This may be slightly off-topic but since this heating system is currently running on wood, I think it is appropriate to the topics at hand. This is kind of a contest. The winner gets.....nothing.....but the satisfaction of being right, and at least as smart as me, which probably ain't saying much. I've wanted to replace the ugly and basically non-functioning hot water baseboards in our kitchen with a cast iron radiator for some time. Now when you don't need a cast iron radiator, they seem to be all over the place. But it seems when you need a specific size and shape, lots 'o luck finding one. I finally found one in Albany, NY, thanks to a classified ad on the internet. Drove over there, paid the guy $40 and hauled the thing home. It was a steam radiator, but my understanding was always that steam rads and hot water rads are interchangable, as long as you can get a bleeder into the top of a radiator rigged up for steam. But when I got to looking at this one, I realized that it has no air flow across the top (aka a "pipe" made with push nipples holding the cast sections together). No airflow means no way to bleed the columns of air, since air rises and they're not connected. Thinking maybe I could get my money back, I called a place locally that gets $100 each for used radiators, and even more for the short ones like this one. The guy offered me $10. I'm not inclined to eat $30 if I don't have to. Turns out this is a really old steam radiator, manufactured before 1880. As such, it's a steam only radiator. But I got it working on my hot water system. There's no air in the columns and the water seems to circulate just fine. How do you think I managed that? Here's a couple of pics show the rad in place but not installed, and a top view, showing the absense of a top air passage.