Problems with my Diplomat HJA 8630 Dishwasher?

Hi can anyone help. When I turn the dishwasher on it just sits and hums instead of letting in water. When it first did this I found it had about an inch of water in the bottom so I turned it off and drained all the water then I retried it on a cold cycle. It sounded as though it had started ok but after a few minutes sat there and hummed again. When I opened the door there was just an inch of water inside again. The humming to me sounds like a solenoid valve isn't openeing. Has anyone got any ideas?