Lennox Split & Multi-Split

Lennox Error Code E424

Split & Multi-Split

E424 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

  • The liquid line temperature sensor has malfunctioned.
  • Faulty outdoor liquid line sensor

Causes & actions from Lennox

The liquid line temperature sensor has malfunctioned.

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: E424

Check connections between pin 3 and 4 of the four pin liquid/ suction temperature plug on the bottom left corner of the control. Check resistance of resistor. Nominal 10K Ohms at 77F. Error code occurs if sensor is open or shorted.

Applicable models & manual sources
  • EL18XCV

    The liquid line temperature sensor has malfunctioned.

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

    EL18XCV manual, page 37

  • EL18XPV

    The liquid line temperature sensor has malfunctioned.

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

    EL18XPV manual, page 37

  • EL19KPV

    The liquid line temperature sensor has malfunctioned.

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

    EL19KPV manual, page 43

  • EL21KLV

    The liquid line temperature sensor has malfunctioned.

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

    EL21KLV manual, page 46

  • EL22KCV

    The liquid line temperature sensor has malfunctioned.

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

    EL22KCV manual, page 40

  • SL22KLV

    The liquid line temperature sensor has malfunctioned.

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

    SL22KLV manual, page 43

  • SL25KCV

    The liquid line temperature sensor has malfunctioned.

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

    SL25KCV manual, page 37

  • SL28XCV

    The liquid line temperature sensor has malfunctioned.

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

    SL28XCV manual, page 31

Faulty outdoor liquid line sensor

10 models

EL18XCV, EL18XCV-024, EL18XCV-036, EL18XCV-048, EL18XCV-060, EL22KCV, EL22KCV-024, EL22KCV-036, EL22KCV-048, EL22KCV-060

How it shows
  • Outdoor control 7-segment display: E424

Sensor is open or shorted. Replace the sensor.

Applicable models & manual sources
  • EL18XCV

    Faulty outdoor liquid line sensor

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

    EL18XCV manual, page 75

  • EL22KCV

    Faulty outdoor liquid line sensor

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

    EL22KCV manual, page 75

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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