The instructions say to use wood chunks and suggest up to 6 oz. (170.097 grams). The CooShack SM160 owners manual can be found here: Cookshack Smoker Manual . From my reading of this manual, there is a door switch on your unit, and this switch should turn your unit off when the door is open. This is a safety feature, so leaving the door open will not help. That being said, I do use pellets and wood chips in my SMO66 when I want to get a good smoke on meat that I am not going to have in the smoker very long. I do tri-tip with a reverse sear, so it is only in the smoker long enough to get to 110F degrees internal temp. Something tells me that there might be a disruption in the air flow. Did you line the bottom of the smoker with aluminum foil? There is a drain/vent hole in the bottom of your smoker. You need to make sure that the foil is opened up over this drain/vent hole, and that this hole is approximately the size of the drain/vent hole. How long are you letting your smoker run? The heat in the smoker will have an effect on how the smoker draws. Remember hot air rises, and opening and closing the door has a big impact on the temperature in your smoker. I would read the section in the owners manual about seasoning your smoker. put 2 oz. of wood chunks in the box, close the door and set the temp for 225F degrees. Let the smoker run like this for 4 hours. Take some notes on how long it takes for the smoker to come up to temp, how long it takes for the white smoke to clear and go to a thin bluish color. You can contact Cookshack without having to call them. Go to this page, and fill out the form. They will email you back: Cookshack, Inc.: Contact Us .