How Your RV Water System Works
Your RV water system pulls water from your fresh water tank or from the city water hookup. From the fresh water tank your water pump pushes water through the RV. You don't need to use the water pump if your connected and using a city water hookup.
The water from your water tank or city water hookup will always be cold water. To have hot water it must flow from the water tank into the water heater. The water is heated and flows to your hot water fixtures like your shower.
If you store your RV in a cold climate, you'll need to winterize it by draining all the water lines and adding weatherization products like Camco's full timer's choice Antifreeze that is safe for your fresh water plumbing.
Camco RV products also offers wintering kits, hand pumps, blowout plugs all designed to prepare and protect your RVs water lines for storage. Antifreeze products are designed for use when storing your RV, but not if you live in it full time even in a cold climate.