keeping capped radiator supply pipes from freezing
I have hot water radiators in a two-story house. Everything is on the same circuit. There is one supply circuit in the basement and all the radiators branch off it. Everything is steel pipes. The radiators on the 2nd floor were disconnected and capped off for a renovation. The supply pipes for those run through outside walls.
The renovation is taking a lot longer than planned so now it’s winter and it’s starting to hit the mid teens at night. I’m worried the water in the capped off supply lines will freeze. They aren’t completely full because the water got drained down out of the system and there are pockets of air inside but I don’t know how far up the water goes.
I’ve been keeping the heat turned up at night so those pipes are kept warm from the bottom but is there some way to warm them from the top as well? I thought of heating cable but there are only a few inches sticking out of the floor upstairs and I don’t want to bust up the floor and walls to get at the pipes inside.
Replies
The return lines still there?
Run a temporary line between the radiator supply and return lines to allow a trickle flow.
Catmandeux's solution is great. If you cant do that then use heat trace on the pipes. Failing that a simple oil filled electric heater left on to keep the area from freezing will work.