BoilerFaultCodesTechnical 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 is a high severity fault. Stop using the boiler and call a Gas Safe registered engineer. Do not attempt gas-related repairs yourself.
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