BoilerFaultCodesYour boiler is trying to ignite but cannot establish a flame, meaning you have no heating or hot water.
Book a Gas Safe engineer within 24–48 hours. Your boiler may be unsafe or could break down completely if left.
Technical description: No flame during start-up.
What causes this fault?
This fault occurs when the boiler's control system attempts to start a flame but fails to detect one within a safe timeframe. The most common reasons include a lack of gas supply to the unit, a worn-out ignition spark plug, or a component failure that prevents the gas valve from opening correctly.
This fault is more frequent during extreme cold snaps, as external gas meters or pipes can sometimes freeze, restricting the pressure required for the boiler to ignite.
DIY fix possible
Check if other gas appliances, like a hob, are working to ensure gas is reaching the property.Verify that your gas emergency control valve is in the 'on' position.If you have a pre-payment meter, check that you have sufficient credit.Press the reset button once to see if the boiler restarts.
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 F004 — no call-out fees, no surprises.
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Could it be time for a new boiler?
If repair costs are adding up, a new energy-efficient boiler could be the smarter long-term choice.
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