BoilerFaultCodesYour boiler is struggling to detect a stable electrical signal from the mains power supply, causing it to shut down as a safety precaution.
Book a Gas Safe engineer within 24–48 hours. Your boiler may be unsafe or could break down completely if left.
Technical description: Mains supply frequency incorrect – may be a problem with the power supply
What causes this fault?
This fault occurs when the boiler's internal computer detects that the incoming electricity from your home is not at the steady frequency it requires to operate safely. The most common reason is an issue with the local power grid or faulty electrical wiring within the property that is interfering with the power signal. In some cases, the boiler's main control board may have developed a fault, causing it to misread an otherwise healthy power supply.
Engineer required
This fault requires a Gas Safe registered engineer. Do not attempt gas-related repairs yourself.
Find a Gas Safe engineer
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