Check the drain hose is not too low or else it will syphon the water out. Drain hose must come up to the height of the top deck before going down to the drain. If water valve keeps going then you may need to fit a new inlet valve. Try opening the lid and if water continuous to flow turn off the tap and then turn it back on. If water has now stopped the valve is sticking, replace it.
Lincoln Appliance NZ, August 2011