How to Clean a Smelly Dishwasher and Kill Odors for Good

A sour, fishy, or sewage-like smell every time you open the dishwasher is one of the most common appliance complaints we hear — and cleaning it the right way removes the trapped food, grease, mineral scale, and hidden mold behind the odor, restoring a fresh smell and better wash results in about 30 minutes of hands-on work. Almost every dishwasher smell traces back to the same handful of causes, and inexpensive household items fix the vast majority of them. Here’s exactly how to do it.

Why Does My Dishwasher Smell? Common Causes of Odor

Before you start cleaning, it helps to understand what you’re fighting. A dishwasher is warm, dark, and damp — the ideal environment for bacteria and mold. A widely cited study published in PLOS ONE found that the rubber seals of most home dishwashers harbor black yeasts and other fungi that thrive on leftover food and detergent residue. That biofilm is often the real source of a lingering smell.

Here are the most common reasons your dishwasher stinks, what each one smells like, and where to look:

A few notes worth calling out. Hard water is common across South Central Pennsylvania, and the mineral deposits it leaves behind trap odor and reduce cleaning power over time. A sewage smell usually points to a drainage problem rather than the dishwasher’s interior — often a clogged drain hose, a hose that isn’t looped high enough, or a blocked air gap or garbage disposal. And a burnt, chemical odor frequently means a plastic lid or utensil melted onto the heating element. Identifying which of these you’re dealing with is the first step toward a fresh-smelling kitchen.

Essential Supplies for Cleaning Your Dishwasher

Cleaning your dishwasher requires only a few inexpensive items you probably already own. Having them ready makes the process quick and effective — no harsh chemicals needed. Gather the following before you begin:

• White vinegar — a natural degreaser and deodorizer.
• Baking soda — neutralizes odors and lifts stains.
• A soft brush or old toothbrush for scrubbing the filter and seals.
• A microfiber cloth or soft rag for wiping down surfaces.
• Mild dish soap for grease and stuck-on residue.
• A toothpick or thin wire for clearing blocked spray-arm holes.
• Optional: a commercial dishwasher cleaner or citric-acid tablet for hard-water areas.

Step 1: Empty and Inspect the Dishwasher

Begin by unloading your dishwasher completely. Remove all dishes, utensils, and detachable racks so you have unobstructed access to every part of the interior.

Next, perform a thorough inspection. Food particles love to hide in corners and folds, so check for:

• Leftover food scraps in the corners and around the sump.
• Buildup along the rubber door seals.
• Foreign objects such as broken glass, labels, or bits of melted plastic.

Identifying these trouble spots early makes the rest of the cleaning far more effective. An empty, inspected dishwasher sets the stage for a proper deep clean.

Step 2: Remove and Clean the Filter

The filter is the single biggest cause of dishwasher odor, and the most overlooked. It sits at the bottom of the tub, usually under the lower spray arm, and twists out with a quarter-turn. Consult your owner’s manual if you’re not sure where yours is.

Once removed, rinse the filter under warm running water to flush away trapped food. For a deeper clean, scrub the mesh with a soft brush and a little mild dish soap to break down grease and stuck-on residue. Rinse until the water runs clear, let it dry, then reinstall it securely — a loose filter can leak debris back into the tub.

Because the filter collects debris so quickly, this is the one task worth doing far more often than a full clean. A quick rinse every one to two weeks prevents the vast majority of dishwasher smells before they start.

Step 3: Clean the Spray Arms and Door Seals

Clogged spray-arm nozzles reduce water pressure, leave dishes dirty, and let odor-causing residue build up. Remove the spray arms if your model allows it, then use a toothpick or thin wire to clear each spray hole — pay special attention to holes blocked by hard-water mineral deposits. This restores full water pressure during every cycle.

Next, turn to the door seals. These rubber gaskets trap food, moisture, and the mold and mildew that cause that classic musty smell. Wipe them down with a damp cloth and a little mild detergent, and:

• Gently pull open the folds of the seal to reach hidden grime.
• Check for black or pink spots that indicate mold or mildew, and scrub them thoroughly.
• Rinse with a clean, damp cloth to remove any soap residue.

Keeping the spray arms and seals clean prevents a stinky dishwasher, improves wash quality, and extends the life of the appliance. If you frequently battle mold here, the same damp-environment principles apply to other appliances — our guide on how to prevent washing machine mold covers the habits that keep rubber seals fresh.

Step 4: Deep Clean the Interior with Vinegar

A hot vinegar cycle is the most effective way to sanitize and deodorize the whole tub at once. Vinegar’s acidity cuts through grease, dissolves soap scum and mineral scale, and neutralizes odors — all without harsh chemicals. Here’s how to do it:

1. Make sure the dishwasher is completely empty.
2. Fill a dishwasher-safe cup with one to two cups of white vinegar and place it upright on the top rack.
3. Run a full cycle on the hottest setting available, with the heated-dry option off.
4. When it finishes, check for any lingering stains or smells and repeat if needed.

The heat helps the vinegar loosen stubborn residue on the walls and door. In hard-water areas, a citric-acid dishwasher tablet works even better than vinegar at removing limescale — a useful upgrade if your dishes come out cloudy.

Step 5: Deodorize with Baking Soda

Baking soda is the perfect finishing touch after a vinegar cycle. It absorbs any remaining odor and gently scours away light staining, leaving the interior bright and fresh. For best results:

• Sprinkle about one cup of baking soda across the bottom of the empty tub.
• Let it sit overnight so it can absorb odors (or at least a few hours if you’re short on time).
• Run a short hot-water cycle in the morning to rinse it away.

Vinegar vs. Baking Soda vs. Commercial Cleaner: Which Should You Use?

All three work, but each has a job it does best. Use this quick comparison to decide what to reach for:

For most households, vinegar plus baking soda once a month is plenty. If you live in a hard-water area or your dishwasher gets heavy daily use, adding a commercial or citric-acid cleaner every couple of months keeps performance high.

Step 6: Check and Clean the Drain and Other Components

The drain is a critical, odor-prone component. Food particles and grease collect around the sump at the bottom of the tub and, over time, produce foul smells. Start by clearing any visible debris with a damp cloth. If your model has a removable drain cover, detach it and clean underneath, then make sure water flows freely.

Most dishwashers drain through a hose connected to your kitchen sink’s garbage disposal or drain line, so odor problems often originate outside the appliance. A couple of extra checks:

• Run the garbage disposal before starting a wash — trapped food there can send smells back up the shared drain. Our guide to unclogging a garbage disposal walks through it.
• Confirm the drain hose is looped high (or connected to an air gap) so dirty sink water can’t flow back into the dishwasher. If yours is sluggish, see how to clean a dishwasher drain hose without removing it.
• If water is pooling in the bottom after a cycle, that’s a drainage fault, not just an odor — our walkthrough on troubleshooting a dishwasher that won’t drain covers the likely causes.

Regular attention to the drain, hose, and disposal resolves the majority of stubborn sewage-type odors that a simple interior clean can’t fix. Finish the job by wiping the exterior door, handle, and control panel with a soft, damp cloth — on stainless steel, wipe in the direction of the grain and avoid abrasive pads.

How to Eliminate Persistent Odors (Fishy, Sewage, or Chemical Smells)

If a smell survives a full clean, the specific odor tells you where to look next:

• Fishy or rotten smell: Almost always trapped food in the filter, sump, or drain. Re-clean the filter and run a hot vinegar cycle.
• Sewage smell: A drainage issue — a clogged or low-looped drain hose, a blocked air gap, or a dirty garbage disposal. Check the hose routing and disposal first.
• Musty or moldy smell: Mold on the door gasket or in standing water. Scrub the seals and leave the door ajar to dry between uses.
• Burnt or chemical smell: Often melted plastic on the heating element, or off-gassing from a brand-new unit. Remove any melted debris once cool, and air out a new dishwasher with a couple of empty rinse cycles.

If you’ve cleaned the filter, seals, drain, and hose and the smell still returns — or you notice standing water, slow draining, or a musty smell paired with a leak — the problem is likely mechanical: a failing drain pump, a cracked hose, or a check valve that isn’t sealing. That’s the point to bring in a technician rather than repeating the same clean.

How Often Should You Clean Your Dishwasher?

Consistency beats intensity. A light routine prevents the buildup that causes odors far more effectively than an occasional heavy scrub. Here’s a simple maintenance schedule to follow:

Preventative Maintenance Tips for a Fresh Dishwasher

Beyond the monthly clean, a few everyday habits keep odors from ever taking hold and extend the appliance’s lifespan:

• Scrape (but don’t over-rinse) dishes before loading to keep large food scraps out of the filter.
• Run the garbage disposal before starting a cycle.
• Run the hot-water tap at the sink for a few seconds first, so the dishwasher fills with hot water immediately.
• Use a rinse aid to improve drying and reduce hard-water spotting.
• Leave the door slightly open after a cycle so the interior dries out instead of staying damp.
• Keep the vent and air gap clear, and don’t overload the racks.

These habits take seconds but make the biggest difference. Applied consistently, they keep your dishwasher hygienic, efficient, and pleasant to open.

When to Call a Professional Appliance Repair Technician

Cleaning solves the vast majority of dishwasher odors, but some smells are a symptom of a mechanical problem that DIY steps won’t fix. Consider professional service if you notice any of these:

• A persistent sewage or musty smell that returns after a thorough clean.
• Standing water in the bottom of the tub, or slow, incomplete draining.
• Leaks around the door or under the unit paired with a moldy smell.
• A burning smell during operation — a possible heating-element or wiring fault. Stop using it and unplug it.
• Dishes that stay dirty or filmy no matter how you clean the machine.

If you’re in Harrisburg, York, Mechanicsburg, Camp Hill, Hershey, or anywhere in South Central Pennsylvania, Sarcon Repair offers fast, same-day service from experienced technicians. Not sure whether it’s worth fixing? Our breakdown of dishwasher repair cost vs. replacement helps you decide before you spend a dollar.

Frequently Asked Questions About Dishwasher Odors

Resources and References

The research and best-practice guidance referenced in this article comes from official and peer-reviewed sources. It’s worth reading them directly for deeper background:

Related Reading & Services

This guide is for general home-maintenance purposes only. Always consult your appliance owner’s manual and follow the manufacturer’s care instructions. If you notice electrical faults, burning smells, or persistent leaks, stop using the appliance and contact a qualified technician.