Lennox Furnace Code E290
Soft lockout
Ignitor circuit fault. Either the hot surface ignitor has failed or the circuitry that fires it has failed. The furnace goes into a one hour soft lockout.
Manual wording: “Ignitor circuit fault - Failed ignitor or triggering circuitry. Measure resistance of hot surface ignitor. Replace if open or not within specifications. 1-hour soft lockout.”
Documented for: EL296UHE and SLP98UHV series
Likely causes, most common first
- Failed or cracked hot surface ignitor
- Failed ignitor triggering circuit on the control board
- Loose or damaged ignitor wiring
What you can safely check yourself
- Turn the furnace power switch off for 30 seconds and back on once
When to call a technician
The manual's action is to measure ignitor resistance and replace it if it is out of specification. Have a technician do it.
A Lennox furnace throwing this code repeatedly has a reason — clearing the code without fixing the cause just hides it.
Sources
- 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
- SLP98UHV Service Literature (Corp. 1029-L7), Table 14 - LED 7 Segment Status / Error Code and Integrated Control Diagnostic Codes (Lennox Industries Inc., SLP98UHV series variable-capacity communicating gas furnace (66,000-132,000 Btuh)) · checked 2026-08-25