Lennox SLP98UHV Error Code E 290: Ignitor Circuit Fault
What Does Code E 290 Mean?
Error code E290 on the Lennox SLP98UHV indicates a fault in the ignitor circuit, which could be either the hot surface ignitor itself or the triggering circuitry on the control board. The furnace cannot light the burners until this issue is resolved.
This code is related to E207 (ignitor sensed open) but is broader in scope — it covers not only ignitor failure but also problems with the control board's ability to send voltage to the ignitor. The ignitor may have cracked from thermal stress, or the control board's ignitor relay or driver circuit may have failed.
A technician should first test the ignitor's electrical resistance to determine if it is within specification. If the ignitor tests good, the problem is likely on the control board side, and the board may need replacement. If the ignitor is open or out of specification, replacing it should resolve the issue.
Common Causes
| Cause | Likelihood | DIY? |
|---|---|---|
| Hot surface ignitor has burned out or cracked | Most common | ✗ Call a pro → |
When to Call a Professional
Contact a licensed HVAC technician if:
- The furnace will not ignite and displays E290
- The ignitor does not glow at all when the furnace attempts to start
- A new ignitor was installed but the code persists, suggesting a control board issue
✓ Verified against manufacturer service manual — March 2026