BoilerFaultCodesYour boiler's internal computer brain has developed a memory error and can no longer process its instructions correctly.
Book a Gas Safe engineer within 24–48 hours. Your boiler may be unsafe or could break down completely if left.
Technical description: Main PCB memory fault
What causes this fault?
This fault occurs when the boiler's main control board suffers a hardware failure, specifically within its internal memory chip. It is usually caused by electrical wear and tear over time or a sudden power surge that corrupts the data the boiler needs to operate safely. Effectively, the board can no longer read its own internal instructions and must be replaced.
This fault is slightly more common during the winter months when boilers are under higher operational stress and stormy weather increases the risk of electrical surges.
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 F63 — no call-out fees, no surprises.
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