A few minutes into the cycle the dishwasher overfills causing an E15. It drains fine, just overflows consistently at the same point in the cycle every time it runs.

I have verified that is overfilling with the door cover off and there are no other leaks. Dishwasher washes for a few minutes and then water rushes out the corners of the door and down the overflow guttter.

Does anyone know how this dishwasher regulates water level? I have checked that the dishwasher is level and also tried partly closing the water valve.

Possibly related, had an E24 "filter clogged" due to some sort of biscuit dough about a week ago, but cleared the filter and it worked for about a week before the present problem.

Thanks!
Steven