Troubleshoot a Smoky Mountain smoker by seasoning the inside of the smoker, attaching a gasket to the lid, utilizing an accurate thermometer, regulating the water pan and adjusting the air vents. Replace the side door of the smoker as a last resort.
Smoky Mountain smokers tend to maintain a temperature that is above the recommended cooking range when they are new. Seasoning new smokers is necessary to allow layers of smoke and grease to build up on the inside. When this happens, less heat is reflected inside of the smoker and can radiate out of the smoker walls. Season your smoker by burning a few rounds of charcoal without any food or water in it. Add some wood and fatty pieces of meat during the final round of seasoning.
Attach a gasket to the lid of the smoker to force the lid to fit the smoker more tightly. Having a tighter seal on the lid and side door allows for better airflow and more efficient temperature control. Stainless steel side doors are available to replace less durable doors on your smoker.
Make sure that your thermometer is accurate and of good quality. In addition, make sure that you are taking the temperature down where the meat sits in the smoker instead of in the dome.
If your Smoky Mountain smoker is running too hot, keep the water pan full while smoking. If your smoker runs too cool, reduce the amount of water in the water pan. Opening and closing the air vents also helps regulate temperature.