6 Reasons Your Dishwasher Could Have a Terrible Smell—and How to Fix It

If you notice a strange odor lingering in your kitchen, try opening your dishwasher and taking a sniff. A smelly dishwasher can overpower even the scent of freshly baked cookies. The smell won’t vanish on its own, so it’s time to identify the cause and tackle these six common reasons why your dishwasher stinks.

You Haven’t Scraped Off the Food Residue

Some people firmly believe that rinsing or pre-washing dishes before loading them into the dishwasher is unnecessary, as it defeats the purpose of having one in the first place. The only task needed is to scrape off large food scraps. Dishwasher detergent performs best when there are small food particles to cling to before the hot water takes over to rinse and sanitize the dishes.

However, if you skip removing the larger food pieces, your dishwasher's filter (which we’ll discuss more later) and drain line can get clogged with food particles, promoting the growth of bacteria that causes the unpleasant smell.

You’ve Never Cleaned the Dishwasher Filter

Did you know that your dishwasher has a filter? Every dishwasher is equipped with a filter to catch food scraps and prevent clogging in the drain line. Typically, it’s located at the bottom of the dishwasher drum. To clean it, pull out the bottom rack, locate the filter, and, holding your breath, remove it and give it a good scrub.

Unless you have a dishwasher with a self-cleaning filter, you should clean it at least once a month. Even if your filter does self-clean, it’s a good idea to clean it every other month. If you don’t scrape off food before loading the dishwasher, you may need to clean both types of filters more often.

You never initiate a cleaning cycle.

Despite the hot water and dishwasher detergent flowing through the appliance, the interior surfaces and racks can develop a greasy layer that traps mold spores, bacteria, and food remnants that emit a foul odor.

Once the dishwasher filter is cleaned, be sure to run a cleaning cycle using either a commercial dishwasher cleaner or your trusted distilled white vinegar and baking soda from the pantry. Just ensure the dishwasher isn't filled with dirty dishes, and you'll be surprised at how the smell disappears.

You allow a plastic lid to slip off the upper rack.

A burnt plastic smell in your dishwasher should never be ignored as it could indicate wiring issues. However, it's most likely due to a piece of non-dishwasher-safe plastic caught near the heating element.

Take a moment to remove the bottom rack and check for any issues. Remove the problem and use a non-metallic utensil to scrape off any plastic stuck to the floor of the dishwasher, then run a cleaning cycle to refresh the interior. Placing a bowl of baking soda on the top rack of an empty dishwasher will also help absorb any odors.

You have a slow or clogged drain.

Remember that dishwasher filter you never cleaned, or perhaps didn't even know about? If it gets clogged, the dishwasher will drain slowly and may emit unpleasant odors from the drain. Cleaning both the filter and the dishwasher should help, but if a large clog causes water to back up into the bottom of the dishwasher, you’ll need a plumber to clear the drain line.

You don’t clean your sink disposal unit.

If you have a sink disposal, it shares the same drain line as your dishwasher. If the disposal is clogged, food and dirty water from your dishwasher won't drain properly. Run and flush your disposal to ensure there’s no food trapped inside, which should help clear the clog. Afterward, clean the disposal and run a dishwasher cleaning cycle to remove any lingering odors.

Tips for keeping your dishwasher smelling fresh.

• Use your dishwasher regularly. Waiting for it to be completely full may save a little on utilities, but food left on dishes can quickly start to smell.
• Always empty the clean dishes and ensure the dishwasher's interior is dry before leaving. Placing a box or bowl of baking soda on the top rack and closing the door will help absorb any odors.
• Check your hot water heater's temperature setting to ensure the water is hot enough to clean and sanitize your dishes. Avoid taking hot showers or washing clothes in hot water while the dishwasher is in use.