Intertek MES80 Installation Instructions Manual page 31

Troubleshooting Chart
Furnace Status LED Code¹ Fault Description(s)
• Furnace fails to
operate.
• Control LED is
flashing SIX (6)
RED flashes.
☼
6 Flashes
RED
• No furnace
operation.
☼
7 Flashes
• Control LED is
RED
flashing SEVEN
(7) RED flashes.
• No furnace
operation.
☼
8 Flashes
• Control LED is
RED
flashing EIGHT
(8) RED flashes.
☼
• LED is steady
on Steady On
AMBER
• Control LED is
flashing ONE (1)
AMBER flash. ☼
1 Flash
AMBER
• Control LED is ☼
flashing TWO (2) 2 Flashes
AMBER flashes. AMBER
• Control LED is
☼
flashing THREE
3 Flashes
(3) AMBER
AMBER
flashes.
• LED is steady ☼
on Steady On
GREEN
• Integrated ☼
control module Rapid
LED is flashing flashes
GREEN
rapidly.
• Integrated
control module ☼
LED is flashing 1 Flash
ONE (1) GREEN GREEN
flash.
• Integrated
control module ☼
LED is flashing 2 Flashes
TWO (2) GREEN GREEN
flashes.
• Integrated
control module ☼
LED has THREE 3 Flashes
(3) GREEN rapid GREEN
flashes.
• Burner temperature • Excessive flame.
switch open.
• Blocked flue and/or air inlet
pipe, or a failed induced draft
blower.
• Loose or improperly
connected wiring.
• Faulty burner temperature
switch.
• Gas valve circuit • Bad wiring
shorted.
• Faulty integrated control
module.
• Excessive inducer • Vent blockage or inducer
motor speed or drive hindrance.
signal is required.
• Faulty wiring to the pressure
sensor.
• OEM test mode • N/A
• Low flame sense • Flame sensor incorrectly
positioned in burner flame.
• Flame sensor is coated/
oxidized.
• Lazy burner flame due to
improper gas pressure or
combustion air.
• ID plug failure • Improper ID plug.
• Integrated control • Blown fuse.
module fuse is blown.
• Normal operation, idle/
· N/A
standby.
• Clear error history. · N/A
• Call for heating. · N/A
• Call for cooling. N/A
• Continuous fan • N/A
operation.
Possible Causes
• Check and correct gas
supply pressure.
• Replace bad gas valve or
gas orifice size.
• Check flue and air
inlet piping for blockage,
proper length, elbows, and
termination.
• Check induced draft blower
for proper performance.
Replace, if necessary.
• Check burner temperature
switch. Replace if necessary.
• Check wiring connections.
• Inspect and replace wiring
as needed.
• Replace bad integrated
control module.
• Inspect vent and inducer for
blockage or excessive wear
and replace as needed.
• Check and correct pressure
sensor wiring.
• Inspect for proper sensor
alignment.
• Clean flame rod.
• Compare current gas
pressure to rating plate info.
Adjust as needed.
• Replace ID plug.
• Replace integrated control
module fuse (3A).
• Press and hold the SW1
button for more than 5 secs
results in the display of this
mode.
31
Corrective Action Cautions & Notes
• See "Vent/Flue
Pipe" section for
piping details.
• Replace induced
draft blower with
proper replacement
part.
• Replace burner
temperature
switch with correct
replacement part.
• Turn power OFF
prior to repair.
• Read precautions
in "Electrostatic
Discharge" section of
manual.
• Turn power OFF
prior to repair.
• Replace induced
draft blower with
proper replacement
part.
• Turn power OFF
prior to repair.
• Clean flame sensor
with steel wool.
• See rating plate for
proper gas pressure.
• Turn power OFF
prior to repair.
• Turn power OFF
prior to repair.
• Release the button
while LED is flashing
GREEN to clear error
history.