Ten year old Enviro Maxx. Had various issues, usually POF sensor failing. This time the Hi-limit sensor opened, stove was very hot. First time that this ever happened. Let it cool, turned it off, waited a few minutes and turned it on again. Pellet auger ran continuously - that would certainly cause overheating. Seemed that the control board might have failed. Left the stove off for 24 hrs. Then tried it again, now runs normally. So could this be a one time thing? Replacement control board and membrane $450. Don't want to spend that $$$ if not needed, but also don't want to live with the prospect of a shutdown from overfiring occurring at any time. Especially as we get into the coldest months and there is no other heat source in that part of the house.