Outdoor Heat Exchanger Sensor (ThOR) Defective or Connection Issue

What does E37 mean?

The outdoor unit's heat exchanger sensor (ThOR) is defective (open circuit) or has a poor connection to the outdoor unit PCB. This affects the system's ability to accurately monitor and control refrigerant temperatures within the outdoor coil.

1. 1

   Measure the resistance of the ThOR sensor at its leads — compare to a resistance-temperature chart if available.

2. 2

   Inspect the ThOR sensor's connector on the outdoor unit PCB — verify it is securely seated and free from corrosion.

3. 3

   Check for damage to the sensor wiring between the sensor and the PCB using a multimeter for continuity.