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.

Additional Steps

Steps 1–2 are listed in Priority Fix.

1. 3

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

2. 4

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