Lennox SLP98UHV Error Code E 290: Ignitor Circuit Fault
What Does Code E 290 Mean?
The E 290 fault on the Lennox SLP98UHV indicates a fault in the ignitor circuit — the path that runs from the SureLight control's triggering circuitry out to the hot surface ignitor. When the board cannot properly energize the ignitor, or cannot confirm the circuit is behaving normally, it flags E 290 and the furnace cannot light the burners.
This code is broader than E 207 (hot surface ignitor sensed open). E 207 specifically reports that the ignitor element itself reads open, while E 290 covers the whole ignitor circuit, including the board's ignitor relay or driver that sends voltage to the ignitor. So the failure may be a cracked or burned-out ignitor from normal thermal wear, or it may be the control's triggering circuitry that has failed. Both prevent ignition and produce a no-heat condition.
Because the fault can live on either the ignitor or the board side, diagnosis focuses on isolating which one. A technician measures the ignitor and, if it is within specification, turns attention to the control's ignitor circuit — which is why E 290 sometimes ends in a control-board replacement rather than a simple ignitor swap.
What You'll Notice
- No heat — the furnace runs its startup sequence but never lights the burners
- The ignitor does not glow when the furnace attempts to start
- The inducer and pre-purge run, then the unit stops without ignition
- A recently replaced ignitor still won't fire and the code persists
- The 7-segment display shows E 290 in the fault history
Common Causes
| Cause | Likelihood | DIY? |
|---|---|---|
| Hot surface ignitor has burned out or cracked | Most common | ✗ Call a pro → |
How This Is Diagnosed
A technician starts at the ignitor, measuring its electrical resistance with the power off to see whether it is open or out of specification, which overlaps with the E 207 diagnosis. An ignitor that reads good shifts suspicion to the board side.
From there they verify that the control's ignitor circuit actually delivers voltage to the ignitor during the trial for ignition. If the ignitor is sound but the circuit is not energizing it correctly, the SureLight control board is the likely fault and is replaced; if the ignitor is open, replacing it resolves the code.
When to Call a Professional
This code involves components that are not homeowner-serviceable, so have a licensed HVAC technician diagnose and repair it. Keep in mind:
- The furnace will not ignite and displays E 290
- The ignitor does not glow at all when the furnace tries to start
- A new ignitor was installed but the code persists, pointing to the control board
- The furnace also shows E 207 in its fault history
Frequently Asked Questions
Does E 290 mean I need a new control board?
Not always. E 290 covers the whole ignitor circuit, so it can be a failed ignitor or a fault in the board's triggering circuit. A technician measures the ignitor first; only if the ignitor tests good and the board isn't energizing it correctly does the control board become the likely repair.
How is E 290 different from E 207?
E 207 reports the ignitor element itself as an open circuit. E 290 is the broader ignitor-circuit fault that can also implicate the control board's ignitor triggering circuitry. They're related, which is why the manual and technicians cross-reference the two when diagnosing a no-ignition problem.
I replaced the ignitor and E 290 came back — why?
If a new, correct ignitor doesn't clear E 290, the problem is likely upstream in the board's ignitor circuit rather than the ignitor itself. That points to the SureLight control, which a technician should confirm before replacing.
✓ Verified against manufacturer service manual — March 2026