BoilerFaultCodesYour boiler has detected an electrical fault within its internal sensors or control board, which has caused the system to shut down for safety.
Book a Gas Safe engineer within 24–48 hours. Your boiler may be unsafe or could break down completely if left.
Technical description: Electronics/sensor fault: Short-circuit in flow or return sensor or electronics defective
What causes this fault?
This fault occurs when the boiler's internal computer receives conflicting or impossible signals from its temperature sensors. It is usually caused by a short circuit in the wiring or a total failure of the NTC sensors that measure water temperature, but it can also indicate that the main control board is no longer processing data correctly. To prevent overheating, the boiler immediately shuts down until the faulty electrical component is replaced.
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 F.64 — no call-out fees, no surprises.
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