Goodman GMH8 Installation Instructions Manual page 30

TROUBLESHOOTING CHART
• Circulator blower runs
continuously. No furnace
operation.
• Integrated control module
diagnostic LED is flashing
FOUR (4) flashes.
• Induced draft blower and
circulator blower runs
continuously. No furnace
operation.
• Integrated control module
diagnostic LED is flashing
FIVE (5) flashes.
• Furnace fails to operate.
• Integrated control module
diagnostic LED is flashing
SIX (6) flashes.
• No furnace operation.
NormaI furnace
operation.
Integrated control
module diagnostic LED
is flashing SEVEN (7)
flashes.
Induced draft blower runs
continuously. No furnace
operation.
Integrated control module
diagnostic LED is flashing
continuously.
4 FLASHES
5 FLASHES
÷
6 FLASHES
÷
7 FLASHES
÷
CONTINUOUS
FLASHING
• Primary limit
circuit is open.
Flame sensed
with no call
for heat.
Rollout limit open.
Integrated control
module fuse is
blown.
• Flame sense
mlcroamp signal is
low.
• Polarity of 115
or 24 volt
)ower is
reversed.
• 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.
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.
• Short in 24 volt AC
control circuits or
safety circuits.
•Faulty rollout limit.
Flame sensor is coated/
oxidized.
Flame sensor incorrectly
)ositioned 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.
• Red and blue wires to
transformer are
reversed.
• Poor unit ground.
STEADY Normal operation.
• LED is steady on ON
• Check primary 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.
• Correct short at flame
sensor or in flame
sensor wiring
• 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.
• Repair short in 24 volt AC
control/safety circuit(s).
• Replace integrated
control module fuse (3A).
• Sand flame sensor.
• Inspect for proper sensor
alignment.
• Compare current gas
pressure to rating plate
info. Adjust as needed.
• Review wiring diagram to
correct polarity.
• Verify proper ground.
Correct if necessary.
• Reverse red and blue
wires connected to
transformer.
2 LED Flash code will cease if power to the control module is interrupted through the disconnect or door switch.
3O
• Turn power OFF
prior to repair.
• Replace primary
switch with
proper
replacement part.
• Replace blower
with correct
replacement part.
Turn power
OFF prior to
re )air.
• See "Vent/Flue
Pi)e" section for
piping details.
• Replace induced
draft blower
with proper
re )lacement )art.
• Replace
integrated control
module fuse with
3A automotive
fuse.
• Read precautions
in "Electrostatic
Discharge"
section of
manual.
• Replace rollout
limit with correct
re 3lacement )art.
• Turn power OFF
prior to repair.
• Clean flame
sensor with steel
wool.
• See "Vent/Flue
Pi 3e" section for
piping details.
• See rating plate
for proper gas
)ressure.
• Turn power OFF
prior to repair.