Thanks, guys. Strange that when I brought the heating problem up a few months ago, it was the heat riser valve that everyone agreed was the problem. It is definitely stuck closed, and it's not suppose to be. And I never had a problem with overheating before it was stuck. I'll check things out and see what comes up, but the first thing on the list right now is to get that butterfly valve unstuck. Makes no sense to me to do anything else until that's done.
And thanks for the tip on the brass nuts, K. Will do.
R- How would you knock out the valve plate without leaving openings on each end of it where it pivots? Are you saying that the whole part comes out? And if not, what will hold the valves balance weight and bi-metallic spring attachment in?
