How do I get an awful, rotten smell out of my dishwasher?

"This sounds to me like the drain hose is incorrectly connected to the drain, causing kitchen sink wastewater to back up into the dishwasher.

The dishwasher drain hose sits lower than the sink drain, and this must be accounted for to keep from having a back-flow situation. There is a simpler way to do this than my instructions below, and while it may work, any future clogged drains will cause your issue again.

The proper and most sanitary way would be to install an air gap into the sink. This device fits into one of the extra holes on the top of your sink and has a cap (usually chrome) to make it look nice. The air gap device has two connections, one that comes in from the dishwasher and the other that flows back down to the drain. The air gap keeps you from having a direct hose connection between the dishwasher and the drain and will allow for the dishwasher to overflow into the sink if the drain pipe gets clogged.

Search google for ""dishwasher air gap"" and you'll find all the information you need. iFixit also has a Whirlpool dishwasher not draining page with fixes for wastewater drainage problems (it says “Whirlpool” but really it applies to dishwashers in general).

Good luck!"

My new dishwasher is properly installed and I recently had the sewer gas vent checked. I too had an awful smell in my dishwasher and although I only run the washer every 2nd day or so, I've never had this problem before. In addition to the smell, or maybe the cause, I found weird mold stuff growing down in the filter. I cleaned it periodically with boiling hot water, tide detergent and an oxyclean type bleach alternative (sodium carbonate peroxide) which did a good job of cleaning and removing grease, but the smell would return days later. Finally after much research, I came across some information about copper which I found interesting. Apparently, copper kills fungus, mold, and bacteria. It's suggested that by putting discs cut from copper plumbing pipe in the washer and running vinegar twice a month, it will eliminate mold, and bacteria that may be growing in the dishwasher. Apparently the copper leaches out of the pipe, and kills unwanted organisms. Sounded strange, but I know roofers use copper infused roof tiles to prevent organisms from growing on roofs. I put some discs of copper pipe in my dishwasher and leave them there (they're too big to get down the drain). I run vinegar twice a month and I finally have NO bad smells. It's suggested that using copper plumbing pipe will insure a clean metal, not a copper that may be alloyed with some other toxic metal. Pennies won't work. I know this may sound odd, but google what copper will kill, and you'll see why this works!

"Many dishwasher installation instructions state the drain hose should be looped up higher than the pump to prevent backflow.

Many installers ignore this.

The high loop is easy to install and test.

Here is some info from http://www.structuretech1.com/2010/07/di...

Kenmore: “The high loop or air gap must be used to prevent potential backflow contamination of the dishwasher. Local plumbing codes generally dictate the requirements in your area. Section 807.4 of the Uniform Plumbing Code states: “No domestic dishwashing machine shall be directly connected to a drainage system or food waste disposer without the use of an approved dishwasher airgap fitting on the discharge side of the dishwashing machine. Listed airgaps shall be installed with the flood level (FL) marking at or above the flood level of the sink or drainboard, whichever is higher, or separately trapped with the airbreak located on the stand pipe.”

GE: “If an air gap is not required, the drain hose must have the high loop from the floor to prevent backflow of water into the dishwasher or water siphoning out during operation.”

Bosch: The high loop in the drain hose of your dishwasher is to keep water from settling in the hose if it were hanging down any lower or horizontally. This keeps the drain hose dried out and keeps any odors from backing up into the dishwasher.

Viking: In testing our dishwashers, we have found that the additional high loop in the back of the dishwasher is required for proper draining of the water. We have seen when this piece is not applied that over time the consumer will have issues with the water back up and causing issues with proper drainage and water pooling in a particular area."

"Had a real bad odour in my 1 year old Samsung dishwasher. Took apart the pump screan and found it to be clean of any food particles. I then checked under the door bottom on the inside!!!!! OMG! The amount of food residue that was trapped in there was ridiculous. What a stupid design. I cleaned this up with a solution of water,a touch of laundry soap and bleach. Armed with a small paint brush and a spray bottle full of my cleaning solution I got her done in no time. Ps,to those who think you need to wash your dishes prior to placing them in the dishwasher,get real. That is the dishwasher's job! You are simply wasting water. If you feel you need to do that then you either have a bad dishwasher,the wrong dishwasher soap or you don't know how to load a dishwasher properly!

Josh"

Strange as it may seem, that bottom door rubber thing may be the culprit. I followed Josh's suggestion and cleaned it. It was not very dirty (perhaps because my dishes are rinsed of all food before going into the machine) so I didn't think the little bit of grayish scum (like what's in the filter) that I wiped off could make much difference ... but it's been a couple weeks now, I've repeated the process once more, and the smell seems to be gone. I'll remember to do this whenever I wash the filter.

"Purchase a dishwasher cleaning solution and run through about every three months also rinse dishes off prior to placing into dishwasher and wash as soon as possible

Ianf"