Thank you for replying Frodo. It is a Kitchenaid Gallery series, stainless inside and out, around 11 years old. I can't read the model number even with my reading glasses. I do have an extended warranty and the first time I called Sears for repair, the technician ran a cycle said it was fine and he couldn't fix something that wasn't broken. However it took two more times of it happening for me to be 100 percent certain that it was filling up when not running.
So is this a part that comes with the dishwasher that could be expected to be covered under the average warranty? When I call the guy back I don't want to get the run around again.