How To Know If A Dehumidifier Is Working

High humidity levels promote the growth of mold, mildew, pests, and other organisms. Excess moisture and its effects can lead to respiratory conditions like allergies and asthma, damage wooden materials in your home, and compromise the overall structure of your home. To avoid this, a dehumidifier is a good investment for homes in humid regions.

Choosing the best dehumidifier may be a daunting task, but keeping your unit working properly for a long time will also take extra care from you. However, no matter how you care for your dehumidifier, there may come a time where its performance starts to decline. Or worse, it stops working. This may be due to the machine’s natural wear and tear, or it may be caused by a faulty component or other external factors. In any case, you’ll be able to tell if your dehumidifier is working by observing its tank, humidity reading, coils, or the noise it makes.

Below, we will dive deeper into these common signs and their possible cause. Then, we’ll give you some troubleshooting tips you can do on your own. Although, if the problem seems serious, it’s always best to consult with your manufacturer’s customer support or contact a licensed HVAC technician to look at your unit.

What Does a Dehumidifier Do?

High levels of moisture in your indoor air can be a cause of discomfort. If left for long, it can even cause serious damage to your house structures and other items. Thankfully, there are many ways you can eliminate extra moisture and decrease humidity levels for good. One of the best solutions is investing in a good dehumidifier for your home.

The primary function of dehumidifiers is to reduce moisture levels in the environment, effectively maintaining ideal humidity. But that’s not all. Depending on external factors, running a dehumidifier will also give you some secondary benefits. 

For one, decreased humidity levels will make your home less susceptible to the growth of mold, mildew, dust mites, and other allergens. This reduces the risks of respiratory diseases and other health problems. 

Additionally, dehumidifiers work to eliminate unpleasant odors and improve air quality. Less humidity in the air helps dry laundry, preserve stored food, protect electronic devices and other important belongings. Outside your home, dehumidifiers are also useful for many commercial applications.

How Does a Dehumidifier Work?

Dehumidifiers work using different methods. They are classified into two main types based on the process in which they collect moisture from the air. These are the refrigerant and desiccant dehumidifiers.

Refrigerant dehumidifiers are what most homeowners are familiar with. This type of dehumidifier uses compressor-powered coils to reduce humidity in the air. Humid air is drawn by a fan and passes through the cold coils. As the air temperature decreases, the air loses its ability to hold water vapor, resulting in condensation. Moisture turns into water droplets that drip down into a tank or flow out through a drain hose. Once the vapor is removed, dry, warm air is then exhausted back into the room.

On the other hand, a desiccant dehumidifier uses a hygroscopic chemical that absorbs or adsorbs moisture from the air. It comes in a wide range of capacities, from disposable and refillable containers, rechargeable mini models, to full-size electrical units. 

The main difference is the desiccant unit doesn’t cool the air to remove the moisture. Instead, moisture is transferred to the desiccant material. Wireless models typically use silica gel technology to extract a small amount of moisture from a tiny, closed space. When they are saturated, you need to plug the unit to dry out and renew the desiccant. 

Benefits of Dehumidifiers

Maintaining optimal humidity levels in your home with a dehumidifier will have long-term benefits to everyone. This includes the following:

Dehumidifiers reduce allergies

High humidity promotes mold and mildew growth, which can cause allergic reactions such as sneezing, runny nose, and eye and skin irritations. It can also lead to allergy-induced asthma attacks and other respiratory conditions. Furthermore, dust mites are another common allergy and asthma trigger that thrives in humid environments.

Dehumidifiers help your air conditioner

Air conditioners alone may not be enough to maintain your comfort during hot and humid summers. While they cool down the air, this helps reduce the humidity level. However, excess moisture makes this task a lot tougher, leading to higher cooling bills and less effective air conditioning.

Dehumidifiers improve indoor air quality

Excess moisture makes the air feel sticky on your skin and difficult to breathe. High humidity levels also increase your risk of dehydration due to the high amounts of water vapor and lower oxygen molecules. Using a dehumidifier keeps out excess moisture and unpleasant odors, greatly improving air quality for your health and comfort.

Dehumidifiers help preserve furniture and structures

Maintaining indoor humidity between 30% to 50% RH helps preserve the structural integrity of your house as well as the furniture and equipment. Maintaining the humidity level within optimal range helps prevent rapid destruction caused by mold, condensation, rust, corrosion, or pest infestation.

How to Know If Your Dehumidifier is NOT Working

There are many signs that will tell you to check up on your dehumidifier. In most cases, you’ll be able to notice when there’s something wrong with the unit and find the appropriate solution for the problem. If you’re not sure, here are some common issues that dehumidifier owners face when operating their units.  

Dehumidifier not collecting water

One of the first problems that concern users is when the dehumidifier is not collecting water. Most dehumidifiers collect moisture in an internal tank. Within a few hours of use, the tank must have a significant amount of water if the humidistat control is set accordingly. 

If you don’t see any water in the tank after a while, this indicates that your dehumidifier is not working properly. This alone can be caused by several reasons, but usually, your dehumidifier’s control board will display a code that determines where the problem is coming from. Your owner’s manual should have adequate troubleshooting measures for basic problems. Otherwise, look for other signs that may tell you what 

No change in humidity levels

Dehumidifiers have a humidistat that senses ambient humidity. Once you set your desired humidity level, the unit will work to maintain this setting. If it senses lower humidity than your setting, the unit will stop dehumidifying. Then, it will start again when humidity rises above your setting. 

The current humidity should be displayed in the unit’s control panel. If, after a few hours of running, there are no changes in the humidity readout, then the humidistat or the unit’s cooling system itself may be faulty. To be sure, you can also compare the unit’s humidity readout with a separate device.

Dehumidifier is leaking

This is another common problem that can be traced to several possible causes. If you notice water leaking from your dehumidifier, then there may be a problem with its tank, coils, or drain hose connection. Whether you’re using a tank or hose, check for holes or cracks and make sure that the water collected is only where it should be. 

Remember that your dehumidifier is an electrical appliance and surrounding water can lead to accidents. Standing water around the unit can also become a breeding ground for mold and bacteria. If your unit is leaking other fluids besides water, turn it off and have it checked by an expert. Refrigerants are toxic chemicals and are best handled by a professional.

Dehumidifier is icing up

Low temperatures are a weakness to refrigerant dehumidifiers. When the ambient temperature drops below 65F, frost may start to form inside the unit. The refrigerant system needs to cool the coils, which cools the air. However, if the air is already cold, the water vapor may freeze on the coils instead. Most dehumidifiers have a defrost function to stop the compressor when frost starts to build up. 

After a defrost cycle, the dehumidifier may leak water from the melted ice. If your unit does not activate auto defrost, the unit may ice up, damaging its coils and other internal components. If the auto defrost is functioning well but the airflow is blocked, the fan may not be able to fully melt the ice. 

Dehumidifier is making a loud noise

Compressor-based dehumidifiers are naturally loud. The noise may be coming from the fan motor, the fan, or any loose parts. If your unit is unusually noisier, then there is likely a problem with its compressor or another internal component. Check for any loose screws then tighten them. If this isn’t the problem, then you may need to replace some broken part that’s making the noise. Some manufacturers offer replacement parts that may be free of charge depending on your warranty coverage.

These are only some common signs that are usually easily noticed by users. If your dehumidifier doesn’t seem to be working as it used to but you can’t point out the problem from the list above, then we highly recommend that you call your manufacturer or a licensed HVAC technician to help you find the problem and the best solution. 

Why is Your Dehumidifier Not Working?

If you’ve found the problem why your dehumidifier is not working, there are a few easy fixes you can do on your own. However, be reminded that professionals will know best what to do in response to any issue. If you still want to try solving the problem yourself, the following are some solutions for common dehumidifier problems.

Blocked Filter

Dehumidifiers use filters to catch impurities from the air as they enter the unit. When dust and dirt collect on the air filter, they obstruct the airflow and eventually go back into the air circulating through your home. Keep your filter clean or replace it when needed. Use a vacuum cleaner to remove any remaining dust or debris. Some dehumidifiers have an indicator light to remind you to check the filter after a certain period of use. Consult your manual for filter cleaning or replacement instructions.

Misaligned Water Tank

If the water collection tank is not placed properly, the dehumidifier may leak water when it runs. The auto shut-off feature prevents the unit from continuously dehumidifying when the water tank is full. It will also stop the unit when the tank is emptied but not reinstalled properly.

Blocked Hose

Instead of emptying a tank, you can use a hose with most dehumidifiers so that the water collected will simply flow out automatically. However, if the drain hose is not attached securely, water may leak. Or, if the hose is bent or coiled, water will not flow smoothly and back up into the tank. Consequently, when the tank is full, the unit will stop working.

Frozen Coils

Frozen coils may hinder the dehumidifier’s proper functioning. When temperatures drop, water vapor may freeze on the evaporator coils. If your dehumidifier is functioning properly, it should activate auto defrost to melt frost buildup completely before resuming normal operation. If the unit does not defrost but you notice frost, turn it off and let the ice melt by operating in fan mode or using a separate heating system. To avoid frozen coils, try not to run your unit in cold conditions. Usually, cold weather comes with low humidity anyway. If you really need a dehumidifier, it’s best if you use it in tandem with your heater.

Wrong Placement

In some cases, a dehumidifier may simply not work if it’s not installed in the correct place. Make sure you’re using the right type and size of dehumidifier for the room. Keep the unit a few inches away from walls, furniture, or any obstruction to maintain proper airflow and avoid overheating the components.

Overheated Compressor

If frost develops on the coils, or there’s a buildup of dust and other impurities, then the compressor can become overheated. If you regularly perform proper maintenance and you’ve checked all components but your unit is still not working, then the compressor could be the issue. This can be hard to tell without expert knowledge, so it’s still best to ask your manufacturer or get a professional to check your unit and assess the problem.


Where should you place a dehumidifier?

Generally, a dehumidifier must be put where it can tackle the source of humidity. These spaces are usually in the basement, bathrooms, kitchen, or crawl space of your house. Isolate the room by closing all windows and doors when operating the dehumidifier.

Should a dehumidifier run constantly? 

No, you don’t need to keep the dehumidifier running constantly. It should be enough to run the unit until the humidity level is between 30% to 50%.

How long does it take for a dehumidifier to work?

In most cases, you can notice a change in humidity within a few hours of running the dehumidifier. When dehumidifying for the first time, it can take 12 hours up to a couple of days to get the humidity down to the ideal range, but it all depends on the size and dampness of the space beforehand. 

How much water should a dehumidifier collect in a day?

The exact amount depends on a lot of factors, including the dehumidifier capacity, room size, humidity, and temperature. Although, in general, it can go anywhere from one to six gallons or 10 to 50 pints. 

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