In troubleshooting where water came from, I found no leaks on any hoses or O-rings or seal underneath dishwasher. However I did find that water from the drain or pumpout hose connection that I have connected to my garbage disposal can back up( back flow) into the dishwasher tub and overflow the tub. This apparently happened when disposal had too much solid material(grits) and did not allow water to drain. While this scenario has happened many times with my disposal, this is the first time that water backflows into the dishwasher.

My question is this. Is ther a backflow preventer such as a checkvalve in the dishwasher pump or flapper of some sort that is malfunctioning??

Thanks
Glen

My drain hose was lower than the connection and I have since raised it to form an air gap. Thank you for the response and the link.

Glen