FieldBench
Lennox codes

Lennox

E204

Lockout

Gas valve mis-wired

Valve harness does not match what the IFC commanded.

Walk E204 in Diagnose

2 plates — walk the one on the cabinet

First check

1 Damper position vs command

On Lennox EL195NE look at the economizer before the compressor. Commanded open? Blade actually open? Linkage off the shaft is a rooftop weekly. Stage 1 / stage 2 leads on the correct valve terminals. Pinched or swapped harness.

Expect: Blade matches the module command. Stuck open = overventilation. Stuck closed = no free cooling.

The rest of the walkthrough is Diagnose.

On the plates

  • Stage 1 / stage 2 leads on the correct valve terminals. Pinched or swapped harness.
  • Clears when the wiring is repaired — do not replace the IFC first.

Plates that use E204