Lennox Split & Multi-Split

Lennox Split & Multi-Split Error Code E3

Split & Multi-Split

E3 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

  • Indoor fan speed error
  • Communication error between outdoor unit main control and IPM control.
  • MLA, MPA, MPB: Communication malfunction between IPM board and outdoor main control board
  • Programmable Wired Controller: Indoor coil temperature sensor error (T2)
  • Indoor fan speed error (DC motor)

Causes & actions from Lennox

Indoor fan speed error

10 models

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

Mini-split unit (indoor)

How it shows
  • corp1816 cassette ducted floor display: E3
  • corp1816 running light: 4 times
  • corp1816 timer light: Off
  • corp1816 wall indoor display: E3
  • Indoor receiver display: E3

Indoor fan speed error (Running Light: 4 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

Communication error between outdoor unit main control and IPM control.

10 models

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

Mini-split unit (indoor)

How it shows
  • corp1816 old indoor display: E3

This manual entry does not list further causes or actions.

Applicable models & manual sources
  • MWMA

    Communication error between outdoor unit main control and IPM control.

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

    MWMA manual, page 6

Communication malfunction between IPM board and outdoor main control board

Models: MLA, MPA, MPB

Mini-split unit (outdoor)

How it shows
  • corp1816 multizone outdoor display: E3

This manual entry does not list further causes or actions.

Applicable models & manual sources
  • MPA

    Communication malfunction between IPM board and outdoor main control board

    MPA, MPB, MLA

    MPA manual, page 6

Indoor coil temperature sensor error (T2)

Models: Programmable Wired Controller

Indoor fan speed error (DC motor)

5 models

M22A, MCFA, MCFB, MFMA, MMDB

Mini-split unit (indoor)

How it shows
  • 507550 indoor display: E3

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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