Lennox EL296UHV Error Code E 205: Gas Valve Control Relay Contact Shorted
What Does Code E 205 Mean?
Inside the SureLight integrated control of the Lennox EL296UHV, relays act as the electronic switches that open and close the gas valve on command. Error E205 means one of those gas-valve relay contacts is shorted — stuck in a way that no longer switches the valve circuit properly.
This is a high-severity, safety-related fault. A shorted relay contact can leave the gas-valve circuit energized even when the control is not calling for heat, which is exactly the uncontrolled-gas condition the control is designed to prevent. When it detects the short during its self-check, it locks the system out.
The relay is a component on the control board and cannot be repaired on its own, so once wiring is ruled out, addressing E205 means replacing the control. This is the internal-relay counterpart to E204, which concerns external gas-valve wiring, and it sits beside E206, where the second-stage gas-valve relay fails instead of shorting. Together they cover the ways the two-stage gas-valve control path can fail on this board.
What You'll Notice
- The seven-segment display shows E 205
- The furnace is locked out and will not run
- The burners may have behaved abnormally before the lockout
- Any gas smell near the furnace (leave immediately and call your gas company)
How This Is Diagnosed
A technician first inspects the wiring between the control and the gas valve to rule out an external fault that could mimic a shorted relay. Loose or damaged connections are corrected before anything is condemned.
If the wiring is correct and the control still reports a shorted gas-valve relay, the fault is internal to the board. Because the relay is soldered to the control and cannot be serviced individually, the technician replaces the integrated control to restore safe gas-valve switching.
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 is locked out with E205 and will not restart
- The burners behaved abnormally just before the lockout
- The control board is suspected to need replacement
- You smell gas near the furnace at any time
Frequently Asked Questions
Why is E205 considered a safety issue?
A shorted relay contact can keep the gas-valve circuit energized when no heat is being called for. That risk of uncontrolled gas flow is why the control locks the furnace out until it is repaired.
Can the relay be fixed without replacing the board?
No. The gas-valve relay is soldered to the integrated control and is not a separately serviceable part, so a genuinely shorted relay means the control board is replaced.
Could E205 be caused by something other than the board?
Wiring between the control and gas valve is checked first, since a wiring fault can look similar. If the wiring is sound and the short remains, the control itself is the cause.
✓ Verified against manufacturer service manual — March 2026