Your boiler is unable to send gas to the burner because of a communication failure between the main control board and the gas valve.

Fault: Fuel valve actuation - The gas valve assembly cannot be actuated

What causes this fault?

This fault occurs when the boiler's main internal computer cannot properly communicate with the gas valve that lets fuel into the burner. The most common reason is an electronic failure within the gas valve itself or a fault on the printed circuit board that prevents it from sending the correct starting signal. In some cases, it can be caused by dampness or loose connections in the wiring that links these two vital components.