BoilerFaultCodesYour boiler has detected an issue with the electrical frequency coming from the mains power supply or a fault within its internal control board.
Book a Gas Safe engineer within 24–48 hours. Your boiler may be unsafe or could break down completely if left.
Technical description: Wrong power supply (HZ)
What causes this fault?
This fault occurs when the boiler's internal computer detects that the electrical supply timing, known as frequency, does not match the required UK standard. This is usually caused by a glitch in the local power grid or a malfunctioning control board inside the boiler that can no longer process the incoming electricity correctly. In rare cases, using a backup generator or an unstable power source can also trigger this shutdown.
Engineer required
This fault requires a Gas Safe registered engineer. Do not attempt gas-related repairs yourself.
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