Checked the air gap and the hose from the dishwasher and they were OK. The float was free to move up and down. Debris screen clean. Seemed like the pump may be no good, but who knows? I did not want to pull and disassemble the dishwasher to check. But...I decided to look to see what it would take and saw that returns were accepted. I watched a video on how to replace the pump and it was too easy, a monkey could do it. Ordered part. Maybe it took 45 minutes to perform repair and most of that time was sucking the water out of the sump and pulling the dishwasher. Back together and normal operation restored..for about $70.