Lennox Split & Multi-Split

Lennox Split & Multi-Split Error Code E1

Split & Multi-Split

E1 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

  • Communication error between indoor and outdoor units (E2 for outdoor code)
  • Communication error between indoor unit and outdoor units

Causes & actions from Lennox

Communication error between indoor and outdoor units (E2 for outdoor code)

10 models

3WMB036, M22A, M33A, M33B, MCFA, MCFB, MMDA, MMDB, MWMA, MWMB

Mini-split unit (indoor)

How it shows
  • corp1816 cassette ducted floor display: E1
  • corp1816 running light: 2 times
  • corp1816 timer light: Off
  • corp1816 wall indoor display: E1
  • Indoor receiver display: E1
  • mini outdoor fault display: E2

Communication error between indoor and outdoor units (E2 for outdoor code) (Running Light: 2 times, Timer Light: Off)

Other manual wording

M22A, M33A, M33B, MCFA, MCFB, MMDA, MMDB

This manual entry does not list further causes or actions.

Applicable models & manual sources
  • MWMA

    Communication error between indoor and outdoor units (E2 for outdoor code)

    MWMA, MWMB, 3WMB036

    MWMA manual, page 9

  • M22A

    Communication error between indoor and outdoor units (E2 for outdoor code)

    M22A, M33A, M33B, MMDA, MMDB, MCFA, MCFB

    M22A manual, page 10

  • M22A

    Communication error between indoor and outdoor units (E2 for outdoor code)

    M22A, M33A, M33B

    M22A manual, page 27

Communication error between indoor unit and outdoor units

6 models

M22A, MCFA, MCFB, MFMA, MMDB, Programmable Wired Controller

Mini-split unit, Mini-split unit (indoor)

How it shows
  • 507550 indoor display: E1
  • 507550 wired controller: E1

This manual entry does not list further causes or actions.

Applicable models & manual sources
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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