BoilerFaultCodesYour boiler has stopped trying to light itself because the small starter flame failed to ignite within the safety time limit.
Book a Gas Safe engineer within 24–48 hours. Your boiler may be unsafe or could break down completely if left.
Technical description: The pilot will attempt to light, if the pilot does not light within 60 seconds (due to air in the system) the boiler controls will go to 'Lockout' and the LED on the user controls will go Red.
What causes this fault?
This fault occurs when the boiler's internal safety system detects that the small pilot flame hasn't lit correctly. The most common reasons are a build-up of debris on the ignition part or air trapped in the gas supply, which prevents the spark from catching. If the boiler cannot confirm a healthy flame within 60 seconds, it shuts down to prevent unburnt gas from escaping.
This issue is more frequent during the autumn when a boiler is turned back on after months of inactivity, as air or debris can settle in the pilot assembly during the summer.
DIY fix possible
Locate the reset button or turn the control knob to the 'Reset' position.Hold for 5 seconds and release.If the fault persists after three attempts, contact a Gas Safe engineer to clear air from the gas line.
Find a Gas Safe engineer
Search the official register for a qualified engineer in your area.
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A boiler cover plan would cover faults like Lockout (Red LED) — no call-out fees, no surprises.
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