FieldBench
Lennox codes

Lennox

E274

Lockout

Soft lockout — last recycle limit open or limit >3 min

Hardened E250.

Walk E274 in Diagnose

4 plates — walk the one on the cabinet

First check

1 Airflow before you touch the limit

On Lennox EL195NE a limit is airflow or overfire until proven otherwise. Do not replace the limit first. Filter, blower wheel, A-coil, and the heat-speed setting for THIS motor (tap, model plug, or communicating CFM — not a sister SKU chart). Hardened E250. VS CFM, media cabinet, rise.

Expect: Rise in the rating-plate window. Static vs this cabinet’s blower chart.

The rest of the walkthrough is Diagnose.

On the plates

  • Hardened E250. VS CFM, media cabinet, rise.
  • If a rollout is open in that string, stop and inspect the exchanger before you up the CFM.
  • Heat tap, static, rollout string.

Plates that use E274