BoilerFaultCodesYour boiler has shut down because the electrical power coming into it is too weak or unstable to run safely.
Book a Gas Safe engineer within 24–48 hours. Your boiler may be unsafe or could break down completely if left.
Technical description: Burner fault. Mains voltage is too low. Check the power supply.
What causes this fault?
This fault occurs when the boiler's internal computer detects that the incoming electricity supply has dropped below a safe working level. The most common reason is a problem with your home's electrical circuit or a failing component on the boiler's main control board that can no longer process power correctly.
This issue can occasionally trigger during peak winter months if the local electrical grid is under heavy strain or during stormy weather that causes fluctuations in power stability.
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 0C — 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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