BoilerFaultCodesYour boiler has detected that the electricity supply coming into your home is at a dangerously high voltage, which could damage the internal electronics.
Book a Gas Safe engineer within 24–48 hours. Your boiler may be unsafe or could break down completely if left.
Technical description: High Mains Voltage: Contact electricity provider
What causes this fault?
This fault occurs when the boiler's internal sensors detect that the incoming electrical supply from the national grid has exceeded safe operating limits. While it can sometimes be a sign of a faulty control board, it is usually caused by an external surge or a problem with the local power infrastructure in your street. The boiler shuts down as a safety precaution to prevent the high voltage from frying its sensitive electronic components.
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 F14 — 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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