BoilerFaultCodesYour boiler has stopped working as a safety precaution, often due to an issue with the gas supply or a failure to light the burner.
Book a Gas Safe engineer within 24–48 hours. Your boiler may be unsafe or could break down completely if left.
Technical description: BOILER LOCKOUT
What causes this fault?
This fault occurs when the boiler tries to light the burner but fails after several attempts, leading the system to shut down for safety. The most common reasons are a lack of gas reaching the unit, a worn-out ignition spark, or a blockage preventing the burner from catching properly.
This fault is more common during the first cold snap of winter when components that have been idle over summer are forced to work under high demand.
DIY fix possible
Check if your gas meter has credit (if on a prepayment meter)Check if other gas appliances, like a cooker, are working to confirm gas supplyPress and hold the reset button (often marked with a flame symbol) for 3-5 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 F — no call-out fees, no surprises.
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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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