Outdoor Unit Heat Exchanger Sensor (ThOR) Defective / Cooling High Pressure

What does E35 mean?

The outdoor unit heat exchanger sensor (ThOR) is defective, indicated by an open or closed circuit resistance, or by a poor connection of the sensor connector on the outdoor unit PCB. This can also be caused by high pressure in the cooling system, impacting heat exchange.

• Outdoor unit heat exchanger temperature sensor (ThOR, e.g., P17) is faulty or shorted.
• High discharge pressure detected.
• Poor airflow over the outdoor unit heat exchanger.
• Overcharged refrigerant system.
• Faulty fan motor in the outdoor unit.

Click steps to track your progress.

1. 1

   Measure the resistance of the outdoor unit heat exchanger sensor (ThOR) and compare it to the specified temperature-resistance chart.

2. 2

   Inspect the ThOR sensor connector on the outdoor unit PCB for secure and clean connection.

3. 3

   Measure the cooling system high pressure using a manifold gauge set, ensuring it is within operational limits.

4. 4

   Verify refrigerant charge and inspect condenser coils for cleanliness and obstructions impacting airflow.