Bryant Furnaces Error Codes

11

Furnace does not start; status LED shows code 11 (one short, one long flash) indicating no previous code stored.

Normal Power-Up / No Fault Stored

12

Furnace attempts to start but stops; status LED shows code 12 (blower on after power-up).

Blower On After Power-Up / Normal Post-Power Cycle

13

Furnace shuts down; LED flashes code 13 indicating limit switch lockout or flame rollout lockout (depending on model).

Limit or Flame Rollout Lockout

14

Furnace attempts ignition but locks out; LED shows code 14 (ignition lockout).

Ignition Lockout

21

Furnace stops and LED shows code 21 indicating gas heating lockout (often after multiple failed ignition attempts).

Gas Heating Lockout

23

Furnace LED shows code 23; unit may not start or may shut down shortly after starting the inducer.

Pressure Switch Did Not Close

24

Furnace LED shows code 24; blower may run but no heat, or furnace may be completely inoperative.

Secondary Voltage Fuse Open / 24V Control Circuit Fault

31

Furnace LED shows code 31; inducer may run but burners do not light, or unit shuts down mid-cycle.

Pressure Switch Open or Failed to Close

32

Furnace LED shows code 32; blower may run at low speed, limited or no heat output.

Low Heat Pressure Switch Open

33

Furnace runs briefly then shuts down; LED shows code 33 (limit or flame rollout open). Blower may continue to run.

High Limit or Flame Rollout Switch Open

34

Furnace LED shows code 34; ignitor may glow but burners fail to light or light inconsistently.

Ignition Proving Failure

41

Furnace LED shows code 41; blower may run at incorrect speed or airflow seems weak.

Blower Motor Fault / CFM Fault

42

Furnace LED shows code 42; unit may short-cycle or fail to respond correctly to thermostat calls.

Inducer or Blower Communication Fault (ECM/Variable-Speed Models)

43

Furnace LED shows code 43; unit may not modulate correctly or may stay in one stage.

Pressure Switch Calibration or Modulation Fault

44

Furnace LED shows code 44; unit may shut down unexpectedly or not respond to thermostat.

Control Board Internal Fault

45

Furnace LED shows code 45; furnace may lock out and require power cycling to restart.

Control Circuit Lockout

55

Furnace LED shows code 55; indicates no previous fault stored in memory.

No Fault in Memory

Symptom

Bryant communicating furnace displays communication error with thermostat; furnace may revert to default operation or not run.

Communicating Control Network Fault

Symptom

Burners light but go out after a few seconds; furnace retries several times then locks out.

Flame Sensing Failure

Symptom

Furnace blower starts and stops repeatedly without burner ignition; cool air may blow briefly.

Fan-Only or Control Board Misoperation

Symptom

Furnace cycles on and off rapidly (every few minutes) and the thermostat temperature overshoots or undershoots.

Thermostat or Control Calibration Issue

Symptom

Furnace ignites and runs but shuts off when the blower starts; burners relight after blower stops.

Blower-Induced Flame Disturbance or Ground Fault

Symptom

Furnace or ductwork produces a high-pitched whistling noise during operation.

Airflow Restriction Noise

Symptom

Furnace produces heat but airflow from registers is weak; some rooms are cold.

Insufficient Airflow

Symptom

Furnace runs but carbon monoxide detector in the home alarms during operation.

Combustion / Venting Safety Hazard

Symptom

Furnace runs but makes loud banging or booming noises at startup or shutdown.

Delayed Ignition or Duct Expansion Noise

Symptom

Furnace runs but some rooms are too hot while others are too cold.

Uneven Heating / Zoning or Duct Imbalance

Symptom

Furnace starts and runs but shuts off before reaching thermostat setpoint; frequent short cycles.

Short Cycling

Symptom

Furnace starts but shuts down with a loud click shortly after ignition; house smells like exhaust.

Flame Rollout or Blocked Heat Exchanger

Symptom

Furnace will not start at all; no blower, no inducer, no LED lights on the control board.

No Power to Furnace

Symptom

Indoor blower runs continuously even when thermostat is not calling for heat or fan.

Blower Stuck On

Symptom

Inducer starts, ignitor glows, but burners do not light; after several tries the furnace shuts down.

Failure to Ignite Burners

Symptom

Strong burning or electrical smell when the furnace runs.

Overheating Components or Debris on Heat Exchanger

Symptom

Thermostat calls for heat but furnace inducer never starts; LED is on and shows normal or no-fault indication.

Inducer Motor Failure or Inducer Circuit Fault

Symptom

Water dripping from metal vent pipe on an 80% Bryant furnace or staining ceiling above furnace.

Flue Condensation / Venting Problem

Symptom

Water leaking around the base of a high-efficiency (PVC vented) Bryant furnace.

Condensate Leak