'''Most Frequent Causes for Dryer won't stop'''
Cause 1
Air Flow Problem
If the vent is clogged or partially clogged, it will restrict the airflow through the dryer, substantially increasing the drying time. To ensure proper dryer performance, you should clean your dryer’s venting system at least once per year.
Cause 2
Blower Wheel
The blower wheel draws air through the dryer and pushes the air out the vent. Clumps of lint, socks, and small articles of clothing can escape the lint filter and get caught in the blower wheel. In addition, the blower wheel sleeve can wear out, allowing the blower wheel to wobble on the motor shaft. If the blower wheel is obstructed or defective, it may take too long to dry clothes. To determine if the blower wheel is working properly, remove the dryer vent and assess the strength of the air flow. If the air flow is weak, check the blower wheel for obstructions. If no obstructions are present, try rotating the blower wheel by hand. If the blower wheel wobbles as it turns, replace it.
Cause 3
Heating Element
The heating element warms the air before the air enters the dryer drum. Over time, the heating element can burn out. If the heating element isn’t working, the clothes will take substantially longer to dry. To determine if the heating element has burned out, use a multimeter to test it for continuity. If the heating element does not have continuity, replace it.
Cause 4
Lint Filter
The lint filter might be clogged. Dryer sheets and fabric softener can leave a residue on the lint filter, reducing the air flow. If the lint filter is clogged, clean it.
Cause 5
Moisture Sensor
The moisture sensor monitors the clothing’s moisture level and sends a signal to the control board when the clothes are dry. If the moisture sensor is malfunctioning, it could inaccurately report that the clothing is still moist, causing the dryer to keep running even though the clothes are dry. However, this is rarely the case. Before replacing the moisture sensor check all the more commonly defective parts. If you have determined that all of the other components are working properly, replace the moisture sensor.
Cause 6
Thermistor
If the dryer won’t stop, the thermistor might be defective. Some dryers have a thermistor. The control board uses the thermistor to monitor the dryer temperature and cycle the heat on and off. If the thermistor is defective, it may turn off the heat too early, considerably lengthening the drying time. However, this is rarely the case.