Display shows F6, heater may overheat quickly or shut down soon after starting.

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

Open or shorted DHW temperature sensor, Sensor not seated in hot water outlet, Wiring fault between sensor and PCB

Safety: Isolate electrical supply and allow hot water pipework to cool.

Locate DHW thermistor: Usually mounted on or near the domestic hot water outlet pipe from the heat exchanger or plate heat exchanger.
Check seating: Confirm the sensor is fully inserted into its pocket or firmly clipped to the pipe with thermal paste or good contact.
Inspect wiring: Check for damage or loose connectors at both the sensor and the control board.
Reset: After reseating, restore power and reset the heater. If F6 returns, arrange for sensor replacement.

Medium 3/5

DHW Outlet Thermistor

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