I burn nothing but hardwood. I try to stay in the range of 400-500 degrees. Worried about going over 550 because I have gone through a chimney fire once with regular fireplace. Ive been told it is safe to burn at 600? Also, just yesterday had it cleaned. I was told I could go 6 cords now that I see the amount of creason (sp) that cam out I know I was pushing it. I am now getting it cleaned every 2-2.5 cords. when the chimney was cleaned yesterday I took a look at the tubes after he left and noticed the front tube, holes faced towards the door. Middle tube, holes towards back and back tube, holes faced towards door. Call the prof cleaner and he said it didn't matter. I went ahead and changed the middle tube back to facing the door (forward) this morning. My question is does it matter what direction it faces. Also how hot can I burn this and feel safe. A Chimney fire experience makes you rattled. Before I would damper down at 500 and burn an hour before another load and repeat process. Also as a side note the way I prepare the fire before I go to bed.. Throw a good piece of wood when at 450-500, flare it up for a few then damper all the way down. Any suggestions?