How to Prevent Mold and Musty Odors in Laundry Steam Closets

Your steam closet is one of the most convenient and innovative appliances you can have in your home. It refreshes, sanitizes, and de-wrinkles your clothes with ease, saving you trips to the dry cleaner and keeping your wardrobe looking its best. But there’s one thing no one wants to smell when opening their steam closet: that unmistakable musty, moldy odor.

If your steam closet is starting to smell damp or sour, or if you’re worried about mold growth in the first place, you’re in the right place. In this guide, we’ll show you how to prevent mold and musty odors from ever taking hold in your steam closet, plus how to clean and maintain it so it stays fresh, clean, and performing at its best.

Let’s get started.

The information in this article may not apply to your specific appliance model. We recommend consulting your manufacturer’s documentation or contact us with any questions.

Why Do Mold and Musty Smells Happen in Steam Closets?

Steam closets operate by creating warm, moist air that penetrates fabrics and cleans them. That’s great for your clothes, but it also creates the perfect environment for mold and mildew to thrive if the moisture doesn’t drain or evaporate properly.

Here are the most common causes of mold and musty odors:

• Standing water left in the drain tray or at the bottom of the closet
• Poor ventilation inside the chamber
• Lint and dust buildup mixed with moisture
• Dirty steam generator or clogged drain
• Hard water mineral deposits harboring bacteria

Daily Habits That Keep Mold Away

One of the easiest ways to stop mold and odors before they start is by developing a few good habits every time you use your steam closet.

After Every Cycle:

1. Wipe down the interior walls and door with a dry microfiber cloth.
2. Empty and rinse the drain tray.
3. Leave the door slightly open to let the chamber air out and dry completely.

These simple steps remove excess moisture and improve airflow, making it harder for mold to grow.

Weekly Maintenance You Can Do Yourself

In addition to your daily habits, set aside a few minutes each week to give your steam closet a little extra attention.

Clean the Drain Tray and Drain Hole

1. Remove the drain tray and wash it with warm, soapy water.
2. Use a soft brush or pipe cleaner to clear any lint or debris from the drain hole.
3. Pour a little warm water down the drain to make sure it flows properly.

Dust and Vacuum the Interior

1. Use a dry microfiber cloth to dust vents, walls, and the door gasket.
2. Vacuum around the bottom of the closet and behind it if accessible to prevent dust buildup.

Check the Door Gasket

1. Wipe down the rubber door seal to remove lint and keep it flexible.
2. Inspect it for cracks or hard spots, replace if it’s damaged to ensure a good seal.

Deep Cleaning Your Steam Closet

Even with good habits, it’s a good idea to give your steam closet a deeper cleaning once a month. This removes any hidden buildup and keeps odors at bay.

Descale the Steam Generator

Hard water minerals can accumulate in the steam generator, creating rough surfaces where bacteria and mold can grow.

How to descale:

1. Unplug the steam closet.
2. Access the steam generator according to your manual.
3. Drain any standing water.
4. Fill the generator with a 50/50 mixture of white vinegar and water. Let it sit for 30 minutes.
5. Drain and flush with clean water several times to remove all residue.

Clean the Vents and Nozzles

1. Use a small brush or pipe cleaner to clear lint or residue from the steam vents.
2. Wipe the nozzles with a damp cloth to ensure even steam distribution.

Wipe the Entire Chamber

1. Mix warm water with a little mild dish soap.
2. Wipe all interior surfaces, including walls, door, gasket, and floor.
3. Dry thoroughly with a clean towel before closing the door.

Keep the Air Moving

One often overlooked factor in mold prevention is proper airflow. After running a cycle, keep the door open just a crack for at least 30–60 minutes. This lets the remaining moisture escape and allows the chamber to dry fully between uses.

If your laundry room is particularly humid, consider using a small dehumidifier nearby to reduce moisture in the air.

Watch Your Water

The type of water you use can also affect how quickly mold and odors develop.

1. If you live in an area with hard water, use distilled or filtered water in your steam closet. This helps prevent mineral buildup, which can trap bacteria and create odors.
2. Check and clean the water inlet filter regularly if your model has one.

When to Replace Worn Parts

Sometimes the best way to prevent mold and musty smells is to replace worn parts that are no longer doing their job.

Door Gasket

If your gasket is cracked, stiff, or no longer sealing properly, warm moist air can escape and condense where it shouldn’t, promoting mold growth. Replace it as soon as you notice damage.

Drain Pump or Hose

If you notice water pooling inside and not draining fully, check the pump and hose for blockages or wear. Replacing a faulty pump or hose ensures water is removed effectively after each cycle.

Steam Nozzles

If nozzles are clogged and creating uneven steam, clean them thoroughly, and if they remain blocked or damaged, replace them to keep steam flowing and water draining properly.

What to Do If Your Steam Closet Already Smells Musty

If you’re already dealing with odors, don’t worry, you can bring your steam closet back to fresh.

Deep Clean

Follow all the deep cleaning steps above, including descaling the steam generator, scrubbing vents, wiping the chamber, and cleaning the drain thoroughly.

Baking Soda Treatment

After cleaning, place an open box or small bowl of baking soda inside the empty chamber overnight to absorb remaining odors.

Run an Empty Steam Cycle

Run a full steam cycle with the closet empty to flush out any remaining moisture and bacteria. You can even add a splash of white vinegar to the water reservoir for an extra boost.

Repeat if necessary until the smell is completely gone.

Long-Term Maintenance Tips

To keep your steam closet mold-free and smelling fresh for years to come, remember:

• Always empty and clean the drain tray after every few uses.
• Leave the door slightly open after each cycle.
• Use distilled water if possible to prevent mineral buildup.
• Descale monthly or as recommended for your model.
• Replace worn gaskets and components promptly.
• Wipe down the chamber weekly and dry thoroughly.

These simple steps take only a few minutes and make a huge difference.

Where To Find Us 

If you need any replacement parts for your appliances, you can enter your model number at AppliancePartsPros.com to locate and order them quickly. Most orders arrive in just two business days, and we have tons of great information in our repair help section and YouTube videos to help you troubleshoot.

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