Your boiler has detected an electrical problem with the component that controls the gas supply, meaning it cannot safely light the burner to provide heat or hot water.

Gas valve electrical fault

What causes this fault?

This fault occurs when the boiler's main control board detects an unexpected electrical signal or a total loss of communication with the gas valve. The most common reason is an internal electrical failure within the valve itself or a loose connection in the wiring that prevents the system from safely managing the flow of fuel. Because the boiler cannot guarantee the burner will light correctly, it shuts down as a safety precaution.