Take the RV to a dumping station and completely flush all black and gray water tanks.
Turn off the water heater and allow it to sit for 20 minutes, allowing for the water to cool down.
Park the RV in a driveway and open all black and gray water tanks (don't do this in a garage). Flush the water system by turning on all faucets and showers at once and allowing the water to completely exit the system. Expect this to take hours, keep the faucets open until there is no more water dripping from any faucet.
Shut off all faucets and tanks. Add antifreeze designed specifically for winterizing RV water systems to the fresh water tank. Follow the water-to-antifreeze ratios listed on the container. RV antifreeze is available at major RV and camping stores. Do not use antifreeze made for cars. Run the faucets again to ensure that the entire system is filled with the water/antifreeze solution.
Flush and empty the hot water tank. Disconnect the propane tank and electricity to the tank in order to prevent accidental use.
Remove the water filter and water pump (if it is easily accessible). Store the pump in a climate controlled environment such as a heated garage. Discard the water filter and replace it with a new one in the spring.
Disconnect the propane tanks from the RV. Cover them if desired. Never store propane tanks indoors or in the RV.
Use foam to seal off all potential access to the RV from insects and rodents. Cut pieces of foam to fit into all access panels and in fans and skylights.
If the RV is a motorhome, winterize the engine by flushing the heating/cooling systems and adding fuel stabilizers. The exact steps to take depend on whether or not the rig is diesel or gas powered. Check with a qualified mechanic if you are unsure of how to winterize the engine systems.
Park the RV in its permanent winter location. Disconnect all batteries and treat the terminals with a protective silicone spray.
Cover the RV with a cover designed for the RV or secure tarps over the entire rig to protect from dirt, wind and weather.
