Lennox EL296UHV Error Code E 112: Ground Not Detected
What Does Code E 112 Mean?
Error code E112 on the Lennox EL296UHV indicates that the control board cannot detect an earth ground connection. Unlike E117 (poor ground warning), E112 is a critical fault that causes the system to shut down completely. Proper grounding is essential for the flame sensing circuit and overall electrical safety.
The most common cause is a missing or disconnected ground wire at the furnace. This can happen if the ground wire was never connected during installation, if it has corroded and broken at a terminal, or if the ground path back to the electrical panel is interrupted.
The system will resume normal operation within 5 seconds after proper grounding is established. An electrician or HVAC technician should verify that the furnace has a solid earth ground connection, check the ground wire continuity back to the electrical panel, and ensure the panel itself is properly grounded to the home's grounding electrode system.
Common Causes
| Cause | Likelihood | DIY? |
|---|---|---|
| Missing or broken ground wire connection | Most common | ✗ Call a pro → |
When to Call a Professional
Contact a licensed HVAC technician if:
- The furnace displays E112 and has shut down
- The ground wire at the furnace is visibly disconnected or corroded
- The furnace was recently installed and may not have been grounded
✓ Verified against manufacturer service manual — March 2026