man using a dehumidifier

People love dehumidifiers for how effectively they can adjust the relative humidity in a room so you can live more comfortably.

Dehumidifiers are generally easy to care for, requiring some minor weekly maintenance. Other than that, you can set the dehumidifier up and let it run on its own. But if you notice your dehumidifier is blowing out warm air, you may be concerned.

Dehumidifiers can be mysterious, so we’ll explain how they work, why they sometimes blow hot air, and if you should do anything about it.

What Do Dehumidifiers Do?

Dehumidifiers are appliances that remove moisture from the air to lower the relativity in a given space. Many people find overly humid spaces uncomfortable and damp, such as basements or garages.

Dehumidifiers have many benefits that go beyond just a comfortable room. They can reduce mold and mildew in your home and eliminate musty odors. People that reside in basement apartments or live in locations like Florida have to deal with moist, heavy air. This damp air can cause illnesses and allergy symptoms like coughing, sneezing, itchy eyes, runny nose, and more.

How Do Dehumidifiers Work?

Most dehumidifiers work similarly to your refrigerator. There is a cold coil that air passes over, and when it does, the water in the air is condensed and collected in a water basin.

Once the moisture in the air is condensed, the air in the dehumidifier is heated by a different coil and pushed back into the room. Sometimes the heat can help reduce the humidity in a given space. But this isn’t guaranteed.

Why Is My Dehumidifier Blowing Hot Air?

First off, a dehumidifier radiating heat is a normal part of the process. Before the air is pushed back out into the room, it is heated by the coils. So if you feel warm air coming out of your dehumidifier, it likely means the appliance is just doing its job and sucking the moisture from the air.

There is a slight cause for concern if the air blowing out of the dehumidifier is extremely hot. If the air feels hot enough to burn you, you should likely unplug the appliance, so it doesn’t overheat. You can inspect the unit for frayed wires or other electrical problems. If you can’t figure it out and are still concerned, you can contact the manufacturer, call an expert, or try our troubleshooting tips.

Dehumidifier Troubleshooting

If any of the following things keep occurring, you may have a faulty unit and need to replace it or have it fixed.

Randomly Turns Off

If your unit is constantly turning off, it may be because of an excess of moisture. If the constant hum of the coils and the compressor stops every once in a while, there may be a problem with your dehumidifier’s humidity sensor. This means your dehumidifier keeps thinking the relative humidity is fine when it’s too high.

A simpler answer may be that your dehumidifier water basin is full. This just means your dehumidifier sucks as much water out of the air as it had room for. All you need to do is empty the water basin and then replace it in the dehumidifier, and that should get it running again.

Strange Sounds

Odd clicking or buzzing noises indicate the unit may be overheating. These noises happen when the metal and electronic parts expand from the heat. It’s usually nothing to worry about because the dehumidifier is just working, but if the sounds become excessive, you should turn the unit off.

If this turns out to be a problem with the compressor and thermostat. The thermostat may be broken and can’t recognize that the unit is getting too hot, or the compressor may have a broken part. 

Unresponsive Unit

There can be other problems with the thermostat if it’s working too well. The thermostat is designed to sense when the unit is overheating so it can shut itself off, but a malfunctioning sensor can misread the temperature and shut off constantly, or not turn on at all.

Luckily, these sensors can usually be replaced by contacting the manufacturer or calling an HVAC expert.

Warm Coils

For the dehumidifier to work properly, the coils need to be cold so they can condense the moisture in the air into water droplets. This usually means you have a refrigerant leak. Unfortunately, if this is the case, you need to replace the whole dehumidifier. Fixing a refrigerant leak will likely cost more than a new unit.

Bottom Line

The bottom line is it’s perfectly normal for a dehumidifier to release some warm air while it’s pulling in moisture. So if you feel the warm air when you walk by the dehumidifier, there is no cause for concern.

Keep in mind our troubleshooting tips, and the solution is often simpler than one may think. Sometimes it’s as simple as emptying the water basin.

Frequently Asked Questions

Dehumidifier with touch panel
Source: Shutterstock

Are there combination dehumidifiers and heaters?

Yes, there are combination dehumidifiers and heaters. If you want low humidity and high heat, you can get one of these units. However, as we discussed in this article, dehumidifiers on their own will produce hot air for your home.

Can dehumidifiers blow cool air?

They can, but that’s not what you want. Humidifiers should blow cool air, but dehumidifiers that blow cool air may not be working. If your dehumidifier is blowing cold air, it may be malfunctioning and not taking moisture out of the air for you.

Can the hot air be dangerous?

If the air is searing hot enough to burn you, this poses an obvious risk of injury. The best thing to do is immediately unplug the unit to give it time to cool down. This most commonly happens with older dehumidifiers that may need replacing.