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Troubleshooting chart – Goodman Mfg GKS9 User Manual

Page 34

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34

1

Integrated control module will automatically attempt to reset from lockout after one hour.

Troubleshooting Chart

• Furnace lockout due

to an excessive
number of ignition
“retries” (3 total)

1

.

• Locate and correct

gas interruption.

• Check front cover

pressure switch
operation (hose, wiring,
contact operation).
Correct if necessary.

• Replace or realign

igniter.

• Check flame sense

signal. Sand sensor if
coated and/or oxidized.

• Check flue piping for

blockage, proper
length, elbows, and
termination.

• Verify proper induced

draft blower perfor-
mance.

• Turn power

OFF prior to
repair.

• Igniter is

fragile, handle
with care.

• Sand flame

sensor with
emery cloth.

• See “Vent/Flue

Pipe” section
for piping
details.

• Furnace fails to operate.

• Integrated control module

diagnostic LED is
flashing ONE (1) flash.

1

1 FLASH

• Failure to establish flame.

Cause may be no gas to
burners, front cover
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.

• Pressure switch

circuit is closed.

• Induced draft

blower is not
operating.

• Replace induced draft

blower pressure
switch.

• Repair short.

• Turn power OFF

prior to repair.

• Replace pressure

switch with proper
replacement part.

• Furnace fails to operate.

• Integrated control module

diagnostic LED is
flashing TWO (2)
flashes.

2

2 FLASHES

• Induced draft blower

pressure switch contacts
sticking.

• Shorts in pressure switch

circuit.

• Inspect pressure

switch hose. Repair, 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.

• 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.

• Pressure switch

circuit not closed.

• Induced draft blower

is operating.

• Induced draft blower

runs continuously with
no further furnace
operation.

• Integrated control module

diagnostic LED is
flashing THREE (3)
flashes.

3

3 FLASHES

• Turn power

OFF prior to
repair.

• Replace

pressure
switch with
proper
replacement
part.

Fault Description(s)

Possible Causes

Associated

LED Code

2

• Normal Operation

• Normal Operation

• None

• Normal Operation

ON

CONTINUOUS

ON

• 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.

• 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.

• Assure 115 and 24 volt

power to furnace
integrated control
module.

• Check integrated control

module fuse (3A).
Replace if necessary.

• Check for possible shorts

in 115 and 24 volt circuits.
Repair as necessary.

• Replace bad integrated

control module.

• Turn power OFF

prior to repair.

• Replace integrated

control module
fuse with 3A
automotive fuse.

• Read precautions

in “Electrostatic
Discharge” section
of manual.

• Furnace fails to operate.

• Integrated control module

diagnostic LED provides
no signal.

NONE

Fault Description(s)

Possible Causes

Corrective Action

Cautions and Notes

Symptoms of Abnormal

Operation

Associated

LED Code

2

2

LED Flash code will cease if power to the control module is interrupted through the disconnect or door switch.

• LED is Steady On.