Why does my dishwasher smell like sewage?

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In our last guide, we looked at how to fix a dishwasher that smells when running. Today, I will be answering this common dishwasher question: Why does my dishwasher smell like sewage?

In addition to the possible causes, I will also tell you how you can clean your dishwasher to get rid of the smell.

Table of Contents

Why does my dishwasher smell like sewage (and how to get rid of the smell)

Several possible reasons might cause your dishwasher to smell like sewage.

But since each of these has its own troubleshooting and cleaning steps, we’re going to look at them individually.

The filters might be dirty

Dirty filters are among one of the most common causes for your dishwasher to smell like sewer.

Here’s the thing: As these filters fill with food particles, they become breeding grounds for bacteria.

Over time, these bacteria might result in the production of the foul garbage smell coming from your dishwasher.

Here’s an interesting fact: When the filters are dirty, they might also result in the dishwasher recirculating dirty water which might cause your dishwasher not to clean properly.

How you can fix the problem

The best way to fix this problem is by regularly cleaning the filters. If possible, clean them after every couple of washes.

Usually, you will find the filters at the bottom of the wash tub.

To remove the filters, gently rotate them counterclockwise and pull them out.

Next, clean them with warm soapy water and use a soft sponge to scrub any troublesome food residues.

Quick tip: In some dishwasher models such as GE dishwashers, take care not to clean the filters using a brush or scouring pad to avoid damaging them.

The garbage disposal might be dirty

If you are not regularly cleaning the garbage disposer, food particles might accrue inside it.

And with time, as the food particles continue to accumulate, they will start to give off a garbage-like smell.

Fortunately, you can quickly pinpoint if the garbage disposal is the cause of the problem…

If it’s the cause of your dishwasher smelling like sewage, you will notice the smell coming from the disposer after you remove the hose connecting it to the dishwasher.

There might be food particles buildup inside the dishwasher

Just like with your shower, your dishwasher is prone to building up a layer of scum over time.

Here’s where it gets interesting: This soap scum acts as glue and traps food particles to the dishwasher walls.

If you do not regularly clean your dishwasher, this food particles buildup might act as a breeding ground for bacteria and other microorganisms.

And over time, this might start giving off the foul sewer smell coming from your dishwasher.

What you can do to fix the problem – how to remove bad smell from dishwasher

To fix this problem, all you need to do is wash your dishwasher using white vinegar…

Start by pouring two cups of white vinegar into a dishwasher-safe bowl and place it on the bottom rack of the dishwasher.

Quick tip: Make sure that the dishwasher is empty and do not add any detergent.

Next, run the dishwasher on a normal cycle.

Something else: Instead of choosing the heat dry option, opt for the air dry option.

The air gap might be clogged

As a result, it will not work properly in preventing the backflow of waste water.

And, this might result in the foul sewage smell flowing back from the sewer line and coming out through the air gap or dishwasher.

Having that in mind, the best way to troubleshoot and fix this problem is by unscrewing the air gap’s head and cleaning any food debris that might be caught in there.

The high rise loop might be loose or not properly installed

If your dishwasher does not have an air gap it will need a high loop to prevent the backflow of waste water.

Quick tip: A wrongly installed high loop drain hose is one of the most common reasons for brand new dishwashers smelling like rotten eggs.

In most dishwasher models, the high loop should have a minimum height of 32” as shown:

What happens is that when the high loop is loose or below 32” in height, it will allow water from the sewer system to flow back into your dishwasher.

And, this might be what is causing that foul sewer smell coming from the dishwasher.

With that in mind, be sure to confirm that the high loop is properly installed.

Additionally, make sure that it is properly held in place with a drain hose hanger or zip tie.

Why does my brand-new dishwasher smell like rotten eggs?

If your brand-new dishwasher smells like rotten eggs, chances are that you have not properly installed the drain hose loop.

And, this might result in a backflow of waste water from the sewer line – the waste water is the cause of the rotten eggs smell.

With that in mind, be sure to confirm that you’re adhering to the minimum and max drain hose loop height installation instructions – they are found in the installation guide that came with your dishwasher.