Your boiler has detected an internal communication problem between its electronic brain and the gas supply system, meaning it cannot safely light the flame.

Valve drive error - possible gas valve or control box fault.

What causes this fault?

This fault occurs when the boiler's main control board loses the ability to communicate with or operate the gas valve safely. The most common reason is an electrical failure within the gas valve's motor or a fault on the circuit board that prevents it from sending the correct starting signal. In some cases, it can be caused by loose or damaged wiring connections between these two vital components.