BoilerFaultCodesYour boiler has detected an internal error, likely caused by a failed ignition attempt or a temporary problem with the electronic control board.
Book a Gas Safe engineer within 24–48 hours. Your boiler may be unsafe or could break down completely if left.
Technical description: Specific fault condition (Refer to page 48/51 of fault finding).
What causes this fault?
This fault occurs when the boiler's control center loses communication with its internal sensors or fails to confirm a successful flame after several attempts. It is usually caused by an electrical glitch on the main circuit board or a physical failure of the components that spark the gas into life. Essentially, the boiler has timed out or 'crashed' for safety reasons because it cannot verify that it is firing correctly.
This issue often surfaces during the first cold snap of autumn when the boiler is pushed to work harder after sitting idle throughout the summer months.
Engineer required
This fault requires a Gas Safe registered engineer. Do not attempt gas-related repairs yourself.
Find a Gas Safe engineer
Search the official register for a qualified engineer in your area.
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A boiler cover plan would cover faults like Green LED flashing (4 times per second) — no call-out fees, no surprises.
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