Most RV’ers know that it’s essential to empty and clean your grey and black holding tanks when storing your RV for the winter months. You’re probably also aware that you should put some RV Antifreeze in your holding tanks, since you can’t be sure that there isn’t some water left. A question we are asked a lot is “Should I leave my valves open or closed when storing my RV?” The valves should be left in the open position which allows the seals to be in a relaxed position over the winter as opposed to pressing on the gate, causing a potential for stiction.
But won’t the antifreeze just run right out of the tank if you leave the valves open? Our suggestion is to run enough antifreeze through the toilet and into the holding tank to insure no water is left in a low spot in the holding tank. Then pour some in the toilet without flushing, so there is antifreeze in the bowl.
Have questions about winterizing the rest of your RV? Check out this article from The RV Doctor.