BoilerFaultCodes.com
35 High Lockout

Your boiler has stopped working because the internal fan, which safely clears exhaust gases, isn't spinning or communicating correctly with the system.

Call an engineer soon

Book a Gas Safe engineer within 24–48 hours. Your boiler may be unsafe or could break down completely if left.

Technical description: fan error

What causes this fault?

This fault occurs when the boiler's control system detects that the fan is either not spinning fast enough or has stopped altogether. The most common reason is a mechanical failure of the fan motor or a buildup of dust and debris that prevents it from rotating freely. In some cases, the main circuit board may be failing to send power or signals to the fan, causing the boiler to shut down for safety.

Typical repair cost £180-450 (including labour)

Engineer required

This fault requires a Gas Safe registered engineer. Do not attempt gas-related repairs yourself.

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