Lennox Split & Multi-Split

Lennox Error Code E351

Split & Multi-Split

E351 means different things on different Split & Multi-Split models. Enter your model number to see only your reading, or find your model below.

What It Means

  • CBX40UHV: Heat section / Stage 1 failed (Pilot relay contacts did not close or the relay coil in electric heat did not energizing)
  • CBK48MVT: There is a problem with the air-handler's first stage electric heat. Either the pilot relay contacts did not close, or the relay coil in the electric heat section did not energize.

Causes & actions from Lennox

Heat section / Stage 1 failed (Pilot relay contacts did not close or the relay coil in electric heat did not energizing)

Models: CBX40UHV

Air handler (indoor)

How it shows
  • Single-character display: E351

This manual entry does not list further causes or actions.

Applicable models & manual sources
  • CBX40UHV

    Heat section / Stage 1 failed (Pilot relay contacts did not close or the relay coil in electric heat did not energizing)

    CBX40UHV manual, page 21

There is a problem with the air-handler's first stage electric heat. Either the pilot relay contacts did not close, or the relay coil in the electric heat section did not energize.

Models: CBK48MVT

How it shows
  • Single-character display: E351

Heat section / stage 1 failed. Pilot relay contacts did not close, or the relay coil in the electric heat section did not energize. The alarm clears after stage 1 relay is detected.

Applicable models & manual sources
  • CBK48MVT

    There is a problem with the air-handler's first stage electric heat. Either the pilot relay contacts did not close, or the relay coil in the electric heat section did not energize.

    CBK48MVT manual, page 52

Disclaimer: This information is for general reference. Code wording and instructions vary by model. Always follow the service manual for your exact unit.

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