BoilerFaultCodesYour boiler is failing to light the gas flame required to heat your water and radiators.
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 detected
What causes this fault?
This fault occurs when the boiler tries to ignite but fails to establish a sustained flame after several attempts. The most common reasons include a lack of gas supply to the unit, worn-out ignition components that can no longer create a spark, or a dirty sensor that cannot 'see' the flame even if it has lit.
This fault is more common during extreme cold snaps, as external gas meters or regulators can sometimes freeze and restrict the flow of gas to the property.
DIY fix possible
Check if other gas appliances, like a hob, are working to ensure gas is reaching the propertyEnsure your gas pre-payment meter (if applicable) has creditCheck that the gas isolation valve under the boiler is in the open positionPress the Reset button on the boiler control panel
Find a Gas Safe engineer
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A boiler cover plan would cover faults like 501 — 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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