[mark Campbell]

Ocassionally the dishwasher collects water in the bottom and fills up to the point where it leaks on the floor thriough the bottom of the door. I can hit the drain button and it drains fine, but I will come back later and more water starts collecting. What is causing the water to collect or backup in the bottom of the dishwasher? I checked the hose to the disposal and it is installed correctly and not clogged. I shut off the water supply and it still collects. It can go for weeks without doing this, and then it will start again.

[TechnicianBrian]

If you turned the water supply off then you have eliminated a bad fill valve. That leaves the drain line as the only source of water to the unit. The drain line should run up to a high point under the counter before it connects to the disposer. If the line runs up to the disposer, it is possible for water to filter back into the unit over a period of time.

TechnicianBrian