Why does my dishwasher smell? Possible causes & fixes

 A functioning dishwasher that is used and maintained as prescribed in the owner’s manual should not develop any bad odors. Persistent or strong smells can be a sign that something needs attention. Keep reading to discover which smells may require troubleshooting.

• Plastic smell: This is normal for new models and should dissipate in about two weeks. Consider using affresh®Dishwasher Cleaner¹ to help. 

• Petroleum smell: Some models have sound-deadening material that smells like petroleum; the smell usually dissipates in four to six weeks.

• Varnish smell: Some dishwasher parts are treated with a varnish. This smell should wear off in approximately one month.

1. Affresh^® brand products and the recommending brands’ products are all owned and distributed by Whirlpool Corporation.

• If your dishwasher smells like fish or rotten food, you may have a clogged dishwasher drain or a dirty filter. 

• A sewage or wet dog smell can point to a drainage problem which may require professional inspection. For these types of smells, continue reading to learn more about their causes and potential fixes.

Dishwashers are an important component to kitchen creativity, simplifying cleanup so you can spend more time preparing the meals you love. However, they can become a source of frustration if they smell unpleasant. 

Dishwasher smells can range from the plastic aroma of a new appliance to unusual spoiled smells that come from standing water or rancid food. There are various reasons why your dishwasher may be emitting odors, including food debris, clogged filters and drainage problems. A dishwasher that is functioning and cared for correctly should not smell bad. Fortunately, there may be steps that you can take to tackle some of these issues and help your appliance smell fresh again. Keep in mind that the following smells are rough descriptions and may smell differently, depending on circumstances.

Odor Clue: Rotten food or fishy smell

A dirty filter is usually the primary culprit behind unpleasant smells coming from your dishwasher. The filter in your dishwasher can accumulate food debris, which, without regular cleaning, can cause unwanted odors. A clogged filter can also hinder proper cleaning of your dishes by recirculating dirty water.

Dishwashers typically have one of two filter types: a manual-clean filter, which collects food particles and requires regular cleaning, or a hard food disposer, which uses a built-in chopper or grinder to break down debris and requires no routine maintenance. Consult your product manual to confirm your filter type and cleaning instructions.

Odor Clue: Rancid, sour or stale food smell

Another issue that can cause an unpleasant odor in your dishwasher is grease buildup. Grease can accumulate in the drain and filter as well as the interior of the dishwasher. Over time, grease and oils can accumulate on the interior walls, racks, spray arms, and door gasket, even in a machine designed to cut through grime. That buildup tends to trap odors, which may be the culprit behind a stale smell.

Odor Clue: Sewage-like or wet dog smell

The drain hose in your dishwasher plays a vital role in disposing dirty water and food particles into the sink's disposal unit. A malfunctioning drain hose can be the reason behind the unpleasant smell emanating from your dishwasher.

A sewage or wet dog smell may point to a drainage problem. These problems may include a clog or a kinked, crushed or sagging hose. Similarly, a hose that lacks a proper high loop or air gap can allow wastewater to flow back into the dishwasher.

Odor Clue: Rotten or fishy smell

Odors may occur from dirty dishes and food soils that fall into the tub or other parts of the dishwasher. Food debris can get trapped in the filter, spray arms and the bottom of the tub, and even after a wash cycle, small food particles may remain. The door edges are another area to check, as residue can accumulate there as well. If you notice a rotten, fishy or garbage-like smell, inspect these areas for visible food buildup or debris. Scraping dishes before loading, running regular cycles and cleaning leftover food out of the dishwasher can help ensure that it smells fresh and your dishes come out clean.

Odor Clue: Sewage-like smell

Standing water in the dishwasher can result in a sewage-like smell. Note that a small amount of water in the filter area is normal, as it helps keep the seals from drying out. However, an inch or more of standing water pooled in the tub after a completed cycle can indicate a clog that impedes drainage. If this is the case, you might notice that the smell also comes from your kitchen sink drain since dishwashers are often connected to the same drain.

Odor Clue: Musty smell

Without regular maintenance and cleaning, the warm and moist environment created by your dishwasher can possibly cause visible buildup and a slimy feel or dark residue to appear in the folds and crevices of your dishwasher's gasket seals, resulting in a musty odor. One area that is particularly susceptible to this phenomenon is the gasket seal on the dishwasher door.

Dishwashers are a great convenience in the kitchen and keeping them fresh can help ensure your dishes come out clean. Below are some practical steps that you can take to deodorize your dishwasher and help restore its freshness. Note that deodorizing a dishwasher may help remove residue and trapped debris, but it will not correct a leak, drain blockage or electrical problem—for those issues, it’s best to reach out to a professional. 

Many dishwasher odors might be resolved with the cleaning and maintenance steps in this guide. If you’ve worked through them and the problem persists, or if you notice any of the following, contact a qualified technician:

• Drainage that fails to improve after clearing the filter and checking the drain hose

• A persistent or overwhelming sewage odor, which could indicate a drainage problem 

• Water pooling on the floor or visible signs of leaking

• A cracked or damaged dishwasher gasket or door latch, which could lead to leaking

• A burning smell or damaged wiring

For KitchenAid^® Dishwasher owners, a convenient option is to visit the KitchenAid^® service center and schedule a repair service for your KitchenAid^® appliance. A professional technician can thoroughly examine the dishwasher and potentially provide effective solutions to eliminate the odor and restore optimal functioning.

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With a few consistent habits, including keeping up with filter cleaning and other general maintenance, you can often prevent many dishwasher odors. A functioning and regularly maintained dishwasher shouldn’t have any odors. Read the following tips to help keep your dishwasher smelling fresh.

• Clean your dishwasher filter regularly, on average every three to six months, to help prevent food particles from accumulating.

• Avoid overloading your dishwasher racks to allow water and soap to pass through each dish and help break down food debris.

• Use dishwasher cleaning agents, such as affresh^® Dishwasher Cleaner, to reduce odor-causing residues and maintain a fresh scent.

• Run a Rinse Only cycle if you don’t have a full load ready to keep dishes moist and help prevent odor buildup.

• Leave your dishwasher door slightly ajar for a few hours after running a cycle to help improve air circulation and reduce the amount of moisture trapped inside.

These easy steps can help maintain your dishwasher's optimal performance and prevent unwanted odors.

Learn more about troubleshooting a dishwasher.

From “wet dog” to sewage smells, learn how to help mitigate dishwasher odors by reading answers to the common questions below.

The dishwasher trap, also called the filter, catches food particles and debris during the wash cycle. Cleaning it regularly helps prevent buildup that can cause odors. Follow the steps below to clean your dishwasher’s trap. Consult your owner’s manual for specific instructions as they may vary by brand, model and dishwasher design: 

1. Turn the upper filter assembly ¼ turn counterclockwise and lift it out.
2. Grasp the lower filter in the circular opening, lift slightly and pull forward to remove.
3. Rinse the filter under running water until most soils are removed. If you have hard-to-remove soils or calcium deposits from hard water, a soft brush may be required.
4. Replace the filter by placing the lower filter under the locating tabs at the bottom of the dishwasher so the round opening for the upper filter assembly lines up with the circular opening in the bottom of the tub.
5. Insert the upper filter assembly into the circular opening in the lower filter.
6. Slowly rotate the filter clockwise until it drops into place. Continue to rotate until the filter is locked into place. If the filter is not fully seated (still turns freely), continue to turn the filter clockwise until it drops and locks into place.

Clean your dishwasher about once every 30 days. Over time, food particles, greasy residue and mineral deposits can accumulate, causing unpleasant odors and decreasing cleaning performance. Regular cleanings can help mitigate such buildup. To learn more about maintaining a fresh dishwasher, you can check out this comprehensive guide.

If your dishwasher still smells after cleaning, food debris may remain trapped in the filter, spray arms or tub. Stagnant water or mineral buildup can also be sources, as can slimy residue on the gasket seals. A persistent sewage odor may indicate a drain hose clog requiring professional service. Contact professional help if you have checked all these and the issue remains, or if you are unsure how to proceed.

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