Luxaire

Luxaire Furnaces Error Codes

Complete list of fault codes and troubleshooting guides. Use the search below to find your specific error.

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1 FLASH
Furnace will not start; status LED shows 1 flash repeating; inducer and blower are off.
Ignition Failure Lockout
10 FLASH
The furnace does not respond to the thermostat; the status LED shows 10 repeating flashes; no call for heat is recognized.
Communication or Thermostat Circuit Fault
11 FLASH
The furnace intermittently stops mid-cycle; the status LED shows 11 repeating flashes; it may restart on its own.
Blower Motor Fault or RPM Loss
12 FLASH
Furnace displays 12 flashes after a power interruption; it may not start immediately after power is restored.
Low Line Voltage or Brownout Lockout
13 FLASH
Furnace LED displays 13 flashes; the unit may not start or may shut down unexpectedly.
Limit Circuit Lockout or Multiple Limit Trips
2 FLASH
Furnace attempts to start but shuts down quickly; the status LED shows 2 repeating flashes; the inducer may start then stop.
Pressure Switch Stuck Closed
24
Furnace LED displays code 24; no response to the thermostat; the 24V control circuit appears dead.
Secondary (24V) Fuse Open
3 FLASH
The furnace starts the inducer but does not ignite; the status LED shows 3 repeating flashes; the unit may cycle the inducer several times.
Pressure Switch Stuck Open or Failed to Close
33
Furnace LED displays code 33; the unit may run briefly then shut down; the blower may continue to run.
Limit or Flame Rollout Switch Open
34
Furnace LED displays code 34; the ignition sequence starts but the burners do not light or light inconsistently.
Ignition Proving Failure
4 FLASH
The furnace lights but shuts off after a few seconds; the status LED shows 4 repeating flashes; it may retry ignition several times.
Flame Sense Failure
41
Furnace LED displays code 41; the blower may run at an incorrect speed or fail to start.
Blower Motor Fault (ECM or PSC)
42
Furnace LED displays code 42; the inducer may not start or may run erratically.
Inducer Motor or Pressure Switch Error
44
Furnace LED displays code 44; the unit may shut down unexpectedly during operation.
Flame Sense Out of Sequence or False Flame
5 FLASH
The furnace will not start the heating cycle; the status LED shows 5 repeating flashes; the blower may run continuously.
Rollout Switch or Flame Rollout Trip
55
Furnace LED displays code 55; this indicates a control board memory or configuration error; the furnace may not operate.
Control Board Fault or Configuration Error
6 FLASH
The furnace shuts down due to high temperature; the status LED shows 6 repeating flashes; the blower may run continuously to cool the unit.
Limit Switch Open (Overtemperature)
7 FLASH
The furnace does not respond to the thermostat; the status LED shows 7 repeating flashes; there is no inducer or blower operation.
Lockout Due to Too Many Ignition Retries
8 FLASH
The furnace runs the inducer and ignitor, but the gas valve does not open; the status LED shows 8 repeating flashes.
Gas Valve Fault or Low Gas Pressure
9 FLASH
The furnace intermittently shuts down; the status LED shows 9 repeating flashes; this may be accompanied by the blower running unexpectedly.
Line Voltage Polarity or Ground Fault
Symptom
Furnace cycles on and off frequently (short cycling) without reaching the set temperature.
Short Cycling
Symptom
Furnace emits a burning dust smell when it starts, especially at the beginning of the season.
Dust Burn-Off on Heat Exchanger
Symptom
Furnace emits a strong chemical or burning plastic smell.
Electrical Overheating or Foreign Object in Duct
Symptom
Furnace makes a loud booming or banging noise at startup.
Delayed Ignition
Symptom
Furnace produces a high-pitched whine or screech during operation.
Blower or Inducer Bearing Failure
Symptom
Furnace rattles or vibrates loudly when running.
Cabinet or Duct Vibration
Symptom
Furnace runs but does not produce enough heat; the home never reaches the set temperature.
Underfiring or Low Heat Output
Symptom
Furnace runs but some rooms are much colder than others.
Airflow Imbalance
Symptom
Furnace starts then shuts off after a few minutes; blower continues to run with cool air.
Overheating and Limit Cycling
Symptom
Furnace will not start at all; no lights, no blower, no inducer.
No Power to Furnace
Symptom
Rust-colored water or staining around furnace or vent connections.
Condensate Corrosion or Flue Leak
Symptom
The blower runs continuously even when there is no call for heat or cool.
Continuous Fan Operation
Symptom
The furnace blower starts and stops repeatedly without any heat call (fan surging).
Blower Control or ECM Module Issue
Symptom
The furnace runs but the carbon monoxide detector in the home alarms during operation.
Combustion or Venting Problem
Symptom
The furnace starts normally but shuts off when the blower starts, then retries.
Flame Disturbance Due to Airflow
Symptom
The inducer motor runs but the burners do not light; no error code is displayed.
Ignition Sequence Interruption
Symptom
The thermostat calls for heat but the furnace only clicks and does not start the inducer or blower.
Control Board Relay Failure or Low 24V Signal
Symptom
Water leaking around the base of the furnace, especially on high-efficiency (PVC-vented) models.
Condensate Drain Leak or Blockage
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