All The Reasons Why Your Dehumidifier Is So Loud – And How To Fix It

A dehumidifier makes noise because of loose parts, uneven placement, a wobbly blower fan, unstable bucket or a faulty compressor. A clogged filter, debris in the unit, incorrect fan settings, or a lack of space around the unit can also result in a loud dehumidifier.

Dehumidifiers are handy appliances that can reduce the moisture content of the air in your room. While almost all dehumidifiers produce a soft, humming sound, sometimes their noise can get so loud that it can disturb your sleep or concentration. If that’s the case, it’s quite likely that there are problems in your dehumidifier that need fixing.

In this post, we look into each of these causes in detail so that you can identify why your dehumidifier is so loud. We also discuss the steps that you can take to solve these issues.

Is the noise produced by your dehumidifier normal?

Before we go about diagnosing the cause for the noise produced by your dehumidifier, it’s important that we first make sure the noise your are hearing is not normal.

Almost all dehumidifiers contain two essential components that are capable of producing noise:

• A compressor, whose job is to condense the air in your room and allow moisture to be extracted from it, and,
• A fan, whose job is to pull in moist air and/or blow out dry air.

As you can see, both perform important functions in your dehumidifier, and therefore all dehumidifiers produce a certain level of noise when they work. Normally, this feels like a soft hum or a gentle buzz.

To be more technical, these noise levels are measured in a special unit known as ‘Decibel’, or dB. 

Most dehumidifiers produce less than 60 decibels of noise, which means they should feel quieter than a normal conversation. Several dehumidifiers these days produce noise less than 50 decibels, while some particularly quiet brands produce less than 40 decibels of noise. This should be practically inaudible under normal circumstances.

You should be concerned if the noise produced by your dehumidifier is:

• Louder than it normally is, or,
• Is of a different type than a gentle hum or a buzz, or,
• If it is significantly disturbing your sleep or concentration.

10 Reasons Why Your Dehumidifier Is Making Loud Noises

1. Loose internal parts

Loose internal parts are, by far, the most common reason for a dehumidifier to be making excess noise.

Your dehumidifier contains moving parts inside it which produce a subtle vibration when they work. This vibration is responsible for the gentle humming noise you hear from a normal dehumidifier.

However, this vibration also causes the internal nuts, bolts and other parts to shake. Over time, this continuous shaking can cause these parts to loosen up, multiplying the amplitude of vibration and resulting in more noise being produced.

This is the most likely cause if the noise you hear sounds like an oscillation, or a loud buzz. However, depending on the extent of how loose your screws are, the sound could be different. So it’s a good idea to take the following steps any time you hear a noise from your dehumidifier.

Solution

1. Turn your dehumidifier on.
2. Stay at a safe distance from the machine, and gently observe all of the parts visible from the outside. Notice if there are any visibly loose parts.
3. If you could not identify the specific problem area, then turn the dehumidifier off and unplug it. You can also consider removing the front panel of your dehumidifier by unscrewing it from the main housing. You can check your user manual to locate these screws.
4. Carefully check all areas of the dehumidifier to see if anything seems shaky or unstable. 
5. Grab a screwdriver, and tighten up any nuts, bolts or screws that may have slipped out of place. Reassemble the housing once you are done.
6. If you do not feel confident in doing so, do not hesitate to call a technician for help.

2. Uneven placement

Your dehumidifier is designed to work only on level ground. If your dehumidifier is placed at an angle or is tilted with respect to the ground, it can end up making loud, abnormal noises. 

There are two main reasons why this happens.

• First, your dehumidifier being tilted means that not all of its parts are going to sit together as well as they should. Therefore, they vibrate more than usual, producing noise. 

• Another reason for this is that your dehumidifier unit has certain oils and liquids inside it required for the compressor to function properly. Tilting your dehumidifier for a long time can cause these oils to shift, making the mobile parts dry and therefore produce noise.

If this is the problem, the sound will likely be of a rattling nature.

Solution

1. Turn the dehumidifier off and unplug it.
2. Observe the dehumidifier from a distance. Does it appear visibly tilted?
3. If not, try running the dehumidifier and see if gently holding your dehumidifier down reduces the noise. Also check if any of the wheels/legs of the device are free.
4. If you discover that the dehumidifier is unstable, try shifting it to a more level ground.
5. If not, try putting something firm beneath its legs to offset the tilt so that the device housing becomes fully upright.

3. Unstable bucket

Your dehumidifier can make excessive noise if its bucket, which is supposed to collect the absorbed moisture, is not stable. 

This is possible since you will need to manually remove and replace the dehumidifier bucket frequently for the many dehumidifiers that do not have an automatic drain function. 

If you accidentally did not replace the bucket properly, it will vibrate every time the internal parts vibrate, only louder, producing an unpleasant, usually low pitch noise.

To identify if this is the cause, simply hold down the bucket with your hands when the dehumidifier is on. If the sound seems to get quieter, this is likely the problem. 

Solution:

1. Turn the dehumidifier off and unplug it.
2. Remove the bucket from the dehumidifier unit.
3. Check to see if there is any dirt, debris or moving parts between the bucket and its slot. Also check to see if something is stuck to the outside of the bucket itself.
4. If you find anything, remove it.
5. Replace the bucket back into the slot gently. Usually, you will hear a clicking noise when it fits perfectly.
6. If you notice that the bucket itself is broken or chipped, considering purchasing a replacement.

4. Blower or fan is unstable.

If the sound is loud, regular and continuous, it is possible that the blower or the fan have something to do with it.

They can produce abnormal noises under the following conditions:

• The fan could be loosely fitted over the motor shaft.
• If the fit of the fan is so bad that the blades touch the housing, it could create a much louder (and generally more irritating) noise that can also damage your fan.

Solution:

1. Plug the dehumidifier in and run it.
2. Stay at a safe distance and look at the alignment of the fan if it is visible. Ideally, the fan’s motion should be smooth, and it should be perpendicular to the motor shaft. Any angle or deviation suggests a loose fan/blower.
3. If you don’t see the problem right away, unplug the unit, disassemble it if needed, and try rotating the fan by hand. It should rotate smoothly in all 360 degrees and should not be shaky. 
4. If you do notice the issue, first check to see if the fan is not damaged. If it is damaged, your only option is to replace the fan.
5. Otherwise, try tightening any loose nuts and screws that join your fan with the motor shaft. 
6. If you do not feel confident in doing this, or if the problem persists, try to see if there are other issues with you dehumidifier. Do not hesitate to contact a technician to assist you if needed.

5. Clogged filter.

Most dehumidifiers come with one or more filters that help catch dust and other pollutants from air. With prolonged use, the filter becomes dirty and can get clogged up, which compromises the airflow in your dehumidifier system.

This can directly produce noise on its own, but it may also affect the functioning of your blower fan or your compressor, which can contribute to making your dehumidifier noisy.

This could be the case if your dehumidifier keeps shutting off at very short intervals. To make matters easier, many dehumidifiers come with indicator lights that show how the filter health is, and some models even go on to show how long it is before the next replacement is due. 

Solution

1. Turn your dehumidifier on and check to see if the filter reset light is on. It may appear as a red or blinking light. Even if the light is not on, consider checking the filter if it has been a while since you last cleaned it. 
2. Remove the filter from the housing. The way to do this could be different for every dehumidifier, but most of the filters have a small handle that projects from the main housing that can be pulled out. Almost all dehumidifier manuals show how the filter can be removed, so consider consulting the user manual if you are confused.
3. Check how the filter looks. A dirty filter may appear dark grey to black.
4. If your filter is dirty, it can usually be cleaned with lukewarm water and then dried to be reused. Do make sure your filter model has a reusable filter before doing this. Consider buying a replacement if the filter appears visibly damaged.

6. Faulty compressor.

If your dehumidifier is producing a loud screeching, cracking or banging noise, the most likely culprit is the compressor.

This noise could be produced either because the compressor is not fitting properly and has loose parts within it, or because there are issues in the compressor’s functioning itself.

Of course, as we mentioned earlier, all compressors make a small amount of noise. It only becomes an issue if the noise has recently changed or become louder.

Solution:

If you think the noise is coming from the compressor being loose, proceed to disassemble the housing and then tighten the loose parts. You may consult your user manual to know where the screws are which can disassemble the housing. Please refer to the first point in our post for details.

However, if you think the noise is coming from the compressor body itself, we’re afraid there is little to be done at this point.

This is because compressors are built to last for years, and if the compressor is truly faulty, it is a good idea to get a new dehumidifier itself rather than looking for a compressor requirement.

7. Dirt or debris inside the unit.

If there is dirt or debris in any part of your dehumidifier, it can produce a loud, rattling, or sometimes even a whistling noise. 

This is especially true if the debris is present in one of the moving parts of your machine, namely the fan, the motor and its adjacent parts.

This could either be because the debris is disturbing the motion of the moving parts of your dehumidifier, or because it is creating an obstruction in the airflow.

Solution:

1. Turn off your dehumidifier and unplug it.
2. Gently disassemble the housing with the help of a screwdriver.
3. Check the air vent, the fan, the coils, and the air filter. See if there is any build-up of dirt, debris or anything that shouldn’t be there.
4. Clean these parts using warm water and a soft sponge. The specific cleaning instructions will be available on your user manual.
5. Finally, reassemble the parts and make sure to tighten the screws properly.
6. If you are not confident in performing any of these steps, do not hesitate to contact your company’s technician.

8. Incorrect fan or operating settings.

Most modern dehumidifiers have at least two functioning modes, an ‘auto’ mode and a ‘continuous’ mode.

Normally, the compressor is designed to work intermittently, while the blower fan can either work continuously or intermittently. When your dehumidifier is set in continuous mode, both the compressor and the fan work continuously, which amplifies the noise produced.  

Solution:

The continuous mode is only supposed to be used in situations where the humidity in the room is very high, or if there is a continuous source of humidity, like a flooded basement. Otherwise, you can safely work with the ‘auto’ mode at all times. 

Similarly, the fan speed of your dehumidifier can also be adjusted, with the faster speeds being louder. Under normal settings, low to medium speeds should work just fine.

You can change these settings from your device’s control panel.

9. Not enough clear space around your dehumidifier.

Your dehumidifier has an inlet vent, through which it sucks in air, and an outlet vent, through which it releases dry air. These vents could be located on any side of your device, including the top. 

For the dehumidifier to work properly, it is necessary that the vents have enough clear space around them to suck in and release the air. If there is any blockage, you can hear a loud suction or a whistling noise.

Solution:

1. Check to see where the vents of your dehumidifier are located.
2. Make sure there is nothing (furniture, plants, walls, decor items and the like) obstructing the airflow. 
3. Most manufacturers require at least six inches of space between your dehumidifier and the nearest object. Consult the user manual of your specific model to know how far you need to place your dehumidifier, and follow accordingly.

10. The compressor is not noise-optimised.

Very often, the biggest cause of noise in your dehumidifier is the intrinsic noise produced by the compressor (and sometimes the fan) itself.

For someone new to the world of dehumidifiers, even the normal noise generated by your dehumidifier may therefore feel loud if your device is not noise-optimised.

To identify the issue, check the details of your device for something called ‘Decibels’ or ‘dBA’ values. Ideally, it should be less than 50 decibels for the dehumidifier to feel quiet.

It is also a good idea to check consumer reviews to see whether the model itself is loud, or if it is just your device that is faulty.

Solution:

If you have already purchased a loud dehumidifier, unless you have a money-back option, we’re afraid there is little to be done at this point. You can, however, consider muffling the sound by placing it on top of a sound absorbing carpet or foam.

The best thing would be, of course, to do due research and select dehumidifiers that produce less than 50 decibels of noise.

A dehumidifier contains almost the same parts as a refrigerator, and therefore the sound of your dehumidifier’s compressor resembles a similar gentle humming or a vibrating noise. 

It should not be rattling, banging or whistling when normally functioning.

How to muffle a dehumidifier

To muffle a dehumidifier, place the entire housing on top of a level, thick carpet. For better results consider acoustic foam for this purpose, which is usually more expensive but has a greater effect on noise reduction.

Of course, frequent cleaning, running the dehumidifier on medium to low fan settings and performing regular maintenance can also help make your device more quiet.

Are desiccant dehumidifiers quiet?

Desiccant dehumidifiers are usually very quiet due to the fact that they do not contain a compressor, which is the most common source of noise in regular dehumidifiers.

A compressor filter needs to condense the air and cool it to remove the moisture. A desiccant dehumidifier, on the other hand, uses a desiccant wheel that uses heat and absorption to remove the moisture. This makes the desiccant dehumidifier significantly quieter than compressors or condenser dehumidifiers, although not completely silent.