There are some basic expectations about dishwashers that I think everyone can agree on. We all want a dishwasher that produces sparkling clean dishes. And absolutely no one wants to open their dishwasher and be greeted by a rancid smell as if the machine were exhaling bad breath.
This smelliness, however, can occur if you don’t maintain your dishwasher.
“It’s typically a sign that food particles, moisture, and bacteria are hanging around,” says Justin Bovard, executive director of product management for dishwashers at GE Appliances. One of the reasons why a smelly dishwasher can be a particular headache is that you might not immediately know where the smell is coming from, which makes it a harder problem to fix.
So we asked CR’s dishwasher expert and manufacturers about the most common causes of a stinky dishwasher. Here are the most likely culprits, followed by our suggestions on how to prevent your dishwasher from becoming smelly in the first place.
Reasons why your dishwasher is smelly
You haven’t cleaned your dishwasher filter. If your dishwasher smells less than rosy, the first thing you should check is the filter. Chances are, the filter—located at the bottom of your dishwasher and designed to trap any pieces of food removed from your dirty dishes—is the source of the stench.
If you have a manual filter and don’t know that you have to clean it, the food particles trapped in the filter could cause a foul smell, says Larry Ciufo, who oversees dishwasher testing at Consumer Reports. A manual filter, which is common in modern dishwashers, requires regular cleaning, unlike a self-cleaning filter.
A dirty filter can do more harm than just producing foul odours. Without regular cleaning, it can also hinder your dishwasher’s performance, says Lindsay Jones, the integrated brand manager at Maytag.
The dishwasher drain is clogged. Food debris from your dishwasher or your dishes could be clogging your drain and producing odours, Jones says. Scraping large pieces of food off your dishes before you load them can prevent this.
Your dishwasher interior has collected food remnants. Over time, sticky soap scum can build up on your dishwasher’s walls and trap food particles, Jones says. Instead of rinsing away down the drain, these food particles can cling together over time and produce an odour.
Your dishwasher door is dirty. Bits of food might have gotten trapped against the edge of your dishwasher where the door opens, Ciufo says. People can also easily miss any buildup around the dishwasher’s doorframe.
There could also be mould around the door seal. “With the amount of moisture and heat a dishwasher produces, mould and mildew can accumulate in the door gasket seal and produce a foul-smelling odour without regular cleaning,” Jones says.
How to prevent your dishwasher from smelling
If you want your dishwasher to be stink-free, you can’t skimp on regular cleaning and maintenance.
Jones says you should clean your dishwasher’s filter once a month. First, empty the filter of any debris and rinse it with hot water. If food particles or soil are still stuck to the filter, try soaking it in warm, soapy water. Afterward, you can use a toothbrush to remove stubborn remnants or residue.
If you’re unsure whether your dishwasher’s filter is manual or self-cleaning, read our detailed guidelines on how to identify your filter and clean it.
Periodically cleaning your dishwasher’s interior with a soft, damp cloth or sponge can help remove food and dirt particles, says Marty Olson, an engineer at LG Home Solutions Quality.
If your machine has a self-cleaning cycle, run the cycle with an empty tub once a month. Olson says adding 3 teaspoons of citric acid or a dishwasher cleaning agent recommended by the manufacturer to the detergent dispenser can help eliminate any residual soil, odour, white spots, and dirt.
If your machine doesn’t have a self-cleaning cycle, Bovard says you can give it a quick clean by placing a cup of white vinegar in a dishwasher-safe container on the top rack and running it on its hottest cycle.
If you spot any mould or mildew inside the dishwasher, Bovard suggests wiping the interior clean with a solution of 1/8 cup bleach to 1 gallon of water. Then, run a normal cycle on your empty dishwasher without detergent. If your dishwasher’s interior is made of stainless steel, however, you should avoid using bleach because it might damage its finish.
To clean your dishwasher without bleach, run a sanitize cycle with an empty dishwasher. Or consider using a dishwasher cleaner with citric acid, Bovard says. If your dishwasher has a regular mould problem that won’t go away, it could be a sign that the unit isn’t getting to a high enough temperature. If that’s the case, you should schedule a service call to get your dishwasher checked out.
Mould and mildew might also occur on the lips of the gasket seal, so it’s important to periodically inspect the seals of the dishwasher door for any buildup. If you spot any residue on the gasket, clean it with a fresh sponge and warm, soapy water. When you’re done, wipe the gasket seal dry with a clean rag to ensure no moisture is left behind, Jones says.
If you follow all the above steps—regularly cleaning your filter, dishwasher interior, and gasket—you’ll reduce the likelihood that you’ll be greeted with an unpleasant odour the next time you open your dishwasher door.
Article written by Pang-Chieh Ho, Consumer Reports Senior Home & Appliances Writer