Medium Warning
1-b3 on Worcester Bosch Greenstar 8000 Life/Style

Your boiler has detected that the hot water is getting too hot, likely due to a sensor measurement issue or a temporary building of heat in the system.

Reviewed by the BoilerFaultCodes Editorial Team · Last reviewed

Book a service

This fault should be looked at by a Gas Safe engineer within the next week or two. It may get worse if left.

Technical description

DHW actual temperature: Actual hot water temperature.

What causes this fault?

This fault occurs when the boiler detects that the water coming out of your hot taps is reaching an unsafe or unexpectedly high temperature. The most common reason is a faulty temperature sensor (NTC) providing an incorrect reading to the control board, or a small blockage in the heat exchanger that prevents heat from being transferred efficiently.

DIY fix possible

Turn off the hot water tap and wait for the boiler to cool downPress the 'Reset' button on the boiler display panelMonitor the boiler to see if the hot water temperature stabilises

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Related fault codes

224VView →

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