Troubleshooting - Goodman Amana AMH8 Service Instructions Manual

TROUBLESHOOTING

T
ROUBLESHOOTING
Symptoms of Abnormal Symptoms of Abnormal 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.
C
HART
Associated Associated Associated
Associated Associated Associated Fault Fault Fault
Fault Fault Fault
Description(s) Description(s) Description(s)
LED Code
2
• No 115 volt power to
NONE
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 1 1
number of ignition
"retries" (3 total)
• Pressure switch
circuit is closed.
2 2 2
• Induced draft
blower is not
operating.
• Pressure switch
circuit not closed.
3 3 3
• Induced draft
blower is operating.
A/GMH8, GDH8, ADSH8
Possible Causes Possible Causes
Possible Causes Possible Causes Possible Causes Possible Causes
• Manual disconnect switch
OFF, door switch open,
or 24 volt wires improp-
erly 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
pressure switch stuck open,
1 .
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 (improper
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.
Corrective Action Corrective Action
Cautions and Cautions and Cautions and
Corrective Action
• Assure 115 and 24 volt
• Turn power OFF
power to furnace
prior to repair.
integrated control
• Replace
module.
integrated
• Check integrated control
control module
module fuse (3A).
fuse with 3A
Replace if necessary.
automotive
fuse.
• Check for possible shorts
in 115 and 24 volt
• Read precau-
circuits. Repair as
tions in
necessary. "Electrostatic
Discharge"
• Replace bad integrated
section of
control module.
manual.
•Normal Operation
• None
• Locate and correct
• Turn power
gas interruption.
OFF prior to
• Check front cover
repair.
pressure switch
• Igniter is
operation (hose,
fragile, handle
wiring, contact
with care.
operation). Correct if
necessary.
• Sand flame
• Replace or realign
sensor with
igniter.
emery cloth.
• Check flame sense
• See "Vent/
signal. Sand sensor if
Flue Pipe"
coated and/or
section for
oxidized.
piping details.
• Check flue piping for
blockage, proper
length, elbows, and
termination.
• Verify proper induced
draft blower perfor-
mance.
• Replace induced draft • Turn power OFF
prior to repair.
blower pressure
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
• Replace
inlet air piping for
pressure
blockage, proper
switch with
length, elbows, and
proper
termination. Check
drain system. Correct replacement
as necessary.
part.
• Correct pressure
switch setpoint or
contact motion.
• Tighten or correct
wiring connection.
Notes
41