If you're noticing that your dishwasher smells of sewage, there are a variety of reasons this can be happening. Before you start poking and prodding inside your dishwasher, you should clean your filter, check the walls and gasket, scrub everything and don't keep dirty dishes sitting in your dishwasher for long periods.
Dishwasher Stinks of Sewage
According to Mr. Rooter Plumbing, you must clean your filter periodically because this can be a common cause for dishwasher odor. Before you start cleaning the filter, you should read over your manual to figure out how to properly remove your filter. Once you learn how to remove your dishwasher filter, all you have to do is clean it with hot water and soap. You can also clean the area around the filter with a bit of this soapy water solution as well.
If your dishwasher still smells, check the area around the walls and gasket. Periodically wipe the door and walls of the dishwasher with hot water and soap. Sometimes food can get stuck on the dishwasher walls or door, and this can cause dishwasher odor. Don't forget to clean the seal around your dishwasher door as well. The seal around the dishwasher door is known as the gasket, and old food can get caught here.
In addition to scrubbing the inside of the dishwasher and gasket, you should also clean the racks and the bottom side of your dishwasher. Dirt and grime frequently build up here, which contributes to dishwasher odor. One of the smallest things you can do is to try and not leave dirty dishes in your dishwasher for long periods. Food can harden and start to smell on plates, so you should try and run your dishwasher only when you have a full load of dishes.
Run a Clean Cycle
After you scrub your entire dishwasher, you should run a clean cycle. To run a clean cycle, you're going to pour 1 cup of distilled white vinegar in a bowl and put it on the top rack of your dishwasher. When you run a cycle, the dishwasher will wash the bowl with the vinegar inside.
The vinegar, which is a light acid, will knock out any remaining dishwasher smells. After you run the cycle with vinegar, for good measure, sprinkle a bit of baking soda underneath the dishwasher blade. Run a short cycle, and your dishwasher odor should be gone.
Dishwasher Drain Hose
After going through all of these steps, if your dishwasher is still clogged, according to Sears, your dishwasher drain hose could be bent, your dishwasher hose could be positioned too low or your dishwasher air gap could be clogged or blocked. If your dishwasher drain hose is kinked or twisted, this can cause wastewater to come back into the dishwasher, which is what could be causing the sewage smell. Straighten the drain hose, and this will stop wastewater from backing up into your dishwasher.
If your dishwasher drain hose is too low, this could also be causing water to come back into the bottom of your dishwasher. Try to elevate and loop the drain hose. This will ensure that water doesn't flow back into the dishwasher. Lastly, make sure the air gap isn't clogged or blocked. Some dishwashers don't have one, but you'll know if you do if there is a small silver cylinder by your faucet.