Indesit D41 Dishwasher?

when switched on, the machine starts as normal but wthin a couple of minutes a lot of water floods the baseplate and cuts out the machine via the float switch. There aren't any obvious leak paths, other than the overflow tube. I've dried it a couple of times but it repeats the problem. The speed suggests that the solenoid valve opens but the water goes straight into the baseplate.
Any ideas please?