BoilerFaultCodesYour boiler started to light but the flame went out unexpectedly while it was running, causing the system to shut down 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: Ignition fault - Flame failure during operation
What causes this fault?
This fault occurs when the boiler successfully starts but cannot maintain a steady flame, causing the system to shut down for safety. It is usually caused by a dirty or worn-out sensing probe that can no longer 'see' the fire, or a faulty gas valve that isn't providing a consistent flow of fuel. In some cases, a build-up of carbon or debris on the burner can also interfere with the combustion process.
DIY fix possible
Check if other gas appliances in your home, like a hob, are working to confirm your gas supply is active.Check if your prepaid gas meter has credit.Reset the boiler by pressing the reset button or turning it off and on again.
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 F04 — no call-out fees, no surprises.
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Glow-worm 30ci 30si 35ci 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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