BoilerFaultCodesYour boiler has failed to light several times and has locked itself for safety, meaning you currently have no heating or hot water.
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: Gas present and at correct pressure; Combustion CO2 level; Flue condition; Ignition electrodes/cables/connections; Flame sense electrode/cables/connections; Gas valve (coils 140-190Ω); Otherwise replace control board.
What causes this fault?
This fault occurs when your boiler tries to start up but cannot confirm that a stable flame has been established, causing it to shut down for your safety. The most common reasons are worn-out components that create the spark or sensors that have become too dirty to detect the fire once it starts. In some cases, it can also be caused by a faulty internal valve that isn't allowing enough gas into the burner to keep the flame lit.
DIY fix possible
Check if your gas supply is active by testing another gas appliance like a hobEnsure your credit meter has sufficient balancePress and hold the reset button for five 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 Slow flash (normally off, flashes on) — no call-out fees, no surprises.
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Worcester Bosch Greenstar 12Ri 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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