Dryer Basics - How They Work

To get a deeper understanding of how they work, let's look at four areas of a dryer:

#1 The control panel
The control panel is made up of at least two of the following components:

Timer
The timer is usually the largest dial on the main control panel. It may be a mechanical device much like a simple clock. Or it may be completely electronic, which is just a digital readout.

Start switch
After you have set the timer to the proper cycle, you press or turn the start switch to begin the cycle. The dryer shouldn't run until you do this.

Selector switches or knobs
Most dryers have one or more other switches or knobs on the control panel. They let you adjust certain settings of the dryer, such as heating temperature, end-of-cycle signal, timer cycle, and so on. Normally, the dryer functions, running the cycle selected by the timer, regardless of how these switches or knobs are set.

#2 The door switch and interior light
There is usually a door switch inside the main cabinet of the dryer. Look for a button or small lever protruding from the main cabinet on or near the dryer door frame. When you close the dryer door, it contacts the button or lever, which activates the switch and lets the dryer operate if it's started.

When you open the door, the switch interrupts the power to most of the dryer's internal components and turns on the interior light, if there is one.

Warning! If the dryer doesn't stop when you open the door, don't use the dryer! If you use a dryer that has a defective door-switch, serious injury may result.

#3 The drive motor and related parts
Your dryer motor serves three main functions:

1. The drum is turned by the motor, the drive belt attaches to one side of the drum.
2. If the drum doesn't rotate at the correct speed, the heat doesn't turn on.
3. A fan blade is attached to the other side of the drum and draws warm air through the drum and pushes it out the exhaust vent.
   

#4 The burner assembly and related parts
The burner assembly for an electric dryer consists of a heating element and one or more thermostats. In a gas dryer; the thermostats, gas valve, igniter and sensor, and gas valve collectively make up the burner assembly. Either electricity or gas supplied to the heating element is turned on and off by the timer, as follows:

1. First--when you close the dryer door, set the timer, and press or turn the start switch--the motor starts. When it reaches full speed (in about a second), a switch on the motor turns on, which allows electricity to flow to the heating element through a thermostat.
   
2. The heating element then glows red hot. Air from the blower flows over the element, through the drum and out the exhaust vent.
   
3. When the dryer reaches the pre-set drying temperature, a thermostat turns off the flow of electricity to the heating element.
   
4. When the temperature in the dryer falls about 20 to 30 degrees, the thermostat turns on the power to the heating element again and the cycle starts over.
   
5. If you selected the Automatic setting, the cycle continues until the clothes are dry, then the timer advances and turns the dryer off. If you selected a timed setting, the cycle continues until the time has expired, then the timer turns off the dryer.

Dryer Buying Tips

1. Dryers are available in either gas- or electric-powered models. Gas dryers are generally cheaper to operate over the life of the appliance, but typically are priced about $50 more than electric dryer.

2. How dryers determine when to stop is a key element in how they are priced. Dryers either use sensors or thermostats to assess how dry the clothes are. Sensor, can judge the amount of moisture remaining in clothing, a thermostat measures the temperature of the escaping air. The sensor is typically more costly to purchase, but generally considered more efficient, easier on your clothes and therefore cheaper to operate in the long run. Look for a dryer with sesnors.

3. Shoppers often purchase dryers as a set when they buy a washer. Style and aesthetic appeal can drive the cost of the unit higher. In reality, the matched set doesn't perform any better. But, it does look great. Unfortunately, when one machine needs to be replaced, getting a matched piece is not always possible. For best value, consider replacing only the machine that breaks down.

4. Special features that add unique features or flexibility also will cost more. Newer models include heated cabinet that have multiple racks to dry delicates gently and an overhead rack to hang garments while steam circulates, removing wrinkles and even odors. Some models have reversible doors if you ever need to move the dryer location. Look for models that have large, accessible lint filters for ease of cleaning.

Tricks to Keep Your Dryer Maintained

Vent - Routinely check the entire length of the vent pipe for lint build-up at least once a year--or more often if the dryer gets a lot of use. Remove the lint from the duct - don't just push it back into the dryer or let it clog any part of the vent.

Warning! Make sure you have an aluminum vent pipe. The white vinyl duct that was common several years ago no longer meets most building codes, because if your dryer ignites it, a fire may start in your home.

Interior of dryer cabinet - The lint produced by clothes tumbling in a dryer is normally trapped by the lint filter. However, some lint invariably escapes and accumulates on the inside of the dryer cabinet. At least once a year, check the inside of the cabinet, and clean it if necessary. Do this more frequently if the dryer is used heavily.

Lint filter and Area under lint filter - Check and clean the lint filter after every drying cycle. If the lint filter has any rips or tears, replace it. If the filter gets clogged by fabric softener residue or any other residue, you can easily clean it with a soft-bristle brush and a little detergent.

You can also clean the chute, duct, or area the lint filter fits into. If necessary, use a vacuum cleaner to reach into the duct and clean out any lint.