BoilerFaultCodesYour boiler has tried to start but could not create or detect a flame, causing it to shut down 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 fault (lockout) Failed to light
What causes this fault?
This fault occurs when the boiler attempts to ignite but cannot confirm a stable flame is present. It is usually caused by a lack of gas reaching the burner, worn-out spark electrodes, or a buildup of debris on the internal components that prevents the ignition process from completing safely.
This fault can be more frequent during the first cold snap of autumn when old electrodes or gas valves struggle to operate after being idle over the summer.
DIY fix possible
Check if your gas supply is active by testing another gas appliance like a hob.Ensure your gas meter has credit if you use a pre-payment meter.Press the reset button (indicated by a flame with a cross through it) for three 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 F1 — no call-out fees, no surprises.
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Vaillant ecoMAX Pro 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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