Lennox Furnace Code E274
Soft lockout
Soft lockout. The furnace used up its maximum number of recycles and the last one failed because the limit circuit opened, or the limit stayed open longer than three minutes. The unit shuts down for one hour.
Manual wording: “Soft lockout - Exceeded maximum number of recycles. Last recycle failed due to the limit circuit opening or limit remained open longer than 3 minutes.”
Documented for: EL296UHE and SLP98UHV series
Likely causes, most common first
- Dirty air filter restricting airflow
- Closed or blocked supply and return registers
- Blower not moving enough air
- Furnace overfired or blockage inside the heater
What you can safely check yourself
- Check the air filter and replace it if it is dirty
- Make sure supply and return registers are open and unblocked
- After the furnace has cooled, turn the power switch off for 30 seconds and back on once
When to call a technician
The manual's action is to check firing rate and air flow and look for blockage. Repeated limit lockouts need a technician. Never jumper or bypass a limit switch.
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