GMES8 GCES8 Installation Instructions

32
T ROUBLESHOOTING C HART
PCBBF145 CONTROL BOARDS
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.
• Furnace lockout due to
an excessive number
of ignition attempts. (3
total)
1
• Auxiliary Limit Open
• Locate and correct gas
interruption.
• Replace or realign
igniter.
• Check flame sense
signal. Clean sensor if
coated and/ or
oxidized.
• Check flue piping for
blockage, proper
length, elbows, and
termination.
• Verify proper induced
draft blower
performance.
• Check circulator
blower speed and
performance. Correct
speed or replace
blower if necessary.
• Turn power OFF prior
to repair.
• Igniter is fragile,
handle with care.
• Clean flame sensor
with steel wool.
• See “Combustion
and Ventilation Air
Requirements” and
“ Category I Venting
(Vertical Venting)”
section for details.
• See Product Data
Bulletin for
allowable rise
range and proper
circulator speed.
• 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, 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 or
improper induced draft
blower performance.
• Insufficient conditioned air
over the heat exchanger.
Blocked filters, restrictive
ductwork, improper
circulator blower speed, or
failed circulator blower.
• M ain power interruption
during heat cycle causing
auxiliary limit to open.
• 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 for blockage,
proper length, elbows,
and termination.
• Correct pressure switch
setpoint or contact
motion.
• Tighten or correct wiring
connection.
• Inspect masonry chimney
and flue; remove
blockage.
• Pressure switch hose
blocked, pinched or
connected improperly.
• Blocked flue or weak
induced draft blower.
• Incorrect pressure switch
setpoint or malfunctioning
switch contacts.
• Loose or improperly
connected wiring.
• Blockage in flue or chimney.
• Pressure switch circuit
not closed.
• Induced draft blower is
operating.
• If installed, manual
reset limit switch is
open on M asonry
Vent Kit (MVK).
• 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.
• See “Combustion and
Ventilation Air
Requirements” and
“ Category I Venting
(Vertical Venting)”
section for details.
• Replace pressure
switch with proper
replacement part.
• Replace masonry
vent kit limit switch
with correct
replacement part.
• Integrated control
module has an
internal fault.
• Integrated control module has
an internal fault.
• Turn power OFF prior
to repair.
• Read precautions in
“ Electrostatic
Discharge” section
of manual.
• Furnace fails to operate.
• No 115 volt power to
furnace, or no 24 volt
power to integrated
control module.
• Blown fuse or circuit
breaker.
• M anual disconnect switch
OFF, door switch open, or 24
volt wires improperly
connected or loose.
• Blown fuse or circuit breaker.
• Assure 115 and 24 volt
power to furnace
integrated control
module.
• Check for possible shorts
in 115 and 24 volt circuits.
Repair as necessary.
• Replace bad integrated
control module.
• Turn power OFF prior
to repair.
• Furnace fails to operate.
• Integrated control module
diagnostic LED provides no
signal.
NONE
Cautions
& Notes
Corrective
Action
Possible
Causes
Fault
Description(s)
Symptoms of
Abnormal Operation
Associated
LED Code
2