Lennox E229 / Flame Failure After Ignition
E229 on Lennox iComfort/S30-style systems reports flame failure after a trial for ignition. Homeowners can clean or replace the flame sensor; gas pressure and board faults need a licensed tech.
Updated July 2026 · 6 min read · Canada
Symptoms
- Thermostat shows E229 or flame failure
- Burners light briefly then drop out
- Heat call ends in lockout after retries
Likely causes
- Contaminated flame sensor
- Weak ground / sensor wiring
- Ignitor weakening
- Improper gas manifold pressure
What to do
1. Note the alert and power down
Screenshot the thermostat alert, then shut off power at the furnace switch before opening panels.
2. Clean the flame sensor rod
Remove and polish the rod. Avoid bending it; reinstall with a snug ground path.
3. Inspect the ignitor
Replace if cracked. Match the OEM-style connector used on your Lennox chassis.
4. Clear the alert and retest
Restore power, clear the thermostat alert, and run one heat cycle. Recurring E229 after a clean sensor needs a tech.
Stop and call a pro when
- Alert returns immediately
- Communicating outdoor unit shows related faults
- Unit is under Lennox extended warranty
Related guides
- Goodman 1 Flash — Diagnose Goodman 1-flash ignition failure: dirty flame sensor, weak ignitor, and gas-valve issues — plus the parts homeowners most often replace.
- Carrier Code 13 — Carrier/Bryant code 13 is a limit lockout after repeated trips. Fix airflow first, then check filters or capacitors.
FAQ
Is E229 a refrigerant code?
No. It is a flame/ignition alert on the gas furnace or air handler heat section.
Need a licensed tech instead?
If the guide says to stop — or the part swap did not clear the fault — get free quotes from licensed local HVAC contractors.
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