Goodman GMH95 Installation Instructions Manual page 36

Associated
Symptoms of Abnormal
Operation
LED Code
• Circulator blower runs
continuously. No furnace
operation.
• Integrated control module
4 FLASHES
diagnostic LED is
flashing FOUR (4)
flashes.
• Induced draft blower,
and circulator blower
runs continuously. No
furnace operation.
5 FLASHES
• Integrated control module
diagnostic LED is
flashing FIVE (5) flashes.
• Circulator blower runs
continuously. No furnace
operation.
• Integrated control module
6 FLASHES
diagnostic LED is
flashing SIX (6) flashes.
• No furnace operation.
• Normal furnace
operation.
• Integrated control
module diagnostic
7 FLASHES
LED is flashing
SEVEN (7) flashes.
• Furnace fails to
operate.
• Integrated control
module diagnostic LED
CONTINUOUS/
is flashing continu-
RAPID FLASH
ously.
2
LED Flash code will cease if power to the control module is interrupted through the disconnect or door switch.
TROUBLESHOOTING CHART
Fault Description(s)
2
• Primary or auxiliary
4 limit circuit is open.
• Flame sensed with
no call for heat.
5
• Rollout limit circuit is
6 open.
• Integrated control
module fuse is
blown.
• Flame sense
microamp signal is
7
low.
• Polarity of 115 or 24
C volt power is
reversed.
Possible Causes
• 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.
• Short to ground in flame
sense circuit.
• 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.
• Flame sensor is coated/
oxidized.
• Flame sensor incorrectly
positioned in burner flame.
• Lazy burner flame due to
improper gas pressure or
combustion air.
• 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.
36
Corrective Action Cautions and Notes
• Check primary/ • Turn power OFF
auxiliary limit. Replace prior to repair.
if necessary.
• Replace primary/
• Check filters and auxiliary switch
ductwork for block- with proper
age. Clean filters or replacement part.
remove obstruction.
• Replace blower
• Check circulator with correct
blower speed and replacement part.
performance. Correct
speed or replace
blower if necessary.
• Tighten or correct
wiring connection.
• Correct short at flame • Turn power OFF
sensor or in flame prior to repair.
sensor wiring.
• Check burners for
• Turn power OFF
proper alignment.
prior to repair.
• Check flue and air inlet
• See "Vent/Flue
piping for blockage,
Pipe" section for
proper length, elbows,
piping details.
and termination.
• Replace rollout limit
Correct as necessary.
with correct
• Check induced draft
replacement part.
blower for proper
• Replace induced
performance. Replace,
draft blower with
if necessary.
correct replace-
• Tighten or correct
ment part.
wiring connection.
• Replace integrated
control module
• Repair short in 24 volt
fuse with 3A
AC control/safety
automotive fuse.
circuit(s)
• Read precautions
• Replace integrated
in "Electrostatic
control module fuse
Discharge" section
(3A).
of manual
• Sand flame sensor if
• Turn power OFF
coated/oxidized.
prior to repair.
• Inspect for
• Sand flame sensor
proper sensor
with emery clot.
alignment.
• See "Vent/Flue
• Check inlet air piping
Pipe" section for
for blockage, proper
piping details.
length, elbows, and
termination.
• See rating plate for
• Compare current gas
proper gas
pressure to rating plate
pressure.
info. Adjust as needed.
• Review wiring diagram • Turn power OFF
to correct polarity. prior to repair.
• Reverse orange and
gray wires connected
to transformer.
• Verify proper ground.
Correct if necessary.