Troubleshooting Chart - Goodman *MSS9* Installation Instructions Manual

T C
ROUBLESHOOTING HART
Associated
Symptoms of Abnormal
Operation
LED Code
•Circulator blower runs
continuously. No
furnace operation.
•Integrated control
module diagnostic LED
4 FLASHES
is flashing FOUR (4)
flashes.
•Induced draft blower
and circulation blower
runs continuously. No
furnace operation.
•Integrated control
5 FLASHES
module diagnostic LED
is flashing FIVE (5)
flashes.
•Circulator blower runs
continuously. No
furnace operation.
•Integrated control
module diagnostic LED
6 FLASHES
is flashing SIX (6)
flashes.
•Normal furnace
operation.
•Integrated control
module diagnostic LED
is flashing SEVEN (7)
7 FLASHES
flashes.
•Furnace fails to
operate.
•Integrated control
module diagnostic LED
is flashing continu-
ously.
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.
Fault
Description(s)
2
•Primary or auxiliary
limit circuit is open.
4
•Flame sensed with
no call for heat.
5
•Rollout limit circuit
is open.
6
•Flame sense
microamp signal is
7
low.
•Polarity of 115 or
C
24 volt power is
reversed.
CONTINUOUS/
RAPID FLASH
Possible Causes
•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.
•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.
•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.
42
Corrective Action
•Check primary/
•Turn power OFF
auxiliary limit.
Replace if necessary.
•Replace primary/
•Check filters and
ductwork for
blockage. Clean filters
or remove obstruc-
•Replace blower
tion.
•Check circulator
blower speed and
performance.
Correct speed or
replace blower if
necessary.
•Tighten or correct
wiring connection.
•Correct short at •Turn power OFF
flame sensor or in prior to repair.
flame sensor wiring.
•Check burners for
•Turn power OFF
proper alignment.
prior to repair.
•Check flue and air
•See "Vent/Flue
inlet piping for
Pipe" section for
blockage, proper
piping details.
length, elbows, and
•Replace rollout
termination. Correct
limit with correct
as necessary.
replacement part.
•Check rollout limit.
• Replace induced
Replace if necessary.
draft blower with
•Check induced draft
correct replace-
blower for proper
ment part.
performance.
Replace, if necessary.
•Tighten or correct
wiring connection.
•Sand flame sensor if •Turn power OFF
coated/oxidized.
•Inspect for proper •Sand flame sensor
sensor alignment.
•Check inlet air piping •See "Vent/Flue
for blockage, proper
length, elbows, and
termination.
•Compare current gas
•See rating plate
pressure to rating
plate info. Adjust as
needed.
•Review wiring •Turn power OFF
diagram to correct prior to repair.
polarity.
•Reverse orange and
gray wires going to
transformer.
•Verify proper ground.
Correct if necessary.
Cautions and
Notes
prior to repair.
auxiliary limit with
proper replace-
ment part.
with correct
replacement part.
prior to repair.
with emery clot.
Pipe" section for
piping details.
for proper gas
pressure.