
SYSTEM OPERATION
91
T
ROUBLESHOOTING
C
HART
ADV8, AMV8, ACV9, AMV9, GMV8, GCV9, GMV9
Fault
Description(s)
Symptoms of Abnormal
Operation
4
4 FLASHES
Associated
LED Code
2
• Circulator blower runs
continuously. No furnace
operation.
• Integrated control module
diagnostic
LED
is flashing
FOUR
(4) flashes.
7
7 FLASHES
• Normal furnace
operation.
• Integrated control
module diagnostic
LED
is flashing
SEVEN
(7)
flashes.
• Furnace fails to operate.
• Integrated control module
diagnostic
LED
is flashing
continuously.
C
CONTINUOUS
FLASHING
• Primary limit
circuit is
open.
• Polarity of
115 volt
power is
reversed.
• Flame
sense
microamp
signal is
low.
• Insufficient conditioned
air over the heat
exchanger. Blocked
filters, restrictive
ductwork, improper
circulator blower speed,
or failed circulator
blower.
• Flame rollout.
• Misaligned burners,
blocked flue and/or air
inlet pipe, or failed
induced draft blower.
• Loose or improperly
connected wiring.
Possible Causes
Corrective Action
Cautions and Notes
• Check filters and ductwork
for blockage. Clean filters or
remove obstruction.
• Check circulator blower
speed and performance.
Correct speed or replace
blower if necessary.
• Check burners for proper
alignment.
• Check flue and air inlet
piping for blockage, proper
length, elbows, and
termination. Correct as
necessary.
• Check induced draft blower
for proper performance.
Replace, if necessary.
• Tighten or correct wiring
connection.
• Turn power OFF
prior to repair.
• See Product Data
Bulletin for
allowable rise range
and proper
circulator speed.
See “Vent/Flue
Pipe” section for
piping details.
• Replace pressure
switch with proper
replacement part.
• Polarity of 115 volt AC
power to furnace or
integrated control
module is reversed.
• Poor unit ground.
• Flame sensor is
coated/oxidized.
• Flame sensor
incorrectly positioned
in burner flame.
• Lazy burner flame due
to improper gas
pressure or combus-
tion air.
• Review wiring diagram to
correct polarity.
• Verify proper ground.
Correct if necessary.
• Check and correct wiring.
• Sand flame sensor is
coated/oxidized.
• Inspect for proper sensor
alignment.
• Check inlet air piping for
blockage, proper length,
elbows, and termination.
• Compare current gas
pressure to rating plate info.
Adjust as needed.
• Turn power OFF
prior to repair.
• Turn power OFF
prior to repair.
• Sand flame sensor
with emery clot.
• See “Vent/Flue
Pipe” section for
piping details.
• See rating plate
for proper gas
pressure.
• 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 neces-
sary.
• Correct pressure switch
setpoint or contact motion.
• Tighten or correct wiring
connection.
9
9 FLASHES
• Furnace not operating.
• Integrated control module
diagnostic
LED
is
flashing
EIGHT
(8)
flashes
.
• Furnace operating on
low stage gas with high
stage induced draft
blower
• High stage circulator
blower (temperature, of
conditioned air, lower
than typical).
• Integrated control module
diagnostic
LED
is flashing
NINE
(9) flashes
.
8
8 FLASHES
• High stage
pressure
switch
circuit
does not
close in
response
to high
stage
induced
draft
blower
operation.
• Problem
with
igniter
circuit.
• Improperly connected
igniter
• Bad igniter
• Poor unit ground
• 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.
• Check and correct wiring
from integrated control
module to igniter
• Replace bad igniter
• Check and correct unit
ground wiring
• Turn power OFF
prior to repair.
• Replace igniter
with replacement
part.
• Turn power OFF
prior to repair.
• Replace
pressure switch
with proper
replacement
part.
• Integrated control
module diagnostic LED is
flashing
FIVE
(5) times.
• Induced draft blower
and circulator blower
run continuously. No
furnace operation.
• Flame
sensed
with no call
for heat.
• Correct short at flame
sensor or in flame sensor
wiring.
• Check for lingering flame
• Verify proper operation of
gas valve
• Short to ground in flame
sense circuit.
• Lingering burner flame.
• Slow closing gas valve
• Turn power OFF
prior to repair.
5
5 FLASHES
1
Integrated control module will automatically attempt to reset from lockout after one hour.
2
LED flash code will cease if power to control module is interrupted throught the disconnect or door switch.
4
Applies to ADV8, AMV8, GMV8 only.