Hello,
I have been firing coal boilers for over 20 years, recently we replaced our old National 200 eight section cast iron boiler because it literally began falling apart. We replaced it with a National 300 Heat Extractor which is in better shape,this one has seven sections. I never had trouble firing a coal boiler before but even though I have a hot fire in this one I can't seem to get the water temp above 100 degrees. Everything is working right except that I noticed the base becomes so hot I can actually smell a hot metal odor sometimes. I think the heat that's supposed to give me hot water is being dissipated into the base. I wonder if there is supposed to be some kind of insulating gasket between the water sections and the base and if possibly the guys who put this thing together failed to install one, because I never had this happen on any of my other boilers. I used to be able to get good heat even with a small fire just burning on the middle grates in the old one and I never had the base get that hot. I am about ready to chuck this boiler because all I'm doing is burning coal without any benefit. Is it possible to insulate the base from the rest of the boiler? I know I'm talking about an old piece of equipment, but really 100 degrees, I need more heat than that.