Why is my humidifier leaking from the bottom? (How to Fix It)

One of the concerns that you might have while using your humidifier is a leaking problem, which might make you wonder why is my humidifier leaking from the bottom and how exactly can I fix this problem.

Several reasons could explain why your whole-house humidifier is leaking from the bottom and understanding the exact cause of the leaking problem can be the first step towards fixing the leaking problem.

If left unattended, small leaks can turn into major issues in your home. Some of the signs that might help you notice a leaking humidifier include noticing patches of dampness on your carpeted floor, pools of water on uncovered floors, low levels of water than expected in the water tank, and other forms of dampness in the surrounding area.

Some of the reasons why your humidifier is leaking from the bottom include having an overfilled water tank, high water pressure, mechanical damage, hard water damage that can erode inner parts of the humidifier, and wrong placement of the water tank.

Water leaks from humidifiers can cause irreversible damage to sub-flooring and wood floors. The unfinished underside of the hardwood floors absorbs water and expands more than the upper part leading to distortion of the shape of the wood.

Both the whole house and small humidifiers are prone to water leaks. If you find yourself wondering, why is my humidifier leaking from the bottom, then this article will answer all your queries.

This article explains some of the reasons why your humidifier might be leaking from the bottom, the safety measures that you should take before attempting to fix your humidifier, and the measures that you can take to address these water leakage problems.

Why is My Humidifier Leaking from the Bottom?

The Solenoid valve

One of the main reasons that humidifiers meant for the whole house might leak from the bottom is a defective solenoid valve or float. If your humidifier system uses a solenoid valve to regulate the amount of water entering the unit, an improperly placed solenoid valve might be the problem.

A solenoid valve is a floating valve that controls the entry of water into the humidifier. If there is dirt or any debris stuck between the plunger of the valve, you might notice some leakage.

Aside from that, if the solenoid valve has been damaged either through a previous attempt to fix the water leaking problem or excessive accumulation of debris on the plunger, then you might need to call a professional plumber to replace it.

Poorly Secured Water Tank

Most of the small humidifiers require you to refill the water tank yourself. If you fill the water tank but fail to secure the water tank securely on the humidifier, you are likely to experience water leaks or other operational problems like dealing with a humidifier that will not start working.

If the water tank is tilted on one side, water flow in the humidifier might be impaired leading to risks of water leaks.

Poorly Closed Water Tank Opening

Most water tanks have a knob or plug that prevents the water from leaking out after refilling the tank. Ensure that the opening of the water tank is tightly closed before returning it to the humidifier. If you are using a humidifier, always ensure that the water tank has been closed properly.

In some humidifiers, the opening of the water tank is placed upside down after refilling. In such cases, if the knob used to close the water tank is not tight enough, you are likely to experience water leaks.

The Evaporator pad/ Water Panels

The evaporator pad or humidifier filter is supposed to be changed at least monthly or after every month. Hard water can contribute to the accumulation of mineral deposits in your humidifier, which can affect the effectiveness of your humidifier and contribute to water leaks.

If you have allowed the mineral deposits to build up for a long time, you might need to replace the evaporator pad or humidifier filter for better results. Humidifier filters can be bought online or in retail stores.

The Drainage Tube from the Unit

A blockage on the drainage tube could cause the unit to malfunction and leak. Ensure that you check whether there is anything blocking water flow in the drainage unit.

You should note that, if anything is blocking the flow of water anywhere within the drainage pipe, the blockage could cause water to back up and the water pressure could lead to leaks.

If you are using an old humidifier, the drain tube might have worn out with time, leaving it with holes. Check the drainage line for any holes that might be leaking and either replace the drainage tube or fix the areas that are leaking.

Incoming Water Pressure

The incoming water pressure in your humidifier can contribute to water leakage. If the incoming water pressure is too high, you are likely to experience constant water leaks. For guidance, you should ensure that the incoming water pressure for your unit is not above 125 psi.

Over Filling the Water Tank

If you overfill the water tank of your humidifier, you might notice some leakage after closing the water tank. If this is the cause of the water leaks, you will only notice the dampness or water pool near the humidifier immediately after you have refilled the water tank.

If you clean up the excess water spilling from the water tank immediately after noticing that you had overfilled your water tank, you will not notice any more spillage.

If you dry the damp floor and still notice some dampness or a pool of water below your humidifier after a few hours, there is a high likelihood that your humidifier has another problem.

Every time you refill your water tank, ensure that you check the level of water that you have added to your humidifier to prevent overfilling the water tank. You should also ensure that you follow the specific instructions for refilling your humidifier since humidifier brands have varying designs.

For instance, if you are using a pure enrichment humidifier, you should follow the specific steps for refilling a pure enrichment humidifier to avoid overfilling the tank or spillage incidents.

Mechanical Damage

If you just bought a humidifier and notice that it is leaking, there is a likelihood that it might have some mechanical issues. Attempt to check where the water is leaking from to determine if it’s a cracked pipe or cracked water tank.

If you notice a hole or crack on the water tank or pipe you can contact the manufacturers to fix it for you. Ensure that your warranty is valid before contacting the manufacturers.

Poorly Assembled Humidifiers

When putting together your humidifier for the first time, you might have assembled the parts of the humidifier incorrectly, making it susceptible to water leaks.

While small humidifiers do not require advanced plumbing skills, assembling whole-house humidifiers can be quite challenging to install. Any misstep or error during the assembling process can lead to leaking problems.

Safety Measures to Consider When Fixing Your Humidifier

When attempting to fix your humidifier, you should first remember that a humidifier is an electronic device just like your television, washing machine, or other electronic devices in your home.

The integration of moisture or water from the humidifier and electricity can lead to electric shocks or issues related to short-circuiting the device.

A short circuit can cause more damage to the humidifier or lead to a fire in your home. Follow these steps to promote your safety and that of the inhabitants of your home when repairing your humidifier.

Step 1: Turn Off the Electricity

If you notice water leaks below your humidifier, the first step should be to turn off the electricity on the electric outlet connected to the humidifier. Turning off the electricity ensures that you avoid electrocuting yourself when touching any part of the humidifier.

It is particularly important to turn off the electricity when dealing with a whole-house humidifier because you might not be sure about the specific part of the humidifier that needs to be repaired.

Step 2: Disconnect the Device

Ensure that you disconnect the device from the electrical outlet before you attempt to fix it. If you are using a small-sized humidifier or mini-humidifier, you should ensure that you disconnect it from the electric outlet before attempting to address the water leakage problem.

Disconnecting it from the electrical outlet will also ensure that you have an easy time fixing the humidifier without worrying about short circuits or being electrocuted.

Step 3: Empty the Water

Always ensure that you empty the water tank from the humidifier before you begin repairing it.

Emptying the water tank is important in eliminating the risks of water spills on the control board or other parts of the humidifier that should not come into contact with water. After emptying the water tank, you can proceed to assess the damage to your humidifier.

How to Fix a Humidifier that is Leaking from the Bottom

Clean the Drain Line

You can clean the drain line using warm water and bleach to eliminate any dirt that might have stuck on the drain line. Cleaning the drain line applies to large humidifiers meant for whole house purposes. Clean the drain line by opening it up and pouring a mixture of 50% warm water and 50% bleach.

The solution should clear out any dirt from the drain line. You could also use a mixture of 50% warm water and 50% vinegar solution to clean your drain line.

Avoid Over-Filling the Water Tank

If you are using a small humidifier, an over-filled water tank is a common reason for water leaks.

While you might think that overfilling your water tank reduces the number of times you will need to refill your humidifier per day, the water spills from the tank can ruin your flooring and affect the effective functioning of your humidifier.

If you keep over-filling your water tank, you will also have to keep cleaning the mess caused by the excess water.

If you are using a specific humidifier like the pure enrichment humidifier, check the procedure for refilling its water tank and emptying it to ensure that you understand how to use it. It is important to note that different humidifiers have varying features.

Most humidifiers have calibrated water tanks that help you know the amount of water you should put in the water tank.

Other water tanks have markings indicating where the water added to the tank should reach. Ensure that you do not fill water in the tank past the mark used to indicate the appropriate water level.

Check the Solenoid Valve

If you suspect that the reason for water leaks in your humidifier is linked to its solenoid valve, you can check whether there is any debris on the plunger.

To check the solenoid valve, ensure that you shut off the water flow and disconnect any electric power getting into the humidifier unit.

Then remove the solenoid valve and clean it with low-pressure water under a tap. If there is any debris, this approach should clear that and restore the function of your humidifier. You can also try to blow out the dirt or debris to dislodge the dirt.

Also, check if the solenoid valve is correctly positioned. You can adjust its positioning by checking whether it has been screwed in place well.

Fix the Evaporator pad/ Water Panels

One of the ways that you can fix the evaporator pad or humidifier filter is by removing it from the humidifier and rinsing it with clean water to remove any dirt, mineral deposits, or debris that might be stuck on the humidifier filter.

You could also replace the humidifier filter if you have been using it for a few months or if you had already tried to rinse it and did not succeed in removing all the dirt and debris from the filter.

Regular Maintenance

Conduct regular maintenance to ensure that your humidifier functions properly. Some of the factors that you should consider when conducting regular maintenance include cleaning the humidifier and its water tank if you are using a small humidifier and replacing the evaporator pad of the humidifier filter.

You should also clean the water tank to eliminate any dirt and mineral deposits that might have accumulated in the water tank. Taking these measures will ensure that you avoid common issues that can interfere with the performance of your humidifier.

Dealing with a Poorly Assembled Humidifier

If you are using your humidifier for the first time and you suspect that the problem might be connected to how you assembled it, simply check the manual and review all the processes that you followed when assembling your humidifier.

If you were simply replacing your humidifier filter and noticed the water leaks afterwards, check whether you placed the filter correctly.

If you experience this problem with your whole-house humidifier, instead of trying to fix it yourself, you could call a professional plumber to try and assess any assembly problems that might have caused the leakage. Addressing the problem early on when dealing with whole-house humidifiers could reduce the risks of water damage.


I have come across several people who have asked me “why is my portable humidifier leaking from the bottom.” In most cases, the leaking problem has been associated with overfilling the water tank, poor assembly of the humidifier parts, and inability to close the water tank opening well.

Addressing water leak problems can improve the performance of your humidifier. It is important to ensure that you assemble your humidifier properly to eliminate the risks of water leaks.

If after reviewing your humidifier and assessing the issues discussed in this article you notice that your humidifier is still leaking, you can consider calling the manufacturer of your humidifier so that they can assess for other mechanical issues.

Why is my humidifier leaking from the bottom?
Meet the Author

The author is a blogger, interior design and home improvement enthusiast, and researcher, with a passion for helping people improve their homes by creating a calming and beautiful environment. Check out the about author page to learn more about her work