4 Surprising Reasons Your Dishwasher Smells Bad — and What a Plumber Says to Do About It

The dishwasher is the true MVP of the kitchen. Instead of spending time hand-washing dishes and carefully playing dish Jenga on the drying rack, you just load the dishwasher, press a few buttons, and let the machine do all the work. Who doesn’t love that valuable time back on busy days? 

While dishwashers have their perks, there’s some maintenance you have to keep up with. Sometimes, quite honestly, they start to stink — you know the sour, funky smell. If your dishwasher smells bad, don’t worry — it’s completely normal and, according to the pros I talked to, easy to take care of. But before you break out the cleaning gloves, read on to learn why your dishwasher smells bad in the first place. 

There could be several reasons why your dishwasher has a pungent odor, including the following: 

If your dishwasher smells bad, check its filter. The filter can get pretty gunky because it catches all the food cleaned off the dishes.  

“Many people forget to clean it regularly, and food particles get trapped there, decomposing over time and causing bad smells,” says Omarr Picken, founder of OP Plumbing Services and a plumber of 30+ years. If the filter is clear, check the spray arms and the drain hose for clogs as well. 

Standing water can cause some serious odors in the dishwasher, especially when food debris is breaking down in it. If you open your dishwasher and see standing water, it may have drainage issues. These issues can stem from the clogs mentioned above or from malfunctioning parts like the check valve and float switch. 

The dishwasher can be a natural breeding ground for mold or mildew due to its hot and humid environment. While it may be easy to spot in the dishwasher tub (a.k.a. the main part of the dishwasher where everything is loaded in), Picken says many people forget to look in the door gasket, a hot spot for mold and mildew buildup. 

Another smelly culprit could be the detergent you’re using. Picken says detergents that don’t dissolve properly can leave behind a residue that causes unpleasant odors. You should also monitor how much detergent you’re putting in; putting too much can also cause smelly buildup. 

Good news: It’s pretty easy to remove that less-than-pleasant stench coming out of your dishwasher. The best part? You can do it with some common household items you likely already have.

If your dishwasher has a slight odor to it, try using this simple method from Picken for a quick deodorizing: 

What you’ll need: 

• A dishwasher-safe bowl 
• 1 cup white vinegar 
• 1 cup baking soda 

1. Make sure all dishes and utensils are out of the dishwasher. 
2. Pour 1 cup of white vinegar into a dishwasher-safe bowl and place the bowl on the top rack. The vinegar will help break down grease and eliminate odors. 
3. Run a hot water cycle. 
4. After the cycle is complete, sprinkle 1 cup of baking soda on the bottom of the dishwasher. 
5. Run a short hot water cycle so the baking soda can help clean and deodorize. 

If your dishwasher has a strong stench that just won’t go away, your best bet is to get to scrubbing. I asked Marla Mock, president of Molly Maid, how to clean a dishwasher so it smells fresh as a daisy. She provided some brilliant cleaning methods using items you may already have in your kitchen. 

What you’ll need: 

• A soft brush 
• A dishcloth 
• A towel 
• A sponge 
• Dish soap 
• Vinegar 

1. Take out the bottom rack and find the filter (it’s typically at the bottom). 
2. Remove the filter and rinse under warm water to remove debris. 
3. Use a soft brush to gently scrub the filter to remove residue and any remaining debris. 
4. Rinse the filter with warm water and put it back in the dishwasher. 

1. Mix ½ teaspoon of dish soap with 1 cup of warm water and dampen a cloth within. 
2. Look for buildup on the rubber gasket around the dishwasher door; pay extra attention to crevices. 
3. Wipe the gasket with the damp cloth until the debris is gone. 
4. Rinse the gasket with clean water and dry it with a towel.

1. Remove the top and bottom racks from the dishwasher and check them for debris and stains. 
2. Scrub the racks with a soft brush with warm, soapy water. If the racks have stubborn stains, create a paste using baking soda and water, apply it to the stains, and let it sit for a few minutes before scrubbing.
3. Rinse the racks with warm water. 
4. Put the racks back in the dishwasher. 

1. Remove the sprayer arms from the dishwasher and inspect them for any clogs or debris.
2. Use a small soft brush to remove any food particles stuck in the spray holes.
3. Create a 1:1 solution of warm water and vinegar and soak the sprayer arms in it for 15-20 minutes. 
4. Rinse the sprayer arms with warm water and reinstall back into the dishwasher.

1. Mix ½ teaspoon of dish soap with 1 cup of warm water and dampen a cloth with it. 
2. Wipe the inside of the dishwasher door with the cloth, paying extra attention to edges and corners where dirt and grime can gather. If the interior has stubborn stains, create a paste using baking soda and water, apply it to the stains, and let it sit for a few minutes.
3. Rinse the inside of the door with warm water and dry with a towel. 
4. Remove the top and bottom racks of the dishwasher and follow steps 1 through 3 for the interior walls.
5. Repeat steps 1 and 2 for the exterior of the door; wipe away water with a sponge and dry with a towel. 

1. Remove the bottom rack and use a damp cloth to wipe away visible debris. 
2. Pour a 1:1 ratio of baking soda and vinegar down the drain to break up grease and food residue. 
3. Let the mixture sit for 15-20 minutes, then flush the drain with hot water. 
4. Put the bottom rack back into place. 

If you often notice your dishwasher smells bad, here are some ways to prevent it from stinking up the joint going forward: 

Food and grease are the top two enemies for foul dishwasher odors. Picken says to make sure you scrape and rinse dishes before loading them to minimize the amount of debris carried into the dishwasher. 

Both Mock and Picken say it’s best to scrub the dishwasher at least once a month to help keep it odor-free. “Clean the filter, door seal, and spray arms at least once a month,” Picken advises. “Also make it a habit to run a rinse cycle once a month to break down any built-up residues.” 

A dishwasher’s damp environment can make it an ideal spot for mildew growth, which is why that moisture needs to find its way out. Picken says to let your dishwasher air out by leaving the door slightly open when not in use.

Picken’s final piece of advice: Use the best dishwasher detergent possible each time you run the workhorse appliance. That way, you reduce the amount of residue taking up shop in it while helping your dishes shine bright.