Backflow Freeze Protection

Your backflow device on your sprinkler system is probably in a box in the ground, so in that case you are good a do not need to worry. I don't recall an instance of a backflow device freezing in the ground. You may have a device that is installed above ground however. In this case beware of freezing temps. They can and will freeze and are expensive to replace. Your first line of protection is the backflow blanket as seen here:

The blanked is an insulated bag that goes over the device to insulate it from the cold. Your next step is a fake rock or "hot box."

The fake rock is not insulated, but does add a layer of protection. The "hot box" is an insulated box that provides extra protection. As I tell our customers I can't guarantee that your device will not freeze with these measures, but I can guarantee that it will freeze if you do not have them. Keeping the water dripping on real cold days also helps, but in the case of exceptionally cold weather some type of artificial heat source may be. needed as well. Do what you can a do keep your fingers crossed!