Comfortmaker Furnace E1 Error Code — What It Means
The Comfortmaker E1 error code is a system lockout — the furnace has exceeded the maximum number of ignition retry attempts or has tripped a safety device (pressure switch, high-limit, or rollout switch) enough times to trigger a hard lockout. The control board will not allow another heating attempt until the fault is manually reset or the lockout timer expires. Comfortmaker furnaces are ICP/Carrier products and share the same control platform as Heil, Tempstar, and Arcoaire.
Common Causes
- Ignition failure lockout — The furnace tried to light 3–5 times without proving flame; most often caused by a dirty flame sensor or weak ignitor.
- Pressure switch lockout — Repeated pressure switch faults due to a blocked flue, condensate in the hose, or a faulty switch led to lockout.
- High-limit lockout — Repeated high-limit trips from restricted airflow triggered the soft lockout.
- Rollout switch trip — A manual-reset rollout switch tripped due to flame rollout and physically requires a reset push before the E1 clears.
Step-by-Step Fix
- Check for a tripped rollout switch — Locate the rollout switch(es) on the burner bracket — small circular bimetal devices with a red reset button. If the button has popped, press it to reset. Do not reset without first identifying why it tripped (blocked flue, cracked heat exchanger, etc.).
- Reset the control board — Cut power at the disconnect for 60 seconds, restore, and call for heat. Watch the ignition sequence closely.
- Clean the flame sensor — If the fault was ignition-related, clean the flame sensor rod with fine steel wool before the next attempt.
- Check the air filter — If the fault was limit-related, replace the filter and confirm all registers are open before resetting.
- Inspect the flue — If the fault was pressure-switch-related, check both vent pipes for blockage and drain any condensate from the pressure switch hose.
- Confirm full operation — After reset, allow the furnace to complete a full heating cycle. Watch the status LED; it should show solid-on or a normal standby flash once operation is stable.
Parts Often Needed
| Part | Notes |
|---|---|
| Flame sensor rod | Address ignition lockouts first — easiest and cheapest fix |
| Air filter | For limit lockouts; replace and confirm blower operation |
| Rollout switch | Manual-reset thermal fuse; match temperature rating |
Need Replacement Parts?
Finding the right replacement parts for your equipment is critical to getting it running again. Check current prices on Amazon — prices and availability change frequently.
When to Call a Pro
If the rollout switch tripped, do not simply reset it and move on. Rollout indicates that flames extended outside the burner box — caused by a blocked flue, blocked heat exchanger passages, or cracked heat exchanger. This is a carbon monoxide and fire hazard. Have a technician inspect before returning the furnace to service.