42
T
ROUBLESHOOTING
C
HART
•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 obstruc-
tion.
•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.
4
4 FLASHES
•Faulty primary or auxiliary
limit switch.
•Insufficient conditioned
air over the heat ex-
changer. 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.
•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.
7
7 FLASHES
•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)
flashes
.
•Flame sensed with
no call for heat.
•Correct short at
flame sensor or in
flame sensor wiring.
•Turn power OFF
prior to repair.
5
5 FLASHES
•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.
•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.
6
6 FLASHES
•Flame rollout.
•Misaligned burners,
blocked flue and/or air
inlet pipe, or failed induced
draft blower.
•Loose or improperly
connected wiring.
•Faulty rollout limit.
•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/
•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.
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.
RAPID FLASH
