A friend has an outdoor wood furnace going to a building. He put two radiators (the old cast iron type) in the lower level and they heat well. He put another radiator in the upper floor and that one will not fill up. It's only heating the bottom of that radiator. I opened the bleeder while it was running, and no air or water comes out. I then removed the entire bleeder and still nothing comes out. There does not appear to be a clog behind that bleeder.
I am thinking one of two possibilities. Either the pump on the furnace does not have enough pressure to lift the water to that second level, or else that radistor needs some sort of restriction on it's OUTPUT side to force the water to the top of the radiator. Currently he just has both pipes going to the radiator, one to the bottom left, the other to the bottom right.
(This is a HOT WATER, -NOT- a Steam heat setup).
Anyone have any suggestions?