Lennox Furnace Code E229
Status
Information only. The furnace lit on high fire instead of low fire. This happens either because the low pressure switch did not close, so the control sped up the inducer to close both switches and lit on high fire, or because continuous fan was running and the furnace lights on high fire for 60 seconds to warm the heat exchanger faster.
Manual wording: “Ignition on High Fire - Information Only.”
Documented for: EL296UHE series
Likely causes, most common first
- Low pressure switch failing to close on a normal low-fire start, often from a partially restricted vent
- Continuous fan mode active at the start of the heat call, which is normal behavior
What you can safely check yourself
- Check the outdoor intake and exhaust pipes for snow, ice or debris if the code shows up repeatedly
- Check the air filter and replace it if it is dirty
When to call a technician
On its own this code is informational and needs no action. If it appears on every heat call along with pressure switch codes such as E223 or E227, have a technician check the vent and inducer.
A Lennox furnace throwing this code repeatedly has a reason — clearing the code without fixing the cause just hides it.
Source
- EL296UHE Service Literature (Corp. 1246-L10), Table 4 - Integrated Control Diagnostic Codes (Lennox Industries Inc., EL296UHE series 96% AFUE two-stage upflow/horizontal gas furnace (EL296UH045XE36B, EL296UH070XE36B, EL296UH090XE48C)) · checked 2026-08-25