John -
First, assure that the two Winterize valves function properly. Some valves are mounted in such a fashion that the labeling for the valve means nothing. (See other threads, there are several.) Engage the Water Heater By-Pass, pull the anode rod from the water heater to drain, and leave it open. Try running some hot water through the outdoor shower and see if any water is pumped into the hot water tank. If it is, the Hot Water Tank By-Pass valve is backwards to the labeling. (Stick on labels work well to correct this problem.) I stored the anode rod and put a plastic 3/4" plug in its place.
Next is easier. Get about 3 or 4 gallons of RV antifreeze. Attach a short hose to the Winterize hose input and put the other end into a gallon of antifreeze. (Actually, if my DW helps, I put a bucket beneath the WaterWorks, the hose in the bucket, and my DW keeps the antifreeze level in the bucket above the hose end.) Now go inside the Alpine and start with the closest water valves -outside shower, toilet, lavatory, shower, kitchen sink, etc. If you are doing this yourself, you will get quite a bit of exercise running back and forth to the gallon jug of antifreeze or bucket of antifreeze to make sure it still has something in it!
Run both the cold and hot water until it runs pink antifreeze.
Did you get a washer/dryer? If not, connect a short hose to the washer water connections and put the other end of the hose in the drain. Run each until you see pink antifreeze. If you do have a washer/dryer, this means that you will probably have to get behind them to do this and also winterize the washer. Personally, we did not opt for this feature, we would rather get this whole chore done at one time at a nearby laundromat. In fact, beneath the bathroom lavatory, you will probably find a water line T that supplies C/H water to the washer connection. I installed shutoff valves on these lines about three inches from the T. I ran antifreeze through these lines and the washer drain, then blew the C/H lines out with compressed air. I then shut the valves - probably for good. Now I don't have to worry about those lines ever freezing or winterizing them again.
Now all that is left is winterizing the fresh water tank and the black tank spray. For this you will need a hand pump. I pumped about 3/4 gallon of antifreeze into the black water spray. Be aware that the anti-siphon (located right behind the WaterWorks area) will dump about half this antifreeze back when you disconnect the pump. If you aren't ready, it can be a mess. (Also a good reason to use an anti-siphon connection on the outside end of the hose when using the black water spray.) I pumped about two gallons of antifreeze into the fresh water fill line to clear it of any water and to put antifreeze into the fresh water tank. Verified this by looking at what drained from the fresh water tank drain.
Now all that's left is to put some antifreezee in the gray water tanks and leave about an inch of antifreeze in the toilet to cover the seals. Also, pour a little antifreeze (to be sure) in all the drains unless you allowed enough antifreeze to run from the water lines into the drains.
Long post, but it's actually quite easy and simple. It took me as long to clean up from the black water spray antifreeze backwash as it did to winterize the whole system
That won't happen again!
Ron