How to winterize an RV, step by step

Water that freezes in your lines can crack fittings, faucets, the pump and the water heater. Here's the checklist from a working RV tech, in the order we'd do it, including the spots people miss most.

Part 1: Drain everything

1. Turn off the water heater and let it cool. Shut off both power and gas. Never drain a hot water heater: the water is scalding and the tank is under pressure. Give it a few hours.
2. Drain the fresh water tank. Open the drain valve. Water left in the tank can freeze and crack the tank or the valve.
3. Dump and flush the black and gray tanks. Flush the black tank if you have a flush port. Waste left over winter dries hard and the smell sets in.
4. Drain the water heater. Open the relief valve at the top first to let air in, then pull the plug. Suburban heaters use an anode rod, so check it while it's out.
5. Open the low-point drains and run the pump briefly. The drains are usually under the coach near the water lines. Run the pump for just a few seconds, because running it dry will damage it.
6. Remove and drain the water filter cartridge. Antifreeze ruins filter cartridges. Take it out, empty the housing, and put the housing back on empty.

Part 2: Protect the lines

1. Put the water heater in bypass. This keeps antifreeze out of the tank and saves about 6 to 10 gallons of it.
2. Blow out the lines or pump in RV antifreeze. If you use air, stay at 40 psi or less, because more can split fittings. Many techs blow out the lines, then add antifreeze for extra protection.
3. Run each faucet, hot and cold, until the antifreeze shows pink. Start with the faucet closest to the pump and work out to the farthest. Don't forget the hot side: that line freezes too.
4. Do the toilet, outside shower, ice maker and washer. These get missed most. Hold the toilet pedal until pink shows. Ice makers and washers each have their own steps in the manual.
5. Pour a cup of antifreeze into each P-trap and the tanks. P-traps hold water that can freeze and crack. Antifreeze protects them and keeps sewer smell out.
6. Close all drains and valves. Close everything you opened so bugs and mice stay out.

Part 3: Finish up

1. Leave a "WINTERIZED" note by the sink. It keeps someone from turning on the water heater or drinking antifreeze in the spring.
2. Charge and store the batteries, or use the battery disconnect. A dead battery can freeze and crack. Charge it fully, disconnect it or store it somewhere it won't freeze, and top it off monthly.