Lennox Furnace Code E112
Warning
Ground not detected. The control cannot find a proper earth ground and shuts the system down.
Manual wording: “Ground not detected. System shuts down. Provide proper earth ground. System resumes normal operation 5 seconds after fault recovered.”
Documented for: EL296UHE series
Likely causes, most common first
- Ground wire missing, loose or corroded at the furnace
- Furnace chassis not bonded to a proper earth ground
What you can safely check yourself
- Check that the furnace disconnect switch and breaker are on
- Turn the furnace power switch off for 30 seconds and back on once
When to call a technician
Providing a proper earth ground for the furnace is electrical work. Have an electrician or HVAC technician verify and correct the ground.
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