Instruction manual

41
■ Induced draft
blower runs
continuously
with no further
furnace
operation.
■ Integrated
control module
diagnostic LED
is flashing
3flashes.
3 flashes
■ Pressure switch
circuit is 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/
replace, 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 off power
prior to repair.
■ Replace pressure
switch with
correct
replacement part.
■ Replace induced
draft blower with
correct
replacement part.
■ Circulator
blower runs
continuously.
No furnace
operation.
■ Integrated
control module
diagnostic LED
is flashing
4flashes.
4 flashes
■ Primary limit 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 limit
switch.
■ Loose or improperly
connected wiring.
■ Check primary limit
switch. 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 off power
prior to repair.
■ Replace primary
switch with
correct
replacement part.
■ Replace
circulator blower
with correct
replacement part.
■ Induced draft
blower and
circulator
blower runs
continuously.
No furnace
operation.
■ Integrated
control module
diagnostic LED
is flashing
5flashes.
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 off power
prior to repair.
■ No furnace
operation.
■ Integrated
control module
diagnostic LED
is flashing
6flashes.
6 flashes
■ Rollout limit
switch 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
switch.
■ Check burners for
proper alignment.
■ Check flue and air inlet
piping for blockage,
proper length, elbows
and termination.
Correct as necessary.
■ Check rollout limit
switch. Replace if
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 off power
prior to repair.
■ 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 switch with
correct
replacement part.
■ See “Vent/Fluie
Pipe” section for
piping details.
Symptoms of
Abnormal
Operation
Associated
LED Code Fault Description Possible Causes Corrective Actions
Notes and
Cautions