If your Whirlpool clothes dryer overheats, you'll want to figure out why. Although it has a heat-sensitive safety device that shuts off power to your dryer to prevent a fire from starting, overheating is a serious problem that you'll want to address. Since there are a variety of reasons why your dryer might overheat, you'll need to troubleshoot the problem to narrow down the list of possibilities. Only after the problem has been resolved should you resume use of your dryer.
Heat-Sensitive Safety Device
Most Whirlpool clothes dryers have a heat-sensitive safety device, called a thermal fuse. It's a small plastic sensor that cuts power either to the heating element or your entire dryer, depending upon how it's set up on your model, when the air temperature in the drum reaches its preprogrammed trip temperature. The trip temperature is usually the point at which the dryer starts overheating. Your dryer's function is limited once the device activates. For example, even though you might be able to select a dry setting and lights come on, the drum might not spin and the dryer might not produce heat. The benefit to having to replace the safety device to restore the dryer's full function is that it prevents you from using your dryer until you determine what prompted the dryer to overheat in the first place.
A Whirlpool clothes dryer has an extensive exhaust system that transports hot air from the drum to the outside. It generally consists of a hose, duct and vent. If any one of the exhaust system's components becomes blocked with lint or debris, airflow is restricted. As a result, the air temperature in the drum just continues to increase until overheating occurs. Review your dryer's user guide for instructions on cleaning the exhaust system.
Broken Cycling Thermostat
On the interior wall of your Whirlpool clothes dryer's drum is at least one cycling thermostat. It records and regulates the air temperature inside the drum, and alerts the heating element to increase or decrease its hot air output so that a constant air temperature is maintained to effectively dry clothes. However, if the cycling thermostat breaks, it's unable to accurately record the drum's air temperature, and consequently, might send the wrong signals to the heating element. For example, rather than commanding that the heating element lower its output, it might instruct it to increase it, resulting in the dryer overheating. Inspect the cycling thermostat for damage and replace it if it's not working properly.
Bad Heating Element Sensor
The heating element on your Whirlpool clothes dryer has a sensor. The sensor intercepts instructions from the cycling thermostat. If the sensor goes bad, the heating element might continue to pump heat into the drum, despite directives from the cycling thermostat to stop. When this occurs, the air temperature in the drum continues to steadily rise until it reaches the point of overheating and the safety device trips. Contact a dryer repair specialist to evaluate the heating element's performance. If warranted, have him change out the defective sensor.