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Dehumidifiers

Welcome to AP Wagner. You have come to the source for keeping your Dehumidifier and other appliances running like new! Below is some very beneficial information about how dehumidifiers work, as well as what can go wrong with them. You will find answers to many common questions, and learn how to properly maintain your dehumidifier. We provide many repair and service tips about dehumidifiers. A handy do-it-yourselfer can use this valuable information to determine what's wrong with their dehumidifier, and can use this knowledge to repair their dehumidifier using the appropriate appliance parts. We provide a model lookup feature and an easy to use appliance parts finder to make your repair jobs easier. We also have appliance cleaning products, and an easy to use shopping cart.

The following information should help you repair your Dehumidifier. The information applies to most makes and models including: Amana, Crosley, General Electric, Gibson, Haier, JC Penney, Kelvinator, Kenmore, Kitchen Aid, Maytag, Montgomery Ward, Sears, Westinghouse, Whirlpool, White-Westinghouse, and more.

Warning! Reduce your risk of personal injury or death. Disconnect your appliance from its power source before you start any troubleshooting or repairs. Danger of electric shock when working on electric appliances. Appliances have many razor-like machined edges; use caution when working inside any appliance.

How do Dehumidifiers work?


Dehumidifiers are very similar to air conditioners in that they both have hot and cold coils. Dehumidifiers use refrigeration and condensation principles to remove water from the air, and thereby reduces the relative humidity of the room.

The basic components of a dehumidifier include a circulating fan, a compressor, a condenser coil (hot coil), and an evaporator coil (cold coil).

A compressor compresses the refrigerant gas, which causes it to become a hot, high-pressure gas. Next, this hot gas flows through a set of condenser coils where it dissipates its heat, and condenses into a liquid. Following that, the liquid flows through what’s known as an expansion valve or capillary tube. During this process, the liquid expands and evaporates to become a cold, low-pressure gas. This cold gas flows through another set of coils called evaporator coils, which allows the gas to absorb heat. By absorbing that heat, it also collects moisture by condensing it from the air. A fan blows over the hot and cold coils to help in the process of heat transfer.

The cold coils act just like a cold glass of lemonade on a hot summer day. The moisture in the air that goes past it condenses on the sides of it, and then drips down the sides of it forming a little puddle.

In a dehumidifier, the fan pulls room air over the cold evaporator coils, which allows the water in the air to condense on the coils. This water drips into a collection bucket which you empty periodically. The air is then pulled over the warmer condenser coils which warms the exiting air. Because the air is heated as it exits, it further lowers the relative humidity of the air.

Most dehumidifiers have sensors to detect when the bucket is full. When the sensor detects that the bucket is full, it will send a signal to turn off the dehumidifier until the bucket is emptied. This will help prevent overflow and spillage of the condensed water.

Because dehumidifiers constantly have moisture sitting in the holding tanks and on the evaporator coils, you must clean them often to prevent mold spores and bacteria from growing.

Normal operating sounds can be caused by the compressor, fan, or coil tubes vibrating.
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Common Questions about Dehumidifiers (FAQs)

Here are some common questions about Dehumidifiers

Why won't the Dehumidifier turn on? Plug something else into the same outlet. If it works, you know you have power to the Dehumidifier. If it doesn't work, you’ll need to check for any blown fuses or tripped circuit breakers. If you have power, it could be one of several problems that are keeping it from running.

Another reason that the dehumidifier won't turn on may be that the humidity level you set your unit for has been reached. If you need or desire a lower level of humidity, adjust the humidistat to reflect this.

Many dehumidifiers have a safety device which senses when the reservoir is full. The tank either presses against a switch, or there may be a sensor connected to the tank that triggers a switch when the tank is full. This is to prevent any water damage to your property. Always remember water and electricity do not mix well. Empty the tank. This should solve the problem if the tank was full. If you empty it, and the unit still doesn't run, look around the tank to see if there's a switch or other device that controls the dehumidifier. Look for a bucket switch. You may be able to throw a switch by hand.
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Why don’t I feel any air flow from the Dehumidifier? The circulating fan controls the air flow over the coils. If there's no air flow, your fan motor may be seized or burned out.
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Why doesn't the reservoir fill? There is a humidity selector on most models. The first thing to check is the setting of this control. If it is set too high, the humidity level may have been achieved and the dehumidifier doesn't need to run. Set it to a lower humidity level and it should start working.

If the unit is running regularly, but the reservoir remains empty, then there is probably a problem with the refrigeration system of the dehumidifier. Get all the dust and dirt out of the inside of the dehumidifier and if there is a filter make sure that it is clean. If it is still not working, contact a professional appliance repair person for help.
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Why is the reservoir filling so fast? If you don't like emptying the reservoir manually, there are drain hose attachments for most models. If the reservoir is filling too fast, it usually means that there is a lot of water in the air. If this continues to happen, there is a source of moisture near the dehumidifier. Finding and controlling the source will reduce the expense of continually running the dehumidifier.
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Is it expensive to run a Dehumidifier? Dehumidifiers can be expensive to run. Since the refrigeration components are similar to a small air conditioner, it costs about the same to operate. Like all refrigeration products, if you look for Energy Star certified dehumidifiers, it should cost less to operate.
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How often do I need to empty the Dehumidifier? As long as your unit has a safety shut off control, you don’t have to worry, it won’t overflow, it will just stop running until the reservoir is emptied. Most units also have attachments for a drain hose either in the reservoir or before it. Check your owners manual for how it works on your model.
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Why are the evaporator coils freezing up? A well running dehumidifier will have really cold evaporator coils on the back of the machine. When moist air is drawn across these coils, the moisture condenses. Occasionally, the air over the coils is too cold, and the condensing water can freeze. Turn off the unit for a little while and let everything thaw out. Some temporary frosting can occur during the first 10 to 15 minutes of operation. If frost or ice remains, the room temperature may be too low for your model. Many non-basement models can not operate below 65 F. They become too efficient and cause the evaporator to freeze up. Some basement models operate well down to 38 F by using a de-icing mechanism.
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Can I run it year round? You can run it all you want, or as needed. Once you get it set for the humidity level you like, you can let it cycle itself as needed.
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What is relative humidity? Relative humidity is the percentage of how much water vapor is in the air compared to how much water vapor could be present at that particular air temperature and pressure.

What it boils down to is this: 100% relative humidity is the maximum amount of water vapor that a certain volume of air can hold at a certain pressure and temperature. When air is warmer, it can hold more water vapor. When air gets colder, it can hold less water vapor. So, in effect, when the warm air goes past the cold coils, the air can hold less water vapor, and the excess condenses on the coils, removing it from the air and lowering the relative humidity of the air in the room or home.
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Why does the Dehumidifier run so much? There are several reasons why the unit may appear to run too much. The humidistat may be set to the highest setting. If that's the case, the unit will not stop running unless the full bucket sensor shuts it off or you lower the setting. Open doors or windows near the dehumidifier may keep the humidity level too high for the unit to turn off. Also, the grill on the front of the unit may be blocked with dust and does not allow for proper airflow. The coils on back may be dirty and will not transfer heat or cool the air sufficiently. Lastly, the area may just be too large for the unit to operate efficiently.
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Maintenance Tips for Dehumidifiers

Household appliances have average lifetime expectancies. Maintaining your appliances properly can extend their lifetime indefinitely.

If you have to do any kind of repair or maintenance on this unit, make sure to unplug it from the power supply.

Use a properly grounded outlet.

Never run your appliances off of an extension cord. Some appliances require a lot of power. Trying to run yours off an extension cord can cause overheating or fire.

Clean and replace any filters as recommended by the manufacturer.

It is very important that you do not turn the unit off and back on right away. The systems’ pressure needs to equalize for several minutes before you turn it back on.

Keep your appliance clean and dust-free. Check the evaporator coils for frost or ice buildup. Keeping it clean and ice-free will help to prolong the life of the compressor motor.

A certain level of humidity is necessary in the home. Very dry air can make it difficult for you and your pets to breath, so don’t turn the humidistat up too high. This will make your unit run too much and probably won’t help very much. Too dry can be very uncomfortable, and can also make wood shrink, which leads to creaking, air gaps, and higher fuel costs.
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