P3 error on Certikin heat pump; unit may run but with poor performance.

This repair may involve working with high voltage components or water connections. Always unplug the appliance before removing any panels.

If you are not confident in your ability to perform this repair safely, we strongly recommend contacting a professional technician.

Possible Causes

Defective outlet water sensor, Poor thermal contact with pipe, Wiring fault between sensor and PCB, Sensor out of calibration

Safety first: Isolate power before working on sensors.

Locate outlet sensor: Find the outlet water temperature sensor on the heat pump’s water circuit.
Check mounting: Ensure the sensor is firmly clamped to the pipe or inserted into its pocket with good thermal contact.
Inspect wiring: Check for damage or loose connections at both the sensor and control board.
Reset: Restore power and test operation.

Persistent P3 errors require sensor resistance checks and possible replacement.

Medium 3/5

Certikin heat pump outlet water temperature sensor

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