Carrier Furnace Igniter Not Working — What’s Happening
When a Carrier furnace igniter is not working, the furnace calls for heat but the ignition sequence does not complete because the igniter does not heat up, glow, or create ignition when commanded. The furnace cannot prove flame and will lock out or stop the ignition sequence. This is a symptom, not a standalone fault code. The exact LED fault code depends on the furnace model and control board, so the code must be read from the unit’s diagnostic legend rather than assumed.
Most Likely Causes
- Worn or failed igniter Carrier states that ignitors wear out over time, and cracks, deformation, or visible damage can prevent operation.
- Thermostat problem Incorrect settings, dead batteries, loose wiring, or a failed thermostat can prevent the heat call from reaching the furnace.
- No power to the furnace A tripped breaker or blown fuse can mimic an igniter failure.
- Gas supply problem The gas shutoff may be closed, the gas utility interrupted, the supply blocked, or the gas valve not opening.
- Dirty filter or blocked vents Restricted airflow can overheat the furnace and trip the high-limit switch, interrupting ignition attempts.
- Inducer or control proving failure If the inducer does not establish draft or the board does not receive the correct proof signals, ignition will not proceed.
- Blocked venting or combustion air issue A blocked chimney or venting can prevent proper ignition and flame establishment.
How to Diagnose and Fix
- Set the thermostat to Heat, raise the setpoint above room temperature, and confirm the thermostat has power and correct fan settings.
- Check the furnace breaker, fuse, and service disconnect to confirm power is reaching the unit.
- Inspect and replace a dirty filter, verify supply and return vents are open, and look for airflow restrictions that may have tripped the limit.
- Verify the manual gas shutoff is open and the gas utility is available by testing other gas appliances if appropriate.
- Observe the ignition sequence on a call for heat: the inducer should start, then the igniter should heat or glow, then the gas valve should open, then flame should light.
- Check the furnace fault code on the control board LED and follow the model-specific diagnostic chart for ignition-proving codes.
- Inspect the igniter physically for cracks, white burn lines, chips, or deformation, and test electrically by checking for 120 volts at the igniter (if voltage is present but no glow occurs, the igniter is bad).
- Replace the failed component after confirming the root cause, then run a full heat cycle and verify stable ignition and flame carryover.
Parts You Might Need
| Part | Notes |
|---|---|
| Hot surface igniter | Amazon | Confirm the correct model-specific part number before ordering. |
| Furnace air filter | Amazon | Match the size printed on the old filter frame. |
Related Error Codes
If your appliance also shows a code on the display, these match this problem:
- Carrier Furnace 13 error code
- Carrier Furnace 14 error code
- Carrier Furnace 31 error code
- Carrier Furnace 34 error code
When to Call a Pro
If you are not comfortable working with gas appliances, call a technician to inspect and replace the igniter. Gas supply, burner, and igniter work should be performed by a qualified professional. If the igniter has been replaced and the furnace still does not ignite, or if fault codes point to control board, gas valve, or inducer issues, a technician with metering equipment and model-specific training is required to diagnose and repair the system safely. For gas line, burner, or igniter work, or if you ever smell gas, stop and call a licensed technician.