Install Instructions

1. Ground yourself properly before installing the new ICM2811 control board.
2. Mount the new control using any screws and fasteners previously removed.
3. Connect all line/low voltage, accessory, thermostat and ground wires.
4. Verify the sequence of operation.
Install New Control
LED Fault Codes
LED
Status Description Trouble Shooting Tips
ON Normal operation
OFF Control board failure
Check for proper input voltage and check the fuse; if not resolved replace control.
1 Ignition failure (soft
lockout)
Clean or replace ame sensor, check igniter for proper operation & input voltage, check the
transformer’s common is grounded to earth ground.
2 Pressure switch stuck
closed
Check for contaminated or defective pressure switch.
3 Pressure switch stuck
open
Check for obstructed pressure switch tubing or defective pressure switch. Check for oxidation
on terminals, broken wires, or defective inducer motor .
4 Limit switch fault Checked for blocked airow, blocked ductwork, and dirty lter. Check or replace high limit
switch if defective.
5 Flame out of sequence Check for intermittent or defective gas valve and check for dirty or defective ame sensor.
6 Roll out switch fault Check for a cracked heat exchanger, defective rollout switch , broken wires on the roll out
switch, or replace roll out switch if required.
7 Weak ame Weak ame is caused by carbon build up on the ame sensor, poor grounds, or improper
placement of ame sensor . Clean or replace ame sensor, reassure grounds, ensure ame
sensor is fully enveloped in the ame.
8 Miswired gas valve Check for shorted or mis-wired gas valve, check harness wires for any shorts or breaks, and
check the pressure switch for proper operation.
9 Unused N/A
10 Hot and neutral reversed Check for proper polarity of incoming voltage on the primary and secondary of the transformer.
11 Brownout A brownout fault indicates a low voltage condition. Check the voltage on the primary and
secondary of the transformer and ensure there is no excessive load on the transformer.
12 Twinning fault Ensure the common of both step down transformers are connected together and grounded to
earth ground. Ensure there is a ground wire connecting the chassis of both furnaces. Verify
there is a twinning wire connected from the twin terminal on furnace one to the twin terminal on
furnace two.
Remove Existing Control
CAUTI ON!
To service control, and prior to disconnection, label all wires.
Failure to do so may result in wiring errors which can cause dangerous operation.
1. Turn thermostat to OFF position or set it to the lowest possible
setting.
2. Turn OFF electrical supply to furnace.
3. Turn OFF gas supply to furnace.
4. Remove furnace blower and control access doors.
5. Remove control box cover.
CAUTI ON!
Failure to turn off gas and electric supplies can result in explosion, re,death, or personal injury.
6. Disconnect thermostat wires and humidier wires (if equipped
with a humidier).
7. Disconnect line voltage, blower, electronic air cleaner wires (if
equipped), and transformer wires.
8. Remove wiring harness from circuit board.
9. Remove screws or any other fasteners and old circuit board.
10. Examine control and control box to check for water
stains.
11. Make repairs if any sources of water leakage are found.
Be sure to check humidiers, evaporator coils, and vent
systems in the area of the control.