I just installed a used Kenmore series 80 washer and am having problems with the standpipe overflowing during rinse cycle. The old washer would suds up around the drain, but never overflowed. The current standpipe is 2" PVC that is 33" high from the floor. The stand pipe goes through the floor into the joists. It 45's and drops about 12 inches then takes another 45 before traveling horizontally for about 48 inches. There is a slight slope in the horizontal run. I have used a "clog buster", bladder type drain cleaner, and have not noticed any difference. I have opened the clean out at the drive way and it appears that I am getting sufficient flow through the plumbing system. I am guessing that standpipe may be too short for this particular washer. I would appreciate any comments or suggestions.