U3 - 3 red flashes, 5 green flashes — Discharge thermistor fault

What does U3 mean?

This error points to a fault with the discharge thermistor (TH4), indicating it might be open, shorted, or disconnected.

• Discharge thermistor (TH4) has an open circuit
• Discharge thermistor (TH4) has a short circuit
• TH4 thermistor is disconnected
• Faulty thermistor or wiring

Click steps to track your progress.

1. 1

   Check the discharge thermistor (TH4) for secure connection.

2. 2

   Inspect the wiring associated with TH4.

3. 3

   Measure the resistance of TH4 to verify its function.

4. 4

   Replace the TH4 thermistor if it is found to be defective.