Drain all water from the RV, including the fresh water tank and the water heater. To ensure you get all the water out of the lines, open all taps and run them until there's no water left. Leave the taps open for the moment.
Dump both the gray water and black water tanks. Flush both with a mix of bleach and water. Mix the bleach according to the manufacturer's recommendations for best results. Rinse both tanks well. Close up the black water tank, but leave the gray water valve open for the moment.
Use the water heater bypass kit to bypass the water heater. Follow the manufacturer's directions to learn how to use the specific kit you purchased. Do not put antifreeze in the water tank.
Use the compressed air and adapter to blow out the water lines. Have a friend watch the open taps. Ask him to tell you when nothing but air emerges from each tap. While you're at it, blow out the shower and toilet lines as well. Get as much water out as you can to prevent freezing in the winter months. Close the taps.
Insert the water intake hose of your RV into the RV antifreeze and start the fresh water pump. This will pump antifreeze through the water lines of your RV. Go to each tap, one at a time, and turn it on. Run the tap until you see antifreeze emerge, then turn it off. Start at the tap farthest from the fresh water tank. Make sure antifreeze is in the lines running to the shower and the toilet.
Close the gray water valve. Pour a little antifreeze into each drain and down the toilet.
Remvoe all batteries from your RV. Store these in a place where they will not get wet and they will not freeze. A basement or storage closet often works well. Also remove all food and drink from the RV.
Spray the RV for insects. You'll want to do this again in the spring. Put out rodent killer or traps and check these every couple of week through the winter. You'll want to remove dead rodents immediately.
