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Why is My Humidifier Spitting Out Water?

Why is My Humidifier Spitting Out Water?

Dry air causes drying of your nasal passages and skin, which makes you more susceptible to respiratory illnesses and skin irritations. That’s why a humidifier is a great home essential for people living in dry climate areas.

Although humidifiers are simple devices that rarely need maintenance, they do have problems once in a while. One of the typical problems is they spit or bubble out water for some reason.

Ideally, a humidifier is supposed to release water in the form of steam or vapor. However, your humidifier is spitting out water; the issues could be due to; too much salt,  water, or mineral deposits in the humidifier.

This article will explain each reason in detail and how you can troubleshoot each cause. We will also include tips on how to prevent this issue.

Why is my humidifier bubbling out?

Ideally, humidifiers add moisture to the air by releasing it as a mist or steam. Therefore your humidifier bubbling out is cause for concern. There are several reasons why your humidifier is bubbling out. The following explains all the possible ones.

Adding salt

Most humidifier manufacturers advise against adding salt to a humidifier. Instead, they recommend filling the tank with distilled water. But there is an exception. You can use tap water when using a vaporizer and add some salt if the device is not producing enough steam. However, if you add too much salt to the vaporizer, it will start to bubble out instead of producing steam.

The difference between a humidifier and a vaporizer is simple. Humidifiers use cool water and release a fine mist into the air, while vaporizers first heat the water and then release warm steam. Vaporizers use carbon electrons connected to the electricity supply to heat the water.

But since distilled water is not very conductive, you have to use tap water and add some salt if necessary to increase conductivity. Improved conductivity will provide more power to heat the water. But when the power exceeds the need for steam, the device will start to spit out water.

Too much water

Too much water in the water tank is a common reason for the water leakage from your humidifier. In addition, boiling water from a vaporizer will naturally bubble, and a portion of the water from the overflowing tank will likely spit out of the machine.

To avoid these issues, it’s important to always get the water level to the water line on the tank’s surface.

Incoming water pressure

If you have a whole-house humidifier leaking out water instead of mist, the culprit could be increased water pressure. Whole-house humidifiers get their water through a small line running from the water supply pipes in the house directly to the humidifier.

However, this water pressure should always be below 125 psi. If the water pressure increases, it will force its way through the cutoff valve inside the unit, and water will overfill your humidifier and spit out through the first opening.

A buildup of mineral deposits

If the water is bubbling out of a warm mist humidifier, the cause is likely the accumulation of mineral deposits on the heating elements. Mineral deposits and dirt on the elements could also stop the humidifier from producing mist smoothly. These elements are for turning the water into steam.

Unfortunately, tap water contains varying quantities of minerals and other impurities. When the water comes into contact with the heating elements, it evaporates, leaving the minerals behind. Over time, they create a crust black or brown coating on the elements, thus creating an insulating layer.

Blocked evaporator pad

Most humidifiers have filters that trap dirt and bacteria from the water, thus allowing the unit to produce clean mist. Any blockage on the filter of a humidifier can also cause bubbling. Whole-house humidifiers produce steam when the machine blows air through an evaporator pad filter.

Over time, minerals and debris from the tap water will accumulate and clog the filter, causing overflowing in the drain, a flooded coil, or a tank chamber. When the humidifier is flooded, it will release water from any opening, including the mist nozzle.

Low power

Humidifiers generally produce a low-level bubbling or gurgling sound when the unit’s base draws water from the tanks. But this noise could also mean your humidifier is receiving very low power. Excess fluid will collect in the atomizer head of your humidifier due to the low power supply.

This is because the machine doesn’t have enough power to vaporize the water quickly enough, thus flooding your coil and causing bubbling or spitting noise.

How do I stop my humidifier from spitting up water?

Now that you understand the most common reasons your humidifier leaks from the top, you can start troubleshooting it. First, no matter the cause of the issue, always unplug the unit from power and allow it to cool before inspecting it. Next, let’s look at how you can fix the issue depending on the cause of the problem.

Add salt correctly

You should follow the manufacturer’s instructions on adding salt to their humidifier. Usually, one or two pinches of salt are enough for a vaporizer to produce steam. Other times, the salt content in the tap water is enough to produce mist and doesn’t need extra salt.

Therefore we suggest observing the humidifier first. If it’s not steaming, start by adding one pinch of salt, then test it again.

Drain excess water

If you don’t add salt to your portable humidifier and it’s spitting out water, check if the water level is too much. Next, unplug the humidifier and allow it to cool down. Then, disconnect the water tank and drain it. Most water tanks in portable humidifiers have a water line that prevents you from overflowing the tank.

Clean your humidifier regularly

If your water supply contains too many mineral salts, it will create more power, causing the humidifier to keep spitting up water. Over time the minerals build up in the tank and continue causing the same issue even when using bottled water.

Therefore, you should clean your humidifier at least once a week to remove buildup. Always unplug the unit before cleaning to avoid electrocution. Then use a vinegar solution to dissolve mineral buildup.

Change the filter regularly.

The frequency of changing the filter in your humidifier depends on the water quality and how often you use your humidifier. Check your manufacturer’s manual on the type of filter to buy. You can clean and reuse some filters, but most require replacing.

If you have a whole-house humidifier, you must change its filter at least once during the winter when you use it daily. If you live in an area with hard water, you will change your filter more frequently. Changing the filter at the beginning of the season is also good after taking it out of storage.

For portable humidifiers, it’s best to change the filters at least every three months. If you use your unit daily, change the filter every two months. Also, when storing your humidifier, you should drain it and remove the filter to avoid bacteria and mold growing on it.

Use filtered or distilled water.

The quality of tap water varies between places. Some places have harder water than others, which contains more mineral salts. If the mineral content is too high, it causes the vaporizer to bubble out without adding extra salt. Therefore, demineralized, distilled, or purified water is best used in a humidifier to prevent mineral deposits from building up in the parts of the humidifier.

Check water pressure

If your whole-house humidifier is spitting out water, check its water pressure. If it’s higher than 125 psi, you should call a professional plumber who will install a pressure-reducing device on the water supply line.

Electrical issues

If you suspect low power and the cause of the bubbling noise in your humidifier, you can test the power source. But, first, unplug your humidifier and test another electrical appliance. If the other appliance works, then your humidifier requires professional repair. But if the other appliance is not working, you need to consult an electrician to check the low power issues in your home.


As you can see, reasons for water leakage from your humidifier are several. But they are all easy to troubleshoot yourself. Remember that proper use and regular maintenance of your humidifier will reduce the frequency of problems and ensure its longevity.

With minimal care, your humidifier will make your home much more comfortable and healthier for a long time.