Originally Posted by JLeising
Hence the trick noted above of taking the outside shower hose and running it over to the gravity fresh water fill point. As you state, water is pumped into the RV water system, out the shower hose, and into the fresh water tank. While I haven't done it, sounds like a neat trick!
I don't have an outside shower in my 2011 Georgetown 327DS but have done the same thing using my water hose and a faucet to hose adapter. The water pump pulls in water from a jug, through the winterizing hose; pressurized water flows out the bathroom sink, through the water hose, and finally into the fresh water fill port for the water tank.
When I dewinterize, I always make sure to also flush the antifreeze input area in case I need to use this technique to fill the water tank.