U3 - Discharge thermistor short/open

What does U3 mean?

The discharge thermistor, which measures the temperature of the refrigerant leaving the compressor, is either short-circuited or open. This prevents accurate temperature readings.

• Damaged discharge thermistor.
• Loose or corroded wiring to the thermistor.
• Faulty connection on the outdoor unit PCB.

Click steps to track your progress.

1. 1

   Turn off the main power supply to the air conditioning unit.

2. 2

   Wait for 30 seconds and then turn the power back on.

3. 3

   If the error reappears, it indicates a sensor fault. Contact a qualified technician for inspection and replacement.