BoilerFaultCodesTechnical description
Air flow proving fault - that is fan or air pressure switch.
What causes this fault?
This fault happens when the boiler's safety system cannot detect a steady flow of air through the unit. It is usually caused by a fan that has seized over time or an air pressure switch that has failed to send the signal that waste gases are being safely removed. In some cases, bits of debris or moisture can block the small plastic tubes that monitor air flow, preventing the boiler from firing up.
This issue often surfaces during the first cold spell of autumn when a boiler that has been idle all summer is suddenly forced to work at high speeds.
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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