BoilerFaultCodesYour boiler is trying to start up but cannot successfully light the gas to create a flame.
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 startup
What causes this fault?
This fault occurs when the boiler's internal sensor fails to detect a flame after several attempts to ignite the gas. The most common reasons are a lack of gas supply to the unit, a worn-out ignition spark, or a buildup of debris on the internal probes that monitor the combustion process.
This fault often occurs during the first cold snap of autumn when a boiler that has been idle over summer is suddenly required to work at full capacity.
DIY fix possible
Check that your gas emergency control valve is in the 'on' positionIf you have a prepaid meter, ensure you have active credit and the meter is not lockedReset the boiler by pressing the reset button to see if it was a temporary glitch
Find a Gas Safe engineer
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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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