Water pouring out of the dishwasher door: Candy CDW 254?

Just installed the dishwasher (secondhand), did a quick flush wash, empty, worked fine. Loaded it up, started cycle, then realised there was a huge puddle...water pouring out of the door (bottom right-hand corner), opened the door, no water in the bottom, so I'm guessing it fills from somewhere near the leak... Seals aren't crushed, all look good. Dad says he's never had a problem with it (ex engineer for Merloni/Indesit/Hotpoint/Bosch etc - can't ask him, he's travelling for the next few days)
I have 7 people here so desperately need the dishwasher working ASAP... Any ideas please?