kenwood kdw12st3a error e1 & water leak?

ok, here goes...

machine is 4yrs old

a couple of weeks ago the dishwasher started to leak water out the front door, we stopped the machine and opened to find it with a couple of inches of water in the bottom. no error code. we bailed out manually and re-used successfully.

last week when machine finished cycle, again lot of water in base. so we bailed out, and ran several cups of vinegar through the machine on a hot wash. now we did this after reading a couple of replies on the forums. The metal filters are taken out and cleaned regular, and no sign of debris in well of machine.

subsequently a couple of days of successful washes. then today, wife tells me machine has water coming from the front again. and a couple of beeps. she opens door to find it full of water, and an E1 message displayed.
I now have it dismantled in the kitchen ? where to check or what needs replaced ? base of machine is surprisingly dry, everything looks in very good order.
fill hose clear, and no issue with water pressure. inlet on machine clear of obstruction. no feed or waste pipes were kinked.
next ?

thank you