Dehumidifier Makes Loud Noise: Very Disconcerting but There are Good Fixes

Dehumidifiers are helpful little machines, sucking up the excess moisture in the air and making your home a more comfortable haven.

However, there are many complaints regarding these devices, ranging from a dehumidifier blowing cold air, to making loud noises.

Some units can be so noisy that it’s enough to drive anyone crazy. Don’t fret!

Before you banish your dehumidifier in the basement, let’s diagnose the cause of the racket and get things peaceful again.

10 Reasons Your Dehumidifier is Too Loud

Reasons Your Dehumidifier is Too Loud

Many times, you will be using a small dehumidifier for the bedroom to make the room comfortable enough to sleep in. But you cannot sleep if it is too loud.

If the noise gets to you, check the following things, which are usually the main causes of a noisy dehumidifier:

1. Dirty air filter

Just like a clogged air filter muffles your vacuum cleaner, a dirty dehumidifier filter restricts airflow, causing the fan to work harder and louder.

2. Clogged drain pan

When the pan collecting condensed water fills up or gets clogged, water can splash and slosh around the drain pan, creating noisy havoc.

3. Uneven surface

Dehumidifiers vibrate naturally, but on an uneven surface, that vibration is amplified, leading to excessive rattling.

Also, for the best effect, remember that the best place for a dehumidifier is high up, rather than on the floor. Just make sure it is on a level, elevated surface.

4. It has loose parts

Screws and brackets can loosen over time, allowing internal components to vibrate and bang against each other. Usually, this happens to old units that have seen better years.

5. Worn-out fan

As fan blades age and become unbalanced, they can wobble and create a droning or scraping sound. In such cases, it is best to replace the dehumidifier if it has seen better years. 

6. The compressor is faulty

The compressor is also the heart of the dehumidifier. However, due to age, it can wear out and make grinding or knocking noises. It can also start switching on and off, which is not good. In fact, this is one of the reasons why a dehumidifier keeps shutting off.

7. Defrost cycle

Some dehumidifiers have noisy defrost cycles, but these should only last a few minutes. If it’s prolonged or frequent, please investigate.

8. Improper placement

Placing your dehumidifier too close to walls or furniture can restrict airflow and amplify noise. The unit needs proper airflow around it, but especially on the side with the vents.

Place it at least 1 foot from the wall or furniture. In the bedroom, place the dehumidifier at least 3 feet from the bed.

9. Oversized unit

A dehumidifier that is too big for the space will cycle on and off more frequently, leading to more noise. 

Buy a small dehumidifier for a 4 by 4 grow tent if that is the space you have. Never buy one that is too small or too big for the intended space.

10. Normal operation

Some dehumidifiers are simply noisier than others. Check the manufacturer’s specifications for expected noise levels. Bigger units can make more noise than smaller ones, and so on.

How to Fix a Noisy Dehumidifier: 9 Simple Tips

A noisy dehumidifier should not go to the trash, well, unless you have had it for more than 10 years. You can fix the noisy hubbub. Try the following things:

1. Clean or replace the air filter

In fact, never wait for a dehumidifier to become so noisy that you can clean it. You should make a habit of cleaning it a few times a week. If neglected, the dehumidifier spreads mold to your home.

The air filters capture all manner of allergens, including mold spores, and if left too dirty, they will spread the same into your indoor air.

2. Empty and clean the drain pan

Because of its regular contact with water, the drain pan collects a lot of dirt. It can also grow mold, which can spread to your home.

Make sure you clean the pan with soap and water, and if there is mold, kill it using white vinegar. You can also clean it using bleach, but make sure you never use bleach with white vinegar because it forms a toxic gas. 

Check the user manual of your dehumidifier to learn how to disassemble and clean it.

3. Place the dehumidifier on a level surface

This is a no-brainer, even when it comes to the proper placement of a humidifier.

Always keep your dehumidifier on a level surface so that all parts work correctly. If you keep it on a tilted surface, it might even flip over, and the bucket will not fill properly.

4. Check for loose screws and tighten them

If the unit has some loose parts moving about, you need to dismantle it and check the loose parts out.

You can fix most of them on your own, without the need of advanced tools. However, if a major part has broken down, you might need to take it to a technician.

5. Inspect the fan blades for damage

If the fan blades have wear and tear, you may have to replace them.

Most dehumidifier parts, including the fan blades, are replaceable. In fact, you can order such parts from the manufacturer,, eBay, or other online marketplaces.

6. Repair or replace the compressor

If the compressor is the culprit, consider calling a professional for repair or replacement. Usually, it is just best to replace the compressor.

7. Check the defrost cycle

Observe the defrost cycle duration and frequency. Consult the manual or manufacturer if it seems abnormal.

8. Place the unit in a space with enough airflow

Ensure the dehumidifier has adequate space around it for proper airflow. It should be at least 12 inches from the wall, but further is preferable. Also, place it in such a way that the vents are not facing the wall or furniture.

9. Get a correctly sized dehumidifier

If the size mismatch is significant, consider a smaller unit for your space. All dehumidifiers have a space rating, so check the label when buying it.

Recommended Noise Levels for Dehumidifiers

Dehumidifier noise levels can vary from 40 to 60 decibels (dB). For comparison, a normal conversation is about 60 dB, while a quiet library is around 40 dB. 

Generally, dehumidifiers below 50 dB are considered quiet enough for most bedrooms.


A noisy dehumidifier doesn’t have to be a constant nuisance. By identifying the culprit and following these simple tips, you can restore peace to your home and let your dehumidifier do its job discreetly.

Remember, if the noise seems abnormal, or you’re unsure about tackling the repair yourself, don’t hesitate to consult a technician.

If the dehumidifier is still under warranty, and you think it has abnormal noise levels, you can email the manufacturer and return it.