How to Winterize RV Washer 1. Ensure your RV water lines have already been winterized. When you turn on the hot or cold water, there should be no water coming out—only pink antifreeze. 2. Select a wash setting and set the water to warm to bring antifreeze through both the cold and hot lines. Start the washer, and antifreeze will flow through the lines. 3. Let it run for about 30 seconds until you see antifreeze in the bottom of the drum, then stop the cycle. 4. Open the washer door and pour at l