ICP 9MAC/E series, Troubleshooting Manual

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SERVICE/STATUS CODE INSTRUCTIONS
If status code recall is needed disconnect the “R” thermostat lead, reset power, and put setup switch “SW1-1” in the ON position. To clear the status
code history put setup switch “SW1-1” in the ON position and jumper thermostat terminals “R”, “W/W1”, and “Y/Y2” simultaneously until the
Heartbeat flashes.
LED CODE STATUS
CONTINUOUS OFF
- Check 115 VAC at L1 and L2, 24 VAC at SEC-1 and SEC-2, and 24V fuse.
HEARTBEAT
- (bright-dim-bright-dim) Control has 24 VAC power.
ON SOLID
- The control is locked out and will auto reset after 1 hour. Lockout could be due to any of the following:
- Flame sense circuit failure.
- Gas valve relay stuck open.
- Software check error.
Reset power to clear lockout. Replace control if status code repeats.
EACH OF THE FOLLOWING STATUS CODES IS A SINGLE OR TWO DIGIT NUMBER WITH THE FIRST NUMBER DETERMINED
BY THE NUMBER OF SHORT FLASHES AND THE SECOND NUMBER AFTER THE (+) SIGN IS THE NUMBER OF LONG
FLASHES.
2 PRESSURE SWITCH DID NOT OPEN
– Check for:
- Obstructed pressure tubing.
- Pressure switch stuck closed.
3 LOW PRESSURE SWITCH DID NOT CLOSE OR REOPENED
– Indicates the low pressure switch input failed to close on a call for
heat, or opened during minimum-heat. If opens during blower on-delay period, blower will come on for the selected blower off-delay. If
opens within 5 minutes after ignition the next heating cycle will be restricted to maximum-heat. Check for:
- Proper vent sizing.
- Air leak between vestibule and blower compartment.
- Restricted vent.
- Plugged condensate drain.
- Low inlet gas pressure (if LGPS used).
- Excessive wind. If problem persists turn setup switch “SW1-3” ON to boost inducer speed.
- Improper pressure switch wiring.
- Failed or “Out-of-Calibration” pressure switches.
- Water in vent piping, possible sagging pipe.
- Disconnected or obstructed pressure tubing.
4 LIMIT CIRCUIT FAULT
– Indicates the limit, or flame rollout is open or the furnace is operating in maximum-heat only mode due to 2
successive limit trips while operating at any rate less than or equal to 71% of maximum rate. Blower will run at intermediate heat airflow
for 4 minutes or until open switch remakes whichever is longer. If open longer than 3 minutes, code changes to lockout #7. If open less
than 3 minutes status code #4 continues to flash until blower shuts off. Flame rollout switch requires manual reset. Check for:
- Loose blower wheel.
- Defective switch or connections.
- Improper minimum- or maximum-heat gas input adjustment.
- Dirty filter or restricted duct system.
- Improper limit switch or no limit gasket.
5 ABNORMAL FLAME-PROVING SIGNAL
– Flame is proved while gas valve is de-energized. Inducer will run until fault is cleared.
Check for:
- Leaky gas valve.
- Stuck-open gas valve.
6 IGNITION PROVING FAILURE
– Control will try three more times before lockout #6 + 1 occurs. If flame signal is lost during blower
on-delay period, blower will come on for the selected blower off-delay. Check for:
- Low inlet gas pressure.
- Control ground continuity.
- Gas valve defective or turned off.
- Defective Hot Surface Igniter.
- Manual valve shut off.
- Oxide buildup on flame sensor (clean with fine steel wool).
- Proper flame sense micro amps (.5 micro amps DC min., 4.0 – 6.0 nominal).
- Green/Yellow wire MUST be connected to furnace sheet metal.
- Inadequate flame carryover or rough ignition.
- Flame sensor must not be grounded.
7 LIMIT CIRCUIT LOCKOUT
– Lockout occurs if the limit, or flame rollout switch is open longer than 3 minutes or 10 successive limit
trips occurred during maximum-heat. Control will auto reset after 3 hours. Refer to status code #4.
440 08 4001 00