High
4 Red Flashes on Main MainEco

Your boiler has detected an issue with the ventilation fan, which means it cannot safely clear exhaust fumes and will not ignite.

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.

What the manual says

Manufacturer manual

Fan Fault

From this model's manual
This code was read directly from the manufacturer service manual for this model.
Plain-English guidance below. Severity, DIY steps, costs and parts are our interpretation to help you act, not text from the manual.

What causes this fault?

This fault occurs when the boiler's control system senses that the fan is not spinning at the correct speed to safely expel waste gases. The most common reasons are a mechanical failure of the fan motor itself, a loose connection in the wiring, or a fault on the main circuit board that prevents power from reaching 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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