“Why Does My Dehumidifier Stink?”

Jul. 10, 2017

“Eww! What’s that gross smell coming from my dehumidifier?”

If you’re smelling a musty, “wet dog” smell or a strong sulfur odor coming from your dehumidifier, it’s usually mold/mildew.

Now, you’re likely to find mold in/on these 3 dehumidifier parts:

A dirty basin
Filthy coils
Dusty fan blades

We’ll go into more details about each of these dehumidifier parts. Then, we’ll explain how to get rid of that awful smell.

What makes a dehumidifier smell bad?

Like we mentioned above, that nasty smell is usually caused by mold. In order for mold to grow, it needs 4 ingredients:

Darkness (UV rays kill mold)
Moisture
Warm temperature (70°–90°)
Food (organic materials like dust and dirt)

Now, your dehumidifier naturally has the first 3 ingredients because...

It’s located indoors, away from the sun
Your dehumidifier extracts moisture from your home’s air
It’s located in a warm area, with temperatures that easily fall within the 70°–90° range

But to create mold, your dehumidifier needs food. We’ll show you 3 places where you’ll find that 4th ingredient to make mold...

#1: A dirty basin

When your dehumidifier removes moisture from your home’s air, that moisture collects in a basin (also called a water reservoir). Over time, this basin can get dirty from dust/dirt particles. This “food,” combined with warm water in a dark place, can foster mold growth.

#2: Filthy coils

Dehumidifiers extract moisture from the air as it blows across copper coils filled with a cold coolant gas. Moisture gathers on these coils because of the difference of temperature between the warm air and the cold coils. When dirt gathers on these damp coils, it creates mold.

#3: Dusty fan blades

Your dehumidifier fan blades could also be harboring mold and mildew. They come in contact with humid air at warm temperatures, and when dust settles on the blades, it completes the recipe for mold growth.

How to clean a smelly dehumidifier

Try each of these steps to see if they remove the smell.

1. Drain and clean your basin: Some dehumidifier models are self-draining while others require you to manually remove the basin and drain the water yourself. If you have a whole-home dehumidifier, it’s likely connected to your plumbing, so you don’t have to empty a water basin.

Once you drain the water from the basin, rinse it with a mild solution of vinegar and water to disinfect of mold spores.

2. Clean the coils: Follow these steps to clean the coils:

Unplug your dehumidifier.
Spray the coils down with a mild solution of vinegar and water (NEVER use chemicals, they damage the fragile coil components).
Take a coil-cleaning brush and very carefully clean the coils.
Allow the unit to dry in a warm place for at least 24 hours.
Plug the dehumidifier back in and see if the smell persists.

3. Scrub your fan blades clean: Follow these steps to clean your fan blades:

Unplug your dehumidifier.
Remove the cage from around the fan with a screwdriver.
Wipe down the blades with a solution of soap and water (don’t use any chemicals).
Clear the blades of any debris like hair or dirt.
Vacuum out the fan motor and the general area.
Reattach the fan cage and test to see if the nasty smell persists.

Did you try these 3 steps and there’s still a strong odor smell coming from your dehumidifier? Or are you worried about damaging the coils? Then you should call a professional to clean your dehumidifier for you.

Want a professional to get rid of that nasty dehumidifier smell?

Contact Air Experts to schedule a dehumidifier cleaning appointment with one of our trusted professionals. We’ll get your air smelling clean again in no time.

We’ve been reliably serving New Jersey families since 1994.