This is my first post, and I have a question about my Buck Model 81 that some of you might be able to answer. I recently had this stove installed as an insert along with a Forever Flex pre-insulated stainless 6" chimney liner. I also had the chimney swept/cleaned before installation. Saturday morning, I filled the firebox with wood on top of a nice bed of coals and opened the primary air all the way.....got a nice rolling fire going. When I had a good secondary burn going on in the top of the firebox where the air inlet tubes are, I closed the primary air to 50%. The flames around the wood subdued, but the coals underneath were glowing red hot, and the secondary burn was really going. It got VERY hot, to the point I got concerned. It was making a "popping" noise as it got hotter. I closed the primary air completely. The secondary burn continued for well over an hour even after the primary air was completely closed, but what scared me was the heat it was giving off & the smell of something getting very hot. All the owner's manual said was" if the connector or chimney glows, you are overheating." You could not touch the top of the stove even for a split milli-second. My question is whether any of you know of a way to control the air flow that feeds the secondary burn, or what can I do to prevent this again? I do not have a thermometer on the stove or the flu but I am considering it. The mfr would not tell me what the maximum temp was for this unit. I have learned that a large fire is NOT the way to go. Any suggestions appreciated.