One of the most common causes for an overheating dryer is restricted airflow. A clogged lint filter, improper venting and dirty ductwork can all restrict airflow.
If the heated air is not vented properly, it can cause the dryer to get too hot. Excessive lint in the lint filter keeps warm air from the dryer from being expelled properly. Cleaning the lint filter after every load helps to ensure lint does not impede air flow.
Dirty ductwork is another cause of improper venting. If clothes taking longer to dry than usual or remain damp after the regular drying cycle, the ductwork may need to be cleaned. Homeowners should replace flexible ductwork with rigid metal ducts to prevent kinking, which can also restrict proper air flow.