Medium Lockout
10 on Potterton Performa 24

Your boiler is likely struggling to provide hot water or maintain the correct temperature because its internal hot water thermometer has stopped working.

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

Fault on Hot Water Sensor

What causes this fault?

This fault occurs when the boiler's internal thermometer for hot water fails to send a clear signal to the main control board. The most common reason is that the sensor has physically degraded or corroded over time, meaning the boiler can no longer tell how hot the water is and shuts down for safety. Occassionally, this can also be caused by loose or damaged wiring connecting the sensor to the rest of the unit.

Engineer required

This fault requires a Gas Safe registered engineer. Do not attempt gas-related repairs yourself.

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