High
Red LED rapid flashing on Potterton Suprima HE

Your boiler has failed to start up or stay burning, so it has automatically shut down 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

Boiler controls will go to 'Lockout' (e.g. if the boiler does not light within 3 attempts due to air in the system).

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.

Find a Gas Safe engineer
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