Lennox Split & Multi-Split

Lennox Error Code E422

Split & Multi-Split

E422 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

  • Compressor top cap switch exceeding thermal limit.
  • 3WPD036S6S-1P: Blockage detected on high pressure pipe during cooling operation

Causes & actions from Lennox

Compressor top cap switch exceeding thermal limit.

40 models

EL18XCV, EL18XCV-024, EL18XCV-036, EL18XCV-048, EL18XCV-060, EL18XPV, EL18XPV-024, EL18XPV-036, EL18XPV-048, EL18XPV-060, EL19KPV, EL19KPV-024, EL19KPV-036, EL19KPV-048, EL19KPV-060, EL21KLV, EL21KLV-024, EL21KLV-036, EL21KLV-048, EL21KLV-060, EL22KCV, EL22KCV-024, EL22KCV-036, EL22KCV-048, EL22KCV-060, SL22KLV, SL22KLV-024, SL22KLV-036, SL22KLV-048, SL22KLV-060, SL25KCV, SL25KCV-024, SL25KCV-036, SL25KCV-048, SL25KCV-060, SL28XCV, SL28XCV-024, SL28XCV-036, SL28XCV-048, SL28XCV-060

Air conditioner (outdoor), Heat pump (outdoor)

How it shows
  • Outdoor control 7-segment display: E422

The top of the compressor is hot. Refrigerant charge may be low, or low mass flow of refrigerant. Check TXV, clogged filter drier, condenser fan motor, indoor blower motor, confirm indoor coil is clean.

Other manual wording

EL18XCV, EL18XCV-024, EL18XCV-036, EL18XCV-048, EL18XCV-060, EL18XPV, EL18XPV-024, EL18XPV-036, EL18XPV-048, EL18XPV-060, EL19KPV,…

The top of the compressor is hot. Refrigerant charge may be low, or low mass flow of refrigerant. Check TXV, clogged filter drier, condenser fan motor, indoor blower motor, confirm indoor coil is clean. Check to make sure the blue wires from the top thermostat did not get pulled off one of the TP terminal on the outdoor control board.

Applicable models & manual sources
  • EL18XCV

    Compressor top cap switch exceeding thermal limit.

    EL18XCV, EL18XCV-024, EL18XCV-036, EL18XCV-048, EL18XCV-060

    EL18XCV manual, page 37

  • EL18XPV

    Compressor top cap switch exceeding thermal limit.

    EL18XPV, EL18XPV-024, EL18XPV-036, EL18XPV-048, EL18XPV-060

    EL18XPV manual, page 37

  • EL19KPV

    Compressor top cap switch exceeding thermal limit.

    EL19KPV, EL19KPV-024, EL19KPV-036, EL19KPV-048, EL19KPV-060

    EL19KPV manual, page 43

  • EL21KLV

    Compressor top cap switch exceeding thermal limit.

    EL21KLV, EL21KLV-024, EL21KLV-036, EL21KLV-048, EL21KLV-060

    EL21KLV manual, page 46

  • EL22KCV

    Compressor top cap switch exceeding thermal limit.

    EL22KCV, EL22KCV-024, EL22KCV-036, EL22KCV-048, EL22KCV-060

    EL22KCV manual, page 40

  • SL22KLV

    Compressor top cap switch exceeding thermal limit.

    SL22KLV, SL22KLV-024, SL22KLV-036, SL22KLV-048, SL22KLV-060

    SL22KLV manual, page 43

  • SL25KCV

    Compressor top cap switch exceeding thermal limit.

    SL25KCV, SL25KCV-024, SL25KCV-036, SL25KCV-048, SL25KCV-060

    SL25KCV manual, page 37

  • SL28XCV

    Compressor top cap switch exceeding thermal limit.

    SL28XCV, SL28XCV-024, SL28XCV-036, SL28XCV-048, SL28XCV-060

    SL28XCV manual, page 31

  • EL18XCV

    Compressor top cap switch exceeding thermal limit.

    EL18XCV, EL18XCV-024, EL18XCV-036, EL18XCV-048, EL18XCV-060

    EL18XCV manual, page 67

  • EL18XPV

    Compressor top cap switch exceeding thermal limit.

    EL18XPV, EL18XPV-024, EL18XPV-036, EL18XPV-048, EL18XPV-060

    EL18XPV manual, page 69

  • EL19KPV

    Compressor top cap switch exceeding thermal limit.

    EL19KPV, EL19KPV-024, EL19KPV-036, EL19KPV-048, EL19KPV-060

    EL19KPV manual, page 72

  • EL21KLV

    Compressor top cap switch exceeding thermal limit.

    EL21KLV, EL21KLV-024, EL21KLV-036, EL21KLV-048, EL21KLV-060

    EL21KLV manual, page 78

  • EL22KCV

    Compressor top cap switch exceeding thermal limit.

    EL22KCV, EL22KCV-024, EL22KCV-036, EL22KCV-048, EL22KCV-060

    EL22KCV manual, page 69

  • SL22KLV

    Compressor top cap switch exceeding thermal limit.

    SL22KLV, SL22KLV-024, SL22KLV-036, SL22KLV-048, SL22KLV-060

    SL22KLV manual, page 73

  • SL25KCV

    Compressor top cap switch exceeding thermal limit.

    SL25KCV, SL25KCV-024, SL25KCV-036, SL25KCV-048, SL25KCV-060

    SL25KCV manual, page 63

  • SL28XCV

    Compressor top cap switch exceeding thermal limit.

    SL28XCV, SL28XCV-024, SL28XCV-036, SL28XCV-048, SL28XCV-060

    SL28XCV manual, page 57

Blockage detected on high pressure pipe during cooling operation

Models: 3WPD036S6S-1P

Mini-split unit (outdoor)

How it shows
  • mini outdoor inverter pcb: E422
  • Mini-split outdoor main board: E422

1. Check if the service valve is open 2. C heck for refrigerant leakage (pipe connections, heat exchanger) and charge refrigerant if necessary 3. C heck if there's any blockage on the refrigerant cycle (indoor unit/outdoor unit) 4. C heck if additional refrigerant has been added after pipe extension

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.

What should you check next?

Continue in ACLogics with guided diagnosis for your equipment and symptoms.

See how guided diagnosis works →