Your boiler has tried to light several times but failed, so it has safely shut itself down to prevent any issues.
Book a Gas Safe engineer within 24–48 hours. Your boiler may be unsafe or could break down completely if left.
Technical description: Ignition lockout. The boiler will have three attempts at ignition before lockout. After a pre-set time if ignition has not taken place the boiler will shutdown.
What causes this fault?
This fault occurs when the boiler's internal safety system detects that the gas has failed to ignite or the flame isn't being 'seen' by the sensor. The most common reasons are a worn-out ignition spark, a faulty gas valve that isn't opening properly, or an issue with the main electronic control board. Occasionally, it can also be triggered by a temporary disruption in your external gas supply.
This issue can be more frequent during the first cold snap of autumn when internal components that have been idle over summer struggle to operate correctly.
DIY fix possible
Check if your gas supply is active (e.g., check other gas appliances like a hob)Locate the reset button on the control panelPress the reset button once to see if the boiler restarts
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 Reset neon being 'ON' and the 'Burner on' neon flashing — 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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