Hack #15 Low-point water drain valves.
Replace those pesky nylon plugs in the water line low point drains with valves for easier functionality.
All you need is two 1/2″ NPT Stainless Steel Valves or PVC valves.
Locate the two low point drain hoses. They are under the trailer in the rear driver’s side between the waste tank drains and the leveling jack.
Remove the existing PVC plugs and replace them with your valves
Use teflon plumber’s tape to ensure a good seal.
Draining the entire water system is now as easy as opening these valves. Also open both the hot and cold water faucets inside the RV to allow the system to drain completely then close all valves when done