Why Your Drain Smells Like Sewage When You Run The Dishwasher And How To Fix It

You've just finished scrubbing down your kitchen, the counters are spotless, the sink is gleaming, and every dish is neatly loaded into the dishwasher. You step back to admire your hard work — and then you catch a nasty sewage smell coming from the running dishwasher. It doesn't make sense, right? Everything looks clean, but the stench tells a different story. In many cases, the smell is a sign that drainage water isn't being removed properly. If you're only focused on sparkling dishes and not the appliance itself, you might be making some of the common mistakes that are causing your dishwasher to clog. The smell could also be caused by a clogged drain or filter, and fixing it means giving your dishwasher a thorough clean-out.

Over time, those little oversights can turn into a big, smelly problem. But getting rid of the odor doesn't have to be complicated. Once you know what to look for and follow the easiest ways to clean your dishwasher, the stink disappears, and your kitchen actually smells as fresh as it looks. 

Most of the time, that nasty smell is coming from the dirty water stuck inside your dishwasher. The usual culprits are a clogged drain hose, drain, or filter. When food particles get trapped in the filter, the water can't drain properly, and after sitting there for a while, it starts to smell. Another big reason for that sewage smell is a missing or faulty air gap in the drain hose. Without it, dirty water can actually flow back into your dishwasher. And the worst mistake you can make with a dishwasher is thinking that only old appliances have this issue. Even brand-new installs can stink if the hose is damaged, installed incorrectly, or not leveled.

Sometimes, the problem isn't the drainage; instead, it's your plumbing. If your sink and dishwasher share a drain (or your dishwasher connects to the garbage disposal), a blockage there can send that awful smell right into your kitchen. And in rare cases, the smell comes from your main water supply line. If contaminated water is flowing back into your dishwasher, the best move is to shut off your water supply until it's fixed.

First off, you need to tackle the source of the smell. Most often, it's hiding in your drain or filter. If your filter's blocked, pull it out and brush off the food particles. Once it looks clear, dip it in warm soapy water. Next, check your drain. Food scraps and greasy buildup love to hide there, and don't forget the crevices either. Even dishwashers with "self-cleaning" filters can collect gunk, so it's worth a peek. Once the filter and drain are sparkling, it's time to check the drain hose. But before doing that, drain out any standing water from your dishwasher. 

Then, place a container under the hose (to catch any unpleasant surprises). Remove the hose and use a drain snake to clear out whatever's left inside. When you've put everything back together, run an empty cycle to make sure it's draining properly and the smell is gone. Some cleaning experts suggest a two-step deodorizing trick. For that, run a hot cycle with a bowl of white vinegar in the dishwasher. After that, add some baking soda at the bottom of the dishwasher for a while.