BoilerFaultCodesYour boiler has failed to light or maintain a flame, meaning your heating and hot water have stopped working.
Book a Gas Safe engineer within 24–48 hours. Your boiler may be unsafe or could break down completely if left.
Technical description: Flame failure
What causes this fault?
This fault occurs when the boiler's control system attempts to start the burner but cannot detect a stable flame. The most common reasons are a lack of gas supply to the unit, a worn-out ignition component that fails to create a spark, or a dirty internal sensor that cannot 'see' the flame once it has lit.
This fault is more common during the first cold snap of winter, as gas valves can occasionally stick after long periods of inactivity during the summer.
DIY fix possible
Check if other gas appliances, like a hob, are working to ensure gas is reaching your homeCheck if your gas meter has creditPress the 'Reset' button on the boiler control panel
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 L-F — no call-out fees, no surprises.
Affiliate links — we may earn a commission at no extra cost to you.
Ideal Mexico HE 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.
Affiliate links — we may earn a commission at no extra cost to you.