Winterizing water tanks and lines on a recreational vehicle is required to prevent water from freezing inside the units and causing costly damage to the RV. There are two common methods to winterize tanks: using compressed air to blow water out of the lines or adding antifreeze to the tanks and lines. Compressed air removes all water from the lines to minimize the risk of frozen and burst lines. Pouring antifreeze into the tanks is less time consuming and costs less because you don’t need any special equipment.
1. Drain the RV’s freshwater and wastewater tanks. Drain water left in the water heater by setting the valve to the bypass position and letting the water run out. The valve is located near the incoming water heater lines.
2. Open all faucets that are closed in the RV. This includes the shower head and toilet flusher.
3. Turn the RV water pump on for 30 seconds. This cleans out the water lines.
4. Attach an air hose to the city water fill connector on the RV. Set the air pressure to 30 pounds or less and blow out the lines until no water comes out of the inside fixtures or lines. Adapters that connect the air hose to the water fill container are available at RV supply stores. Screw the adapter to the fresh water inlet on the RV and use the air hose to blow out the lines.
5. Close all water lines and pour antifreeze into the drains, traps, toilet and tanks to prevent the lines and fixtures from freezing. You need about two gallons of antifreeze. Store the camper for winter.
6. Drain all RV tanks, including the freshwater and wastewater. Set the water heater valve to the bypass position and drain the water heater. The valve is located near the incoming water heater lines.
7. Close all water lines and pour antifreeze into the fresh water tank, filling it above the minimum level for operating.
8. Turn the pump switch on and run the cold water through all fixtures until antifreeze appears. Repeat with the hot water fixtures. Flush the toilet until antifreeze appears and then pour one gallon of antifreeze into the toilet.
9. Pour one gallon of antifreeze down each RV drain to winterize the gray water/wastewater tank. This includes the shower and sink drains. You will need four to six gallons of antifreeze.