High
Slow flash on Worcester Bosch 28 RSF

Your boiler has detected a safety concern or internal fault and has automatically shut down to protect itself, requiring you to attempt a manual reset.

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

Once per second. Can only be cleared by using the facia reset button (press for at least one second).

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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