The float switch would be located in the box itself. Remove the cover, clean out the strainer and all components and re-try. It may just be all gunked up. Other things drain into this box besides the shower.Hello, I recently purchased a 2007 400SS. The Whale Gulper 220 shower sump recently began running constantly. The shower has not been used under my ownership. I am assuming the shower sump float switch has a problem? Where is this located? Thank you.