Why Is My Dehumidifier Running But Not Collecting Water?

The dehumidifier’s primary purpose is to collect water. Therefore, if the dehumidifier is running but not collecting water, it amounts to zero work.

The bad news is that the dehumidifier can stop collecting water for a variety of reasons. Sometimes the reason is as simple as extremely low temperatures, while other times, it’s as complex as a damaged control board. Unfortunately, this makes it very difficult to diagnose the problem.

Fortunately, though, most of the issues are reversible. Although some may require that you involve an HVAC professional, in the end, the dehumidifier should start collecting water again. Very rarely will you need to replace the dehumidifier.

9 Reasons Why a Dehumidifier Can Stop Collecting Water

The following are common reasons why your dehumidifier can stop collecting water. Remember that this guide only applies when the dehumidifier is running. So, begin by making sure the dehumidifier is plugged in and turned on. Sometimes we plug un applies but forget to turn them on. Or, you may turn it when it’s not even plugged in.

If it’s plugged in and switched on but not removing water, it could be one of the following nine problems;

1. Low Temperature

The first thing you should consider is temperature. Different dehumidifiers are designed to operate in different climatic conditions. For instance, most dehumidifiers are designed to run between 60°F and 110°F.

For these models, whenever temperatures dip below 60°F, they find it a little difficult to collect water. The lower the temperature, the worse the problem. At some temperature, several degrees below the lower limit, most dehumidifiers will freeze and stop cooling altogether. Others are designed to turn off when it gets too cold automatically.

Other dehumidifiers can operate in colder conditions without any issues. A few, for instance, operate down to 30°F. However, these are the outliers. Most units will start struggling at 59°F.

Solution: Check your thermostat to find out the prevailing temperatures. If it’s 60°F or lower, then it’s likely that your dehumidifier is struggling with the cold. The good news is that you don’t need dehumidifiers in extremely cold conditions, anyway.

However, if you feel the moisture is too much, you may need to position the dehumidifier in a warmer condition or buy a new unit that can withstand colder conditions.

2. Low Refrigerant Levels 

There are two main types of dehumidifiers – compressor and desiccant. Compressor dehumidifiers operate like air conditioners. They use refrigerants to condense moisture. Meanwhile, desiccant dehumidifiers use desiccant (highly hygroscopic) material to extract moisture from the surrounding environment. Up to 90% of consumers use compressor dehumidifiers. So, it’s likely that yours is also a compressor model.

When a compressor dehumidifier runs low on refrigerant, everything can go wrong. One of the consequences is usually reduced moisture removal capacity. Since the unit relies on refrigerant to extract moisture from your air, low refrigerant can significantly reduce the amount of moisture the appliance can remove per unit time.

Low refrigerant is primarily caused by leaking. Maybe some nuts aren’t tight enough, or one of the refrigerant lines has been pieced. It’s tough to know because refrigerant evaporates almost instantly.

Solution: For refrigerant leaks, you need to call a licensed HVAC professional as most states have strict laws that prohibit non-professionals from handling refrigerant. You may be fined and even jailed for risking the lives of your neighbors.

3. Compressor Malfunction

Still, on compressor dehumidifiers, the compressor unit located inside the appliance is a very delicate area. However, one of its functions is to maintain refrigerant cycling. Therefore, it’s solely responsible for ensuring refrigerant cycles around the pipes to collect and dump moisture appropriately.

However, the compressor can fail, resulting in a situation where the humidifier runs without collecting water. This usually happens for two reasons.

First, the compressor can become overwhelmed. When this happens, a special lever known as an overload trips to protect the motor from damage. When the overload system stops working, it cuts power to the motor. Thus the motor also stops, and the compressor stops too.

Compressors can also fail if the compressor capacitor fails. This is because the compressor capacitor serves as a power reservoir for the motor. To protect the motor, it draws through the capacitor rather than directly from the power source. Thus, when the capacitor fails, the motor will also fail.

Solution: Compressor failure should also be left to the experts as the compressor is a highly delicate unit. Switch off the dehumidifier and call your HVAC services provider.

4. Airflow Issues 

One of the most common reasons a dehumidifier will run without collecting water is freezing inside the unit. All the three issues above can eventually result in internal freezing. Another potential cause of freezing is insufficient airflow.

The dehumidifier relies on the warmth from return air (air entering the dehumidifier from your home) to keep the internal components from becoming too cold – due to the effects of the extremely cold refrigerant. It means that when airflow is compromised, the cold inside the unit can become too much, causing the air inside the dehumidifier to freeze.

Common causes of airflow issues are a bad fan system and blocked filters. For example, a damaged fan may fail to generate the air motion needed to keep the internal components freezing. Meanwhile, a blocked fan may restrict airflow, thus limiting the amount of heat inside the dehumidifier.

Solution: The only solution here is regular maintenance. Inspect the fan regularly to make sure it’s not clogged or broken. Broken blades are particularly a nightmare. If you hear strange sounds coming from the fan area, stop the dehumidifier and inspect the fan for damages. Also, inspect, wash, and change the filter to prevent air blockage as recommended by the manufacturer.

5. Is it a Sizing Problem?

 It may sound counterintuitive. However, dehumidifiers that are too large for the room may create several problems, including a situation where the unit runs without collecting water.

How is that possible? It’s a straightforward explanation. Dehumidifiers are designed to run in on and off cycles. During the ON cycle, the unit collects water and even removes heat (to a small extent).

All this time, the humidistat monitors humidity conditions inside the house. When the humidistat setting is reached, it instructs the dehumidifier to cycle off temporarily. During this OFF cycle, the unit is running but not collecting water.

If the dehumidifier is too big for the application, it will reach the humidistat setting faster. This means the ON cycles will be shorter and the OFF cycles longer. As a result, you may sometimes feel like the unit is constantly running without collecting water.

Solution: Proper sizing is the key here. Never buy a dehumidifier too big for your house (or room), thinking it will perform better. On the contrary, larger dehumidifiers tend to use up more energy and negatively affect the cooling process.

Other Common Reasons

The five above are the most common reasons your dehumidifier can run without collecting water. However, the issue can sometimes occur for reasons you rarely expect, including;

6. The Water Tank is Full

Dehumidifiers are signed such that they will alert you when the water tank is full. In many cases, you’ll hear a sound, while in others, an LED will light up.

However, you may not know that the dehumidifier is also designed to stop collecting water when the tank is full. It will suspend water collection until you empty and return the tank properly.

7. Blocked Hose or Damaged Pump

Many larger dehumidifiers use automatic drainage, with a pipe leading from the dehumidifier tank to the sink or drain hole. Some even have pumps to facilitate the drainage process.

If the drain hose is blocked or the pipe is damaged, the tank’s smooth water is compromised. This can lead to a full tank, which may cause the dehumidifier to suspend water collection automatically.

8. The Air is Too Dry

Dehumidifiers are designed to remove moisture from your home. It means that they can only work when there’s moisture in the air. You can’t expect them to collect when there’s no water to collect.

Fortunately, the humidistat will tell you when the humidity levels are too high such that you need to run the dehumidifier. If you insist on running it even in dry conditions, it will come on and keep running without collecting any water.

9. Electrical Issues

A dehumidifier is an electrical appliance. It depends on electrical current to turn the various motors within the system to draw stale, moist air into the unit and send dry, healthy air back into your home.

Now, imagine a situation where the electrical system is impeded. Perhaps one of the wires connecting two parts within the appliance is loose. Or, maybe, one of the capacitors blows. Sometimes it can affect the water collection process – if the dehumidifier doesn’t stop altogether.


Cases of a dehumidifier running but not collecting water aren’t too uncommon. However, most are caused by fundamental issues such as blocked filters, a full tank, and the wrong thermostat setting, which you can easily diagnose and fix.

At the same time, though, the malfunction could point to deep-lying issues such as a malfunctioned compressor or damaged circuit board. If the issue persists even after you’ve exhausted DIY diagnosis, consult an HVAC professional.