You open the dishwasher expecting clean plates and get hit with a sour, swampy smell instead. It’s a common problem, and if your dishwasher smells bad, it rarely means the machine is failing.
In most cases, the odor comes from food and water trapped somewhere the wash cycle can’t reach. This guide shows you the four places to check, what you can safely clean yourself, and the one sign that means you need appliance repair instead of a scrub brush.
Why Does My Dishwasher Smell Bad?
Most of the time, the reason your dishwasher smells bad is trapped food and dirty water. It hides in four places: the filter, the sump under it, the drain hose loop or air gap, and the rubber door gasket. Cleaning those spots fixes most odors. Water standing over the tub floor after a cycle points to a drain fault.
What the Smell Is Telling You
| What you smell | Most likely source | Where to start |
|---|---|---|
| Sour or rotten food | Filter and sump | Spots 1 and 2 |
| Sewage or drain smell | Drain hose loop, air gap, or disposal connection | Spot 3 |
| Musty or mildew | Door gasket and lower door edge | Spot 4 |
| Plastic or chemical smell in a brand-new machine | Normal break-in odor on many models | Run a few cycles and wait |
| Burning or electrical smell | Not a cleaning problem | Stop using it and call a pro |
Before You Start: Three Safety Steps
- Cut the power. Unplug the dishwasher or switch off its breaker before you reach inside.
- Let it cool. Water and parts can still be hot right after a cycle.
- Wear gloves. Broken glass often ends up in the bottom of the tub. Never put your hand inside a garbage disposal.
Spot 1: The Filter
If your dishwasher smells bad, the filter is the first place to look. Many newer dishwashers use a removable filter instead of a built-in food grinder, so everything the wash removes stays there until someone cleans it out.
Bosch explains that food particles and debris get caught in the filter with every cycle, and that buildup is what starts the smell.
How to clean it:
- Pull out the bottom rack.
- Find the filter in the floor of the tub, usually near the back or under the lower spray arm.
- Twist or lift it out. Most turn counterclockwise, but check your owner’s manual for your model.
- Rinse it under warm running water. Use dish soap and a soft brush for greasy buildup.
- Skip wire brushes and scouring pads. They can tear the fine mesh.
- Put it back and turn it until it locks. A loose filter lets debris slip into the pump.
Whirlpool recommends cleaning the filter at least once a month. If you run the dishwasher every day or skip pre-scraping, check it more often.
Editor note (remove before publishing): PHOTO 1 goes here. Real clogged filter from a Dara job, used with the customer’s permission. Suggested file name: Clogged-Dishwasher-Filter-Chicago.jpg. Suggested alt text: “Clogged dishwasher filter packed with food debris, removed during a Dara Appliance Repair service call.” Caption: “A filter Darkhan pulled from a dishwasher during a recent service call.” If a different technician handled this job, swap in their name.
Spot 2: The Sump Under the Filter
With the filter out, look into the opening below it. That bowl is the sump, where water collects before the drain pump pushes it out.
Food that slips past the filter settles here and sits in warm, damp conditions between cycles. That makes it a prime source of the odor.
What you can safely do:
- Scoop out loose debris with a gloved hand or a paper towel.
- Watch for glass shards, fruit seeds, labels, and small bones.
- Wipe the sump walls with a damp sponge.
- Don’t push screwdrivers or other tools into the pump openings.
What’s normal and what isn’t: A small amount of clear water in the sump is normal on many models. Water that covers the floor of the tub after a finished cycle is not. That usually means the dishwasher isn’t draining, which is covered further down.
Editor note (remove before publishing): PHOTO 2 goes here. Real sump with trapped debris from a Dara job, used with the customer’s permission. Suggested file name: Dishwasher-Sump-Debris-Chicago.jpg. Suggested alt text: “Dishwasher sump with trapped food debris under the filter, found by a Dara Appliance Repair technician.” Caption: “Debris Darkhan cleared from the sump on the same call.” If a different technician handled this job, swap in their name.
Spot 3: The Drain Hose Loop or Air Gap
If the smell is more sewer than leftovers, look under your sink. The dishwasher’s drain hose runs there and connects to your garbage disposal or the sink drain.
That hose needs a way to keep dirty sink water from flowing back into the dishwasher. Most kitchens use one of two setups:
- A high loop: the hose rises up and is fastened near the underside of the countertop before it drops down to the drain.
- An air gap: a small cap on the sink deck or countertop that the hose runs through.
When the hose sags low or the air gap clogs, sink water can drift back and sit in the hose or the tub. That stagnant water is a common reason a dishwasher smells bad even after you clean the filter.
What you can check:
- Look at the hose under the sink. It should loop up high, not lie flat on the cabinet floor.
- Check for kinks or sharp bends that could trap water.
- If you have an air gap, lift or twist off the cap and clear out any gunk you see.
- If your dishwasher drains into a disposal, run the disposal before you start the dishwasher. Whirlpool’s odor guide also suggests clearing food from the disposal as part of fixing a smell.
What to leave alone: Don’t disconnect the hose unless you’re comfortable with plumbing. It holds dirty water and can leak if it isn’t clamped back properly. If you rent a condo or two-flat, check with your landlord or building manager before changing anything under the sink.
Spot 4: The Door Gasket
The rubber gasket around the door seals the water in, but its folds also catch grease, food bits, and moisture. The lower edge of the door is another spot the spray arms don’t reach well.
A musty or mildew smell usually starts here.
How to clean it:
- Wipe the gasket with a damp cloth and a little mild dish soap. Whirlpool’s guide recommends the same approach.
- Use an old toothbrush on the folds and corners.
- Wipe along the bottom edge of the door and the tub lip below it.
- After a cycle, leave the door open a crack so the interior can dry. (Skip this if small kids or pets are around.)
While you’re there, look for cracks, tears, or flattened spots. A damaged gasket can leak, and replacing it is a repair job.
How Do You Get Rid of the Smell After Cleaning?
Once all four spots are clean, run the dishwasher empty on its hottest cycle to flush out what’s left. You can use a dishwasher cleaner or a cup of white vinegar set upright on the top rack.
Two cautions:
- Never mix bleach with vinegar or other cleaners. The combination can release harmful fumes.
- Check your owner’s manual before using bleach at all.
To keep the smell from coming back:
- Scrape plates before loading. Large scraps overload the filter fast.
- If dishes will sit for a day or two, run a rinse-only cycle if your model has one.
- Clean the filter monthly.
- Run the disposal before each dishwasher load.
When Standing Water Means a Drain Fault
Cleaning fixes most odors. But if water is pooling in your dishwasher, the smell is a symptom of a bigger problem.
Look for these signs:
- Water covers the tub floor after the cycle finishes.
- Dirty water reappears in the tub between cycles.
- Water backs up into the sink or spills out of the air gap while the dishwasher drains.
- The smell returns within a few days of a thorough cleaning.
These point to a blockage in the drain hose, a stuck check valve, or a drain pump that isn’t moving water out. Our guide to a dishwasher not draining walks through those causes in detail.
If your dishes are also coming out gritty or filmy, the same trapped debris may be the culprit. See why a dishwasher stops cleaning dishes and what fixes it.
Stop and call a pro if:
- You smell burning or notice an electrical odor.
- Water is leaking onto the floor.
- Water still stands in the tub after you’ve cleaned the filter and confirmed the hose is clear.
How Dara Handles a Smelly Dishwasher
Honest appliance repair starts with telling you when you don’t need us. If cleaning the four spots above clears the smell, you’re done.
Darkhan, Dara’s owner, still goes out on repair calls himself alongside our technicians.
Editor note (remove before publishing): HEADSHOT goes here: darkhan-dara-appliance-repair-owner.jpg. Alt text: “Darkhan, owner and technician at Dara Appliance Repair.” Then add one or two sentences describing the real job shown in Photos 1 and 2 (what the customer noticed, what was found, how it was fixed). Use only the actual job details.
When the smell keeps coming back, our certified technicians start where you did: the filter and sump. Then we check the parts you can’t easily reach: the drain pump and check valve, the hose path behind the machine, and the drain connection under your sink.
If it’s a cleaning issue, we’ll tell you. If it needs a part, you’ll know the price before any work starts. Most repairs fall between $129 and $400, and your exact price depends on the issue.
We repair all major and luxury dishwasher brands across Chicago and the surrounding suburbs, seven days a week from 8 AM to 8 PM. Every repair is backed by a warranty. Learn more about our dishwasher appliance repair service.
Frequently Asked Questions
Is it normal for water to sit in the bottom of my dishwasher? A small amount of clear water in the sump under the filter is normal on many models. Water covering the floor of the tub after a finished cycle is not normal and usually means a drain problem.
How often should I clean my dishwasher filter? Whirlpool recommends at least once a month. If you run the dishwasher daily or load plates without scraping them, check it more often.
Why does my dishwasher smell like sewage? A sewage smell usually comes from the drain side: a sagging drain hose, a clogged air gap, or a disposal holding old food. If those check out and the smell stays, have a technician or plumber inspect the drain connection.
Why does my new dishwasher smell like plastic? Many new dishwashers give off a plastic or chemical smell at first. Whirlpool notes that this is normal and usually fades within a few weeks of regular use.
Can I use bleach to clean a smelly dishwasher? Check your owner’s manual first, since some manufacturers advise against it. Never mix bleach with vinegar or any other cleaner.
Do you repair all dishwasher brands? Yes. Dara Appliance Repair works on all major and luxury dishwasher brands.
Still Smells Bad? We Can Help
If your dishwasher smells bad after you’ve cleaned all four spots, or water won’t drain, it’s time for a closer look. Book online to schedule a visit, or contact our team with questions.
