8G — Heat sink temperature thermistor (THM) open/short

What does 8G mean?

This error indicates a fault with thermistor THM, which monitors the heat sink temperature. This suggests an open or short circuit in the sensor or its wiring.

• Damaged heat sink temperature thermistor (THM).
• Loose or corroded thermistor connection.
• Faulty wiring leading to the thermistor.

Click steps to track your progress.

1. 1

   Turn off the main power to the outdoor unit by switching off its dedicated circuit breaker.

2. 2

   Locate thermistor THM on the heat sink and inspect its wiring connections for damage or looseness.

3. 3

   Ensure the thermistor probe is securely attached to the heat sink.

4. 4

   Power cycle the unit by turning the breaker back on after inspection.

5. 5

   A technician is usually needed to test the thermistor's resistance and replace it if faulty.