Well even though Greenwood folded their technicians may have been worth something? Burning medium to large sized rounds that are truly seasoned makes a huge difference. Last year I was burning dry splits that vaporized and wet or green rounds that killed the btu output. So far my burning dry rounds has made a huge difference. I did play around with the aquastat and have the damper opening at about 170 and closing around 185. Nice clean burn with little smoke and red hot coals. (no need to worry about voiding the warranty, thanks for nothing Greenwood.) Anyway just thought I would post my findings, results. Burn on!