What It Means
- Heat sink temperature sensor fault has occurred (temperature less than 4 ºF or greater than 264ºF after 10 minutes of operation).
Lennox Split & Multi-Split
Lennox Error Code E437
Split & Multi-Split: Air conditioner (outdoor), Heat pump (outdoor)
Causes & actions from Lennox
How it shows
- Inverter code: 65
- Inverter LED flash code: Red 6 flashes, Green 5 flashes (green: flashing ×5, red: flashing ×6)
- Outdoor control 7-segment display: E437
Occurs when the temperature sensor detects a temperature less than 0.4ºF or greater than 264ºF after 10 minutes of operation. If condition is detected, outdoor unit will stop (compressor and fan). Anti-short cycle is initiated. If condition occurs 5 times within an hour, system will lock out. To clear, disconnect power to the indoor unit (24VAC power source to the outdoor control) which will power off the outdoor control and will open the outdoor unit contactor, which interrupts power to the inverter and then re-apply power. If problem persists, replace inverter.
Other manual wording (1 of 2)
EL18XCV, EL18XCV-024, EL18XCV-036, EL18XCV-048, EL18XCV-060, EL18XPV, EL18XPV-024, EL18XPV-036, EL18XPV-048, EL18XPV-060, EL21KLV,…
This occurs when the temperature sensor detects a temperature less than 0.4ºF or greater than 264ºF after 10 minutes of operation. If condition is detected, outdoor unit will stop (compressor and fan). Antishort cycle is initiated. If condition occurs 5 times within an hour, system will lock out. To clear, disconnect power to the indoor unit (24VAC power source to the outdoor control) which will power off the outdoor control and will open the outdoor unit contactor, which interrupts power to the inverter and then re-apply power.
Other manual wording (2 of 2)
EL19KPV, EL19KPV-024, EL19KPV-036, EL19KPV-048, EL19KPV-060
This occurs when the temperature sensor detects a temperature less than 0.4ºF or greater than 264ºF after 10 minutes of operation. If condition is detected, outdoor unit will stop (compressor and fan). Antishort cycle is initiated. If condition occurs 5 times within an hour, the unitary control will cycle the contactor to prevent the unit from locking out. To clear, disconnect power to the indoor unit (24VAC power source to the outdoor control) which will power off the outdoor control and will open the outdoor unit contactor, which interrupts power to the inverter and then re-apply power.
Applicable models & manual sources
- EL18XCV
Heat sink temperature sensor fault has occurred (temperature less than 4ºF or greater than 264ºF after 10 minutes of operation).
EL18XCV, EL18XCV-024, EL18XCV-036, EL18XCV-048, EL18XCV-060
- EL18XPV
Heat sink temperature sensor fault has occurred (temperature less than 4ºF or greater than 264ºF after 10 minutes of operation).
EL18XPV, EL18XPV-024, EL18XPV-036, EL18XPV-048, EL18XPV-060
- EL19KPV
Heat sink temperature sensor fault has occurred (temperature less than 4ºF or greater than 264ºF after 10 minutes of operation).
EL19KPV, EL19KPV-024, EL19KPV-036, EL19KPV-048, EL19KPV-060
- EL21KLV
Heat sink temperature sensor fault has occurred (temperature less than 4ºF or greater than 264ºF after 10 minutes of operation).
EL21KLV, EL21KLV-024, EL21KLV-036, EL21KLV-048, EL21KLV-060
- EL22KCV
Heat sink temperature sensor fault has occurred (temperature less than 4ºF or greater than 264ºF after 10 minutes of operation).
EL22KCV, EL22KCV-024, EL22KCV-036, EL22KCV-048, EL22KCV-060
- SL22KLV
Heat sink temperature sensor fault has occurred (temperature less than 4ºF or greater than 264ºF after 10 minutes of operation).
SL22KLV, SL22KLV-024, SL22KLV-036, SL22KLV-048, SL22KLV-060
- SL25KCV
Heat sink temperature sensor fault has occurred (temperature less than 4ºF or greater than 264ºF after 10 minutes of operation).
SL25KCV, SL25KCV-024, SL25KCV-036, SL25KCV-048, SL25KCV-060
- SL28XCV
Heat sink temperature sensor fault has occurred (temperature less than 4ºF or greater than 264ºF after 10 minutes of operation).
SL28XCV, SL28XCV-024, SL28XCV-036, SL28XCV-048, SL28XCV-060
- EL18XCV
Heat sink temperature sensor fault has occurred (temperature less than 4 ºF or greater than 264ºF after 10 minutes of operation).
EL18XCV, EL18XCV-024, EL18XCV-036, EL18XCV-048, EL18XCV-060
- EL18XPV
Heat sink temperature sensor fault has occurred (temperature less than 4 ºF or greater than 264ºF after 10 minutes of operation).
EL18XPV, EL18XPV-024, EL18XPV-036, EL18XPV-048, EL18XPV-060
- EL21KLV
Heat sink temperature sensor fault has occurred (temperature less than 4 ºF or greater than 264ºF after 10 minutes of operation).
EL21KLV, EL21KLV-024, EL21KLV-036, EL21KLV-048, EL21KLV-060
- EL22KCV
Heat sink temperature sensor fault has occurred (temperature less than 4 ºF or greater than 264ºF after 10 minutes of operation).
EL22KCV, EL22KCV-024, EL22KCV-036, EL22KCV-048, EL22KCV-060
- SL22KLV
Heat sink temperature sensor fault has occurred (temperature less than 4 ºF or greater than 264ºF after 10 minutes of operation).
SL22KLV, SL22KLV-024, SL22KLV-036, SL22KLV-048, SL22KLV-060
- SL25KCV
Heat sink temperature sensor fault has occurred (temperature less than 4 ºF or greater than 264ºF after 10 minutes of operation).
SL25KCV, SL25KCV-024, SL25KCV-036, SL25KCV-048, SL25KCV-060
- SL28XCV
Heat sink temperature sensor fault has occurred (temperature less than 4 ºF or greater than 264ºF after 10 minutes of operation).
SL28XCV, SL28XCV-024, SL28XCV-036, SL28XCV-048, SL28XCV-060
- EL19KPV
Heat sink temperature sensor fault has occurred (temperature less than 4 ºF or greater than 264ºF after 10 minutes of operation).
EL19KPV, EL19KPV-024, EL19KPV-036, EL19KPV-048, EL19KPV-060
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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