Error Code E 206
Low

Lennox EL296UHV Error Code E 206: Gas Valve Second-Stage Relay Failure

TL;DR
Your Lennox EL296UHV's second-stage gas valve relay has failed. The furnace will continue heating on first stage only, which may not keep up in very cold weather.
Disclaimer
This article is for informational purposes only and does not guarantee the accuracy or completeness of the information provided. Always turn off power and gas supply before attempting any repairs. If you smell gas, leave immediately and call your gas company. Consult a licensed HVAC technician for diagnosis and repair. Any actions taken based on this information are at your own risk.

What Does Code E 206 Mean?

Error code E206 on the Lennox EL296UHV indicates that the second-stage gas valve relay on the control board has failed. The EL296UHV is a two-stage furnace, meaning it can operate at a lower firing rate (first stage) for milder conditions and a higher firing rate (second stage) for colder weather. With this relay failure, only first-stage heating is available.

The furnace will continue to operate on first stage for the remainder of any active heating demand, so you will still have heat. However, during extreme cold, first-stage-only operation may not be sufficient to maintain your desired temperature, as the furnace is running at a reduced output.

The error will clear if the relay recovers on its own, but if the second-stage relay has permanently failed, the control board will need to be replaced. A technician should verify the relay condition and replace the control board if second-stage operation cannot be restored.

When to Call a Professional

Contact a licensed HVAC technician if:

Sources

  1. Lennox EL296UHV Unit Information (Corp. 1125-L5)

✓ Verified against manufacturer service manual — March 2026