Overheat protection (Outdoor pipe thermistor)

What does Ud mean?

This fault triggers if the outdoor pipe thermistor (TH1) detects 70°C (158°F) or more during compressor operation. It indicates excessive heat within the outdoor unit, likely due to restricted airflow, a malfunctioning outdoor fan, or a faulty thermistor. Persistent overheating can lead to compressor failure and significant reduction in cooling efficiency.

Additional Steps

Steps 1–2 are listed in Priority Fix.

1. 3

   Check the outdoor pipe thermistor (TH1) for correct resistance values and secure connections.

2. 4

   Turn the unit off and on again. If the error code reappears, address the root cause, possibly replacing the thermistor if it's faulty.