Lennox codes

Lennox

E270 / 7-flash

Lockout

Ignition lockout

Max retries, no flame current (7-seg) or ignition lockout (flash).

Walk E270 / 7-flash in Diagnose

Sign in for the next measurement

First check

1 Measure µA while it is running

Do not clean first and guess. Series-µA the rod on Lennox SL280 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. HSI, gas, rod. If E271 / 6-flash stores, draft died — go back to the vent.

Expect: Typically ≥ 1.0 µA DC on this family — confirm the door card. Rising while running.

The rest of the walkthrough is Diagnose.

On the plates

  • Watch a try. HSI, gas, rod. If E271 / 6-flash stores, draft died — go back to the vent.

Plates that use E270 / 7-flash