The part(s) or condition(s) listed below for the symptom Dryer won't start are ordered from most likely to least likely to occur. Check or test each item, starting with the items at the top of the page.
The door switch activates when the dryer door is closed. On most dryers, the door switch makes an audible clicking sound when it activates. To determine if the door switch is working, try starting your dryer and then listen for the “click.” If the door switch makes a clicking sound, it is probably not defective. If you don’t hear a click, use a multimeter to use the door switch for continuity. If the switch does not have continuity, replace it.
The drive motor turns the drum and the blower wheel to exhaust the air. Before replacing the motor, first check the thermal fuse, start switch, and door switch. If all of these parts are working properly, but the motor is making a humming noise, remove the belt from the motor and check the blower wheel for obstructions. If the blower wheel is clear of obstructions, the dryer motor might be at fault. If you suspect the motor is defective, replace it.
On most dryers, when the dryer belt breaks, the motor will still run, but the drum will not turn. However, some dryers have a switch that shuts off power to the dryer if the drive belt is broken. Check the dryer belt to determine if it is broken. If the belt is broken, replace it.
Dryer drum drive belt. 1/4 inch wide with 4 ribs and 3 grooves. The drive belt is a very long, slender belt that wraps all the way around the dryer drum, around a tension pulley, and then around the drive motor pulley. If the drum will not turn when the dryer is turned on the belt is likely broken.
If you have a gas dryer, unplug the dryer from the wall and plug something else into the outlet to determine if the outlet is working. If you have an electric dryer, check the home circuit breaker or fuses. If the circuit breaker or fuses are working, use a multimeter to test the outlet.
The main control board might be defective. However, this is rarely the case. Before replacing the main control board, check all of the more commonly defective parts.If you have determined that all of the other components are working properly, replace the main control board. (The control board cannot be easily tested, but you can try to inspect it for signs of burning or a shorted-out component.)