Dehumidifier Leaking Water? Here’s What to Do

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Ever come home to find an unexpected indoor puddle? No, it’s not your puppy having an accident – it’s your dehumidifier leaking water. What now?

There can be several possible reasons for a dehumidifier that leaks water. Don’t panic! In most cases, it’s an issue you can resolve without calling a technician.

In this article, I’ll delve into the nitty-gritty details that could lead to water leaks in your dehumidifier.

I’ll explain the possible causes of a leaking dehumidifier and provide you with clear, step-by-step instructions to get your unit back in working order.

So grab your toolset and let’s get started!

Check the Drain Spout for Damage or Incorrect Installation

One of the most common issues leading to water leaks in a dehumidifier is a compromised drain spout or drain hose, typically found at the back or bottom of the unit.

Ordinarily, the moisture from your dehumidifier collects in its drain tank.

However, most dehumidifiers also have a drain spout on the back of the unit.

The drain spout is used to hook up a drain hose if you want your dehumidifier to continually drain – that way you don’t need to empty its tank.

However, if the drain spout is damaged or its cap isn’t installed properly, it can lead to water leaks.

If you spot water leaking from the drain spout, find the origin of the leak:

  • Is the drain spout cap screwed on and secured properly?

Most drain spout caps screw on, so ensure that the threads are lined up and the rubber seal is seated properly within the cap.

  • Is the water seeping from the rubber seal behind the drain spout cap?

If it’s the rubber seal, and it’s damaged, you’ll need to replace it.

If the rubber seal is not damaged but not sealing correctly, find a suitable method to secure the spout to stop the water flow. I recommend wrapping the rubber seal a couple of times with some plumber’s teflon tape to reform the seal and stop the flow.

Ensure the Collection Tank Is Seated Properly

One common and often overlooked issue is the incorrect placement of the water tank.

Seems simple, right? You’d be surprised. If your dehumidifier’s water tank isn’t nestled in its place just right, you could end up with a watery mess.

Check if your collection tank is properly positioned and sits flush within the dehumidifier.

Also, ensure the tank isn’t skewed or tilted, as even a small misalignment can cause leaks.

Check if the Float Switch Is Stuck

The float switch is a crucial part of your dehumidifier – it stops it from flooding your floor by indicating when its water tank is full.

This buoyant component rises with the increasing water level in the collection tank, signaling the dehumidifier’s control board to cease operations when its tank is full.

If the switch gets stuck, the unit might continue to run and overflow the tank, resulting in a leak.

To fix a stuck float switch, take out the collection tank, locate the float switch assembly inside the unit, and manually move it around. If it’s stuck, you may need to clean it out so it can move freely up and down.

Once the float switch moves freely, It will be able to shut off your dehumidifier when its tank is full, preventing future water leaks.

Check for Cracks in the Collection Tank

Another common reason for a leaky dehumidifier is a crack in its collection tank.

The water collection reservoir is susceptible to cracks and damage, particularly under heavy use or accidental impacts.

Examine your tank carefully for any signs of damage. If you spot any cracks, you may be able to seal them with waterproof adhesive or tape.

I’ve used aluminum foil tape to seal up minor leaks on plastic parts since it’s always in my tool bag. It works great for dehumidifier tanks as well – I recommend taping off both sides of the crack if you can.

However, if the crack is large or there is a hole in the tank, you may need to replace the tank – or the entire unit altogether.

Clean the Air Filter

You’d be surprised to know how many dehumidifier issues are caused by a clogged air filter – water leaks included.

A dirty air filter restricts the airflow through the dehumidifier, causing the coils to freeze and subsequently melt, which can result in excessive moisture and an eventual leak.

Regular maintenance involving cleaning or replacement of the air filter can avert such issues and enhance overall unit efficiency.

Remove the filter, rinse it out, and let it dry completely before reinstalling it.

Clean the Dehumidifier’s Coils

While you’re in there cleaning your dehumidifier’s air filter, take a look at its coils too – are they dirty?

In some cases, clogged coils will cause water leaks for the same reason as a dirty filter – freezing and subsequent thawing out.

As with your air filter, it’s essential to keep these coils clean.

To clean your dehumidifier’s coils, take apart the dehumidifier, locate the coils, and remove the build-up.

On most dehumidifiers, you remove the air filter to access the coils. But you might need to take off the entire plastic case to access the entire coil.

For light dust, use a vacuum cleaner to suck dust out of the coil. Never blow compressed air into the coil – it will just make all that dust and debris get even more stuck.

If your dehumidifier’s coils have built up dust and grime, a coil cleaner might be the best solution.

Check if the Drain Pipe Is Clogged, Cracked, or Misaligned

If you use a continuous drain setup with your dehumidifier, a clog or crack in its drain pipe can cause water leaks.

If the drain pipe is clogged, cracked, or misaligned – even just a little – you could end up with a wet mess on your floor.

Pay close attention to the connection point between your drain pipe and the dehumidifier’s drain spout – that’s where a slow leak can occur.

  • To clear a clogged drain pipe: Use a brush or drain snake to dislodge the debris. If you have a wet/dry vacuum another method is to suck or blow the clog out of the pipe.
  • If your drain pipe is cracked: Use some aluminum foil tape to seal the crack. Drain pipes aren’t pressurized, so the aluminum tape should be able to keep water from leaking out of the pipe.
  • If your drain pipe is misaligned with the dehumidifier’s drain spout: Remove the drain pipe and reconnect it. It’s also a good idea to clean the interior of the drain pipe and the exterior of the drain spout at their connection points. This ensures that there is no grime in the way of the seal between the two components. It doesn’t hurt to wrap the exterior of the drain spout a couple of times with some plumber’s teflon tape to create a good seal between the pipe and spout.

Thaw Out the Dehumidifier’s Ice Build-Up

A dehumidifier’s evaporator coil can sometimes freeze up, leading to water leaks when the ice melts.

Remove the air filter from your dehumidifier – if you see a block of ice inside your dehumidifier, you likely have a frozen coil.

To address this, you’ll need to allow the ice to melt and then find the cause of the issue.

Here are some possible causes of a frozen dehumidifier evaporator coil:

  • Dirty air filter: A dirty air filter will restrict airflow and cause your dehumidifier’s evaporator coil to reach freezing temperatures. This causes ice to form on the coil over time.
  • A damaged fan: If your fan is damaged or broken, then the evaporator coil won’t get the required airflow for it to collect heat, causing it to freeze up.
  • Low room temperatures: If you use your dehumidifier in a cold room, its evaporator coil may freeze due to reaching lower temperatures than it usually would.

In all of these situations, water may leak out of your dehumidifier when the evaporator coil thaws out.

Check if the Condensate Pump Is Working

Some dehumidifiers come equipped with an internal condensate pump that’s used to move water out of the unit’s tank – usually to a drain or the outside of your home.

A failure of your dehumidifier’s condensate pump may cause an overflow of its collection reservoir.

Most dehumidifiers have a float switch to detect whether their internal tank is full and will shut off the dehumidifier if that’s the case.

So if your dehumidifier’s condensate pump has gone bad and you find a pool of water on your floor, it’s also a good idea to check if its float switch is stuck too.

What’s Next?

If you were able to get your dehumidifier back up and running without a leak – great job!

If you still can’t figure out why your dehumidifier is leaking water, it might be best to consult a professional or consider purchasing a new unit.

Either way, feel free to drop a comment below to let me know what was (or still is) causing your dehumidifier to leak water.

And if you’re looking for more information on dehumidifiers, check out my article about where you should place your dehumidifier.

Hi, my name is Trey Lewis and I’m the founder and chief editor at HVAC Training Shop. My goal for this website is to help homeowners troubleshoot and maintain their home’s HVAC systems. Whether it’s changing an air filter, troubleshooting a blower motor, or just buying a new humidifier, I want to make sure that you’re covered.

2 thoughts on “Dehumidifier Leaking Water? Here’s What to Do”

  1. Is Freon ever used as a way to stop the water leaking onto the floor? My repairman said that he must buy $50 of freon to put in dehumidifier to stop the water flowing onto the floow, and I don’t get the connection between Freon and the water leak.

    • Hi Bruce,

      A symptom of low freon is ice build up, which will thaw out and leak water onto your floor.

      However the correct way to fix low freon is to repair the leak, then recharge the unit with freon. If your repairman simply recharges the unit with freon without repairing the leak first, then you’ll eventually run into the same issue again a few weeks or months down the line.



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