We have a Bosch SHE46C06UC dishwasher that is 5+ years old. There is a slow flow of water into the main tub that after 48 hrs. or so rises to a level that leaks out of the door. (The water just overfills the bottom of the main tub and the intended level of water.) When I bail the water to inspect the problem, it is approx. 2 gallons of very clean water. The dishwasher runs fine and the main tub is empty after it has run. The main tub fills slowly and overflows when the dishwasher sits for 2-4 days between wash cycles.
I have bailed and sponged the water 5+ times with a cup and a sponge, cleaned and then replaced the check valve. Neither cleaning nor replacement of the check valve improved the situation.
The water seems to be seeping back into the basin from the bottom-from the drain hose or another location.
Where could the water be coming from? What should I try next? Thanks.