Diplomat 8242 Dishwasher won't fill with water?

It's a built in unit from MFI (the second one in 6 years). I have taken it to bits (naturally!) to look for the problem. When turned on, a solenoid clicks and water fills into a clear plastic "maze" system on the RHS. This then seems to just be pumped out or just flows out through the waste pipe. Then a bunch of error lights flash. I love a challenge, anyone know what the problem is? Chris.