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Why Is My Humidifier Spitting Out Water

Why Is My Humidifier Spitting Out Water? 3 Reasons Revealed

A humidifier is a lifesaver for people living in climates where the air is very dry. While it is not an appliance that needs to be maintained very carefully, it can go wrong at some point. Many people have faced one problem: their humidifiers are spitting out water. 

So why is your humidifier spitting out water instead of steam or mist? It can happen due to too much salt, too much water, or too many mineral deposits in your humidifier.    I will explain each of the reasons in detail and teach you how to fix and avoid them in this post. Keep reading if you want to get everything related to this subject at your fingertip.

Why is my humidifier spitting out water?

Recently, the dividing line between vaporizers and humidifiers has become blurred. Vaporizers are also called warm mist humidifiers. People who find their humidifier spit out water are likely using a warm water humidifier. 

Too much salt

adding salt to humidifier

Adding salt to a humidifier is not allowed in most cases. In fact, all the manufacturers recommend we fill the tank with distilled water. However, there is one exception. 

When you use a vaporizer, manufacturers will ask you to use tap water and add some salt to it if the machine can’t produce enough steam. But when you add too much salt, it will start to spit water in lieu of steam.

Vaporizers produce a warm mist by boiling water, meaning that it has to heat the water in some way. More often than not, these humidifiers make use of carbon electrons connected to the electricity supply. 

As you know, distilled water is not very conductive. To increase the conductivity, you should not only use tap water but add some salt to it if necessary. You could also add baking soda, and it is the same story.

When the conductivity is improved, it will provide more power to heat the water. However, when the power exceeds the need for dispersing mist, it will start to spit out water directly. 

Too much water

too much water in humidifier - max line

When water is boiling, the water in the pot will go up and down constantly. For example, we often see the soup propping out from the pot while cooking. 

This also applies to a vaporizer. As I said, it creates steam by boiling water. Therefore, a proportion of the water will constantly bounce in the water tank. 

Usually,  there would be a water line on the tank’s surface. When you fill too much water over the line, it will eventually spit out from the outlet. 

Too many mineral deposits

Mineral deposits clog the Homedics humidifier

The mineral deposit is the culprit of mold and mildew problems in most humidifiers. It could also stop the humidifier from producing mist smoothly. For instance, it would form a layer of insulation outside the heating element of a warm mist humidifier.

However, forming a mineral layer takes time. When these mineral deposits stay in the water, they will play an essential role in increasing water conductivity, just like the salt I mentioned above.

If you live in an area that offers “hard water,” it is possible that it is already very conductive even if you just clean your tank and there is no visible mineral buildup.

How to fix a humidifier that is bubbling out water?

Now you have had a firm understanding of why your humidifier is spitting out water. It is time to learn how to fix this annoying problem.

According to the reasons we just figured out, there are a few ways to avoid this issue.

Learn the correct way to add salt

You should add salt to your humidifier as per the manufacturer’s manual. Typically, one or two pinches are enough for a vaporizer to create steam. 

Sometimes, the tap water is already good enough to produce mist. In this case, nothing needs to be added at all. 

So I suggest you have a test before adding salt. If it doesn’t work, you can start by adding one pinch of salt and then test it again.

Just don’t pour a lot of salt into the tank at once. It is likely to cause water spit.

Remove extra water

This method is pretty straightforward. If you don’t add anything to the tank, but your humidifier is still spitting water. You should observe if the water is too much. 

Then you should unplug the appliance and let the water cool down. Then you should dump some water and test the appliance again.

Clean your humidifier regularly

When there are too many minerals, it will create more power, causing the water to keep spitting out. The mineral deposits could come from the water just being filled or the buildup left in the tank. 

To remove the buildup, you should clean your device regularly, for example, once per week. A 1:3 solution of water to vinegar can often do the trick. 

Cleaning the humidifier is also crucial for extending the lifespan and preventing molds and mildew. 

Use bottled water or filtered water

add bottle water to humidifier

The condition of tap water varies from area to area. People in some districts use really “hard” water. 

The mineral is so much that your warm mist humidifier will bubble out water without any extra salt or buildup. 

Under the circumstances, you may need to use another type of water that contains fewer minerals. Bottled water or filtered water could be a suitable choice. 


Adding salt to a warm water humidifier is a regular operation for producing more vapor. However, it would be the cause of water spit. Other reasons for this issue include too much water and minerals in the tank. 

To fix and prevent this issue, you should understand how to add salt to your humidifier and clean it regularly. In some cases, the hard water in your house can cause the problem. In this case, you may need to replace it with another purer type of water.

Be careful, and don’t let the boiling water burn you.

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Liz Yang is the founder of Airsmartly. She has been working at home for a few years and realizes that the performance of the HVAC system plays such an important role in our life. She has tested more than 150 products in person, including humidifiers, air purifiers, dehumidifiers, and ACs, and wants to share tips about using or troubleshooting these products with you. Her uncle is an HVAC expert with over 30 years of experience in the field, and often offers assistance when she is unsure how to handle a situation. He is also in charge of reviewing the articles on this site.

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