Hmm, can you snap and post a picture? Ours has the pigtail out winterize hose connected on the inlet side of the pump. Turn tank valve off, pigtail on, and it empties 2 jugs of antifreeze through out the system. Well not that much, but I use 2 jugs total. Majority of it goes into the low point drains, toilet, and tanks. The city water line is directly from the side of the unit and has nothing to do with the tank, or pump. I winterize that by blowing it out, and filling a hose with antifreeze and then pressurize it with the air compressor.