BoilerFaultCodesYour boiler's internal computer has encountered a critical error and can no longer communicate with the rest of the system.
Book a Gas Safe engineer within 24–48 hours. Your boiler may be unsafe or could break down completely if left.
Technical description: Main board fault
What causes this fault?
This fault occurs when the boiler's central control unit suffers an internal electrical failure or a memory corruption. The most common reason is age-related wear on the electronic components, though it can also be triggered by a sudden power surge or moisture getting onto the circuit board.
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 13 — no call-out fees, no surprises.
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