TROUBLESHOOTING
44
1
Integrated control module will automatically attempt to reset from lockout after one hour.
2
LED Flash code will cease if power to the control module is interrupted through the disconnect or door switch.
• Circulator blower runs
continuously. No
furnace operation.
• Integrated control
module diagnostic
LED
is flashing
FOUR
(4)
flashes.
• Primary or auxiliary
limit circuit is open.
• Check primary/auxiliary
limit. Replace if
necessary.
• Check filters and
ductwork for blockage.
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 limit with
proper replace-
ment part.
• Replace blower
with correct
replacement part.
• Faulty primary or auxiliary
limit switch.
• Insufficient conditioned air
over the heat exchanger.
Blocked filters, restrictive
ductwork, improper
circulator blower speed,
or failed circulator blower.
• Loose or improperly
connected wiring.
Fault
Description(s)
Possible Causes
Corrective Action
Cautions and
Notes
Symptoms of Abnormal
Operation
Associated
LED Code
2
• Normal furnace
operation.
• Integrated control
module diagnostic
LED
is flashing
SEVEN
(7)
flashes.
• Flame sense
microamp signal is
low.
• Clean 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.
• Clean flame
sensor.
• See “Vent/Flue
Pipe” section for
piping details.
• See rating plate
for proper gas
pressure.
7
• Flame sensor is coated/
oxidized.
• Flame sensor incorrectly
positioned in burner flame.
• Lazy burner flame due to
improper gas pressure or
combustion air.
• Induced draft blower
and circulation blower
runs continuously. No
furnace operation.
• Integrated control
module diagnostic
LED
is flashing
FIVE
(5)
• Flame sensed with
no call for heat.
• Correct short at flame
sensor or in flame
sensor wiring.
• Turn power OFF
prior to repair.
5
• Short to ground in flame
sense circuit.
• Circulator blower runs
continuously. No
furnace operation.
• Integrated control
module diagnostic
LED
is flashing
SIX
(6)
flashes.
• Rollout limit circuit is
open/Control board
fuse open.
• Check burners for proper
alignment.
• Check flue and air inlet
piping for blockage,
proper length, elbows,
and termination. Correct
as necessary.
• Check rollout limit.
Replace if necessary.
• Check induced draft
blower for proper
performance. Replace,
if necessary.
• Tighten or correct wiring
connection.
• 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 control
board fuse.
6
• 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 thermostat wiring.
• Control board fuse.
• Furnace fails to
operate.
• Integrated control
module diagnostic
LED
is flashing
continu-
ously
.
• Polarity of 115 or
24 volt power is
reversed.
• Review wiring
diagram to correct
polarity.
• Reverse orange and
gray wires going to
transformer.
• Verify proper ground.
Correct if necessary.
• Turn power OFF
prior to repair.
C
CONTINUOUS/
RAPID FLASH
• 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.
