Medium
1021 B on Worcester Bosch 30i Junior

Your boiler is unable to provide hot water because the internal sensor responsible for monitoring its temperature has stopped communicating with 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

Hot water temperature sensor is defective – the plug to the hot water temperature sensor may not be connected

Engineer required

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

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