High Lockout
b 29 on Vokera Hydra

Your boiler is struggling to communicate with its internal air-flow system, which prevents it from safely igniting and providing heating or hot water.

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

Incorrect signal from fan

What causes this fault?

This fault occurs when the boiler's control board detects that the fan is not spinning at the required speed to safely clear exhaust gases. It is usually caused by a mechanical failure in the fan motor, a loose connection in the wiring, or a fault on the main circuit board failing to send the correct power signal.

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

b 28View →b 30View →

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