Tip & How-To about Dryers

How a Dryer Works

First, you open the door and place your wet clothes into the tumbler. After you shut the door, you adjust the heat settings. Most dryers have three settings-low, medium, and high heat. Next, you set the timer. It's usually a dial-type timer with various settings. You can set the timer for a specific length of time, like 20 or 80 minutes, or you can let the dryer decide when it's time to turn off. Newer dryers have cycle settings like "optimum dry," "less dry," "fluff," and various others. Some have controls for cotton clothes or permanent press, or other options. Also included is a notification switch, that when set on "loud," sounds a buzzer to let you know the dryer's done. After all the settings are set, you press the "start" button.
The motor begins to turn and the belt rotates the tumbler. At the same time, air is drawn into the dryer. Also at the same time, the heating coil flares to life (or the pilot light ignites the heater in a gas dryer) and warms the incoming air. The tumbling clothes heat up and the water within them turns to steam. The exhaust carries the steam out of the dryer, usually through a duct that sends it outside.
Sounds simple enough, right? But how does the dryer know not to get too hot, and how does the timer actually work?
When you open the control panel on the dryer-which is not recommended unless you know what you're doing, by the way-there will be wires going this way and that. The cycle controller is usually square and has a round device attached to the top of it. The round device is actually a small motor. The motor has a small gear on it that connects to a larger one with a dial inside the cycle controller. As the gear on the motor turns, it turns the dial very slowly. The dial usually has a set of four cams attached to it. As the dial turns, the cams engage certain contacts within the cycle controller. The contacts determine everything that happens, from the length of the drying cycle to whether or not the air gets heated.
To ensure your clothes don't go up in flames, dryers have temperature sensors installed in them. They are little silver discs, about the size of a quarter, and there are usually two of them. In most dryers, one is located near the heating coil and the other is in the front section of the dryer. They also have a set of contacts within them, so that when the temperature gets too hot, the contacts separate and the dryer automatically turns off.
If you take the top and front of the dryer off (again, not recommended), you will see the exposed tumbler. A belt goes around the tumbler and winds around a pulley that's connected to a motor. There are rubber wheels underneath that sit in a groove in the tumbler to ensure an even and smooth rotation. Depending on the dryer you have, the motor may control the exhaust fan as well.
One of the most important factors in how a dryer works is air flow. The dryer has to bring in air to heat in order for everything to work. Most dryers have a hole or ventilation duct located on the front of the machine. It's not visible with the cover on. Air is sucked in through that hole and is forced past the heating element. The heated air flows into the tumbler to heat the clothes. The steam is then sucked out of the dryer through the lint trap and out of the building. The lint trap is usually located right below the door of the dryer. For your dryer to work as efficiently as possible, make sure to clean the lint trap after every load. A fan is used to both bring the air in and send it out. It is located between the lint trap and the ductwork leading outside.
For all intents and purposes, the dryer is a very simple machine. It is designed so well that the only thing that really changes over the years is the look of them. But just because they're designed well doesn't mean you'll never have a problem with them. If you are currently having a problem with your dryer, check out our easy repair guide before calling in an appliance repairman. The problem may be an easy one to fix, and you could save yourself a bundle.

Posted by on

Dryers Logo

Related Topics:

Related Questions:

1 Answer

I own a Bosch Nexxt Series Electric Dryer, the clothes come out with a petrolium smell, grease or something. I have cleaned the trap, duct work, bearing shield to no avial. It is not the washer, the


Instructions

Dryer Does Not Turn On
1

Ensure that the dryer's power supply cord is firmly plugged into an electrical outlet.
2

Inspect the structure's fuse box for a tripped fuse. Each fuse is assigned a single "On/Off" switch. If any fuse switch is in the "Off" position, flip that switch to the "On" position. If the problem persists, contact a professional electrician.

3

Press the "Start/Stop" button on the left side of the dryer's control panel.
4

Close the dryer door firmly so that the door clicks into place. The dryer will not operate if the door is not shut.
Lint Filter
5

Clean the lint filter. Twist the program selector knob on the control panel to the "Off" position, then open the dryer door. Pull the lint filter out of the dryer. The lint filter is located at the front of the dryer's tumbler, and is inserted vertically into the dryer. Gently stroke your hand over the filter to clear the lint, then reinsert the filter and close the door.
6

Turn the dryer off and allow at least 30 minutes for the dryer to cool, as excessive heat can cause a drying program malfunction.
7

Increase the ventilation of the room the dryer is located in, such as by opening a door or window. Excessive heat will cause the dryer to automatically turn off until it cools as a safety measure. Increasing the ventilation will help keep the dryer cool.
Clothing Not Fully Dry
8

Clean the moisture sensor. Open the dryer door to access the moisture sensor. The black-colored sensor consists of two bars, and is located at the front of the dryer's tumbler, to the left of the lint filter. The sensor should be cleaned with a clean cloth and white vinegar once per month.
9

Clean the lint filter. Twist the program selector knob on the control panel to the "Off" position, then open the dryer door. Pull out the lint filter. The lint filter is located at the front of the dryer's tumbler, and is inserted vertically into the dryer. Gently stroke your hand over the filter to clear the lint, then insert the filter back into the dryer and close the door.
10

Spin the laundry at a higher spin speed in the washing machine before placing the laundry into the dryer to reduce the moisture content.
11

Turn the dryer off and allow at least 30 minutes to pass for the dryer to cool, as excessive heat can cause a drying program malfunction.

Jan 09, 2013 | Bosch Nexxt WTMC 3300 Electric Dryer

1 Answer

Whirlpool Cabrio dryer temperature won't get hot? What causes this problem?


Runs but will not heat
1.loose wiring----check terminals & wiring
2.defective centrifugal switch in motor---replace switch ( check linkage to motor)
3.defective timer---replace
4.open heat element---replace heat element
5..defective operating thermostat---test thermostat, replace if defective
6.fan or it's pulley loose on shaft---tighten set screw
7.incorrect heat or timer settings---reset timer
8.clothes to wet when placed in dryer----wring out or extract water from clothes before placing in dryer
9.clogged lint screen or duct (little air motion)---clean out lint screen & duct

Sep 25, 2011 | Dryers

1 Answer

Maytag DG410 gas dryer-no flame, no heat. I replaced the ignitor - that apparently isn't the problem. Other ideas?


Motor runs, but main burner will not ignite
1.heat switch set wrong---correct switch setting
2.defective timer or timer circuit---check timer wiring--replace timer motor or switch as needed
3.defective centrifugal switch in motor---clean switch or replace as needed
4.gas supply valve closed----open gas valve
5.inoperative solenoid coil---test coil for open circuit & the voltage to it
???
Pilot burner goes out
1.insufficient gas supply---- low gas pressure or clogged pilot filter or partially closed gas valve
2.carbon deposit on thermocouple tube---clean tube & check pilot burner for proper combustion
3.improperly adjusted pilot flame--adjust pilot flame until faint yellow tip begins to appear
4.faulty ignition or reset valve or thermocouple---replace

Clothes not drying, but dryer runs & heats
1.defective operating thermostat---test thermostat, replace if defective
2.fan or it's pulley loose on shaft---tighten set screw
3.incorrect heat or timer settings---reset timer
4.clothes to wet when placed in dryer----wring out or extract water from clothes before placing in dryer
5.clogged lint screen or duct (little air motion)---clean out lint screen & duct

Sep 22, 2011 | Maytag PYG4500A Gas Dryer

1 Answer

Mayteg model DE313 clothes dryer that stopped drying clothes.


That is a very accurate assessment of the problem. Check the element for continuity between its two contacts. If there is none, replace it. If there is, look for a fuse on the side with two wires going to it. Test it for continuity. If there is none, replace it.

Jul 21, 2009 | Dryers

Not finding what you are looking for?

397 people viewed this tip

Ask a Question

Usually answered in minutes!

Top Dryers Experts

yadayada
yadayada

Level 3 Expert

76649 Answers

Donald DCruz
Donald DCruz

Level 3 Expert

17130 Answers

Brad Brown

Level 3 Expert

16010 Answers

Are you a Dryer Expert? Answer questions, earn points and help others

Answer questions

Loading...