THE BOX THAT COVERS THE DAMPER CONTROL ARM IS MOUNTED IN SUCH A WAY THAT IT INTERFERES WITH THE DAMPER. THE DAMPER STUCK OPEN AND COULD NT BE CLOSED!! CREATED A VERY DANGEROUS SITUATION. ALSO THERE ARE NO INSTRUCTIONS ON HOW TO MODIFY THE ON/OFF TEMPERATURE CONTROL FOR THE FAN AND SPEED OF THE FAN. THIS IS NOT MY FAVORITE WOOD FURNACE!