BoilerFaultCodesYour boiler has detected an issue with how it moves air and waste gases, so it has safely shut down to prevent a fault.
Book a Gas Safe engineer within 24–48 hours. Your boiler may be unsafe or could break down completely if left.
Technical description: The Air pressure switch has not closed.
What causes this fault?
This fault occurs when the boiler's internal safety sensor cannot confirm that the fan is successfully pushing exhaust gases out of the flue. It is often caused by a buildup of debris in the air tubes, a failing fan motor, or a physical blockage in the pipework leading outside. Because the boiler cannot guarantee that harmful fumes are being safely removed, it shuts down as a protective measure.
This issue is more frequent during periods of heavy wind or extreme cold, as external debris or ice buildup can block the flue terminal and restrict airflow.
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.
Gas Safe Register →Protect yourself from future repair bills
A boiler cover plan would cover faults like 08 — no call-out fees, no surprises.
Affiliate links — we may earn a commission at no extra cost to you.
Glow-worm Energysaver Combi 2 80 100 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.
Affiliate links — we may earn a commission at no extra cost to you.