There are different ideas on winterizing the water system. Each has its merits and risks.
1. Completely draining the system should mean that no water means no broken parts due to freezing. The problem is that you may or may not get rid of all the water in critical areas.
2. Draining the system and blowing it out with compressed air may work, but you still have a potential for water in a low area.
3. Flushing with RV antifreeze, or flushing and draining, may do well at eliminating any pure water areas from freezing. Many people complain about the smell/taste of residual antifreeze the following year.
The owner's manual explains a process of flushing with clear water, then soaking and flushing with a little chlorine bleach in a water solution, and then soaking and flushing with a vinegar and water solution, and finally flushing with clear water. A water purifier chemical can also be added from time to time throughout the season. This can be done anytime and is the main reason I am rambling on about winterizing in the spring.
4. I have also heard of using enough of the cheapest vodka you can find to flush the system. The vodka should not freeze, and won't leave the "antifreeze" taste. Beware that next spring you might have a lot of people showing up with orange juice to "help" you drain the vodka from your water system for cocktails.
