BoilerFaultCodesYour boiler is recording that it has repeatedly failed to light or stay on, leading to multiple safety shutdowns.
Book a Gas Safe engineer within 24–48 hours. Your boiler may be unsafe or could break down completely if left.
Technical description: Number of unsuccessful lockouts
What causes this fault?
This fault occurs when the boiler tries to ignite multiple times but fails to establish a stable flame, causing the system to lock out for safety. The most common reasons include a lack of gas supply, worn-out ignition parts that can no longer spark, or a build-up of carbon on the electrodes that prevents the boiler from 'sensing' the flame.
This fault is more common during extreme cold spells, as frozen external gas regulators or blockages in the flue can prevent the consistent gas flow and ventilation required for ignition.
Engineer required
This fault requires a Gas Safe registered engineer. Do not attempt gas-related repairs yourself.
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A boiler cover plan would cover faults like D.61 — no call-out fees, no surprises.
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Could it be time for a new boiler?
If repair costs are adding up, a new energy-efficient boiler could be the smarter long-term choice.
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