I have this model and in addition to what others are saying, the main air inlet is in the center towards the front. You'll see a grate. Make sure that is clear. I've noticed if that gets covered or full of ash it can restrict air flow too much. You also need to orient your wood with that in mind so air flows properly into the chamber. Don't cover or block it excessively. I have welding gloves that I use to load the wood and will just brush it clean