Your boiler has detected an internal electrical fault with the gas valve, which means it cannot safely light the flame to provide heating or hot water.

Electronic fault | Electronics defect

What causes this fault?

This fault occurs when the boiler's main control board loses electrical communication with the gas valve or detects an incorrect voltage return. The most common reason is an internal electronic failure within the gas valve itself or a fault on the circuit board that prevents it from sending the correct signal to release gas.