How to Winterize Your RV: The Complete Guide to Cold-Weather Storage
Winterizing an RV — preparing its plumbing system for storage in freezing temperatures — is the most consequential seasonal maintenance task for RV owners in most of the continental United States. Water expands approximately nine percent when it freezes, and water remaining in an RV’s water lines, holding tanks, water pump, and water heater that freezes during storage exerts pressures that split the plumbing lines, crack the water pump housing, and damage the water heater tank — repairs that collectively run $500 to $2,000. Correct winterization prevents all of these failures and takes approximately two to three hours to complete.
Method 1: Compressed Air Blowout
The compressed air method forces every water line clear by blowing all standing water out through the faucets and fixtures with compressed air. Disconnect the water heater bypass (if equipped) to exclude it from the process — blowing air into a water heater while connected damages the anode rod. Connect an air compressor to the city water inlet. Open each faucet — hot and cold — one at a time, blow until no water emerges, close it, and proceed to the next. Repeat with each exterior shower, toilet, and outdoor kitchen fixture. Pour RV antifreeze directly into drain traps (P-traps under sinks, shower drain) to prevent freeze damage at these locations.
Method 2: RV Antifreeze
The antifreeze method pumps non-toxic RV antifreeze (pink antifreeze specifically labeled for RV use — never automotive antifreeze, which is toxic) through the water system until antifreeze exits each faucet. This method requires a winterization kit — a bypass kit that allows the pump to draw antifreeze from a jug rather than the fresh water tank — and approximately two to three gallons of antifreeze for a typical RV. It is generally more reliable than the compressed air method for reaching every fitting and trap in the system. In spring, flush the antifreeze from the system by running water through every fixture until the pink color is gone before using the water system.
