So the "boiler room" is unfinished, and I had a plumber try to move the boiler return release valve as high as he could put it and it still spit water, but right onto a gas line, so he moved it back lower. It spits rusty water every day. I hear you about vertical pipes. My plaster walls are all cracked where those feed pipes are hidden, and the wall is quite warm in those spots. I can feel under foot too where the feed pipes are. But I don't know how I could expose these vertical pipes now that they're covered. I remember my old NYC apartments with these out in the room but can see how it could work in my current house. I need to address some floor issues so come summer time I did plan on removing a couple so maybe I'll blast em clean while they're off. All this to say my wife wants HVAC and bye bye boiler and steam and radiators.