Lennox Error Code 437

Priority condition: Service Soon/Service Urgent Heat sink temperature sensor fault has occurred (temperature less than 4ºF or greater than 264ºF after 10 minutes of operation). • When the temperature sensor detects a temperature less than 4ºF or greater than 264ºF after 10 minutes of operation. • Outdoor unit will stop both compressor and fan – moderate condition. • Anti-short cycle is initiated. • If condition occurs five times within an hour, system will lockout – critical condition. • Inverter LEDs will flash code 65. • Refer to the unit service documentation for detailed troubleshooting procedures. Priority condition: Service Soon/Service Urgent Inverter flash code 65. Priority condition: Service Soon/Service Urgent The sequence is: • Red LED: Six Flashes • Green LED: Five Flashes NOTE: Inverter normal operations with no error code present is as follows. Red LED is ON and Green LED is OFF.