Dishwasher Musty Smell When Not Used

Prep checklist

What you will need

• owner's manual (for filter type and removal method)
• soft brush or old toothbrush
• microfiber cloth
• warm water
• mild dish soap
• two cups white vinegar

Normal vs not normal

When a slight odor is expected and when musty smell signals a real problem

A brief, faint smell that dissipates within a few minutes of opening the door after a heated dry cycle is normal. The heated dry leaves residual warmth and moisture that produces a temporary odor, but it clears quickly once the door stays open.

A musty smell that hits you every time you open the door between cycles—even when the machine has not run for days—is not normal. It means moisture is trapped inside the filter well, gasket crevices, or residual standing water, and that moisture is feeding mold and bacteria continuously. The smell will not improve on its own and requires targeted cleaning of the hidden moisture pockets.

Start here

Safe steps to eliminate a musty smell between cycles

1. Clean the filter and scrub the filter well. Remove the filter assembly, scrub the mesh under warm water with a soft brush, and then scrub the filter well cavity—the space where the filter sits—with mild dish soap and warm water. Food sludge in the filter well stays wet between cycles and is one of the most common hidden odor sources. See How To Clean Dishwasher Filter for detailed instructions.
2. Wipe the door gasket, focusing on the bottom corners. Run a damp microfiber cloth along the full length of the rubber gasket around the door opening. Spend extra time on the bottom edge and the two bottom corners, where moisture, mold, and food debris collect most. Use a soft brush to reach into the crevices where a cloth cannot penetrate. Mold in the gasket corners feeds musty odor even when the tub interior looks clean.
3. Clean the lower door edge and lip. The horizontal lip at the bottom of the door opening catches water that does not fully drain after each cycle. Wipe that edge with a damp cloth and inspect for visible food residue or slimy buildup. A wet lip is a persistent moisture source that many people skip during routine cleaning.
4. Run a vinegar cleaning cycle. Place two cups of white vinegar in a bowl on the bottom rack and run the hottest empty cycle. Vinegar dissolves mineral scale and flushes odor residue from tub walls, spray arm passages, and drain pathways that you cannot scrub by hand. Do not pour vinegar directly on the gasket, because prolonged acid contact can degrade the rubber over time.
5. Leave the door cracked open between cycles. After the vinegar cycle and after every future wash cycle, leave the dishwasher door open an inch or two until the interior is fully dry. Trapped moisture is the fuel that feeds musty odor. Once the moisture evaporates, the bacteria and mold that produce the smell cannot grow back quickly.
6. Check for standing water at the bottom of the tub. If you see more than a thin film of water at the bottom after a cycle, the drain may not be clearing completely. Standing water is a direct moisture source for odor bacteria. Clean the filter and verify that it seats firmly; a loose filter can let debris bypass the screen and slow drainage. See Dishwasher Standing Water After Cycle if drainage is the underlying issue.

Common cause pattern

Why dishwashers smell musty between cycles even when they are not running

Musty odor between cycles comes from three hidden moisture pockets that most people do not clean during routine maintenance: the filter well cavity, the door gasket corners, and residual water at the bottom of the tub. Food sludge inside the filter well stays wet because it sits below the drain line and never fully dries between cycles. Mold grows in the bottom corners of the gasket because those crevices trap both moisture and food particles, and they are difficult to reach with a standard wipe. A thin layer of residual water at the bottom of the tub—often left after a cycle that did not drain completely—provides a continuous water source for bacteria.

When the door stays closed between cycles, none of that moisture evaporates. The sealed tub becomes a dark, damp environment that is ideal for mold and bacteria growth. The result is a musty smell that builds up gradually and hits you every time you open the door, even if the machine has not run for several days.

Branch selection

If the musty smell is strongest in the morning

When the odor is most noticeable first thing in the morning, it usually means the dishwasher ran a cycle the previous evening and residual moisture sat inside the sealed tub overnight. The closed door prevented evaporation, so by morning the trapped moisture has fed enough bacterial growth to produce a noticeable smell. Run the steps above, then start leaving the door cracked after every evening cycle so the tub can dry overnight instead of building up odor.

Branch selection

If the musty smell returns within a few days of cleaning

When the smell comes back quickly after a thorough filter and gasket cleaning, the most likely cause is standing water that is not draining completely between cycles. Even a small amount of residual water at the bottom of the tub provides enough moisture for bacteria to regrow within days. Check the filter seating, verify that the drain hose is not partially blocked, and inspect whether an air gap is clogged if your installation has one. See Dishwasher Drain Not Working After Cycle for drainage-specific troubleshooting.

Avoidable issues

Mistakes that make musty odor harder to eliminate

• Cleaning the filter mesh but skipping the filter well cavity underneath. Sludge in the well stays wet and feeds odor even when the filter itself looks clean.
• Wiping only the visible parts of the gasket without reaching into the bottom corner crevices. Those corners are where the worst mold and food debris collect.
• Masking the smell with lemon or fragrance tablets. Fragrance covers the odor temporarily but does not remove the moisture and bacteria that produce it.
• Running bleach through the dishwasher. Bleach can damage the rubber gasket, discolor the interior, and react dangerously if any vinegar residue remains inside.
• Keeping the door fully closed between every cycle. A sealed tub traps moisture and guarantees that musty odor will return regardless of how thoroughly you clean.
• Assuming the smell is just how dishwashers age. Musty odor is always a sign of trapped moisture and bacterial growth that can be eliminated with proper cleaning and ventilation.

Know when to stop

When musty smell requires professional service

• The musty smell persists after cleaning the filter and filter well, wiping the gasket corners, running a vinegar cycle, and leaving the door open between cycles for a full week.
• You see visible mold spreading beyond the gasket onto the tub walls or inner door panel.
• Standing water does not drain at all, or the dishwasher throws drain error codes.
• The next step would require disassembly, plumbing modification, or electrical testing.

At that point, a professional technician can inspect the drain system, test the pump, check for hidden moisture sources behind the tub liner, and address any mold that has spread beyond user-accessible surfaces.

Common questions

FAQ

• Why does my dishwasher smell musty even when I have not run it? Trapped moisture in the filter well, door gasket crevices, and residual water at the bottom of the tub feeds mold and bacteria. When the door stays closed between cycles, that moisture does not evaporate and the musty smell builds up.
• Will leaving the door open stop the musty smell? Leaving the door cracked helps moisture evaporate, but it does not eliminate odor already coming from food sludge inside the filter well or mold in the gasket corners. Clean those sources first, then keep the door open to prevent the smell from returning.
• Is musty smell the same as sewer smell? No. Musty smell comes from trapped moisture and mold inside the tub. Sewer smell comes from wastewater siphoning back through the drain hose or a blocked air gap. They have different causes and different fixes. See Dishwasher Smells Like Sewer After Cycle for sewer odor guidance.
• Can a dirty filter alone cause musty smell between cycles? Yes. Food sludge inside the filter and filter well stays wet and rots continuously, producing musty odor that is noticeable even when the machine is idle.
• How often should I clean the gasket corners? Once a month during your routine maintenance check, and immediately whenever you notice any musty odor between cycles. The corners are the most commonly skipped area and the most common hidden odor source.
• When should I call for service? Call when the smell persists after thorough cleaning, gasket wiping, a vinegar cycle, and door ventilation for a full week. Also call for visible mold beyond the gasket, standing water that does not drain, or error codes.

Fact check

References and fact-check notes

• Cross-check your model's filter type and removal method with the owner manual. Some filters have a two-piece assembly that must be separated for full cleaning.
• Confirm that your gasket material tolerates vinegar exposure. Most rubber gaskets handle a monthly wipe with mild dish soap, but direct vinegar contact should be avoided to prevent rubber degradation over time.
• Verify local plumbing code requirements for air gaps and drain hose routing. Some jurisdictions require air gaps on all dishwasher installations.
• Keep disassembly, pump testing, and mold remediation beyond user-accessible surfaces outside this maintenance-first guide.

Keep reading

Related guides

• How To Clean Dishwasher Filter
• Dishwasher Smells Bad After Wash
• Dishwasher Smells Like Sewer After Cycle
• How To Deep Clean A Dishwasher
• Dishwasher Standing Water After Cycle
• Monthly Dishwasher Maintenance Checklist
• Dishwasher Drain Not Working After Cycle