Lennox SLP98UHV Error Code E 275: Soft Lockout - Flame Out of Sequence
What Does Code E 275 Mean?
Error code E275 on the Lennox SLP98UHV indicates a soft lockout triggered by a previous E241 fault (flame sensed out of sequence). The flame signal that caused the original E241 has since disappeared, but the control board has entered a lockout state as a safety precaution.
The original E241 condition means the flame sensor detected a flame when the gas valve was supposed to be closed. Even though the flame signal has now cleared on its own, the fact that it occurred at all suggests a potential gas valve issue — the valve may have briefly leaked or stuck open before reseating.
This code should be taken seriously. Even though the immediate danger may have passed, an intermittent gas valve leak is a safety hazard that could recur. A technician should inspect the gas valve for proper operation, check for any signs of gas leakage, and test the flame sensing circuit to rule out false readings.
Common Causes
| Cause | Likelihood | DIY? |
|---|---|---|
| Previous gas valve leak condition (E 241) that has since cleared | Most common | ✗ Call a pro → |
When to Call a Professional
Contact a licensed HVAC technician if:
- This code always requires professional inspection — it indicates a potential gas valve leak
- The code appeared even though the furnace now seems to be running normally
- You have smelled gas near the furnace at any point
✓ Verified against manufacturer service manual — March 2026