What Happens With a Bad Thermostat in a Clothes Dryer?

Kristi Waterworth

Clothes dryers contain two thermostats. One is the operating thermostat, which determines the temperature of the air that dries clothing while the dryer is operating. The other thermostat is called the high limit or safety thermostat; this thermostat prevents the dryer from overheating. When a dryer thermostat goes bad, a variety of symptoms can emerge.

Not Heating Enough

Thermostats are vital to the proper functioning of clothes dryers.

A malfunctioning limit thermostat may be the culprit if your dryer doesn't get hot enough. Sometimes the thermostat gets stuck in the open position, telling the dryer that the inside of the dryer is already warm enough. Until the limit thermostat is replaced, the dryer will not heat properly.


Overheating is essentially the opposite problem of a dryer that doesn't heat enough. In many cases, the thermostat is stuck in a closed position, telling the dryer that it is not yet hot enough inside. Again, this is usually a problem of the limit thermostat.

Not Starting

A dryer that does not start can be suffering from a variety of problems. Before a dryer will start, it generally has several different safety items that must be in the correct position. A dryer cannot start if the door switch is open, fuses are not functional or thermostats are bad.

Running Nonstop

Dryers with automatic cycles may run nonstop if one or both of the thermostats have gone bad. During an automatic cycle, the dryer checks its internal temperature and advances the timer if it is high enough. When a thermostat is malfunctioning, it cannot read the internal temperature of the dryer correctly, keeping the timer from moving forward.