Symptoms of Abnormal Associated Fault Description(s) Possible Causes Corrective Action Cautions and Notes

Operation LED Code2

• Furnace fails to operate.

• Integrated control module diagnostic LED provides no signal.

NONE

• No 115 volt power to furnace, or no 24 volt power to integrated control module.

• Blown fuse or circuit breaker.

• Integrated control module has an internal fault.

• Manual disconnect switch

OFF, door switch open, or

24 volt wires improperly connected or loose.

• Blown fuse or circuit breaker.

• Integrated control module has an internal fault.

• Assure 115 and 24 volt power to furnace integrated control module.

• Check integrated control module fuse (3A). Replace if necessary.

• Check for possible shorts in 115 and 24 volt circuits. Repair as necessary.

• Replace bad integrated control module.

• Turn power OFF

prior to repair.

• Replace integrated control module fuse with 3A automotive fuse.

• Read precautions in “Electrostatic Discharge” section of manual.

• LED is Steady On.

ON

CONTINUOUS ON

• Normal Operation

•Normal Operation

• None

•Normal Operation

• Furnace fails to operate.

• Integrated control module diagnostic LED is

flashing ONE (1) flash.

1

1 FLASH

• Furnace lockout due to an excessive number of ignition “retries” (3 total)1.

• Failure to establish flame. Cause may be no gas to burners, front cover pressure switch stuck open, bad igniter or igniter

alignment, improper orifices,

or coated/oxidized or improperly connected flame sensor.

• Loss of flame after establish- ment. Cause may be interrupted gas supply, lazy burner flames (improper gas pressure or restriction in flue and/or combustion air

piping), front cover pressure

switch opening, or improper induced draft blower performance.

• Locate and correct gas interruption.

• Check front cover pressure switch operation (hose, wiring, contact operation). Correct if necessary.

• Replace or realign igniter.

• Check flame sense signal. Sand sensor if coated and/or oxidized.

• Check flue piping for blockage, proper length, elbows, and termination.

• Verify proper induced draft blower perfor- mance.

• Turn power OFF prior to repair.

• Igniter is fragile, handle with care.

• Sand flame sensor with emery cloth.

• See “Vent/Flue Pipe” section for piping details.

• Furnace fails to operate.

• Integrated control module diagnostic LED is

flashing TWO (2) flashes.

2

2 FLASHES

• Pressure switch circuit is closed.

• Induced draft blower is not operating.

• Induced draft blower pressure switch contacts sticking.

• Shorts in pressure switch circuit.

• Replace induced draft blower pressure switch.

• Repair short.

• Turn power OFF

prior to repair.

• Replace pressure switch with proper replacement part.

• Induced draft blower runs continuously with no further furnace operation.

• Integrated control module diagnostic LED is

flashing THREE (3)

flashes.

3

3 FLASHES

• Pressure switch circuit not closed.

• Induced draft blower

is operating.

• Pressure switch hose blocked, pinched or connected improperly.

• Blocked flue and/or inlet air pipe, blocked drain system, or weak induced draft blower.

• Incorrect pressure switch setpoint or malfunctioning switch contacts.

• Loose or improperly connected wiring.

• Inspect pressure switch hose. Repair, if necessary,

• Inspect flue and/or inlet air piping for blockage, proper length, elbows, and termination. Check drain system. Correct as necessary.

• Correct pressure switch setpoint or contact motion.

• Tighten or correct wiring connection.

• Turn power OFF prior to repair.

• Replace pressure switch with proper replacement part.

Symptoms of Abnormal Associated Fault Description(s) Possible Causes Corrective Action Cautions and Notes

Operation LED Code2

• Circulator blower runs continuously. No furnace operation.

• Integrated control module diagnostic LED is

flashing FOUR (4)

flashes.

4

4 FLASHES

• Primary or auxiliary limit circuit is open.

• Insufficient conditioned air over the heat exchanger. Blocked filters, restrictive ductwork, improper circulator blower speed, or failed circulator blower.

• Faulty primary or auxiliary limit switch.

• Loose or improperly connected wiring.

• Check primary/ auxiliary limit. Replace if necessary.

• Check filters and ductwork for block- age. Clean filters or remove obstruction.

• Check circulator blower speed and performance. Correct speed or replace blower if necessary.

• Tighten or correct wiring connection.

• Turn power OFF

prior to repair.

• Replace primary/ auxiliary switch with proper replacement part.

• Replace blower with correct replacement part.

• Induced draft blower, and circulator blower runs continuously. No furnace operation.

• Integrated control module diagnostic LED is

flashing FIVE (5) flashes.

5

5 FLASHES

• Flame sensed with no call for heat.

• Short to ground in flame sense circuit.

• Correct short at flame sensor or in flame sensor wiring.

• Turn power OFF

prior to repair.

• Circulator blower runs continuously. No furnace operation.

• Integrated control module diagnostic LED is

flashing SIX (6) flashes.

• No furnace operation.

6

6 FLASHES

• Rollout limit circuit is open.

• Integrated control module fuse is

blown.

• Flame rollout.

• Misaligned burners, blocked flue and/or air inlet pipe, or failed induced draft blower.

• Loose or improperly connected wiring.

• Faulty rollout limit.

• Short in 24 volt AC control circuits or safety circuits.

• Check burners for proper alignment.

• Check flue and air inlet piping for blockage, proper length, elbows, and termination. Correct as necessary.

• Check induced draft blower for proper performance. Replace, if necessary.

• Tighten or correct wiring connection.

• Repair short in 24 volt AC control/safety circuit(s)

• Replace integrated control module fuse (3A).

• Turn power OFF

prior to repair.

• See “Vent/Flue Pipe” section for piping details.

• Replace rollout limit with correct replacement part.

• Replace induced draft blower with correct replace- ment part.

• Replace integrated

control module fuse with 3A automotive fuse.

• Read precautions in “Electrostatic Discharge” section of manual

• Normal furnace operation.

• Integrated control module diagnostic LED is flashing SEVEN (7) flashes.

7

7 FLASHES

• Flame sense microamp signal is low.

• Flame sensor is coated/

oxidized.

• Flame sensor incorrectly positioned in burner flame.

• Lazy burner flame due to improper gas pressure or combustion air.

• Sand flame sensor if coated/oxidized.

• Inspect for proper sensor alignment.

• Check inlet air piping for blockage, proper length, elbows, and termination.

• Compare current gas pressure to rating plate info. Adjust as needed.

• Turn power OFF

prior to repair.

• Sand flame sensor with emery clot.

• See “Vent/Flue Pipe” section for piping details.

• See rating plate for proper gas pressure.

• Furnace fails to operate.

• Integrated control module diagnostic LED is flashing continu- ously.

C

CONTINUOUS/ RAPID FLASH

• Polarity of 115 or 24 volt power is reversed.

• Polarity of 115 volt AC power to furnace or integrated control module is reversed.

• Orange and gray wires to transformer are reversed.

• Poor unit ground.

• Review wiring diagram to correct polarity.

• Reverse orange and gray wires connected to transformer.

• Verify proper ground. Correct if necessary.

• Turn power OFF

prior to repair.