7 reasons why dishwashers have bad odor | easy fixes for a fresh smell

bosch dishwasher
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Why Does My Dishwasher Smell like sewage, fish, wet dog, or vomit?

In the last month, I had more time to cook at home. I was making lunch and dinner every day. With lots of coking, there are also lots of dishes. At one point, my dishwasher started to smell like sewage, and I was thinking, why does my dishwasher have a bad odor? I did a little research to find the answer.

Most common reasons why dishwashers smell and have a bad odor are:

  1. The dishwasher filters are dirty (particles of food are stuck on it)
  2. The spray arm holes are clogged with food
  3. There are problems with the drain hose or blocked backflow valve on the drain line
  4. The seal at the bottom of the door collects food residue
  5. There is not enough salt in the dishwasher
  6. The sides of the door and door lip are dirty
  7. Look for food or dead mouse under or behind the dishwasher

gunk and food particles on fine cylindrical filter, and coarse mesh filter

How to prevent the dishwasher from having a bad smell

Pre-rinse the dishware

A dishwasher is not a garbage disposal. The best thing you can do to avoid the most problems with the smelly dishwasher is to always pre-rinse your dishware. Don’t prewash your dishware in a dishwasher. Instead, pre-rinse your dishware in a kitchen sink because the less solid crud you put into the dishwasher, the better. Your hoses will be cleaner, there will be fewer food particles stuck on a filter or sides of the door, and you won’t have to clean the dishwasher so often.

High-temperature washing

There are usually extra heat options and programs with higher temperatures on your dishwasher, like heat boost. It is always better to use more heat in the washing process than barely warm water. The rule is, the hotter the water, the better.

Detergent and salt

Most people use detergent to clean the dishes in a dishwasher. But not every detergent is a good one. That is why it is always wise to use a good detergent like Finish – All in 1. Users like it, and they say it is very effective on dirty dishes.

The other thing is that you should also check how hard or soft your water is. Hard water tends to damage the dishwasher. If water has between 1-4 GPG (grain per gallon), it is soft. If it has 7-10 GPG, the water is hard. It is always better to have soft water. To get water softer, add salt into the washing machine salt cup and adjust the measurement of salt depending on the hardness of the water.

Bleach once a month

If you bleach your dishwasher once a month, it will work efficiently against mold and mildew. Add around 1 cup of bleach on the bottom of your dishwasher and run a full program with an empty dishwasher. Do this once a month.

You should never put bleach in a dishwasher with stainless steel interior or use it together with vinegar.

Run the whole cycle on an empty dishwasher with a special cleaner

It is recommended that you run a full cycle without any dishes in the dishwasher. Always do this with the highest temperature available. To get the best possible results, also use a special cleaner like this one Glisten Dishwasher Cleaner & Disinfectant, which cleans and disinfects your dishwasher.

How to clean and get rid of bad smell in dishwasher

The dishwasher filters are dirty

Dishwasher filters are usually placed on the bottom of the dishwasher. Most models include two filters, fine cylindrical filter, and coarse mesh filter. If one of the filters is dirty, the smell is most probably caused by the gunk on these filters.

Remove the fine cylindrical filter by turning it counterclockwise and lifting straight up. Also, remove the coarse filter. Clean them with a sponge and soapy water and place them back in. Before putting them back in also check the sump and make sure there are no solids in there.

fine cylindrical filter, and coarse mesh filter

food particles on fine cylindrical filter

The spray arm holes are clogged with food

First, take the spray arms out of the dishwasher. Check all the holes. If there are food particles in the holes, you need to clean these holes. Take a paper clip, screwdriver, or toothpick and clean the holes. If these holes are blocked, they can’t shoot water on the dishes, and your dishware will not get as clean as they should.

clogged holes spray arm dishwasher

There are problems with the drain hose or blocked backflow valve on the drain line

The most important and the best thing you can do to ensure that you won’t have problems with drain hose is to pre-rinse the dishes before you put them into the dishwasher. If the lines are clogged you should use a dishwasher cleaner which will take the offending debris out most of the time. When you use the cleaner you should always run a full cycle on the highest possible temperature.

If the hoses are clean and you still get a bad smell from your dishwasher check if the hoses are kinked somewhere. The kinked hose can cause draining problems. If your hose is kinked, just straighten it out and squeeze the hose back into its original round shape. If this doesn’t help replace the hose.

The seal at the bottom of the door collects food residue

Clean the seal with a cloth and detergent when you see food particles sticking on it.

The sides of the door and door lip are dirty

Use a clean cloth and detergent or degreaser spray and clean everything thoroughly.

clogged holes spray arm dishwasher

Look for food or dead mouse under or behind the dishwasher

Yes, some people mentioned that the reason for the smell was a dead mouse that was stuck behind the washing machine. The other thing that can cause the bad smell is also rotten food that got stuck or somehow came under the dishwasher. You should somehow reach under the dishwasher and clean the floor thoroughly.

Dishwasher hacks and detergent alternatives 

Use lemons or lemon wedges

Lemons are an excellent way for your dishwasher to smell like fresh citrus. If you make lemonade, don’t throw the squeezed lemon in the garbage. Instead, place it on the top rack in the dishwasher. It will bring a pleasant citrus-like smell into your dishwasher. You can use squeezed or unsqueezed lemon. After three to four full cycles, replace the lemon with a new one.

Lemon peel Make Dishes Fresh and Sparkly. Use Lemon Wedge

Use soda bicarbonate or baking soda

If you run out of dishwasher detergent, a great alternative is using a baking soda or soda bicarbonate. Just add the following ingredients into the detergent cup:

One tablespoon of baking soda

One teaspoon of salt and

A few drops of mild liquid dish soap

This is how you make your detergent, and you will get great results. The dishes will be clean, and the smell will be great.

Use vinegar for your dishwasher as a substitute and cleaner

White vinegar can disinfect your dishwasher and is an excellent substitute for shine detergent. Since I discovered this, I always substitute shine detergent with vinegar. I never use anything else. Vinegar makes my dishes shiny, especially the glasses, and at the same time disinfects them.

To clean the dishwasher place a full cup of white vinegar onto the high rack of the dishwasher. Run a full cycle on the highest possible temp. This will wash away the grease and disinfect your dishwasher at the same time.


I am a kind of person that would sneak a taste out of grandma’s pot when I was barely tall enough to reach it. I grew up in kitchens full of love and liveliness and have spent my whole live learning, experimenting and succeeding in the art of cooking. At Pro Family Chef, every day is an opportunity for a new meal and a brand new flavor. I created this website to connect people that love to cook, with the products designed to make their cooking easier, hassle-free and rewarding every time.

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