Sensor fault in heat pump: how to distinguish a sensor failure from a real problem

A sensor code does not always mean the sensor needs to be replaced immediately.

Open circuit

A cut wire, disconnected plug, or internal break can result in an extreme reading.

Short circuit

Wiring or sensor short circuits can also appear as an unrealistic temperature.

Incorrect positioning

A functional sensor in the wrong position can provide technically valid but operationally incorrect information.

Correct diagnosis

Check resistance, wiring, board connection, and compare with an independent thermometer before deciding on replacement.