Thanks for the advice, but you can't possibly think that wasn't the first thing I tried. Since I posted, I went through the ridiculously difficult process of pulling the manifold out, and disassembled it. Turns out the hole in the tube that is anchored by a pin cast in the manifold, was drilled too far inward, or the tube is just too short (see photo). It's amazing that I didnt have this problem earlier, as I have been running this stove hard for 10 years. The fix was simple, drill another hole (photo 2) and reassemble. This is lousy quality control. I love this insert, I really do, but it has had every problem in the book. Maintainence and repair is insanely difficult. Whoever designed this unit, should be shot.
After reading a lot of the posts here, I can understand the "did you try unplugging it and plugging it back in?" kind of answer, EBL. I'm sorry if my response was a bit snarky. I was having a rough day. I dont understand why they make this manifold so difficult to remove, considering how often it has to come out for cleaning and ceramic baffle replacement. The screws that hold it in are tiny, and seize up almost immediately. They break off almost everytime, and have to be drilled out. Terrible design. The manifold has a pretty thick cast crossmember that keeps the two sides from spreading apart, so unless the heat managed to streach that cast iron substantially, it's unlikely that a warpage was the cause. As you see in the picture, the other pipes are plenty long enough. Seems strange that it took a decade for the too short pipe to finally let go of the tiny fraction of an inch that it was holding on by. I'm just glad it was a free fix, as everything on this insert is astronomically expensive. It is our prime heat source, as our antique furnace has been disabled for many years. Without it, we are stuck with electric space heaters, and a huge electric bill.
Not hard keeping warm... yet. Gets a bit harder when it's 10 below. My insert can keep up as long as I can keep it fed. It was advertised as going for 10 hours, but that was very misleading. It can pump full heat for 4 or 5 hours max. Unfortunately I sleep, and work, for longer than than that. And the dog refuses to help out.
