BoilerFaultCodesYour boiler is trying to start up but cannot safely confirm that the exhaust gases are being cleared, so it has frozen for safety.
Book a Gas Safe engineer within 24–48 hours. Your boiler may be unsafe or could break down completely if left.
Technical description: Go to sections 'J' & 'M'
What causes this fault?
This fault occurs when the boiler's safety system fails to detect a constant airflow after the fan starts spinning. It is usually caused by a blockage in the air tubes, a mechanical failure in the fan, or a faulty sensor that cannot confirm the exhaust gases are being safely pushed out of the flue. Because the boiler cannot guarantee that it won't leak fumes into the home, it stops the ignition process entirely.
This issue often surfaces during periods of high wind, which can create back-pressure in the flue and prevent the air pressure sensor from clicking into place.
Engineer required
This fault requires a Gas Safe registered engineer. Do not attempt gas-related repairs yourself.
Find a Gas Safe engineer
Search the official register for a qualified engineer in your area.
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A boiler cover plan would cover faults like neon flashing (Fan runs at max speed) — no call-out fees, no surprises.
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Potterton Performa 30 HE is discontinued — time for a new one?
Parts for discontinued models can be hard to find and expensive. A new A-rated boiler could save you money on both repairs and energy bills.
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