FieldBench
Lennox codes

Lennox

E240 / E270

Lockout

Flame current / retry lockout

Weak µA or max retries with no flame current.

Walk E240 / E270 in Diagnose

2 plates — walk the one on the cabinet

First check

1 Measure µA while it is running

Do not clean first and guess. Series-µA the rod on Lennox SL297NV during a call. Falling µA is oxide, ground, or a dying flame. A hard drop is often the pressure switch or limit opening, not the rod. Watch a try. Rod, HSI, gas. Same SureLight ignition as EL296V.

Expect: Flame: µA per SLP99 card — same F-menu idea if the board exposes it.

The rest of the walkthrough is Diagnose.

On the plates

  • Watch a try. Rod, HSI, gas. Same SureLight ignition as EL296V.

Plates that use E240 / E270