High Lockout
AL34 on Vokera Syntesi 25

Your boiler has stopped working because the fan that removes waste gases is not spinning at the correct speed or has failed to start.

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

Fan fault

What causes this fault?

This fault occurs when the boiler's control board detects that the fan is either not spinning fast enough to safely clear exhaust gases or has stopped entirely. It is usually caused by a burnt-out fan motor, loose electrical connections, or a defect in the main circuit board that prevents it from sending power to the fan.

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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