High
Flash on Worcester Bosch CDi Classic

Your boiler is failing to light the flame needed to produce heat or hot water, causing it to lock itself out for safety.

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

If the boiler fails to light the BLUE power indicator (M) and reset button (E) will flash alternately.

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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