BoilerFaultCodesYour boiler has detected that the internal fan is spinning, but it hasn't received the signal to proceed with the next step of the ignition process.
Book a Gas Safe engineer within 24–48 hours. Your boiler may be unsafe or could break down completely if left.
Technical description: FAN RUNNING
What causes this fault?
This fault occurs when the boiler's control board detects the fan is spinning but the air pressure switch fails to close the electrical circuit to confirm safe airflow. The most common reasons are a blockage in the small plastic 'venturi' tubes inside the boiler or a mechanical failure within the pressure switch itself. Without this confirmation signal, the boiler will not spark for ignition as a safety precaution.
This issue is more common during the first cold spell of autumn when a boiler that has been idle over summer is suddenly forced to work at high capacity, causing older mechanical switches to stick.
Engineer required
This fault requires a Gas Safe registered engineer. Do not attempt gas-related repairs yourself.
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