BoilerFaultCodesYour boiler has detected an internal electrical communication error, which means the main control board is likely faulty and cannot manage the heating process safely.
Book a Gas Safe engineer within 24–48 hours. Your boiler may be unsafe or could break down completely if left.
Technical description: EMC fault | EMC or electronics defect
What causes this fault?
This fault occurs when the boiler's central brain, the printed circuit board, suffers an internal memory or electrical failure. It is often caused by aged electrical components wearing out over time or a sudden power surge that damages the delicate circuitry. Because the board can no longer safely coordinate the boiler's functions, it shuts down the system.
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.
Gas Safe Register →Protect yourself from future repair bills
A boiler cover plan would cover faults like F.63 — no call-out fees, no surprises.
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