Error E39 / Outdoor Red LED Flashes Once — Compressor discharge temperature sensor fault

What does E39 / Outdoor Red LED 1 flash mean?

Error E39, indicated by one flash of the outdoor unit's red LED, means the compressor discharge temperature sensor (ThOD) is defective (open circuit) or has a poor connection to the outdoor unit PCB.

• Compressor discharge temperature sensor (ThOD) defective (resistance is open circuit)
• Poor connection of sensor connection on outdoor unit PCB

Click steps to track your progress.

1. 1

   Turn off the main power to the outdoor unit.

2. 2

   Locate the compressor discharge temperature sensor (ThOD) and inspect its connection to the outdoor PCB.

3. 3

   Ensure the connector is secure and free from corrosion or damage.

4. 4

   If the connection is good, the sensor itself may be faulty and require replacement.

5. 5

   Contact a professional technician for diagnosis and replacement.