When you’re ready to winterize your RV or boat’s fresh water system, drain all water from your system, including the holding tank and hot water heater. Follow your manufacturer’s directions for this step. Then, remove the cap from the 3-way valve and attach the clear vinyl hose to the 3-way valve and tighten by hand. Place the other end of the hose into a gallon of Camco’s fresh water system antifreeze. Turn the handle on the valve to the “by-pass” position. Turn on each faucet one at a time and allow pure antifreeze to flow through. Let about one cup flow into the drain to protect traps. Finally, when all the antifreeze is drawn from the bottle, turn off the pump, remove the clear vinyl hose from the valve, replace the cap and turn the handle to “open” position.