Why is my two month old dishwasher exuding a terrible smell?

Question

In July I purchased a new Whirlpool Gold Series dishwasher model WDF750SAYW1. The machine has done a great job cleaning dishes, but it recently has begun to emit a terrible smell. The odor is not that of plates waiting to be washed. The smell is more akin to that of rotting garbage. I have cleaned out the upper and lower filter assembly though neither had any trapped food. As expected there was a small amount of standing water underneath the filters.

After running the dishwasher the smell is gone. We run the dishwasher a minimum of four times a week. For seven years we never had a problem with the previous dishwasher (its control panel died necessitating the need for the replacement).

Here are some pictures of the hookup:

What should I be doing to fix this terrible odor? Is this a plumbing issue or something wrong with the machine?

Answer 1

Modern water saving appliances seem to be prone to this. Usually using proper detergent keeps this in check. Since the smell goes away after a wash, it sounds like you are doing this. You might try a different detergent anyway. It may also be a plumbing issue if standing water is consistently left at the end of the cycle.

Unless you're on a septic tank, start a empty wash cycle and let it fill with water. As soon as the water starts circulating, add 1 cup of household liquid bleach. Use 1 pint white vinegar if on a septic tank. Close the door and let the water circulate for 10 seconds, then stop the cycle and let it sit for 1 hour. Restart and finish the cycle.

Clean the filter and screen with hot soapy water. This should get rid of the smell, but it will eventually return.

Clean the filter and screen on a regular basis, perhaps weekly. When the smell returns, redo the bleach treatment.

Answer 2

Maybe there is a dishwasher defect or installation problem which causes some discharge to leak onto the floor or inside the dishwasher: When the accumulated debris is freshly leaked upon, the odor is diluted. But once it dries somewhat it resumes rotting.

Look carefully at the drain hose to the garbage disposal, its drain, trap, and associated plumbing. Feel for any moisture under the sink where the water and drain connections are. If installed properly, there should be absolutely no moisture under the sink nor under or near the dishwasher.

If you can't find a problem under the sink, turn off the d/w circuit breaker, remove the access panel at the bottom of the dishwasher, shine a bright light under there, and feel around. It should also be perfectly dry.

Answer 3

Assuming (as with most) the dishwasher is connected to your kitchen sink drain, I suspect that you're smelling what the inside of your kitchen sink pipe smells like, which is a combination of rotting food and soap residues. It's a distinct smell from sewage, more like a sour/pungent smell than sewage.

If it is a sour/pungent smell, I would check whether the dishwasher drain hose is run properly. It should curve all the way up to the height of the counter (as close to top of sink as possible) before running down to connect to the sink drain. If it does not, you may be back-flowing into the dishwasher or allowing the smell to escape once the water inside the dishwasher evaporates.

If it is a sewage (think driving near a sewage plant) smell, verify that your dishwasher drain hose is connected before the P-trap (as suggested by @Edwin), rather than after, as it again may be allowing the sewer gas to escape once the water has evaporated.

Answer 4

I have the same problem with my brand new Whirlpool dishwasher and I think it has to do with the dirty water not draining all the way because when I take that filter out there is water down in there and the filter has that sour/ dirty smell to it. I have just called Whirlpool for a technician to come out since it's still under warranty. Now, I hope they can resolve it. I can't stand bending over the dishwasher and smelling that smell every time I go to load the dishwasher. It takes your breath away.