High
A8 on Worcester Bosch 24 RSF

Your boiler has lost its connection to the external heating controls, meaning it cannot receive instructions on when to turn on or off.

Reviewed by the BoilerFaultCodes Editorial Team · Last reviewed

Call an engineer soon

Book a Gas Safe engineer within 24 to 48 hours. Your boiler may be unsafe or could break down completely if left.

Technical description

Break communication to FX sensor controls electrical connections need checking.

Engineer required

This is a high severity fault. Stop using the boiler and call a Gas Safe registered engineer. Do not attempt gas-related repairs yourself.

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Related fault codes

A7View →E9View →

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