How Dryer High Limit Thermostats Work

High limit thermostats are located close to the heater and are wired in series with the heater. The contacts in a high limit thermostat remain closed at temperatures below 250 degrees.

The contacts will open and interrupt the circuit to the heater when the operating thermostat, thermistor or electronic control fails to cycle properly. The most common condition that causes the high limit thermostat to operate are vent restrictions, blower failure or a defective operating thermostat or thermistor.

Dryer safety thermostats, thermal cutouts and high limit thermostats only come into operation when there is an unusual condition in your dryer that causes too much heat. Under normal dryer operating conditions these items do not cycle.

Vent restrictions are the number one reason dryer safety thermostats, thermal cutouts and high limit thermostats stop the heater from heating or open the circuit to the motor causing the dryer to shut down.

Dryer safety thermostats, thermal cutouts and high limit thermostats are located in close proximity to the heater. When temperatures outside the normal operating range are sensed the dryer safety thermostat, thermal cutout or high limit thermostat interrupts the circuit to the heater or the motor.

How to check for a restricted dryer vent