Had my 2400 insert running with the stovetop running around 400 degrees yesterday. Threw in about 4 or 5 pieces of wood and the top went to 600 degrees. This made my poor wife a wreck. Air control was all the way in. It's hard to believe there's no way to shut it down any further. My question to those who know: is the stove top or the liner in danger if it fires over 600 degrees? How can I shut the air down further?