BoilerFaultCodesYour boiler's main internal computer has developed a technical hardware fault and is unable to operate the 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: Bunner controller has internal fault
What causes this fault?
This fault occurs when the main electronic brain of the boiler suffers a critical hardware failure or a memory error. The most common reason is age-related wear on the electrical components within the control board, preventing it from safely managing the ignition sequence. Because the boiler can no longer verify its own safety checks, it shut downs completely to prevent any accidents.
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 F009 — 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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