Today I had a WHL dishwasher that stumped me. I was at the house a few days ago, unit had a 7-1 error code, indicating a heating issue. The unit would fill with water and stop, and would never start washing...It had no further codes btw. I check the wires to the heater, follow them to the board, and checked continuity at the board. heater tested at about 13 ohms. So after reading thru the tech sheet I come to find out the only option left is that the control is bad. so I replace the control today, and it repeats the same exact problem, fills, stops filling, then does nothing. I think ok...check error codes again with the new control, I get 6-4, which is a fill issue. So I drain it and start over. The unit seemed to not be filling with enough water to "float" the float switch. So I stick a screw driver under it to "fool" the computer into thinking the tub is full. the unit does the same thing, just will not begin to wash.
I am going back to this house with a sump/motor and a valve...but I was kinda baffled by this one, and running 10 calls a day I ran out of time with this one
Side note, there were no further codes after the 6-4 either??