E39 - Compressor discharge temperature sensor (ThOD) defective or poor connection

What does E39 mean?

This error indicates that the compressor discharge temperature sensor (ThOD) is defective (open circuit resistance) or has a poor connection to the outdoor unit PCB.

• Faulty ThOD sensor.
• Loose or corroded connection of the ThOD sensor on the outdoor unit PCB.
• Damaged wiring to the ThOD sensor.

Click steps to track your progress.

1. 1

   Turn off the main power to the outdoor unit at the circuit breaker.

2. 2

   Have a qualified technician inspect the ThOD sensor and its wiring connections on the outdoor unit PCB.

3. 3

   Ensure all connections are secure and free from corrosion.

4. 4

   The technician will test the sensor's resistance and replace it if it's faulty.