Why does my dishwasher smell like rotten eggs even after I clean it?

You probably cleaned the visible parts but missed the sump well under the filter, the spray arm holes, or the drain hose. Biofilm also clings to the door gasket where most people never wipe. Pull the filter, clear the sump by hand, run a hot vinegar cycle, then a baking soda cycle. If it still smells, check the garbage disposal and the drain hose's high loop.

Is a sewage smell from my dishwasher dangerous?

The odor itself in small amounts is unpleasant but not a medical emergency. What matters is the source. A true sewage smell can mean sewer gas is entering through a low drain hose or a dry P-trap, which points to a plumbing or venting problem. If you smell it at several drains or it worsens after rain, get a plumber to inspect the drain and vent before treating the appliance.

How do I keep the smell from coming back?

Clean the filter every couple of weeks, run a hot vinegar cycle monthly, crack the door open after each load so the tub dries, scrape food instead of pre-rinsing dishes spotless, and keep your garbage disposal clean if the dishwasher drains through it. Those habits handle nearly all return odor.

Dishwasher Smells Like Rotten Eggs or Sewage: Causes and Permanent Fixes

Food & Kitchen · By Odor Removal Experts · Updated June 2026 · Cleveland and Northeast Ohio

If your dishwasher smells like rotten eggs every time you open the door, that sulfur stink is almost always rotting food and bacteria trapped somewhere the water doesn't reach. We get these calls weekly across Cleveland and Northeast Ohio, and the good news is most of them get fixed the same day. The bad news is people usually attack the wrong spot first, so the smell keeps coming back.

Let me walk you through what's actually causing it, what to check in order, and where the line is between a quick DIY clean and a job worth handing off.

The short answer

A dishwasher that smells like rotten eggs is almost always food and bacteria trapped where the water never flushes: the filter, the sump, the spray arms, and the door gasket. Clean those, run a hot vinegar cycle followed by baking soda, and check the drain hose high loop. A true sewage smell usually points downstream to plumbing.

Rotten-egg smell is bacteria feeding on trapped food residue.
Clean the filter, sump, spray arms, and door gasket first.
A true sewage smell often points to a plumbing or venting issue.
Run a hot vinegar cycle, then baking soda, to clear biofilm.

Why your dishwasher smells like rotten eggs

That eggy, sulfur odor is hydrogen sulfide gas. It comes from bacteria feeding on food residue and grease in a warm, wet, dark box that sits closed most of the day. Perfect breeding conditions. On most jobs we find the source isn't the racks or the door you can see, it's the spots water never flushes.

The usual culprits, in the order we check them: the filter at the bottom of the tub, the spray arms, the sump and the small area under the filter basket, the drain hose, the rubber door gasket, and the air gap or garbage disposal connection. Food sludge builds up in any of these and goes anaerobic, which is when the sulfur smell really kicks in.

Clogged filter packed with grease and food bits (the spot people miss most)
Spray arm holes blocked, so the tub never rinses fully
Standing water in the sump from a partial drain clog
Biofilm on the door gasket and along the bottom lip
Low-flow or eco cycles that don't use enough hot water to clear residue

Dishwasher sewage smell cause: when it's the drain, not the dishwasher

Here's where the diagnosis splits. A rotten-egg smell is usually food and bacteria inside the unit. A true sewage smell, that septic, backed-up-drain odor, often means the problem is downstream. This is the dishwasher sewage smell cause people miss because they keep scrubbing the appliance. Check three things:

The drain hose: it should loop up high under the counter (a high loop) or connect through an air gap. If that hose runs flat or sags low, dirty water and sewer gas can flow backward into the tub.
The garbage disposal: if your dishwasher drains through the disposal and the disposal is gunky, that smell migrates straight over. Run and clean the disposal, then smell again.
Your P-trap: if a nearby sink trap has dried out or the drain is partially blocked, sewer gas comes up through the shared line.

Sewage at more than one drain?

If you smell sewage at multiple drains in the house, or it's worse after heavy rain, that's a plumbing or venting issue. No appliance cleaning will touch it. Call a plumber before you call anyone about odor.

The fix that actually lasts

A quick wipe-down covers the smell for a day. To kill it for good you have to remove the food source and the biofilm, not paper over it. Here's the sequence we use, and it works on a standard residential unit. Note that we lean on green, non-toxic cleaners like white vinegar and baking soda here, never ozone or chlorine gas, so the kitchen stays safe for kids, pets, and electronics.

Clean the filter. Pull the bottom rack and twist out the filter. Wash it in hot soapy water and a soft brush. Most have a fine mesh and a coarse cup, do both.
Clear the sump by hand. Reach into the sump (the well under the filter) and clear any sludge or debris by hand. Wear a glove.
Unclog the spray arms. Pop off the spray arms if they lift out, and poke a toothpick through clogged holes, then rinse.
Wipe the gasket. Wipe the door gasket and the bottom lip of the door with a 50/50 white vinegar solution. This is where biofilm hides.
Run vinegar, then baking soda. Run an empty hot cycle with two cups of white vinegar in a bowl on the top rack. Follow it with a cup of baking soda sprinkled on the floor of the tub and another short hot cycle.
Check the drain path. Check the drain hose for a high loop and clean the garbage disposal and air gap.

Dishwasher musty smell fix vs. rotten egg smell

Worth separating these, because the dishwasher musty smell fix is a bit different. Musty and mildewy means mildew growth, usually on the gasket, in the detergent dispenser, or in trapped water after a cycle. The egg smell means active bacteria and food. For musty, focus on drying: crack the door open after each run so the tub airs out, scrub the gasket with vinegar, and clean the detergent cup.

One thing we tell every customer: stop pre-rinsing dishes spotless. Sounds backward, but modern detergents need some food residue to work against, and bone-dry loads sometimes mean the unit runs less aggressively and leaves film. Scrape, don't rinse to a shine.

When to call a pro

DIY handles the great majority of dishwasher odor. Call a professional when the smell survives a full filter clean and two hot vinegar cycles, when you smell sewage at more than one fixture, or when the odor has soaked into the surrounding cabinetry and kitchen air.

That last one is our lane. When a dishwasher has stunk for months, the smell migrates into cabinet wood, drywall, and soft surfaces, and cleaning the appliance alone won't clear the room. We find and remove the source first, then handle the airborne and absorbed odor with HEPA and activated-carbon air scrubbing, enzymatic and oxidizing treatments on porous surfaces, thermal fogging where it helps, and a hydroxyl generator that is safe to run while your kitchen stays in use. We seal anything that needs it. Everything we use is green and non-toxic, never ozone or chlorine, and we never just mask the smell. Most kitchen odor jobs are done in 1-4 hours, same or next day, and backed by our 100% guarantee. We serve Greater Cleveland and Northeast Ohio with fully insured, discreet techs.