I've been trying to figure out why the glass is sooting up so bad on my stove so I been experimenting a little. The glass always gets sooty and the center always seems worse, kind of a v shape. I noticed last night when the door was closed quickly with the dog house plugged that ash was being blown up on the side closest to the door. Tonight I took the doghouse off and the ears where the screws are were bent down so this made about an 1/8" under it. I flattened the ears out and put a small bead of sealant under it so there is no leaks now. I don't have a clue as to how this got bent. Anyway it's sealed up now an so far the glass is staying cleaner. I'm just guessing here that the primary air was coming down and the doghouse air was pushing up making for no air movement on the glass. We'll see once I can run the stove harder. It's too warm to run it very hard right now.