ICM Controls ICM2818 Installation, Operation & Application Manual page 3

LED FAULT CODES
FAULT CODE (# BLINKS)
Red LED
Steady ON
Steady OFF
1
2
3
4
5
6
7
Yellow LED
Steady ON
Rapid
Flash
Flash rate is 0.25 seconds ON and 0.4 seconds OFF, with a 2.0 seconds pause between codes.
FAULT CONDITION
Control OK in standby, heat
or fan modes
Mis-wired gas valve
Limit switch open
Pressure switch stuck open
Pressure switch stuck close
Lockout due to failed ignition
Hot and Neutral reverse
Flame present with gas off
Input signals fail low or high
Flame is sensed
Flame lockout
Flame is week
TROUBLESHOOTING
N/A
Check proper input voltage and fuse; if unresolved, replace control. Check for
shorted or mis-wired gas valve, check pressure switch for proper operation.
Or Check for defective gas valve.
Check for proper polarity of incoming voltage on the primary and secondary
terminals on the transformer.
Check for blocked airflow, ductwork, or dirty filter. Replace limit switch if
defective.
Check for obstructed or defective pressure switch and tubing: oxidation on
terminals, broken wires, defective inducer motor, etc.
Check for contaminated or defective pressure switch.
Clean or replace flame sensor, check input voltage and proper operation of
ignitor. Check that common of the transformer is grounded to earth.
Check for proper polarity of incoming voltage on the primary and secondary
terminals on the transformer.
Check for dirty/defective flame sensor.
N/A
Clean or replace flame sensor
Clean or replace flame sensor
3