Things You Will Need
* Air Compressor
* Blower nozzle
* Short piece of garden hose with a Male connection
* 1-2 gallons of RV Antifreeze
With incoming water line disconnected, attach short piece of garden hose with male connection to main water inlet connection.
Open all faucet valves & drain as much water as possible. If your camper is equipped with a water heater, open drain valve. This should drain most of the water from the system. Also empty all holding tanks.
Using air compressor and blower nozzle,insert blower nozzle in the short piece of hose connected to main water inlet connection. Try to seal it off completely if possible. Pressurize water system to blow out any remaining water, leaving all valves open.
Remove blower nozzle when no more water is visible from any faucets. Close all valves and faucets except the one farthest away from main inlet connection. Remove air blower nozzle and insert funnel into the hose. Pour RV antifreeze into funnel until no more antifreeze will go in. If antifreeze comes out of open faucet, close that faucet. You will probably have to force it by reattaching the air blower nozzle. Sometimes, if you have the funnel above all water lines, you may not need to for antifreeze in with air.
As you pressurize the system again, have a helper close the faucet as soon as antifreeze is present. have your helper open each remaining valve in order of distance from main water connection, and closing it as soon as antifreeze shows up. Add more antifreeze as you go so all lines contain antifreeze. The more antifreeze you can get in the system, the less chance of having a pipe burst due to freezing.
Cap off main water connection when finished. In order to use camper again in summer, connect water hose to main water connection, open all valves again and let water flush through system until there are no signs of antifreeze, approximately 15-20 minutes.
Tips & Warnings
* This procedure is best done with 2 people.
* Don’t worry about antifreeze getting in your drains. It will keep water from freezing in drain traps.
* Leave holding tank drains open to allow residual water to drain.
* Only use antifreeze designed for winterizing RVs.
* DO NOT USE AUTOMOTIVE ANTIFREEZE! It contains Ethylene Glycol which is extremely TOXIC!