On the HepVo drain thread, Discus' initial posting has 2 photographs. The second photograph shows the kitchen sink cabinet floor panel removed. If you look closely at the rear bottom corner of that photo, you will see a small 1" diameter or so corrugated hose which loops up then down, held by a small metal bracket. That hose is the overflow hose from the gray water tank. Exists in front of the driver side rear tire. ,