I also have hot water baseboard heat and last month I had my plumber drain my system and refill it with an anti freeze solution. I did have a water line partially freeze last winter, it was on the zone line for my upstairs which never sees heat other than my pellet stove. I'm more cautious this year and yes, I think the therm guard was one of the best ideas anyone could've ever come up with. The last thing any one of us wants is to have water lines burst and have the expense of replacing them.