43
Troubleshooting Chart
• Circulator blower runs
continuously. No furnace operation.
• Integrated control
module diagnostic
LED
is
flashing
FOUR
(4) flashes.
4 FLASHES
• Primary or auxiliary
limit circuit is open.
• 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.
• 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 replacement
part.
• Replace blower with
correct replacement
part.
• Induced draft blower and
circulation blower runs
continuously. No furnace
operation.
• Integrated control module
diagnostic
LED
is flashing
FIVE
(5) flashes.
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.
• Furnace fails to operate.
• Integrated control module
diagnostic
LED
is flashing
SIX
(6) flashes.
• No furnace operation.
6 FLASHES
• Rollout limit 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.
• Short in 24 volt AC
control circuits or
safety circuits.
• Faulty rollout limit.
• 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 induced draft
blower with correct
replacement part.
• Replace integrated
control module fuse
with 3A automotive
fuse.
• Read precautions in
“Electrostatic
Discharge" section
of manual.
• Replace rollout limit
with correct
replacement part.
• Normal furnace operation.
• Integrated control module
diagnostic
LED
is flashing
SEVEN
(7) flashes.
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.
• Inspect for proper
sensor alignment.
• Compare current gas
pressure to rating plate
info. Adjust as needed.
• Turn power OFF prior
to repair.
• Clean flame sensor
with steel wool.
• See "Vent/Flue Pipe"
section for
piping details.
• See rating plate for
proper gas pressure.
• Furnace not operating.
• Integrated control module
diagnostic
LED
is flashing
EIGHT
(8) flashes.
8 FLASHES
• Igniter Relay Fault
•Improperly connected
igniter.
• Bad igniter.
• Poor unit ground.
• Poor burner ground.
• Faulty integrated
control module.
•Check and correct
wiring from integrated
control module
to igniter.
•Replace bad igniter.
•Check & correct unit
ground wire.
• Replace bad integrated
control module.
• Turn power OFF prior
to repair.
• Replace igniter
w/proper replacement
part.
• Read precautions in
“Electrostatic
Discharge" section
of manual.
4
5
6
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