BoilerFaultCodesYour boiler has detected that the electrical supply from the grid is currently too low for it to operate safely.
Book a Gas Safe engineer within 24–48 hours. Your boiler may be unsafe or could break down completely if left.
Technical description: Low Mains Voltage: Contact Electricity Provider
What causes this fault?
This fault occurs when the incoming electrical supply to your home drops below a level that is safe for the boiler's sensitive electronics to function. The most common reason is an issue with the local power grid or a 'brownout' in your area, though it can occasionally be caused by a fault within the boiler's internal control board incorrectly reading the voltage.
This fault is occasionally more common during periods of extreme cold or high peak demand when the national electrical grid is under heavy strain.
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 F07 — 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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