric switch to OFF position.

11. Turn gas supply manual shutoff valve to OFF position.

12. Turn off furnace power supply.

13. Remove manometer from the inlet pressure tap of the gas valve.

WARNING

FIRE HAZARD

Failure to follow this warning could result in personal injury, death, and/or property damage. Re−install manifold pressure tap plug in gas valve to prevent gas leak.

14. Apply pipe dope sparingly to end of inlet gas pipe plug and re−install in the gas valve.

Adjust Manifold Pressure

1. Adjust manifold pressure to obtain proper gas input rate. (See Figure 3)

a. Turn gas valve ON/OFF switch to OFF. b. Remove manifold pressure tap plug from gas valve.

c. Connect a water column manometer or similar device

to manifold pressure tap. d. Turn gas valve ON/OFF switch to ON. e. Manually close blower door switch.

f. Jumper R and W thermostat connections on control

to start furnace. (See Figure 4) g. Remove regulator adjustment cap from gas valve

pressure regulator (See Figure 3) and turn adjusting

screw (3/16 or smaller flat−tipped screwdriver)

counterclockwise (out) to decrease input rate or

clockwise (in) to increase input rate.

NOTICE

DO NOT set low−heat manifold pressure less than 2.8−in. w.c. (697 Pa) or more than 3.8−in. w.c. (947 Pa) for natural gas. If required manifold pressure is outside this range, change main burner orifices.

h. When correct input is obtained, replace cap that

conceal gas valve regulator adjustment screw. Main

burner flame should be clear blue, almost transparent

(See Figure 13)

i. Remove jumper R to W.

Figure 3

1/2” NPT Inlet

1/8” NPT Inlet Pressure Tap

Redundant Automatic Gas Valve (Single Stage)

ON/OFF Switch

Regulator Seal Cap

Regulator Adjustment Regulator Seal Cap under Cap

1/8” NPT Manifold Pressure Tap

1/2” NPT Outlet

A11153

2. Verify natural gas input rate by clocking meter.

NOTE: Contact your HVAC distributor or gas supplier for metric gas meter Tables, if required.

a. Turn off all other gas appliances and pilots served by

the meter.

b. Jumper R to W.

c. Run furnace for 3 minutes.

d. Measure time (in sec) for gas meter to complete 1

revolution and note reading. The 2 or 5 cubic feet dial provides a more accurate measurement of gas flow.

e. Refer to Table 2 for cubic ft. of gas per hr.

f. Multiply gas rate cu ft./hr by heating value (Btuh/cu

ft.) to obtain input. If clocked rate does not match required input from Step 1, increase manifold pressure to increase input or decrease manifold pressure to decrease input. Repeat steps b through e until correct input is achieved. Re−install regulator seal cap on gas valve.

g. If clocked rate does not match required input from

Step 1, increase manifold pressure to increase input or decrease manifold pressure to decrease input. Repeat steps b through e of Step 1 until correct heat input is achieved. Re--install regulator seal cap on gas valve.

Restore furnace to normal operating condition.

3. a. Turn gas valve ON/OFF switch to OFF. b. Remove water column manometer or similar device

from manifold pressure tap.

c. Replace manifold pressure tap plug to gas valve. d. Turn gas valve ON/OFF switch to ON. e. Check for gas leaks and verify furnace operation

WARNING

FIRE HAZARD

Failure to follow this warning could result in personal injury, death, and/or property damage.

Reinstall manifold pressure tap plug in gas valve to prevent gas leak.

6 440 04 4401 01

Specifications subject to change without notice.

SERVICE AND TECHNICAL SUPPORT MANUAL Gas Furnace: N9MSE

Figure 4 Example of Single Stage Furnace Control for PSC Blower Motor

J2 JUMPER

24ïV THERMOSTAT

TERMINALS

3ïAMP FUSE

LED OPERATION & DIAGNOSTIC LIGHT

115 ïVAC (L2) NEUTRAL

CONNECTIONS

COM/BLUE

NEUTRAL

BLW

HEAT

OFFïDELAY

90 150

24VAC

24VAC/RED

HUM

TWINNING AND/OR

COMPONENT TEST

TERMINAL

120 180

HUMIDIFIER TERMINAL (24ïVAC 0.5 AMP MAX)

TRANSFORMER 24ïVAC CONNECTIONS

P1 ï LOW VOLTAGE MAIN HARNESS CONNECTOR

EAC 1 AMP

BLOWER SPEED

SELECTION TERMINALS

SPARE1

SPARE2

SPARE3

SPARE2

SPARE3

115 VAC (L1) LINE VOLTAGE CONNECTION

XFMR

HUM

HUMIDIFIER TERMINAL 115 ïVAC

IND

HSI

P2ïHOT SURFACE IGNITOR (HSI) & INDUCER MOTOR (IND) CONNECTOR

L11F090

440 04 4401 01 7

Specifications subject to change without notice.

SERVICE AND TECHNICAL SUPPORT MANUAL Gas Furnace: N9MSE

Table 2 Gas Rate (CU ft./hr)

SECONDS

FOR 1 REVOLUTION

10 360 720 1800 50 72 144 360 11 327 655 1636 51 71 141 355 12 300 600 1500 52 69 138 346 13 277 555 1385 53 68 136 340 14 257 514 1286 54 67 133 333 15 240 480 1200 55 65 131 327 16 225 450 1125 56 64 129 321 17 212 424 1059 57 63 126 316 18 200 400 1000 58 62 124 310 19 189 379 947 59 61 122 305 20 180 360 900 60 60 120 300 21 171 343 857 62 58 11 6 290 22 164 327 818 64 56 11 2 281 23 157 313 783 66 54 109 273 24 150 300 750 68 53 106 265 25 144 288 720 70 51 103 257 26 138 277 692 72 50 100 250 27 133 267 667 74 48 97 243 28 129 257 643 76 47 95 237 29 124 248 621 78 46 92 231 30 120 240 600 80 45 90 225 31 116 232 581 82 44 88 220 32 113 225 563 84 43 86 214 33 109 218 545 86 42 84 209 34 106 212 529 88 41 82 205 35 103 206 514 90 40 80 200 36 100 200 500 92 39 78 196 37 97 195 486 94 38 76 192 38 95 189 474 96 38 75 188 39 92 185 462 98 37 74 184 40 90 180 450 100 36 72 180 41 88 176 439 102 35 71 178 42 86 172 429 104 35 69 173 43 84 167 419 106 34 68 170 44 82 164 409 108 33 67 167 45 80 160 400 11 0 33 65 164 46 78 157 391 11 2 32 64 161 47 76 153 383 11 6 31 62 155 48 75 150 375 120 30 60 150 49 73 147 367

1 Cu Ft. 2 Cu Ft. 5 Cu Ft. 1 Cu Ft. 2 Cu Ft. 5 Cu Ft.

SIZE OF TEST DIAL

SECONDS

FOR 1 REVOLUTION

SIZE OF TEST DIAL

8 440 04 4401 01

Specifications subject to change without notice.

SERVICE AND TECHNICAL SUPPORT MANUAL Gas Furnace: N9MSE

Table 3 Orifice Size and Manifold Pressure (in. w.c.) for Gas Input Rate − Single Stage

SINGLE-STAGE FURNACE

(TABULATED DATA BASED ON 20,000 BT UH PER BURNER, DERATED 2%/1000 FT (305M) ABOVE SEA LEVEL)

ALTITUDE

RANGE

ft (m)

092543 3.6 43 3.7 43 3.8 42 3.2

(0) 950 43 3.4 43 3.5 43 3.6 43 3.7

to 1000 44 3.5 44 3.6 44 3.8 43 3.4

2000 1050 44 3.2 44 3.3 44 3.4 44 3.5

(610) 1075 45 3.7 45 3.8 44 3.3 44 3.4

U.S.A. 800 42 3.4 42 3.5 42 3.6 42 3.7

2001 (611) 825 43 3.8 42 3.3 42 3.4 42 3.5

to 850 43 3.6 43 3.7 42 3.2 42 3.3

3000 (914) 875 43 3.4 43 3.5 43 3.7 43 3.8

Canada 925 44 3.5 44 3.6 44 3.8 43 3.4

2001 (611) 950 44 3.3 44 3.4 44 3.6 44 3.7

U.S.A. and Canada

.S.A. On U

l n

.A. O

U.S

y U.S.A. Only U.S.A. and Canada

l n

.A. O

U.S

to 975 44 3.2 44 3.3 44 3.4 44 3.5

4500 (1372) 1000 44 3.0 44 3.1 44 3.2 44 3.3

3001 800 43 3.8 42 3.2 42 3.3 42 3.4

(915) 825 43 3.6 43 3.7 43 3.8 42 3.2

4000 900 44 3.4 44 3.5 44 3.7 44 3.8

(1219) 925 44 3.2 44 3.4 44 3.5 44 3.6

4001 775 43 3.7 43 3.8 42 3.3 42 3.4

(1220) 800 43 3.5 43 3.6 43 3.7 43 3.8

5000 875 44 3.3 44 3.5 44 3.6 44 3.7

(1524) 900 44 3.2 44 3.3 44 3.4 44 3.5

5001 750 43 3.7 43 3.8 42 3.2 42 3.3

(1525) 775

6000 850 44 3.3 44 3.4 44 3.5 44 3.6

(1829) 875 44 3.1 44 3.2 44 3.3 44 3.4

6001 700 42 3.2 42 3.3 42 3.4 42 3.5

(1830) 725 43 3.6 43 3.7 43 3.8 42 3.3

7000 800 44 3.4 44 3.5 44 3.6 44 3.7

(2133) 825 44 3.2 44 3.3 44 3.4 44 3.5

HEATVALUE0.580.600.620.64

AT ALTITUDE Orifice Manifold Orifice Manifold Orifice Manifold Orifice Manifold

(Btu/cu ft) No. Pressure No. Pressure No. Pressure No. Pressure

900 43 3.8 42 3.2 42 3.3 42 3.4

975 44 3.7 44 3.8 43 3.4 43 3.6

1025 44 3.3 44 3.5 44 3.6 44 3.7

1100 46 3.7 46 3.8 45 3.8 44 3.2

900 44 3.7 44 3.8 43 3.5 43 3.6

775 42 3.3 42 3.4 42 3.5 42 3.6

850 44 3.8 43 3.5 43 3.6 43 3.7

875 44 3.6 44 3.7 43 3.4 43 3.5

950 44 3.1 44 3.2 44 3.3 44 3.4

750 42 3.3 42 3.4 42 3.5 42 3.6

825 44 3.8 43 3.4 43 3.5 43 3.6

850 44 3.5 44 3.7 44 3.8 43 3.4

925 44 3.0 44 3.1 44 3.2 44 3.3

725 42 3.2 42 3.3 42 3.4 42 3.5

43 3.4 43 3.5 43 3.7 43 3.8

800 44 3.7 44 3.8 43 3.4 43 3.5

825 44 3.5 44 3.6 44 3.7 44 3.8

900 44 2.9 44 3.0 44 3.1 44 3.2

675 42 3.4 42 3.5 42 3.6 42 3.8

750 43 3.4 43 3.5 43 3.6 43 3.7

775 44 3.6 44 3.7 43 3.4 43 3.5

850 44 3.0 44 3.1 44 3.2 44 3.3

SAGLARUTANFOYTIVARGCIFICEPSSAG.GVA

440 04 4401 01 9

A11253A

Specifications subject to change without notice.

SERVICE AND TECHNICAL SUPPORT MANUAL Gas Furnace: N9MSE

Table 3 (CONT.) Orifice Size and Manifold Pressure (in. w.c.) for Gas Input Rate − Single Stage

SINGLE-STAGE FURNACE

(TABULATED DATA BASED ON 20,000 BT UH PER BURNER, DERATED 2%/1000 FT (305M) ABOVE SEA LEVEL)

ALTITUDE

RANGE

ft (m)

7001 675 43 3.8 42 3.2 42 3.3 42 3.4

(2134) 700 43 3.5 43 3.7 43 3.8 42 3.2

8000 775 44 3.3 44 3.4 44 3.5 44 3.7

(2438) 800 44 3.1 44 3.2 44 3.3 44 3.4

8001 650 43 3.8 42 3.2 42 3.3 42 3.4

(2439) 675 43 3.5 43 3.6 43 3.7 42 3.2

9000 750 44 3.3 44 3.4 44 3.5 44 3.6

(2743) 775 44 3.0 44 3.2 44 3.3 44 3.4

9001 600 42 3.3 42 3.4 42 3.6 42 3.7

(2744) 625 43 3.7 42 3.2 42 3.3 42 3.4

10000 700 44 3.4 44 3.5 44 3.7 44 3.8

U.S.A. Only U.S.A. OnlyU.S.A. Only

(3048) 725 44 3.2 44 3.3 44 3.4 44 3.5

* Orifice numbers shown in BOLD are f actory-installed.

HEATVALUE0.580.600.620.64

AT ALTITUDE Orifice Manifold Orifice Manifold Orifice Manifold Orifice Manifold

(Btu/cu ft) No. Press ure No. Pres sure N o. Pressure No. Pressure

650 42 3.4 42 3.5 42 3.6 42 3.7

725 44 3.8 43 3.4 43 3.5 43 3.6

750 44 3.5 44 3.7 44 3.8 43 3.4

825 44 2.9 44 3.0 44 3.1 44 3.2

625 42 3.4 42 3.5 42 3.6 42 3.7

700 44 3.7 43 3.4 43 3.5 43 3.6

725 44 3.5 44 3.6 44 3.7 44 3.8

650 43 3.5 43 3.6 43 3.7 43 3.8

675 44 3.7 44 3.8 43 3.4 43 3.5

SAGLARUTANFOYTIVARGCIFICEPSSAG.GVA

A11253B

Adjust Temperature Rise

NOTE: Blower door must be installed when taking temperature

rise reading. Leaving blower door off will result in incorrect temperature measurements, due to possible changes in duct static pressure and airflow.

CAUTION

FURNACE DAMAGE HAZARD

Failure to follow this caution may result in:

S Overheating the heat exchangers or condensing

flue gases in heat exchanger areas not designed for condensate

S Shortened furnace life S Component damage

Temperature rise must be within limits specified on furnace rating plate. Recommended operation is at midpoint of rise range or slightly above.

Jumper R to W to check gas-heat temperature rise. Do not exceed temperature rise ranges specified on unit rating plate.

This furnace must operate within the temperature rise ranges specified on the furnace rating plate. Determine the air temperature as follows:

1. Place duct thermometers in return and supply ducts as close to furnace as possible. Be sure thermometers do

not “see” heat exchangers so that radiant heat does not affect thermometer readings. This is particularly important with straight−run ducts.

2. When thermometer readings stabilize, subtract return−air temperature from supply−air temperature to determine temperature rise.

If the temperature rise is outside this range, check the following:

1. Gas input rate.

2. Derate for altitude if applicable.

3. Return and supply ducts for excessive restrictions causing static pressures greater than 0.50−in. w.c. (125 Pa)

4. Adjust temperature rise by adjusting blower speed.

S Increase blower speed to reduce temperature rise. S Decrease blower speed to increase temperature rise.

WARNING

ELECTRICAL OPERATION HAZARD

Failure to follow this warning could result in personal injury or death.

Disconnect 115vac electrical power before changing speed tap.

10 440 04 4401 01

Specifications subject to change without notice.

SERVICE AND TECHNICAL SUPPORT MANUAL Gas Furnace: N9MSE

(Read following caution before changing taps.)

CAUTION

UNIT DAMAGE HAZARD

To avoid operating outside the rise range and avoid component damage:

Refer to the Air Delivery Tables to determine which airflows and settings are allowed for proper heating airflow. DO NOT use the highlighted settings for heating airflow. The highlighted settings are to be used for Cooling and Continuous Fan ONLY.

Change the blower speed taps as required to maintain proper temperature rise for Heating and Cooling as described above. To change blower motor speed selections for heating mode, remove blower motor lead from control HEAT terminal(s). (See Figure 4) Select desired blower motor speed lead(s) from the other motor leads and relocate it/them to HEAT (heating blower tap) terminal(s). Reconnect original lead on SPARE terminal.

Adjust Blower Off Delay (Heat Mode)

If desired, the main blower off time delay period may be lengthened or shortened when operating in the heating mode to provide greater comfort. For position and location of jumpers on control center. (See Figure 4 and Figure 15) The blower off-delay has four adjustable settings from 90 sec to 180 sec. (See Table 4) To change the blower off delay setting, move the jumper from one set of pins on the control to the pins used for the desired blower off delay. Factory blower off-delay setting is 120 sec.

Table 4 Blower Off Delay Jumper Positions

PINS 1 AND 2 2 AND 3 3 AND 4 4 AND 5

Time (in sec.) 90 120 150 180

Adjust Cooling Airflow

The cooling airflow can be set from the remaining blower speed taps. Refer to the Air Delivery Tables in these instructions.

CAUTION

FURNACE OVERHEATING HAZARD

Failure to follow this caution may result in reduced furnace life.

Recheck temperature rise. It must be within limits specified on the rating plate. Recommended operation is at the mid--point of rise range or slightly above.

Adjust Thermostat Heat Anticipator

Mechanical thermostat: Set thermostat heat anticipator to

match the amp. draw of the electrical components in the R-W circuit. Accurate amp. draw readings can be obtained at the wires normally connected to thermostat sub-base terminals, R and W. The thermostat anticipator should NOT be in the circuit while measuring current.

1. Remove thermostat from sub-base or from wall.

2. Connect an amp. meter across the R and W sub-base terminals or R and W wires at wall.

3. Record amp. draw across terminals when furnace is in low heat and after blower starts.

4. Set heat anticipator on thermostat per thermostat instructions and install on sub-base or wall.

5. Install blower access door.

Electronic thermostat: Set cycle rate for 3 cycles per hr.

Figure 5 Amp. Draw Check with Ammeter

THERMOSTAT SUBBASE TERMINALS WITH THERMOSTAT REMOVED (ANITICIPATOR, CLOCK, ETC., MUST BE OUT OF CIRCUIT.)

HOOK-AROUND AMMETER

R Y W G

10 TURNS

FROM UNIT 24-V CONTROL TERMINALS

EXAMPLE:

5.0 AMPS ON AMMETER 10 TURNS AROUND JAWS

0.5 AMPS FOR THERMOSTAT

ANTICIPATOR SETTING

A96316

Check Safety Controls

The flame sensor, gas valve, and pressure switch were all checked in the Start−up procedure section as part of normal operation.

1. Check Main Limit Switch This control shuts off combustion system and energizes air−circulating blower motor, if furnace overheats. By using this method to check the temperature limit control, it can be established that the limit is functioning properly and that the limit will operate if there is a restricted return−air supply or motor failure. If the limit control does not function during this test, the cause must be determined and corrected.

a. Run furnace for at least 5 minutes. b. Gradually block off return air with a piece of

cardboard or sheet metal until the limit trips.

c. Unblock return air to permit normal circulation.

d. Burners will re−light when furnace cools down.

2. Check Pressure Switch(es) This control proves operation of the draft inducer blower.

a. Turn off 115−v power to furnace. b. Disconnect inducer motor lead wires from wire

harness.

c. Turn on 115−v power to furnace.

d. Set thermostat to “call for heat” and wait 1 minute.

When low pressure switch is functioning properly, hot surface igniter should NOT glow and control diagnostic light flashes a status code 3. If hot surface igniter glows when inducer motor is disconnected, shut down furnace immediately.

e. Determine reason low pressure switch did not

function properly and correct condition.

f. Turn off 115−v power to furnace.

g. Reconnect inducer motor wires, replace door, and

turn on 115−v power.

h. Blower will run for 90 seconds before beginning the

call for heat again.

i. Furnace should ignite normally.

440 04 4401 01 11

Specifications subject to change without notice.

SERVICE AND TECHNICAL SUPPORT MANUAL Gas Furnace: N9MSE

Checklist

1. Put away tools and instruments. Clean up debris.

2. Verify that the jumper is removed from the TEST/TWIN terminal. Verify that there is nothing plugged into the PLT connector.

NOTE: If there is a jumper connector plugged into PLT, remove it and discard. (See Figure 4)

3. Verify that the Blower/Heat Off Delay jumpers are set as desired. (See Figure 4 and Figure 15)

4. Verify that the blower (lower door in upflow position) and control (“Main” or upper door in upflow position) doors are properly installed.

Table 5

UNIT SIZE

0401410 SIDE/BOTTOM

0601410 SIDE/BOTTOM

0601714 SIDE/BOTTOM

0801716 SIDE/BOTTOM

0802120

1002114 SIDE/BOTTOM

1002120

1202420

1402420

RETURN-AIR

CONNECTION

BOTTOM or

TWO-SIDES

BOTTOM or

TWO-SIDES

BOTTOM or

TWO-SIDES

BOTTOM or

TWO-SIDES

COOLING AIR DELIVERY - CFM (With Filter 1)

SPEED

TAPS

0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 1.0

Black 1100 1055 1010 960 905 850 795 740 685 620

Yellow 955 915 875 830 790 740 695 645 590 530

Blue 820 795 765 730 695 655 615 570 515 460

Red 730 710 680 655 625 595 555 515 465 400

Black 1340 1295 1245 1190 1130 1065 1005 895 815 725

Yellow 1035 1010 980 945 910 865 795 730 665 605

Blue 845 825 810 785 755 710 670 625 570 515

Red

770 750 730 710 675 640 600 560 510 455

Black 1665 1615 1550 1485 1420 1345 1270 1190 1105 985

Yellow 1340 1320 1295 1260 1215 1165 1110 1045 925 850

Orange 1050 1045 1035 1015 995 960 915 845 785 725

Blue 985 980 975 950 930 900 845 795 740 690

Red

735 720 700 675 650 620 595 560 520 480

Black 1870 1810 1740 1670 1600 1525 1440 1355 1270 1180

Yellow 1525 1495 1460 1415 1365 1305 1240 1170 1090 990

Orange 1375 1355 1330 1300 1260 1210 1155 1090 1025 940

Blue 1045 1040 1030 1010 985 960 920 875 825 745

Red

880 865 850 835 810 785 750 715 665 605

Black 2360 2250 2160 2065 1970 1880 1785 1685 1580 1455

Yellow 2100 2030 1960 1885 1805 1720 1635 1545 1440 1305

Orange 1840 1810 1765 1725 1665 1590 1515 1430 1335 1240

3,4

Blue 1705 1685 1660 1615 1570 1510 1445 1370 1280 1135

Red 1425 1410 1385 1365 1335 1290 1245 1190 1120 1050

Black 1750 1705 1660 1605 1545 1475 1405 1305 1220 1140

Blue 1550 1510 1470 1430 1380 1320 1245 1170 1095 1015

Yellow 1290 1255 1220 1180 1130 1075 1020 960 885 800

Orange 51085 1045 1010 960 915 865 805 740 665 595

Red

860 815 765 715 655 605 540 490 440 380

Black 2415 2330 2245 2155 2065 1965 1865 1760 1645 1530

Yellow 2130 2075 2010 1945 1865 1785 1695 1600 1490 1375

Orange 1830 1815 1785 1740 1685 1625 1550 1470 1370 1255

3,4

Blue 1690 1680 1655 1620 1580 1530 1465 1385 1295 1185

Red 1415 1405 1390 1370 1345 1305 1260 1200 1125 1050

Black 2440 2360 2295 2215 2105 1975 1815 1710 1575 1405

Blue 2300 2245 2185 2090 2005 1855 1745 1635 1505 1370

Yellow 1805 1780 1750 1705 1650 1595 1515 1430 1330 1230

3,4

Orange 51560 1550 1535 1505 1470 1420 1360 1285 1205 1130

Red

1390 1385 1370 1345 1320 1285 1230 1175 1105 1035

Black 2410 2325 2230 2135 2035 1930 1820 1700 1575 1445

Blue 2250 2175 2100 2020 1930 1825 1715 1600 1485 1370

Yellow 51740 1725 1700 1660 1610 1550 1470 1390 1295 1190

3,4

Orange 51500 1495 1485 1465 1435 1390 1335 1265 1185 1090

Red

1350 1345 1335 1315 1290 1255 1210 1150 1080 995

EXTERNAL STATIC PRESSURE (IN.W.C.)

5. Verify that the Status LED glows. If not, check that the power supply is energized and that the blower door is secure. See Figure 14 to interpret diagnostic codes

6. Cycle test furnace with room thermostat to be sure that it operates properly with the room thermostat. Check all modes including Heat, Cool and Fan.

7. Check operation of accessories per manufacturer’s instructions.

8. Review Home Owner’s Information with owner.

9. Attach entire literature packet to furnace.

NOTE:

1. A filter is required for each return−air inlet. Airflow performance includes a 3/4 in. (19 mm) washable filter media such as contained in factory−authorized accessory filter rack. See accessory list. To determine airflow performance without this filter, assume an additional 0.1 in. w.c. available external static pressure.

2. Blower speed taps are not always in the same order. Factory Default blower connections are as follows: Heating airflow − BLUE (also used for Continuous Fan) Cooling airflow − BLACK (enabled when the Y terminal is energized)

3. Airflows over 1800 CFM require bottom return, two−side return, or bottom and side return. A minimum filter size of 20” x 25” (508 x 635 mm) is required.

4. For upflow applications, air entering from one side into both the side of the furnace and a return air base counts as a side and bottom return.

5. Highlighted areas indicate that this airflow range is beyond the range allowed for heating. THESE AIRFLOW RANGES MAY ONLY BE USED FOR COOLING.

ADJUST THE BLOWER SPEED TAPS AS NECESSARY FOR THE PRO PER AIR TEMPERATURE RISE FOR EACH INSTALLATION.

12 440 04 4401 01

Specifications subject to change without notice.

SERVICE AND TECHNICAL SUPPORT MANUAL Gas Furnace: N9MSE

SERVICE AND MAINTENANCE PROCEDURES

WARNING

FIRE, INJURY OR DEATH HAZARD

Failure to follow this warning could result in personal injury, death and/or property damage.

The ability to properly perform maintenance on this equipment requires certain knowledge, mechanical skills, tools, and equipment. If you do not possess these, do not attempt to perform any service and maintenance on this equipment other than those procedures recommended in the Owner’s Manual.

CAUTION

ENVIRONMENTAL HAZARD

Failure to follow this caution may result in environmental pollution.

Remove and recycle all components or materials (i.e. oil, refrigerant, control board, etc.) before unit final disposal.

Figure 6 Multipoise Orientations

Electrical Controls and Wiring

ELECTRICAL SHOCK HAZARD

Failure to follow this warning could result in personal injury or death.

There may be more than one electrical supply to the furnace. Check accessories and cooling unit for additional electrical supplies that must be shut off during furnace servicing. Lock out and tag switch with a suitable warning label.

WARNING

A93041

WARNING

ELECTRICAL SHOCK, FIRE OR EXPLOSION HAZARD

Failure to follow this warning could result in personal injury or death, or property damage.

Before installing, modifying, or servicing system, main electrical disconnect switch must be in the OFF position and install a lockout tag. There may be more than one disconnect switch. Lock out and tag switch with a suitable warning label. Verify proper operation after servicing.

CAUTION

ELECTRICAL OPERATION HAZARD

Failure to follow this caution may result in improper furnace operation or failure of furnace.

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

General

These instructions are written as if the furnace is installed in an upflow application. An upflow furnace application is where the blower is located below the combustion and controls section of the furnace, and conditioned air is discharged upward. Since this furnace can be installed in any of the 4 positions shown in Figure 6, you must revise your orientation to component location accordingly.

The electrical ground and polarity for 115−V wiring must be properly maintained. Refer to Figure 7 for field wiring information and to Figure 15 for furnace wiring information.

NOTE: If the polarity is not correct, the STATUS LED on the control will flash code 10 and prevent the furnace from heating. The control system also requires an earth ground for proper operation of the control and flame−sensing electrode.

The 24−V circuit contains an automotive−type, 3−amp. fuse located on the control. (See Figure 4) Any shorts of the 24−V wiring during installation, service, or maintenance will cause this fuse to blow. If fuse replacement is required, use ONLY a 3−amp. fuse. The control LED display will be off when fuse needs to be replaced.

Troubleshooting

Refer to the service label. (See Figure 14—Service Label) The Troubleshooting Guide − Flow Chart (See Figure 16) can

be a useful tool in isolating furnace operation problems. Beginning with the word “Start,” answer each question and follow the appropriate arrow to the next item.

The Guide − Flow Chart will help to identify the problem or failed component. After replacing any component, verify correct operation sequence.

Proper instrumentation is required to service electrical controls. The control in this furnace is equipped with a Status Code LED (Light−Emitting Diode) to aid in installation, servicing, and troubleshooting. Status codes can be viewed at the indicator in blower door. The green furnace control LED is either ON heartbeat, off or a code composed of 1 or 2 digits. The first digit is the number of short flashes, the second digit is the number of long flashes.

440 04 4401 01 13

Specifications subject to change without notice.

SERVICE AND TECHNICAL SUPPORT MANUAL Gas Furnace: N9MSE

Figure 7 Heating and Cooling Application Wiring Diagram − Single−Stage Thermostat

FIELD 24-V WIRING FIELD 115-, 208/230-, 460-V WIRING FACTORY 24-V WIRING FACTORY 115-V WIRING

FIVE WIRE

THREE-WIRE

HEATING-ONLY

BLOWER DOOR SWITCH

BLK

WHT

115-V FIELD-

SUPPLIED

DISCONNECT

BLK

WHT

GND

AUXILIARY J-BOX

GND

FURNACE

NOTE 2

C O N T R O

24-V

TERMINAL

BLOCK

WCR GY

COM

NOTE 1

NOTES: Connect Y-terminal in furnace as shown for proper blower operation.

For an explanation of status codes, refer to service label located on blower door or Figure 14, and the troubleshooting guide which can be obtained from your distributor.

Retrieving Stored Fault Codes

NOTE: Fault codes cannot be retrieved if a thermostat signal

(24-V on W, Y, G, etc.) is present, or if any delays such as blower off-delays are active.

The stored status codes will NOT be erased from the control memory when 115- or 24-V power is interrupted. See the Service Label (See Figure 14) for more information. The most recent fault code may be retrieved as follows:

1. Leave 115-V power connected to furnace.

2. Observe the status LED through the blower door (the lower door on upflow applications) indicator. Refer to the Service Label (See Figure 14) to interpret the LED.

3. Remove the Main/Control door (the upper door on upflow installations).

4. BRIEFLY disconnect and reconnect ONE of the main limit wires.

5. The LED will flash the last stored fault code. Refer to the Service Label (See Figure 14) to interpret the LED.

6. A component test sequence will follow.

7. Reinstall the Main/Control door.

Component Self−Test

NOTE: The furnace control component test allows all

components to run for a short time; except the gas valve and humidifier terminal HUM 24 VAC are not energized. The EAC terminal is energized when the blower is energized. The HUM terminal is energized when the inducer is energized. This feature helps diagnose a system problem in case of a component failure. The component test feature will not operate if any thermostat signal is present at the control and not until all time delays are completed.

To begin Component Self−Test:

1. Remove blower access door.

THERMOSTAT TERMINALS

CONDENSING UNIT

TWO WIRE

Some thermostats require a "C" terminal connection as shown. If any of the original wire, as supplied, must be replaced, use same type or equivalent wire.

FIELD-SUPPLIED DISCONNECT

GND

208/230- OR 460-V THREE PHASE

208/230-V SINGLE PHASE

2. Disconnect the thermostat R lead from furnace control.

3. Manually close blower door switch.

Caution must be taken when manually closing this switch for service purposes.

WARNING

ELECTRICAL SHOCK HAZARD

Failure to follow this warning could result in personal injury, or death.

Blower access door switch opens 115−V power to control. No component operation can occur unless switch is closed. Caution must be taken when manually closing this switch for service purposes.

4. For approximately 2 sec, short (jumper) the C terminal on control to the TEST/TWIN 3/16—in. (5 mm) quick-connect terminal on control until the LED goes off. Remove jumper from terminals. (See Figure 4)

NOTE: If TEST/TWIN and C terminals are jumpered longer than 2 sec, LED will flash code 10 and ignore component test request.

Component test sequence is as follows:

a. LED will display previous status code 4 times. b. Inducer motor starts and continues to run until Step f of

component test sequence.

c. After 7 seconds the hot surface igniter is energized for

15 sec., then off. d. Blower motor operates on HEAT speed for 10 sec. e. Blower motor operates on COOL speed for 10 sec.

f. Inducer motor stops.

5. Reconnect R lead to furnace control, remove tape from blower door switch, and re-install blower door.

6. Verify furnace shut down by lowering thermostat setting below room temperature.

7. Verify that furnace restarts by raising thermostat setting above room temperature.

A11387

14 440 04 4401 01

Specifications subject to change without notice.

SERVICE AND TECHNICAL SUPPORT MANUAL Gas Furnace: N9MSE

Care and Maintenance

WARNING

FIRE OR EXPLOSION HAZARD

Failure to follow this warning could result in personal injury, death and/or property damage.

Never store flammable or combustible materials on, near, or in contact with the furnace, such as:

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 or plastic containers, gasoline, kerosene, cigarette lighter fluid, dry cleaning fluids, or other volatile fluids.

3. Paint thinners and other painting compounds, paper bags, or other paper products. Exposure to these materials could lead to corrosion of the heat exchangers.

For continuing high performance and to minimize possible furnace failure, periodic maintenance must be performed on this furnace. Consult your local dealer about proper frequency of maintenance and the availability of a maintenance contract.

WARNING

ELECTRICAL SHOCK AND FIRE HAZARD

Failure to follow this warning could result in personal injury, death, and/or property damage.

Turn off the gas and electrical supplies to the furnace and install lockout tag before performing any maintenance or service. Follow the operating instructions on the label attached to the furnace.

WARNING

CARBON MONOXIDE POISONING AND FIRE HAZARD

Failure to follow this warning could result in personal injury, death and/or property damage.

Never operate furnace without a filter or filtration device installed. Never operate a furnace with filter or filtration device access doors removed.

CAUTION

CUT HAZARD

Failure to follow this caution may result in personal injury.

Sheet metal parts may have sharp edges or burrs. Use care and wear appropriate protective clothing, safety glasses and gloves when handling parts, and servicing furnaces.

The minimum maintenance on this furnace is as follows:

1. Check and clean air filter each month or more frequently if required. Replace if torn.

2. Check blower motor and wheel for cleanliness each heating and cooling season. Clean as necessary.

3. Check electrical connections for tightness and controls for proper operation each heating season. Service as necessary.

4. Inspect burner compartment before each heating season for rust, corrosion, soot or excessive dust. If necessary, have furnace and burner serviced by a qualified service agency.

5. Inspect the vent pipe/vent system before each heating season for water leakage, sagging pipes or broken fittings. Have vent pipes/vent system serviced by a qualified service agency.

6. Inspect any accessories attached to the furnace such as a humidifier or electronic air cleaner. Perform any service or maintenance to the accessories as recommended in the accessory instructions.

Cleaning and/or Replacing Air Filter

The air filter type may vary depending on the application or orientation. The filter is external to the furnace casing. There are no provisions for an internal filter with this furnace. See “Filter Arrangement” under the “Installation” section of this manual.

NOTE: If the filter has an airflow direction arrow, the arrow must point toward the blower. To clean or replace filters, proceed as follows:

ELECTRICAL SHOCK, FIRE OR EXPLOSION HAZARD

Failure to follow this warning could result in personal injury or death, or property damage.

1. Turn off electrical supply to furnace.

2. Remove filter cabinet door.

3. Slide filter out of cabinet.

4. If equipped with permanent, washable filter, clean filter by spraying cold tap water through filter in opposite direction of airflow. Rinse filter and let dry. Oiling or coating of the filter is not recommended.

5. If equipped with factory specified disposable media filter, replace only with a factory specified media filter of the same size.

6. Slide filter into cabinet.

7. Replace filter cabinet door.

8. Turn on electrical supply to furnace.

WARNING

Blower Motor and Wheel Maintenance

To ensure long life, economy, and high efficiency, clean accumulated dirt and grease from blower wheel and motor annually.

The inducer and blower motors are pre−lubricated and require no additional lubrication. These motors can be identified by the absence of oil ports on each end of the motor.

The following items should be performed by a qualified service technician. Clean blower motor and wheel as follows:

1. Turn off electrical supply to furnace.

440 04 4401 01 15

Specifications subject to change without notice.

SERVICE AND TECHNICAL SUPPORT MANUAL Gas Furnace: N9MSE

2. Remove blower door.

3. All factory wires can be left connected, but field thermostat and accessory wiring may need to be disconnected depending on their length and routing.

4. If the vent and combustion air pipe passes through the blower compartment, it will be necessary to remove the pipes from the blower compartment.

Disconnect the vent and combustion air pipe by:

a. Loosen the clamps on the vent couplings and

combustion air pipe external to the furnace.

b. Separate the pipes from the couplings and move

them aside.

c. Loosen the clamps on the vent couplings and

combustion air pipe located on the blower shelf.

d. Separate the pipes from the blower compartment and

set aside.

e. Remove the couplings from the pipe adapters and set

aside.

f. After servicing the blower, reverse steps a through e.

g. Tighten all clamps 15 lb−in.

See Figure 8 for steps 5 through 14.

5. Remove screws securing blower assembly to blower shelf and slide blower assembly out of furnace. Detach ground wire and disconnect blower motor harness plugs from blower motor.

NOTE: Blower wheel is fragile. Use care.

6. Clean blower wheel and motor by using a vacuum with soft brush attachment. Be careful not to disturb balance weights (clips) on blower wheel vanes. Do not bend wheel or blades as balance will be affected.

7. If greasy residue is present on blower wheel, remove wheel from the blower housing and wash it with an appropriate degreaser. To remove wheel:

a. Mark blower wheel location on shaft before

disassembly to ensure proper reassembly.

b. Loosen setscrew holding blower wheel on motor

shaft.

NOTE: Mark blower mounting arms and blower housing so each arm is positioned at the same hole location during reassembly.

c. Mark blower wheel orientation and cutoff plate

location to ensure proper reassembly.

d. Remove screws securing cutoff plate and remove

cutoff plate from housing.

e. Remove bolts holding motor mounts to blower

housing and slide motor and mounts out of housing.

f. Remove blower wheel from housing.

g. Clean wheel per instructions on degreaser cleaner.

Do not get degreaser in motor.

8. Reassemble motor and blower wheel by reversing items 7b through 7f. Ensure wheel is positioned for proper rotation.

9. Torque motor mounting bolts to 40 +/− 10 lb−in. when reassembling.

10. Torque blower wheel set screw to 160 +/− 20 lb−in. when reassembling.

11. Verify that blower wheel is centered in blower housing and set screw contacts the flat portion of the motor shaft. Loosen set screw on blower wheel and reposition if necessary.

12. Spin the blower wheel by hand to verify that the wheel does not rub on the housing.

13. Reinstall blower assembly in furnace.

Figure 8 Blower Assembly

MOTOR SHAFT FLAT

SET SCREW

GROMMET

MOTOR ARM

SCREW LOCATION

BLO HSG ASSY

BRACKET

BRACKET ENGAGEMENT

DETAIL A

SEE DETAIL A

CUTOFF, BLOWER

WHEEL, BLOWER

BRACKET

POWER CHOKE

OR CAPACITOR

WHEN REQUIRED

SCREW

(GND)

MOTOR WHEEL HUB

A11584A

SCREW

A11584B

A11584C

A11584D

BLOWER HSG ASSY

MOTOR, BLOWE

A11584

16 440 04 4401 01

Specifications subject to change without notice.

SERVICE AND TECHNICAL SUPPORT MANUAL Gas Furnace: N9MSE

14. Reinstall 2 screws securing blower assembly to blower deck.

15. Reconnect blower leads to furnace control. Refer to furnace wiring diagram, and connect thermostat leads if previously disconnected.

NOTE: Be sure to attach ground wire and reconnect blower harness plugs to blower motor.

ELECTRICAL OPERATION HAZARD

Failure to follow this warning could result in personal injury or death.

Blower door switch opens 115−V power to control. No component operation can occur unless switch is closed. Caution must be taken when manually closing this switch for service purposes.

16. Downflow or horizontal furnaces with vent pipe through furnace only:

a. Install and connect short piece of vent pipe inside

furnace to existing vent.

b. Connect vent connector to vent elbow.

17. Turn on electrical supply. Manually close blower door switch. Use a piece of tape to hold switch closed. Check for proper rotation and speed changes between heating and cooling by jumpering R to G and R to Y on furnace control thermostat terminals. If outdoor temperature is below 70_F (21_C), turn off circuit breaker to outdoor unit before running furnace in the cooling cycle. Turn outdoor circuit breaker on after completing cooling cycle. (See

Figure 4)

NOTE: If R−W/W1 thermostat terminals are jumpered at the

time blower door switch is closed, blower will run for 90 sec before beginning a heating cycle.

a. Perform component self−test as shown at the bottom

of the SERVICE label, located on the blower door.

b. Verify blower is rotating in the correct direction

18. If furnace is operating properly, RELEASE BLOWER DOOR SWITCH. Remove any jumpers or reconnect any disconnected thermostat leads. Replace blower door.

19. Turn on gas supply and cycle furnace through one complete heating cycle. Verify the furnace temperature rise as shown in Adjustments Section. Adjust temperature rise as shown in Adjustments Section.

WARNING

Cleaning Burners and Flame Sensor

The following items must be performed by a qualified service technician. If the burners develop an accumulation of light dirt or dust, they may be cleaned by using the following procedure:

NOTE: Use a back-up wrench on the gas valve to prevent the valve from rotating on the manifold or damaging the mounting to the burner assembly.

WARNING

ELECTRICAL SHOCK AND FIRE HAZARD

Failure to follow this warning could result in personal injury, death, and/or property damage.

Turn off the gas and electrical supplies to the furnace and install lockout tag before performing any maintenance or service. Follow the operating instructions on the label attached to the furnace.

Refer to Figure 9.

1. Disconnect power at external disconnect, fuse or circuit breaker.

2. Turn off gas at external shut-off or gas meter.

3. Remove control door and set aside.

4. Turn electric switch on gas valve to OFF.

5. Disconnect the gas pipe from gas valve and remove pipe from the furnace casing.

6. Remove individual wires from terminals on gas valve.

7. Disconnect Hot Surface Igniter (HSI) wires from HSI.

8. Disconnect Flame Sensor wire from Flame Sensor.

9. Support the manifold and remove the 4 screws that secure the manifold assembly to the burner assembly and set aside. Note the location of the green/yellow wire and ground terminal.

10. Inspect the orifices in the manifold assembly for blockages or obstructions. Remove orifice and clean or replace orifice.

11. Remove the four screws that attach the top plate of the casing to the furnace.

12. Raise top plate up slightly and prop it up with a small piece of wood or folded cardboard.

13. Support the burner assembly and remove the screws that attach the burner assembly to the heat exchanger cell panel.

14. Remove wires from both rollout switches.

15. Slide one−piece burner out of slots on sides of burner assembly.

16. Remove the flame sensor from the burner assembly.

17. (Optional) Remove the Hot Surface Igniter (HSI) and bracket from the burner assembly.

18. Check igniter resistance. Nominal resistance is 40 to 70 ohms at room temperature and is stable over the life of the igniter.

19. Clean burner with a brush and a vacuum.

20. Clean the flame sensor with fine steel wool (0000 grade). Do not use sand paper or emery cloth.

Figure 9 Burner Assembly

BURNER SUPT. ASSY

BURNER ASSY

FLAME ROLL−OUT SWITCH

FLAME SENSOR

(

BELOW BURNER)

Representative drawing only, some models may vary in appearance.

To reinstall burner assembly:

1. Install the Hot Surface Igniter (HSI) and bracket in burner assembly.

2. Install flame sensor on burner.

3. Align the edges of the one-piece burner with the slots in the burner assembly and slide the burners forward until they are fully seated in the burner assembly.

4. Align the orifices in the manifold assembly with the support rings on the end of the burner.

L11F064

440 04 4401 01 17

Specifications subject to change without notice.

SERVICE AND TECHNICAL SUPPORT MANUAL Gas Furnace: N9MSE

5. Insert the orifices in the support rings of the burners.

NOTE: If manifold does not fit flush against the burner, do not force the manifold on the burner assembly. The burners are not fully seated forward in the burner assembly. Remove the manifold and check burner positioning in the burner assembly assembly before re-installing the manifold.

6. Attach the green/yellow wire and ground terminal to one of the manifold mounting screws.

7. Install the remaining manifold mounting screws.

8. Check the igniter alignment. See Figure 9, Figure 10 and Figure 11.

Figure 10 Igniter Position − Top View

1-1/4-in.

(31.8)

2-1/2-in.

(64.4)

A11405

Figure 11 Igniter Position − Side View

2ïin. 50 mm

3/8ïin.

9.6 mm

3/16ïin.

4.6 mm

+ 1/32

1/10ïin.

ï 1/16ïin.

+0.8

2.5 mm ï1.5 mm

L12F041

9. Attach the wires to the roll-out switches.

10. Align the burner assembly with the openings in the primary cell inlet panel and attach the burner assembly to the cell panel.

11. Connect the wire for the flame sensor.

12. Connect the wire for the Hot Surface Igniter.

NOTE: Use propane-resistant pipe dope to prevent leaks. Do not use Teflon tape.

13. Install the gas pipe to the gas valve.

! WARNING

FIRE OR EXPLOSION HAZARD

Failure to follow this warning could result in personal injury, death, and/or property damage.

14. Check for gas leaks with a commercially available soap solution made specifically for the detection of leaks.

15. Turn gas on at electric switch on gas valve and at external shut-off or meter

16. Turn power on at external disconnect, fuse or circuit breaker.

17. Run the furnace through two complete heating cycles to check for proper operation

18. Install control door when complete.

Servicing Hot Surface Igniter

The igniter does NOT require annual inspection. Check igniter resistance before removal. Refer to Figure 9, Figure 10 and Figure 11.

1. Turn off gas and electrical supplies to furnace.

2. Remove control door.

3. Disconnect igniter wire connection.

4. Check igniter resistance. Igniter resistance is affected by temperature. Only check resistance when the igniter is at room temperature.

a. Using an ohm meter, check resistance across both

igniter leads in connector.

b. Cold reading should be between 40 ohms and 70

ohms.

5. Remove igniter assembly.

a. Using a 1/4−in. driver, remove the two screws

securing the igniter mounting bracket to the burner assembly (See Figure 9)

b. Carefully withdraw the igniter and bracket assembly

through the front of the burner assembly without striking the igniter on surrounding parts.

c. Inspect igniter for signs of damage or failure.

d. If replacement is required, remove the screw that

secures the igniter on igniter bracket and remove the igniter.

6. To replace igniter and bracket assembly, reverse items 5a through 5d.

7. Reconnect igniter harness to the igniter, dressing the igniter wires to ensure there is no tension on the igniter itself. (See Figure 9)

8. Turn on gas and electrical supplies to furnace.

9. Verify igniter operation by initiating control board self−test feature or by cycling thermostat.

10. Replace control door.

Flushing Collector Box and Drainage System

ELECTRICAL SHOCK AND FIRE HAZARD

Failure to follow this warning could result in personal injury, death, and/or property damage.

Turn off the gas and electrical supplies to the furnace and install lockout tag before performing any maintenance or service. Follow the operating instructions on the label attached to the furnace.

1. Turn off gas and electrical supplies to furnace.

2. Remove control door.

3. Disconnect pressure switch tube from pressure switch port.

NOTE: Ensure the pressure switch tube disconnected from the pressure switch is higher than the collector box opening or water will flow out of tube.

4. Remove the collector box plug from the top port on the upper corner of the collector box. (See Figure 1)

WARNING

18 440 04 4401 01

Specifications subject to change without notice.

SERVICE AND TECHNICAL SUPPORT MANUAL Gas Furnace: N9MSE

5. Attach a funnel with a flexible tube to port on the collector box.

6. Flush inside of collector box with water until discharge water from condensate trap is clean and runs freely.

7. Repeat steps 4 through 6 with middle plug on upper corner of collector box.

8. Remove the pressure switch tube from the collector box.

NOTE: Do NOT blow into tube with tube connected to the pressure switch.

9. Clean pressure switch port on collect box with a small wire. Shake any water out of pressure switch tube.

10. Reconnect tube to pressure switch and pressure switch port.

11. Remove the relief tube from the port on the collector box and the trap.

12. Clean the relief port on collect box and the trap with a small wire. Shake any water out of the tube.

13. Reconnect relief tube to trap and collector box ports.

Cleaning Condensate Drain and Trap

NOTE: If the condensate trap is removed, a new gasket

between the trap and collector box is required. Verify a condensate trap gasket is included in the service kit or obtain one from your local distributor.

1. Disconnect power at external disconnect, fuse or circuit breaker.

2. Turn off gas at external shut-off or gas meter.

3. Remove control door and set aside.

4. Turn electric switch on gas valve to OFF.

5. Disconnect external drain from condensate drain elbow or drain extension pipe inside the furnace and set aside.

6. Disconnect the condensate trap relief hose from collector box port and condensate trap.

NOTE: If condensate has a heat pad attached to the trap, trace the wires for the pad back to the connection point and disconnect the wires for the heat pad.

7. Remove the screw that secures the condensate trap to the collector box, remove the trap and set aside.

8. Remove the trap gasket from the collector box if it did not come off when the trap was removed.

9. Discard the old trap gasket.

10. Rinse condensate trap in warm water until trap is clean.

11. Flush condensate drain lines with warm water. Remember to check and clean the relief port on the collector box.

12. Shake trap dry.

13. Clean port on collector box with a small wire.

To re-install Condensate Drain and Trap:

1. Remove adhesive backing from condensate trap gasket

2. Install gasket on collector box

3. Align the condensate trap with the drain opening on the collector box and secure the trap with the screw

4. Attach the relief hose to the relief port on the condensate trap and collector box.

5. Secure tubing to prevent any sags or traps in the tubing.

6. Connect condensate drain elbow or drain extension elbow to the condensate trap

7. Connect the leads of the condensate heat pad (if used)

8. Connect external drain piping to the condensate drain elbow or drain extension pipe.

9. Turn gas on at electric switch on gas valve and at external shut-off or meter

10. Turn power on at external disconnect, fuse or circuit breaker.

11. Run the furnace through two complete heating cycles to check for proper operation

12. Install control door when complete.

Checking Heat Pad Operation (If Applicable)

In applications where the ambient temperature around the furnace is 32_F (0_C) or lower, freeze protection measures are required. If this application is where heat tape has been applied, check to ensure it will operate when low temperatures are present.

NOTE: The Heat Pad, when used, should be wrapped around the condensate drain trap. There is no need to use heat tape within the furnace casing. Most heat tapes are temperature activated, and it is not practical to verify the actual heating of the tape. Check the following:

1. Check for signs of physical damage to heat tape such as nicks, cuts, abrasions, gnawing by animals, etc.

2. Check for discolored heat tape insulation. If any damage or discolored insulation is evident, replace heat tape.

3. Check that heat tape power supply circuit is on.

Cleaning Heat Exchangers

The following items must be performed by a qualified service technician.

Primary Heat Exchangers

If the heat exchangers get an accumulation of light dirt or dust on the inside, they may be cleaned by the following procedure:

NOTE: If the heat exchangers get a heavy accumulation of soot and carbon, both the primary and secondary heat exchangers should be replaced rather than trying to clean them thoroughly due to their intricate design. A build−up of soot and carbon indicates that a problem exists which needs to be corrected, such as improper adjustment of manifold pressure, insufficient or poor quality combustion air, improper vent termination, incorrect size or damaged manifold orifice(s), improper gas, or a restricted heat exchanger (primary or secondary). Action must be taken to correct the problem.

1. Turn off gas and electrical supplies to furnace.

2. Remove control door.

3. Disconnect wires or connectors to flame rollout switch, gas valve, igniter, and flame sensor.

4. Using backup wrench, disconnect gas supply pipe from furnace gas control valve.

5. Remove two screws attaching top filler plate and rotate upwards to gain access to screws attaching burner assembly to cell panel.

6. Remove screws attaching burner assembly to cell panel. (See Figure 9)

NOTE: Burner cover, manifold, gas valve, and burner assembly should be removed as one assembly.

440 04 4401 01 19

Specifications subject to change without notice.

SERVICE AND TECHNICAL SUPPORT MANUAL Gas Furnace: N9MSE

7. Clean heat exchanger openings with a vacuum and a soft brush. (See Figure 12)

Figure 12 Cleaning Heat Exchanger Cell

A11273

NOTE: After cleaning, inspect the heat exchangers to ensure they are free of all foreign objects that may restrict flow of combustion products.

8. Reverse items 6 through 1 for reassembly.

9. Refer to furnace wiring diagram and reconnect wires to flame rollout switch, gas valve, igniter, and flame sensor.

10. Turn on gas and electrical supplies to furnace.

11. Check furnace operation through two complete heat operating cycles. Look at burners. Burner flames should be clear blue, almost transparent. (See Figure 13)

Figure 13 Burner Flame

Secondary Heat Exchangers

The condensing side (inside) of the secondary heat exchanger CANNOT be serviced or inspected without complete removal of the heat exchanger assembly. Detailed information on heat exchanger removal can be obtained from your Distributor.

Winterization

CAUTION

UNIT AND PROPERTY DAMAGE HAZARD

Failure to follow this caution may result in unit component or property damage.

If the furnace is installed in an unconditioned space where the ambient temperatures may be 32_ F (0_ C) or lower, freeze protection measures must be taken to prevent property or product damage.

Since the furnace uses a condensing heat exchanger, some water will accumulate in the unit as a result of the heat transfer process. Therefore, once it has been operated, it cannot be turned off and left off for an extended period of time when temperatures will reach 32_F (0_C) or lower unless winterized. Follow these procedures to winterize your furnace:

CAUTION

UNIT COMPONENT DAMAGE HAZARD

Failure to follow this caution may result in damage to the furnace and other property damage.

Do not use ethylene glycol (automotive antifreeze coolant or equivalent). Failure of plastic components may occur.

Burner Flame

Burner

Manifold

WARNING

FIRE OR EXPLOSION HAZARD

Failure to follow this warning could result in personal injury, death, and/or property damage.

12. Check for gas leaks.

13. Replace main furnace door.

A11461

1. Obtain propylene glycol (RV/swimming pool antifreeze or equivalent).

2. Turn off gas and electrical supplies to your furnace.

3. Remove furnace control door.

4. Remove the top unused rubber plug from the port on the collector box opposite the condensate trap. (See Figure 1)

5. Connect a field supplied 3/8−in. (9.5−mm) ID tube to the open port on the collector box

6. Insert a field supplied funnel into the tube.

7. Pour 1 quart of anti−freeze solution into the funnel/tube. Antifreeze should run through the collector box, overfill condensate trap and flow to an open drain.

8. Replace the rubber plug in the port on the collector box.

9. Remove the middle unused rubber plug from the port on the collector box opposite the condensate trap. See Figure 1)

10. Repeat Steps 5 through 8.

11. If a condensate pump is used, check with pump manufacturer to verify pump is safe for use with antifreeze used. Allow pump to start and pump anti−freeze to open drain.

12. Replace main door.

13. When furnace is re−started, flush condensate pump with clear water to check for proper operation before re−starting furnace.

14. Propylene glycol need not be removed before re−starting furnace.

20 440 04 4401 01

Specifications subject to change without notice.

SERVICE AND TECHNICAL SUPPORT MANUAL Gas Furnace: N9MSE

Figure 14 Service Label

440 04 4401 01 21

338310−2 Rev F

Specifications subject to change without notice.

SERVICE AND TECHNICAL SUPPORT MANUAL Gas Furnace: N9MSE

Figure 15 Wiring Diagram

22 440 04 4401 01

338310−2 Rev F

Specifications subject to change without notice.

SERVICE AND TECHNICAL SUPPORT MANUAL Gas Furnace: N9MSE

Is LED status light ON solid, alt ernately

flashing bright

Is there 24V at 24VAC and COM?

Is there 115V at L1 and NEUTRAL?

Is the 24V fuse open?

Is door switch closed?

Replace transformer.

Replace door switch.

Is there 115V going to s witch?

Close the door switch.

Is circuit breaker closed?

Check for continuity in wire from circui t

breaker to furnace.

Close circuit breaker and go back to

START.

Is LED status light alternatel y flashing

bright

Determine status code. The status co de

is a

first

determined by the number of

short flashes and the second

after

of long

flashes.

To recall a status code: Briefly (2 – 3

seconds) connect the

TEST/TWIN terminal

to the “C” thermostat terminal with a jumper

wire

to begin status code re covery and

component test. If a previous status code is

present, the code will re peat 4 times then

go on to component test. If n o previous

code is present, a component tes t will

begin without flashing any status codes.

Component Test Sequence: Gas valve

and humidifier will not be turned on.

Inducer motor will start and remain on until

the end of the blower test, then off. T

following components are o n for 10 – 15

seconds each individuall y: hot surface

igniter,

blower speeds: FAN (if present) ,

HEAT, COOL.

Was there a previous stat us code?

Go to section below for the flash ed status

code.

Does the control respond to W, Y1, Y/Y2,

and G (24V

Run system through a heat , or cooling

cycle to check operation. Status codes

are erased after 72 hou rs.

Is 24V present at W, Y1, Y/Y2 or G

thermostat terminals on the furnace

control? Check room thermostat or

interconnecting cable. Disconnect all the thermostat wires from

the furnace control. Does the problem repeat whe n using a

jumper wire?

Replace furnace control.

The thermostat is not com patible with the

furnace control. Either install a ballast

esistor, connect the C furn ace control

thermostat terminal to the thermostat, or

replace the thermostat.

YES

START

YES

Troubleshooting Guide

Replace furnace control.

YES

Inspect secondary voltage (24V) wiring,

including thermostat leads for short

circuit. Replace fuse

Is LED status light ON solid?

YES

The control is locked out an d will auto-

reset after 1 hour. Lockout could be due

to any of the following: -

Reset power to clear lockout. Replace

control if code repeats.

Figure 16 Troubleshooting − Flow Chart

) thermostat signals?

Flame sense circuit failure. - Gas valve relay stuck open. - Software check error.

number

-dim-bright-dim like a

eartbeat, or flashing ON a nd OFF?

440 04 4401 01 23

Specifications subject to change without notice.

-dim-bright-dim like a h eartbeat? single or two digit number with the

the plus (+) sign, the number

number

SERVICE AND TECHNICAL SUPPORT MANUAL Gas Furnace: N9MSE

1 + 2 BLOWER ON AFTER POWER UP –

W/W1 opens)

during the blower on-delay period.

6 + 1 IGNITION LOCKOUT – System failed to

ignite gas and prove flame in 4

attempts. Control will auto-reset

after 3

hours. Refer to status cod e #6.

5 ABNORMAL FLAME-PROVING SIGNAL

Flame is proved while gas valve is de-

energized. Inducer will r un until fault is

cleared. Check for:

- Stuck open or leaky gas valve.

2 PRESSURE SWITCH DID NOT OPEN –

- Pressure switch stuck closed.

3 LPS or HPS PRESSURE SWITCH DID

NOT CLOSE OR REOPENED – If opens

during blower on-delay period, blower will

come on for the selected blower off-del ay.

If LPS open longer than 5 minutes,

inducer shuts off for 15 minutes before

retry. If HPS open for on e minute, then

furnace will lockout (after th e successive trials) for three hours be fore retry .

Check for:

- Proper vent sizing.

Air leak between vestibule a nd blower

compartment. - Low inlet gas pressure (if L GPS used).

- Disconnected or obstructed pressure

tubing.

- Defective or miswir

ed pressure switches

- Excessive wind.

- Plugged condensate drain

- Water in vent piping, possible sagging

pipe

- Restricted vent.

- Defective Inducer motor.

- Low inducer voltage (115 VAC)

4 LIMIT CIRCUIT FAULT – Indicates the

limit, flame rollout is open. Blower will run

for 4 min. or until open switch remakes

whichever is longer. If open lon ger than 3

min, code changes to lockout #7. If open

less than 3 min. status code #4 continues

to flash until blower shuts off. Flame

rollout switch requires ma nual reset.

Check for:

- Loose blower wheel.

- Defective switch or connections.

- Dirty filter or restricted duct system.

- Improper gas input adjustment

Improper limit switch or no limit gasket.

To determine whether the problem is in

the gas valve, igniter, or flame sensor the

system can be operated in component

test mode. To check the igniter, remove

the R thermostat connectio

n from the

control, reset power, start the comp onent

test. Does the igniter glow o range/white

by the end of the 15 seco nd warm

-up

period?

Unplug igniter harness from control and

repeat component

test. Check for 115V

between

connector P2 (HSI) a nd

NEUTRAL-L2 on the control. Was 115V

present for the 15 second period?

Check connections and retry.

If current is near typical valu e

(4.0

6.0μA DC nominal) and

burners will not stay on,

replace control.

Clean flame sensor with fine steel wool

and recheck current. Nominal current is

4.0 to 6.0

Is current near typical value?

Replace electrode.

Will main burners ignite and st ay on?

Replace furnace control.

Fixed.

YES

Replace furnace control.

Check for continuity in the

harness and igniter. Replace

defective component.

Reconnect the R thermostat lead and set

thermostat to call for heat. Connect

voltmeter across gas valve connections.

Does gas valve receive 24V?

Does gas valve open and allo w gas to

flow?

Do the main burners ignite?

Do the main burners stay on?

Allow blower to come on and

repeat test to check for

intermittent operation.

Check that gas valve electri c

switch is

turned on. Replace

valve.

Check connections. If OK,

replace control.

Check for:

Inadequate flame carryover

or rough ignition.

- Low inlet gas pressure.

- Proper firing rate.

Repeat call for heat and check flame

sensor current during trial for ignition

period. Is the DC

YES

6 IGNITION PROVING FAILURE – If flame is

not sensed during the trial for ignition

period, the control will repeat the ignition

sequence 3 more times befo re lockout #6 +

1 occurs. If flame signal is lost during the

blower on-delay period, blower will come on

for the selected blower off- delay. Check

the followi

ng before going to the next step.

- Gas valve turned off .

- Manual shut-off valve open?

Green/Yellow wire MUST be connected

to furnace sheet metal.

- Flame sensor must not be grou nded.

10 POLARITY – Check for correct line

7 LIMIT CIRCUIT LOCKOUT – Lockout

occurs if the limit, flame rollout is open

longer than 3 minutes. Control will auto-

reset after 3 hours. Refer to status code

#4.

8 GAS HEATING LOCKOUT – Contr ol will

eset. Turn off power a nd wait

Stuck closed gas valve relay on control.

- Miswire or short to gas valve wire.

YES

Figure 16 (CONT.) Troubleshooting − Flow Chart

current below 0.5μA

μA DC.

Check for:

- Obstructed pressur e tube.

24 440 04 4401 01

(115V OR 24V) – Normal operation.

voltage polarity. If units are twinned,

check for proper low-voltag e (24V)

NOT auto r

5 minutes to retry. Check for: -

Specifications subject to change without notice.

transformer phasing.

Blower runs for 90 seconds, if unit is

powered up during a call for heat (R-

W/W1 closed) or when (R-

SERVICE AND TECHNICAL SUPPORT MANUAL Gas Furnace: N9MSE

SEQUENCE OF OPERATION

NOTE: Furnace control must be grounded for proper operation

or control will lock out. Control is grounded through green/yellow wire routed to gas valve and manifold bracket screw. Using the schematic diagram in Figure 15, follow the sequence of operation through the different modes. Read and follow the wiring diagram very carefully. NOTE: If a power interruption occurs during a call for heat (W), the control will start a 90−second blower−only ON period two seconds after power is restored, if the thermostat is still calling for gas heating. The GREEN LED light will flash code 1+2 during the 90−second period, after which the LED will be flashing a heartbeat, as long as no faults are detected. After the 90−second period, the furnace will respond to the thermostat normally. The blower door must be installed for power to be conducted through the blower door interlock switch ILK to the furnace control CPU, transformer TRAN, inducer motor IDM, blower motor BLWM, hot−surface igniter HSI, and gas valve GV.

1. Heating The wall thermostat “calls for heat,” closing the R−to−W circuit. The furnace control performs a self−check, verifies the pressure switch contacts LPS and HPS are open, and starts the inducer motor IDM. a. Inducer Prepurge Period− As the inducer motor IDM

comes up to speed the low pressure switch contacts LPS close to begin a 15 second prepurge period. The high pressure switch contacts HPS are ignored until one minute after the gas valve closes.

b. Igniter Warm−Up− At the end of the prepurge period,

the Hot−Surface igniter HSI is energized for a 17−second igniter warm−up period.

c. Trial−for−Ignition Sequence− When the igniter

warm−up period is completed, the main gas valve relay contacts GVR close to energize the gas valve GV, the gas valve opens, and 24 vac power is supplied for a field−installed humidifier at the HUM 24VAC terminal. The gas valve GV permits gas flow to the burners where it is ignited by the HSI. Five seconds after the GVR closes, a 2−second flame proving period begins. The HSI igniter will remain energized until the flame is sensed or until the 2−second flame proving period begins.

d. Flame−Proving− When the burner flame is proved at

the flame−proving sensor electrode FSE, the furnace control CPU begins the blower continues to hold the gas valve GV open. If the burner flame is not proved within two seconds, the control CPU will close the gas valve GV, and the control CPU will repeat the ignition sequence for up to three more Trials−For−Ignition before going to Ignition−Lockout. Lockout will be reset automatically after three hours or by momentarily interrupting 115 vac power to the furnace, or by interrupting 24 vac power at 24VAC or COM to the furnace control CPU (not at W, G, R, etc.). If flame is proved when flame should not be present, the furnace control CPU will lock out of Gas−Heating mode and operate the inducer motor IDM until flame is no longer proved.

e. Blower−On Delay− If the burner flame is proven, the

blower motor is energized on HEAT speed 25 seconds after the gas valve GV is energized. Simultaneously, the electronic air cleaner terminal EAC is energized and remains energized as long as the blower motor BLWM is energized.

f. Heat−Off Delay− When the thermostat is satisfied, the

R−to−W circuit is opened, de−energizing the gas valve GV, stopping gas flow to the burners, and de−energizing the humidifier terminal HUM 24 VAC. The inducer motor IDM will remain energized for a 15−second post−purge period. The blower motor BLWM and air cleaner terminal

−ON delay period and

EAC will remain energized for 90, 120, 150, or 180 seconds (depending on the heat−OFF delay selection). The furnace control CPU is factory−set for a 120−second heat−OFF delay.

2. Cooling Mode The thermostat “calls for cooling.”

The thermostat closes the R−to−G−and−Y circuits. The R−to−Y circuit starts the outdoor unit, and the furnace control R−to−G−and−Y circuits start the furnace blower motor BLWM on COOL speed. The electronic air cleaner terminal EAC is energized with 115 vac when the blower motor BLWM is operating. When the thermostat is satisfied, R−to−G−and−Y circuits are opened. The outdoor unit will stop, and the furnace blower motor BLWM will continue operating on the COOL speed for an additional 90 seconds. (See Figure 4)

3. Continuous Blower Mode When the R−to−G circuit is closed by the thermostat, the blower motor BLWM will operate on heat speed and EAC terminal is energized as long as the blower motor BLWM is energized. During a call for heat, the blower BLWM will stop during igniter warm−up (17 seconds), ignition (7 seconds), and blower−on delay (25 seconds), allowing the furnace heat exchangers to heat up more quickly, then restarts at the end of the blower−on delay period at HEAT speed. In heating, the furnace control CPU will continue running the blower motor BLWM at HEAT speed after the selected blower−OFF delay period is completed. When the thermostat “calls for cooling”, the blower motor BLWM will operate at COOL speed. When the thermostat is satisfied, the blower motor BLWM will operate an additional 90 seconds on COOL speed before reverting back to continuous−blower speed. Jumper J2 can be cut to reduce the cooling−OFF delay to 5 seconds. (See Figure 4) When the R−to−G circuit is opened, the blower motor BLWM will continue operating for an additional 5 seconds, if no other function requires blower motor BLWM operation.

4. Heat Pump Mode Change Heat Pump to: HEAT PUMP MODE. When installed with a heat pump, the furnace control automatically changes the timing sequence to avoid long blower off times during demand defrost cycles. When the R-to-W-and-Y or R-to-W-and-Y-and-G circuits are energized the furnace control CPU will continue to turn on the blower motor BLWM at HEAT speed, and begin a heating cycle. The blower motor BLWM will remain on until the end of the prepurge period, then shut off for 24 seconds then come back on at HEAT speed. When the W input signal disappears, the furnace control begins a normal inducer post-purge period and the blower switches to COOL speed after a 3 second delay. If the R-to-W-and-Y-and-G signals disappear at the same time, the blower motor BLWM will remain on for the selected blower-OFF delay period. If the R-to-W-and-Y signals disappear, leaving the G signal, the blower motor BLWM will continue running the blower motor BLWM at HEAT speed after the selected blower-OFF delay period is completed.

See Component Self Test

Refer to page 14 for instructions.

440 04 4401 01 25

Specifications subject to change without notice.

SERVICE AND TECHNICAL SUPPORT MANUAL Gas Furnace: N9MSE

Specifications subject to change without notice.

26 440 04 4401 01

PARTS REPLACEMENT INFORMATION GUIDE

Casing Group

Control door Blower door Top filler plate Bottom filler plate Door Knob Assembly

Electrical Group

Control box Junction box Limit switch(es) Circuit board Door switch Transformer 3−Amp fuse Flame Rollout switch Main Wiring harness Blower Motor harness (when used)

Filter Group

Filter(s)

Blower Group

Cut−off Plate Blower housing Blower motor Blower wheel Capacitor (when used) Capacitor strap (when used) Power choke (where used)

Gas Control Group

Manifold Burner Orifice Flame sensor Hot surface igniter Gas valve

Heat Exchanger Group

Primary Heat Exchanger assembly Primary Heat Exchanger cell panel Secondary Heat Exchanger assembly Coupling box Containment Plate Tubing Gaskets

Inducer Group

Pressure switch(es) Inducer assembly Inducer Inducer motor Motor Module (when used) Inducer motor capacitor (when used) Collector box Condensate trap Condensate trap elbow Gaskets

WARNING

FIRE, EXPLOSION, ELECTRICAL SHOCK AND CARBON MONOXIDE POISONING HAZARD

Failure to follow this warning could result in dangerous operation, personal injury, death or property damage. Improper installation, adjustment, alteration, service, maintenance, or use can cause carbon monoxide poisoning, explosion, fire,

electrical shock, or other conditions which may cause personal injury or property damage. Consult a qualified installer, service agency, local gas supplier, or your distributor or branch for information or assistance. The qualified installer or agency must use only factory-authorized and listed kits or accessories when modifying this product.

Have available the product/model number and the serial number located on the unit rating plate to ensure correct replacement parts.

TO OBTAIN INFORMATION ON PARTS: Consult your installing dealer or the classified section of your local telephone directory under the “Heating Equipment“ or “Air Conditioning Contractors and Systems” headings for dealer listing by brand name.

SERVICE AND TECHNICAL SUPPORT MANUAL Gas Furnace: N9MSE

Specifications subject to change without notice.

440 04 4401 01 27

PRODUCT NOMENCLATURE

DIGIT POSITION

1 2 3 4 5 6, 7, 8 9, 10 11, 12 13 14

9 M S E 060 17 14 A 1

G = Mainline Look 1 F = Mainline Look 2 N = Entry 9 = 90% − 100% EFFICIENCY M = Multiposition H = Horizontal U = Upflow D = Downflow

FEATURE

A = Modulating Variable Speed ECM V = Variable Speed X = ECM S = Single−stage T = Two−stage

FEATURE

B = Base AFUE Efficiency E = Extra AFUE Efficiency C = Communicating D = Dual Certified 2−pipe or 1−pipe R = 2−pipe only S = Single−stage T = Two−stage N = Standard L = Low Nox

FEATURE

040 = 40,000 BTU/hr 060 = 60,000 BTU/hr 080 = 80,000 BTU/hr 100 = 100,000 BTU/hr 120 = 120,000 BTU/hr

INPUT HEAT

14 = 14−3/16” 17 = 17−1/2” 21 = 21” 24 = 24−1/2”

CABINET WIDTH

10 = 1000 CFM (max) 14 = 1400 CFM (max) 16 = 1600 CFM (max) 20 = 2000 CFM (max) 22 = 2200 CFM (max)

COOLING AIRFLOW

SALES (MAJOR) REVISION DIGIT ENGINEERING (MINOR) REVISION DIGIT

International Comfort Products, LLC

Consumer Relations Department

P.O. Box 128

Lewisburg, TN 37091, USA

931−270−4100

International comfort products N9MSE0601410A, N9MSE1002120A, N9MSE1002114A, N9MSE0401712A, N9MSB0401410B Service And Technical Support Manual

Specifications and Main Features

Frequently Asked Questions

User Manual