The first step to winterizing any RV is to completely drain the water system. A handy tool to help clear the water lines is the Camco RV Blowout Plug with Brass Quick Connect (http://goo.gl/Z8aD0H). This little solid piece of brass helps the removal of water from your RV water lines.
Screw this blowout plug into your RV's city water inlet connection, and then attach an air compressor. Open your RV water lines, turn on the air, and voila! Water is pushed out of the lines. (Click the pic to get your own.)
How does it work? You simply screw the plug into your RV’s city water inlet, open all drains and faucets, and then connect an air compressor (http://goo.gl/eS8iho) quick connect hose.
The blowout plug leaves your hands free to open faucets and flush out water lines without assistance. It allows you to completely clear your water lines. Simply flip on the compressor and air will begin pushing excess water through your open lines.
Sometimes small gadgets like the Camco RV blowout plug make a big difference when working on an RV.