Freezing Temps RV Prep for Cold Weather 1. Fill Your Propane Tanks. Ensure you have enough propane to keep your RV warm during the freeze. 2. Test the RV Furnace. • Run your furnace to keep pipes from freezing. • If your RV has an enclosed underbelly, it will likely be heated by the furnace, protecting water lines and tanks in mild freezing. • If your RV has exposed water lines and tanks, it’s more vulnerable. Winterize it to avoid damage in deep freezes. 3. Sanitize the Freshwater System (Optio