Both the restrictor and the air thingy can be adjusted while the stove is running. So far it is burning beautifully since I pulled out the air thingy a notch. The guy from Lopi was a great help and sent me the right manual. It shows the restrictor and the thingy which, now looking at the manual, is called the intake restrictor. The one on the left is the exhaust restrictor. Go figure. So the guy also said that there are lots of reasons that the restrictor(s) would need to be adjusted........the temp setting on the stove, the outside temp and how the stove is vented are just a few. They need to be adjusted accordingly.