Medium
Ad on Worcester Bosch ZB 7 27 HE

Your boiler has lost its connection to the sensor that measures how hot your stored hot water is, so it may stop heating your hot water cylinder.

Reviewed by the BoilerFaultCodes Editorial Team · Last reviewed

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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

Cylinder temperature sensor not detected

Engineer required

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

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