BoilerFaultCodesYour boiler has shut itself down for safety because it cannot successfully light or maintain 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: A flame failure device is incorporated into the control system... should the flame fail for any reason, or should ignition fail to initiate a satisfactory start, the boiler is automatically locked out for safety.
What causes this fault?
This fault occurs when the boiler's internal computer can no longer detect a stable flame during the ignition process. The most common reasons are worn-out sparks that fail to light the gas, a dirty sensor that can't 'see' the flame, or an inconsistent gas supply preventing a steady fire from forming.
This fault is more common during the first cold snap of winter, as internal components like the gas valve can seize up after being inactive during the summer months.
DIY fix possible
Check if your other gas appliances (like a cooker) are working to ensure gas supplyEnsure your decorative gas fire or meter valve hasn't been accidentally turned offPress and hold the reset button for five seconds once gas supply is confirmed
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 Lock-out Indicator — no call-out fees, no surprises.
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Worcester Bosch Greenstar HE 12/22 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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