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Why Does My Dryer Smell Musty or Like Mildew?
A musty dryer means moisture is staying where it should not. Here is how to find the cause, clean the drum and tell this smell from a burning or gas one.
Last reviewed October 1, 2026. Written and reviewed by the Plano Dryer Pros team. How we create content
A musty or mildew smell in a dryer means moisture is staying inside. The usual causes are damp laundry left in the drum, a blocked vent that keeps humid air from leaving, wet lint in the housing or duct, or a leaking duct joint. Wipe the drum, clean the lint screen and housing, and run the ten-minute vent test.
Key takeaways
- A musty smell means moisture is trapped, often from a blocked vent or damp laundry.
- Wipe the drum, wash the lint screen and clear the lint housing.
- Run the ten-minute vent test, because humid air that cannot leave breeds mildew.
- A burning or rotten-egg smell is different: stop and see the burning smell and gas guides.
Why a dryer smells musty
| Cause | What gives it away | What fixes it |
|---|---|---|
| Damp laundry left in the drum | The smell comes when you open the door, mostly after a day or two | Remove laundry promptly, and leave the door open to air out |
| A blocked or restricted vent | Clothes take two cycles, and the laundry room is humid | Clear the vent: see the cleaning guide |
| Damp lint in the housing or duct | Lint feels damp, or the screen stays wet | Wash the screen, and vacuum the lint housing |
| A leaking or disconnected duct | Moisture or lint at the base of the dryer or in the wall | Reconnect or replace the duct |
| Residue or mildew on the drum | Visible film or spots inside the drum | Wipe the drum clean |
Why does my dryer smell musty?
A musty smell means moisture is staying inside the dryer. The usual causes are damp laundry left in the drum, a blocked vent that keeps humid air from leaving, wet lint in the housing or duct, or a leaking duct joint.
How to get rid of the smell
- Unplug the dryer.
- Wipe the inside of the drum with a cloth dampened with warm water and mild dish soap, or a vinegar and water mix, then wipe it dry. Do not use harsh chemicals or spray cleaners on the parts.
- Wash the lint screen with soap and water, and let it dry fully.
- Vacuum the lint housing under the screen with a narrow attachment.
- Run the dryer empty on high for ten minutes, and check the air and the flap at the outside hood.
- Leave the door open after use, so the drum dries out.
How do I clean the inside of my dryer drum?
Unplug the dryer and wipe the drum with a cloth dampened with warm water and mild dish soap, or a vinegar and water mix, then wipe it dry. Avoid harsh chemicals and never spray cleaner onto the parts. Clean the lint screen and housing too, and leave the door open.
Can mold grow inside a dryer?
It can, if moisture lingers. A dryer that is not venting properly, or one with damp lint and laundry left inside, gives mildew a place to grow. It is more likely in a humid laundry room. Keeping the vent clear, removing laundry promptly and leaving the door open afterward prevents it.
Is it musty, burning or gas?
| Smell | Likely cause | Read |
|---|---|---|
| Musty or sour, like damp towels | Trapped moisture | This page |
| Hot dust, scorched lint or rubber | Lint or a belt overheating | Dryer smells like burning |
| Rotten eggs or sulfur | A gas leak | Gas smell: what to do |
Could a musty smell mean my vent is leaking?
Yes. A duct joint that has come apart, or a duct that ends indoors, lets humid air into the wall or the room, where it can smell musty and cause mildew. Look for moisture, lint or stains around the base of the dryer and inside the wall. A blocked vent can also keep the air in.
Sources
- National Fire Protection Association, Clothes Dryers and Washing Machines fact sheet (2010 to 2014 annual averages)
- Your dryer’s installation and service manual, which governs over any general guidance on this page
- Plano Dryer Pros estimates of typical local repair pricing, checked against national consumer cost guides for context. See our Editorial Policy.
Frequently asked questions
Is a musty dryer smell dangerous?
The smell itself is not an emergency, but it points to trapped moisture, which can mean a blocked vent, and that is a heat and fire concern. Check the vent, and treat a burning or rotten-egg smell as a different and more serious problem.
Why does my clothes smell musty after drying?
Clothes can smell musty if they went into the dryer already damp or sour, if the drum or lint housing has mildew, or if the vent is not carrying moisture out. Clean the drum and housing, rewash the clothes and check the vent.
Should I leave the dryer door open?
Yes, after use, with the dryer off, so the drum dries out. Keep pets and children away from an open door, and close it before running the dryer again.
Can a dryer sheet fix the smell?
A dryer sheet can mask it for a load, but it does not fix the cause, and the film dryer sheets leave can restrict airflow. Fix the moisture problem first: clean the drum, the housing and the vent.
When should I call a technician?
If the smell stays after cleaning, if the dryer takes two cycles, if you find moisture around the duct or if you notice a burning smell. A technician checks the vent run and the dryer together.
Get your dryer working again
Call and a person will answer, or request a repair online. You get the full price in writing before any work starts.