I have a 1930's house with a gas fired boiler for radiant heat. Unfortunately some of the pipes are located such that there is a risk of them freezing in very cold weather (talk about broken lines and water emergencies at -33C!). Currently there is no anti-freeze in the system, but I would like to add some this spring when I'm able to shut the system down and drain it. I'm looking for some helpful hints from anyone with related experience. Also, I've been told there is a silicone additive of some sort which can be added to keep the pump internals nicely lubricated...looking for guidance related to that as well.