Learn how your appliance is supposed to operate so you can determine if it is malfunctioning.
The dryer control console is located on top of the dryer cabinet. There will always be a dryer cycle control (timer) and usually a start switch. Depending on the model of dryer, you may also have a buzzer loudness control and possibly a separate temperature selector switch. Some models may incorporate the start switch into the timer requiring the timer knob to be pressed in to start the machine.
The timer knob is always the largest control on the console because it provides the most options to the user. The timer assembly inside the console is basically a rotary switch driven by a synchronous motor. The sequence of drying events versus time is controlled by the timer. You select the temperature range of heat applied to the clothes when you select a cycle such as "Normal" or "Permanent Press". No heat is applied in the "Air" cycle. The drive motor turns the drum to tumble the clothes at one speed. The timer merely turns everything off a measured number of minutes after the start control is pushed.
Pressing or turning the start button will apply power to the drive motor if the door is closed. The door switch is wired in series with the start switch and must be closed to start the motor. The start switch is actuated by simply pushing the start control button in or turning the start knob momentary.
Pushing the start button in enables current to flow to the drive motor start windings if a cycle has been selected with the timer. A centrifugal switch in the motor closes just before the motor comes up to full speed. If the thermostats are closed, the heater will come on after the motor is running and the clothes are tumbling. The dryer may be stopped by opening the door. The dryer must always be restarted by pushing the start button. Closing the door will enable the dryer to start when the start button is pushed.
Some dryers have a start switch that opens one circuit and closes another when the start control is pushed in. The drive motor start winding is energized when the button is pushed in. A centrifugal switch in the motor energizes the run windings and de-energizes the start windings within one second of pushing the start control in. When the start control is released, the buzzer is enabled when the drying cycle is complete and the motor is deenergized.
All of the information in these Appliance Clinic procedures is provided FREE OF CHARGE. No liability is assumed by the author for the accuracy of the contents or damages caused by the use of these procedures.