I installed a Heartstone phoenix this weekend that is not working correctly. Mechanical details. Stove - Phoenix stove pipe - 6" Single wall, 10 ft. Chimney - 6" Class A 12 ft. Problem. The stove will NOT damper down to a satisfactory level. When I load the stove with wood 3-4 large pieces of wood (oak, ash, cherry mix) , It only burns for around 2 hours fully dampered. It burns at between 350-400 degrees F at the stack FULLY DAMPENED. This stove is brand new. It was seasoned correctly. It did not fully load it until the third day of burning. Needless to say, I am very dissatisfied. The stove is burning too hot, for too short a period in the FULLY dampened setting. The damper does appear to work. But NOT completely. According to theliterature I should get a 12 hour burn from a fully loaded stove at around 200 degrees fully dampened. Any Ideas?