BoilerFaultCodesYour boiler is trying to start up but cannot light the gas burner, so it has locked itself for safety.
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 appliance will enter a lockout condition in the event of the burner failing to ignite. If the burner fails to light after 5 attempts the electricity supply to the gas valve will be interrupted.
What causes this fault?
This fault occurs when the boiler is unable to create a flame despite multiple attempts, leading it to shut down for your safety. The most common reasons include a lack of gas reaching the appliance, or a component like the spark electrode being unable to ignite the fuel properly.
This fault is more common during extreme cold snaps, as the external gas meter regulator can freeze or the condensate pipe may become blocked with ice, preventing the ignition process.
DIY fix possible
Check if your gas prepay meter has creditEnsure other gas appliances in the home are working to confirm gas supplyReset the boiler by turning the control knob to the 'reset' position for 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 Central heating demand indicator flashes slowly (approximately once per second) — no call-out fees, no surprises.
Affiliate links — we may earn a commission at no extra cost to you.
Worcester Bosch 25/28si 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.