Medium
815 W/B on Worcester Bosch 30i Junior

Your boiler has detected a problem with a temperature sensor that monitors how heat is moving through your system, which may prevent your heating from working correctly.

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

Low loss header temperature sensor faulty – check the sensor port or check the differential sensor for incorrect installation position or breakage

Engineer required

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

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Related fault codes

B1View →E9View →

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