BoilerFaultCodes.com
H6 High Lockout

Your boiler has stopped working because the internal fan, which safely exhausts gases from the unit, is not spinning correctly.

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 internal fan is either not spinning at all or is spinning at the wrong speed to safely remove exhaust gases. The most common reasons are a mechanical failure within the fan motor itself, a loose connection in the wiring, or the electronic circuit board failing to send the correct signals to the fan.

Typical repair cost £250-£450 (including labour)

Engineer required

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

Find a Gas Safe engineer

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Protect yourself from future repair bills

A boiler cover plan would cover faults like H6 — no call-out fees, no surprises.

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