protecting water maker from freezing?

[Photonsailor]

Aaargh, poking around under the water maker installation I noticed a big filter housing with a wide crack. This boat lived in the W Indies before we bought it and shipped it to colder waters in Sweden. Sailing here I always put my boat on the hard during winter and I am very particular winterizing everything with water in it. I am pretty sure that left over water, or pickling fluid froze in the system during winter, maybe even ruining its HP and low pressure pumps
Alas, I did not think of the water maker since I have not needed to use it (we have large water tanks and very good water is available in marinas).

Now, it is an old Sea Recovery system, and eg. all instruments are broken and not working and the installation is a rats nest, so I was considering a new one anyway. But, before getting a new one....

My question to you cold water sailors: How do you protect your water maker from freezing and cracking during winter?? Antifreeze? Vacuuming?