Why Does My Dehumidifier Keep Shutting Off?

High humidity can cause extreme discomfort and even lead to allergic reactions due to mold spores and dust mites when left unattended for long. Over time, excessive dampness can also damage furniture and other belongings in your home. To prevent this, the most effective solution to humidity control in the house is a dehumidifier. 

It can be overwhelming to choose a dehumidifier from the many types and sizes available, but it also takes time and effort to keep your unit functioning properly. However, no matter how well you maintain it or how often you clean it, there may be unexpected instances when your dehumidifier stops functioning normally. If your dehumidifier keeps shutting off, it will not be able to remove the required amount of moisture to maintain proper humidity.

This may be due to faulty components, but usually, it’s simply because the ambient temperature is too low, the set humidity level is too high, or the airflow is blocked. We will give you some possible causes as well as troubleshooting steps you can do on your own. In any case, it’s always best to check your manual first and contact a licensed HVAC technician to check your dehumidifier for mechanical or electrical failures.

How Dehumidifiers Work

The main purpose of a dehumidifier is to reduce humidity. Maintaining the humidity level properly helps keep your home less susceptible to the growth of mold, mildew, dust mites, and other allergens. This reduces the risks of allergies, asthma attacks, and other respiratory conditions. Additionally, dehumidifiers work to eliminate unpleasant odors and improve indoor air quality. 

Dehumidifiers work using different moisture removal 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 or compressor dehumidifiers are what most homeowners are familiar with. Similar to how air conditioners work, this type of dehumidifier uses condensation to remove excess moisture from the air. Humid air is drawn in by a fan and passes through the cold coils. As the air cools down, it loses its ability to hold water, resulting in condensation. The water formed drips down into a tank or flows out through a drain hose. Once the water is removed, dry, warm air is then released back into the room.

Since this type of dehumidifier relies on condensation, its performance declines in lower temperatures but is highly effective in warm and humid environments. Most residential dehumidifiers will shut off once temperatures drop as low as 41°F and their efficiency starts to decrease at 65°F. 

How Does a Dehumidifier Work

On the other hand, the other type of dehumidifier called desiccant uses a hygroscopic chemical that extracts moisture from the air until the desiccant is saturated. It comes in a wide range of capacities, from disposable and rechargeable mini dehumidifiers to full-size units. 

The main difference is that the desiccant doesn’t need to cool the air to remove the moisture. Instead, moisture is transferred from the air to the desiccant. Electric units typically use silica gel to extract a certain amount of moisture from a small room. When the silica gel is fully saturated, it needs to be heated up to renew the desiccant and remove more moisture. Because of this, desiccant units are more suitable for cold environments.

Why Does My Dehumidifier Keep Shutting Off?

There are many possible reasons your dehumidifier keeps shutting off on its own. In most cases, you’ll be able to tell what’s wrong and find the appropriate solution. Below are the common issues that may cause your dehumidifier to turn off and stop working. Some will cost you nothing and take only a few moments to check. 

Once you’ve identified the problem, there are a few easy fixes you can do on your own. Firstly, it’s important to observe proper maintenance as required by each dehumidifier model. However, if you find a more severe problem, a licensed HVAC technician will know the best solution to any issue. Meanwhile, the following are the steps you can follow to rule out a few common reasons for a dehumidifier shutting off.

Low Temperature

As mentioned, refrigerant dehumidifiers do not work well with low temperatures. When the ambient temperature drops, frost may start to form inside the unit. Naturally, it will shut off when temperatures are too low. Remember that the dehumidifier’s refrigerant system needs to cool the coils and then the air. So if the air is already cold, the moisture may freeze on the coils instead. 

Most refrigerant dehumidifiers have auto defrost function to stop the operation when frost starts to form. If your dehumidifier has shut off automatically, check the temperature or inspect the coils for frost. 

Frozen coils may damage your dehumidifier’s components. If the unit is functioning properly, it should activate auto defrost to melt the frost before resuming normal operation. You may notice that the fan is still running. If the unit does not defrost but you find frost on the evaporator coils, turn the unit off and allow the ice to melt by operating in fan mode or using a separate fan or heater. 

While defrosting, the dehumidifier will produce water in the tank. However, if the auto defrost feature is functioning well but there is limited airflow, the fan may not be able to fully melt the ice, causing the unit to turn on and off repeatedly. A blocked airflow is another problem we will solve below. To avoid frozen coils, try not to run your unit at low temperatures. Usually, cold air has less moisture content anyway.

Full Tank or Misaligned Tank

Draining Options of a Dehumidifiers

Portable dehumidifiers come with a water collection tank to hold the water removed from the air. When this container becomes full, you will need to empty the water into the drain or sink. Most dehumidifiers are equipped with an automatic shut-off function to prevent water overflow. If your dehumidifier keeps shutting off, it may be simply because the tank is already full.

The tank has a float switch that senses the water level and tells the compressor to stop when a certain level is reached. If the water tank or the float switch is not placed properly, the water may leak. While the auto shut-off feature prevents the unit from working when the tank is full, it will also stop the unit when the tank is not reinstalled properly.

Instead of having to empty the tank, you can connect a hose so that the water will flow out continuously. However, if the drain hose is not secured or it’s bent or coiled, water will not flow down smoothly. This can also cause the unit to stop working.

Clogged Filter

Honeywell Dehumidifier 

Dehumidifiers use filters to trap impurities in the air and protect the internal components. When dust and dirt accumulate on the filter, it can obstruct the airflow, causing the motor to heat up and eventually stop. Dirty filters also allow the impurities to get circulated around your home. Keep your filter clean or replace it when needed. Some dehumidifiers have an indicator light to remind you to check the filter after a certain period of use.

Remove your filter from behind the air inlet and wash it with warm soapy water until all dust and dirt are gone. Use a vacuum cleaner with a soft brush attachment to remove any remaining debris. Let the filter dry completely before placing it back into the unit. Consult your manual for more specific filter cleaning or replacement instructions.

Blocked Airflow

Blocked Airflow

If the air filter is clogged with dust, dirt, and other impurities, it also blocks the airflow. Limited airflow can cause the fan motor to heat up. If the dehumidifier is turned on but you don’t hear a whirring sound from the fan, then you may be dealing with a faulty fan motor. This is the component that facilitates air circulation. If there are no blockages and the air filter is clean, but there is still limited airflow, then the fan itself may be broken or simply too dirty. Unplug the unit, remove the cover panel, and check the fan motor and blades. Tighten any loose screws and wipe off all the dust and dirt that has accumulated.

Wrong Placement

Placing your dehumidifier in the wrong location can also affect its performance, causing it to stop dehumidifying if the air is blocked. The air inlet or outlet may be blocked if the unit is too close to walls, furniture, or other items. 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, and other appliances or any obstruction to maintain proper airflow and avoid overheating the electrical components. Remember to keep doors and windows in the room closed when running a dehumidifier.

Humidistat Malfunction

Humidistat Malfunction

Portable dehumidifiers have a built-in humidistat that tracks and adjust the humidity. Once you set your desired humidity level on the electronic control board, the unit will work to maintain this setting. If it senses the room humidity is lower than your setting, the unit will stop dehumidifying. When it senses humidity above your setting, it will resume operation. 

The relative humidity in the room should be shown in the unit’s control panel display. If you notice that there are no changes in the humidity after a few hours of running, then the humidistat itself may be faulty. To be sure, you can also compare the unit’s humidity readout with a separate hygrometer.

Check the humidity sensor in the dehumidifier. In some models, the digital screen may display an error code that indicates the type of electrical error it has encountered. Check the manual for specific instructions and troubleshooting steps.

Refrigerant Leak

The refrigerant in the dehumidifier is pumped to and from the condenser to evaporator coils to facilitate the cooling system. This could happen when the coils are damaged. In case the refrigerant leaks, the warm air from the room could get hotter and hotter as it passes through the coils, preventing it from cooling down and removing moisture. If your unit is leaking refrigerant, it produces a hissing noise due to the gas coming out. Turn the unit off and have it checked by a licensed HVAC contractor. Refrigerants are toxic chemicals and must only be handled by a professional.

Faulty Compressor and Other Mechanical Problems

If frost develops on the coils, or there’s a buildup of dust, dirt, and other impurities on other components, it can overheat the compressor. If you’ve checked the temperature and humidity, performed proper maintenance, and checked all components but your unit still keeps shutting off, then the issue could be the compressor circuit, faulty wirings, or another mechanical or electrical problem. This can be hard to tell by yourself, so we recommend you contact the manufacturer or hire a technician to evaluate the problem with your dehumidifier. Check your warranty if you can get a free repair for the unit. If you’re not sure what to do, do not attempt to disassemble and fix the unit yourself. 

Conclusion

By observing proper usage and maintenance and performing regular cleaning, you can keep your dehumidifier functioning properly for a long time. In case you notice your unit keeps shutting off for unknown reasons, the first things you can check are the temperature and humidity sensor, the water tank, and the air filter. You can follow the basic tips above to help find and solve your problem. If you can’t identify the problem and solve it on your own, it’s always best to call a professional technician or contact the manufacturer for troubleshooting.

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