BoilerFaultCodesYour boiler has failed to light the gas flame or cannot detect that it is lit, so it has 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: Flame failure
What causes this fault?
This fault occurs when the boiler attempts to ignite but cannot establish or maintain a steady flame, causing it to shut down for safety. The most common reasons include a worn-out ignition spark, a blocked burner, or a faulty gas valve that isn't letting enough fuel into the combustion chamber.
This issue is more frequent during extreme cold spells, as frozen external gas meters or blocked pipes can restrict the constant flow of gas required for ignition.
DIY fix possible
Check that you have credit on your gas meter if you have one.Ensure other gas appliances like your hob are working to confirm gas supply.Press and hold the reset button for 2 seconds.
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 Fault led (B) illuminated (Flame failure) — no call-out fees, no surprises.
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Ideal Boxer C 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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