Original installer used a regular rubber drain hose. When hot water heated up the hose it collapsed because 1) It was not the correct hose. & 2) It was forced through a small opening in the cabinet wall along with the copper supply line. Two sources of heat combined with the small opening in the cabinet wall caused the no drain situation. I replaced the hose with the corrugated hard plastic hose that comes with the dishwasher, problem solved. I don't know why the original installer did not use the correct hose. He said it was too short, but I had no problem at all.