Lennox Split & Multi-Split

Lennox Error Code P1

Split & Multi-Split

P1 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

  • High or low voltage protection - outdoor display E5
  • High or Low voltage protection
  • MLA, MPA, MPB: High pressure protection
  • High pressure switch open

Causes & actions from Lennox

High or low voltage protection - outdoor display E5

10 models

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

Mini-split unit (indoor)

How it shows
  • corp1816 cassette ducted floor display: P1
  • corp1816 running light: 2 times
  • corp1816 timer light: Flash
  • corp1816 wall indoor display: P1
  • Indoor receiver display: P1
  • mini outdoor fault display: E5

High or low voltage protection - outdoor display E5 (Running Light: 2 times, Timer Light: Flash)

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

    High or low voltage protection - outdoor display E5

    MWMA, MWMB, 3WMB036

    MWMA manual, page 9

  • M22A

    High or low voltage protection - outdoor display E5

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

    M22A manual, page 10

  • M22A

    High or low voltage protection - outdoor display E5

    M22A, M33A, M33B

    M22A manual, page 27

High or Low voltage protection

5 models

M22A, MCFA, MCFB, MFMA, MMDB

Mini-split unit (indoor)

How it shows
  • 507550 indoor display: P1

This manual entry does not list further causes or actions.

Applicable models & manual sources

High pressure protection

Models: MLA, MPA, MPB

Mini-split unit (outdoor)

How it shows
  • corp1816 multizone outdoor display: P1
  • corp1816 new indoor error: P6

This manual entry does not list further causes or actions.

Applicable models & manual sources

High pressure switch open

10 models

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

Mini-split unit (indoor)

How it shows
  • corp1816 old indoor display: P1

This manual entry does not list further causes or actions.

Applicable models & manual sources
  • MWMA

    High pressure switch open

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

    MWMA manual, page 6

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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