BoilerFaultCodesWhat the manual says
Manufacturer manualLockout. Boiler requires permanent live and switched live (minimum 190V). Check for reversed polarity or fuse issues.
What causes this fault?
This fault occurs when the boiler's internal computer detects that the incoming electricity is too weak or unstable to power the safety components. The most common reasons are a loose connection in the wall socket wiring, a failing printed circuit board, or a wider issue with the power grid entering your home.
This fault is more common during winter or periods of extreme weather when the national grid is under heavy load, which can lead to slight drops in local voltage.
Engineer required
This is a high severity fault. Stop using the boiler and call a Gas Safe registered engineer. Do not attempt gas-related repairs yourself.
Avoid the next call-out bill
A cover plan would handle faults like Electrical Supply Fault: no call-out fees, no surprise bills.
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