Troubleshooting Chart - Goodman GKS9 Installation Instructions Manual

Symptoms of Abnormal
Operation
• Furnace fails to operate.
• Integrated control module
diagnostic LED provides
no signal.
• LED is Steady On.
• Furnace fails to operate.
• Integrated control module
diagnostic LED is
flashing ONE (1) flash.
• Furnace fails to operate.
• Integrated control module
diagnostic LED is
flashing TWO (2)
flashes.
• Induced draft blower
runs continuously with
no further furnace
operation.
• Integrated control module
diagnostic LED is
flashing THREE (3)
flashes.
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.

Troubleshooting Chart

Associated
Associated
Fault Description(s)
Fault Description(s)
2
LED Code
LED Code 2
NONE • No 115 volt power to
furnace, or no 24 volt
power to integrated
control module.
• Blown fuse or circuit
breaker.
• Integrated control
module has an
internal fault.
• Normal Operation
ON
CONTINUOUS
ON
• Furnace lockout due
to an excessive
1
number of ignition
"retries" (3 total)
1 FLASH
• Pressure switch
circuit is closed.
2
• Induced draft
blower is not
2 FLASHES
operating.
• Pressure switch
circuit not closed.
3
• Induced draft blower
is operating.
3 FLASHES
Possible Causes
Possible Causes
• Manual disconnect switch
OFF, door switch open, or
24 volt wires improperly
connected or loose.
• Blown fuse or circuit
breaker.
• Integrated control module
has an internal fault.
• Normal Operation
• Failure to establish flame.
Cause may be no gas to
burners, front cover
1 pressure switch stuck open,
.
bad igniter or igniter
alignment, improper orifices,
or coated/oxidized or
improperly connected flame
sensor.
• Loss of flame after
establishment. Cause may
be interrupted gas supply,
lazy burner flames (im-
proper gas pressure or
restriction in flue and/or
combustion air piping), front
cover pressure switch
opening, or improper
induced draft blower
performance.
• Induced draft blower
pressure switch contacts
sticking.
• Shorts in pressure switch
circuit.
• 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.
34
Corrective Action
Cautions and Notes
• Assure 115 and 24 volt
• Turn power OFF
power to furnace
prior to repair.
integrated control
module.
• Replace integrated
control module
• Check integrated control
fuse with 3A
module fuse (3A).
automotive fuse.
Replace if necessary.
• Read precautions
• Check for possible shorts
in "Electrostatic
in 115 and 24 volt circuits.
Discharge" section
Repair as necessary.
of manual.
• Replace bad integrated
control module.
• None
• Normal Operation
• Turn power
• Locate and correct
OFF prior to
gas interruption.
repair.
• Check front cover
pressure switch
operation (hose, wiring,
contact operation).
Correct if necessary.
• Replace or realign
• Igniter is
igniter.
fragile, handle
• Check flame sense
with care.
signal. Sand sensor if
• Sand flame
coated and/or oxidized.
sensor with
• Check flue piping for
emery cloth.
blockage, proper
• See "Vent/Flue
length, elbows, and
Pipe" section
termination.
for piping
• Verify proper induced
details.
draft blower perfor-
mance.
• Replace induced draft
• Turn power OFF
blower pressure
prior to repair.
switch.
• Replace pressure
switch with proper
• Repair short.
replacement part.
• Inspect pressure • Turn power
switch hose. Repair, if OFF prior to
necessary, repair.
• Inspect flue and/or inlet • Replace
air piping for blockage, pressure
proper length, elbows, switch with
and termination. Check proper
drain system. Correct replacement
as necessary. part.
• Correct pressure
switch setpoint or
contact motion.
• Tighten or correct
wiring connection.