Medium
A8 on Worcester Bosch CDi

Your boiler has lost its connection to your room thermostat or control panel, meaning it no longer knows when to turn your heating on or off.

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

Break in communication to TD200 or/and RT10.

Engineer required

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

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Related fault codes

A7View →

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