Many clothes dryers control the dry time with a knob. You turn the knob to the desired setting to tell the dryer how much heat to apply and how long to apply it. Many dryers allow you to turn the knob in either direction; however, turning the knob counter-clockwise may wear it -- and the timer assembly -- out or cause the dryer to be set on a lower heat setting.
Many dryers allow you to turn the timer knob either way. Whether you turn it clockwise or counterclockwise, you will eventually get to the setting that you want to get to. Once the dryer knob is at the correct setting, press the start button or push in the knob, depending on your dryer, to get the dryer to turn on.
Although you can turn the knob either direction on many dryers, it often causes less wear and tear on the dryer knob if you turn it clockwise. If you turn the knob counterclockwise, it may wear the knob out more quickly, and then you won't be able to set the dryer timer to the correct time. Some warranties don't cover dryer knobs, although many of them do cover the timer itself.
Some dryer timer knobs, such as the knob on the Equator washer-dryer, are designed so the dryer receives a different amount of heat depending on which way you turn it. If you turn the knob on this type of dryer counterclockwise, you'll get more heat than if you turn the dryer knob clockwise. Thus, the way you turn the knob depends on your load size and your energy needs.
If your timer knob breaks due to turning it the wrong way, it may be a simple repair. However, sometimes when the timer knob breaks, the timer assembly itself breaks too, and then you'll need to replace the entire assembly. This is more complicated and may require the help of a service technician. Thus, you should always turn the knob in the same direction to avoid potentially costly and complicated repairs.