Why does my dishwasher smell? 3 tips to get rid of bad odors.

1. Mold or mildew.

If the smell coming from your dishwasher is musty, the most likely culprits are mold and mildew. These fungi feel most at home in an environment that offers food, warmth, darkness, and moisture. A dirty dishwasher often provides the perfect conditions for mold growth.

The smell of mold is distinctive, but there will most likely be visible signs as well. If you notice discolored, slimy-looking spots in your dishwasher, you almost certainly have mold.

How to fix: Try running a wash cycle with hot water and some white vinegar. If the dishwasher still smells, your problem may be something else.

Related: How long do dishwashers last? Signs yours is going bad.

2. Filter or drainage issues.

A sharper odor of sewage or a “wet dog” smell may indicate a drainage problem. There are several potential reasons your dishwasher doesn’t drain properly. For example, a dirty drain filter can trap food particles and dirty water. You could also have a more severe issue, like a clogged drain hose or line.

How to fix: Cleaning the dishwasher filter is usually enough to eliminate odors resulting from drainage issues.

If you have standing water even after cleaning the filter and running a cycle, the drain line is more likely the culprit. Follow these steps to clean your dishwasher's drain. If that doesn't work, you may need a repair professional's help.

3. Leftover food residue.

In some cases, you may be wondering, “Why does my dishwasher smell like rotten eggs?” Even if your dishwasher doesn’t have mold, food residue can lead to odors on its own. Over time, food residue will start to rot and attract bacteria.

How to fix: You can prevent the buildup of food residue in several ways. For example:

• Scrape excess food off of dishes, and rinse them in warm water before loading them into the dishwasher. You may even want to soak them in soapy water before loading the dishwasher.
• Don't overcrowd dishes. If there isn’t enough space, the spray arms can’t circulate water around all the dishes to clean them.
• Try not to leave dirty dishes in the dishwasher for too long before running a cycle.

Is vinegar bad for dishwashers?

There's a bit of debate over whether or not vinegar is bad for your dishwasher.

Some experts recommend using distilled white vinegar when deep cleaning your dishwasher and getting rid of bad smells. Others warn that it may be too acidic for certain parts of your dishwasher (like the rubber gaskets, seals, and hoses). Over time, the vinegar can break down these parts and cause leaks.

When cleaning your dishwasher with vinegar, remember these tips to prevent damaging your appliance:

• Do not pour vinegar into the dispenser.
• Do not pour or spray vinegar all over your dishwasher's interior.
• Do pour the vinegar into a dishwasher-safe bowl, place it on the rack and run a full cleaning cycle.

Can you use baking soda to deodorize a dishwasher?

Baking soda is great at breaking down grease, grime, and tough-to-remove buildup. It can also help remove bad smells.

After you've completed the vinegar cycle, sprinkle 1 cup of baking soda on the bottom of the dishwasher. Then, run a short hot water cycle.

Prevent a smelly dishwasher in the future.

In addition to knowing the reasons for odors, proper maintenance will help keep your dishwasher smelling fresh and clean. These simple maintenance tips can prevent your dishwasher from starting to smell:

• Regularly clean your dishwasher: Periodically, you should clean the interior of your dishwasher, as well as the door and its rubber gasket. Use a toothbrush or small scrub brush to clean in tight crevices.
• Clean the drain filter: Your dishwasher’s filter catches food particles to prevent them from recirculating in the wash. Every once in a while, you should check the filter for any buildup and rinse it out.
• Use a dishwasher cleaner: In addition to natural cleaners like vinegar and baking soda, you can use specialized cleaning agents. These cleaners work like regular detergent pods to clean and freshen the interior of your dishwasher.
• Run your dishwasher regularly: Even a small dishwasher load tends to save water over hand-washing. Try not to let dishes sit in the dishwasher for too long, or it could lead to foul smells.

Still experiencing dishwasher issues? Contact a pro.

In most cases, you can eliminate unpleasant smells in your dishwasher with a deep clean. However, if a stubborn smell lingers even after following the steps in this article, you should hire a pro.

With Thumbtack, you can easily find the best dishwasher repair technicians, plumbers, handymen, house cleaners, and other pros in your area. 

Download the Thumbtack app today to find a qualified professional to fix your dishwasher issues.

FAQs.

How do I run a sanitize cycle on my dishwasher?

A dishwasher's sanitize cycle is often a good way to effectively remove bacteria and food grime due to hotter water and longer wash times.

Check your owner's manual for instructions on how to run a sanitize cycle on your dishwasher. If you can't locate your manual, look for labels that say "Sanitize," "Sani-Wash" or "Sani-Rinse" and press the button.

Can I bleach a stinky dishwasher?

Avoid using bleach to clean a stinky dishwasher. Although bleach is great at killing germs, it can actually damage metal and stainless steel.

Check your dishwasher's material, and consult your owner's manual to confirm if bleach can be used for cleaning. When in doubt, stick to white vinegar or a store-bought cleaning product. You should also avoid mixing bleach with other chemicals and cleaners. Doing so could introduce toxic fumes into your home.