FieldBench
Lennox codes

Lennox

E240

Protect

Low flame current — run mode

Flame is present but µA is below the run threshold.

Walk E240 in Diagnose

4 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 EL195NE 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. F menu for live µA. Clean the rod — not sandpaper. Neutral-to-ground and E117.

Expect: Flame (F menu): µA per EL296 card. Rising while running.

The rest of the walkthrough is Diagnose.

On the plates

  • F menu for live µA. Clean the rod — not sandpaper. Neutral-to-ground and E117.
  • Clears at the end of the heat call. Repeating E240 becomes E270 / E273.
  • F menu, rod, ground. Repeating E240 becomes E270 / E273.

Plates that use E240