Dishwasher Smells Bad? How to Identify and Eliminate Odors Instantly

There are few things worse than opening your dishwasher after a cycle, expecting the fresh scent of steam and soap, only to be hit by a wave of rotting food, mildew, or even sewage. It defeats the purpose of the appliance. Instead of clean plates, you feel like you are sanitizing your kitchen with dirty water.

At Fair Appliance Repair, we know that when a dishwasher smells bad, it is rarely a mystery; it is biology. Bacteria, mold, and trapped food particles thrive in the warm, damp environment of a dishwasher. Whether you are detecting a musty odor, a rotten egg smell, or a burning scent, this guide will help you identify the root cause and show you exactly how to remove bad smell from dishwasher units permanently.

1. The "Sewage" Smell (Drain & Plumbing Issues)

A distinctive "rotten egg" or sulfur smell usually means sewer gas is backing up into your machine. This is the most alarming odor, but the fix is often plumbing-related rather than a machine failure.

Why it happens:

If the dishwasher smells like sewage, dirty water from your kitchen sink or garbage disposal is likely flowing backward into the dishwasher drain hose. This happens if the drain hose is lying flat on the cabinet floor instead of being elevated.

Where to look:

• The "High Loop": Check the drain hose under your sink. It must loop up higher than the drain pipe before connecting to the disposal. If it lacks this loop, sewer gas travels straight into the tub.

• The Air Gap: If you have a silver cylinder on your sink deck (the air gap), check it for blockages. A clogged air gap forces water back into the unit, causing a bad smell from sink when dishwasher starts.

• Standing Water: If you see a pool of gray water at the bottom of the tub, the drain pump may be failing, leading to dishwasher smells bad standing water issues.

The Fix:

• Secure the drain hose as high as possible under the counter using a zip tie or bracket.

• Clean the air gap by removing the chrome cover and unscrewing the plastic cap to remove debris.

• Run the garbage disposal for 30 seconds before starting the dishwasher to clear the path.

2. The "Rotten" Food Smell (Cleaning & Maintenance)

If your dishwasher smells like fish or rotting garbage, the culprit is almost always organic matter—trapped food that is decomposing inside the machine.

Why it happens:

Small bits of meat, pasta, and vegetables get washed off plates and settle in the "sump" (the pit at the bottom) or get caught in the mesh filter. Over time, this organic matter decomposes, releasing foul gases every time the unit heats up. This is the main reason why do my dishes smell bad after dishwasher cycles.

Where to look:

• The Filter Assembly: This is ground zero for a rotten food smell dishwasher complaint.

• Spray Arms: Food particles can get lodged inside the hollow spray arms, rotting from the inside out.

The Fix:

• Deep Clean the Filter: Twist and lift the cylindrical filter out. Wash it in the sink with hot water and dish soap. Technician Tip: Reach into the hole where the filter sits (the sump) and scoop out any slimy debris. We often find bones, glass, and corn kernels here.

• Flush Spray Arms: Remove the arms and shake them. If they rattle, use a toothpick to poke food particles in dishwasher smell sources out of the spray holes.

3. The "Moldy" or "Musty" Smell (Gasket & Moisture)

Sometimes a clean dishwasher smells bad because the source isn't food—it's mold. This is common in humid environments or if the door is always kept tightly closed.

Why it happens:

Mold loves the dark, damp folds of the rubber door seal. If you have a dishwasher smells bad inside that smells like a wet basement, you likely have mildew growing where the door meets the tub. This can even happen with a new dishwasher smells bad scenario if residual water from factory testing sat stagnant in the warehouse.

Where to look:

• The Door Gasket: Run your finger along the rubber seal. If it comes back with black residue, that is your source.

• The Detergent Dispenser: Old, caked-on detergent can grow mold if it stays damp.

The Fix:

• Scrub the Gasket: Dip a damp cloth in white vinegar and wipe the entire rubber seal. Pay special attention to the bottom edge where water collects to fix dishwasher smells bad even after cleaning the filter.

• Air It Out: Leave the dishwasher door slightly ajar between cycles to allow moisture to evaporate.

4. The "Burning" Smell (Technical & Wiring)

If the dishwasher smells bad when running—specifically a chemical or burning odor—this is a safety concern.

Why it happens:

• Melted Plastic: The most common cause is a plastic container or utensil that fell off the rack and landed on the heating element. When the dry cycle starts, the plastic melts and fumes.

• Wiring Issues: A bad smell when dishwasher runs that smells like burning rubber or ozone could indicate a failing motor or melting wire insulation.

The Fix:

• Check the Heater: Inspect the metal heating coil at the bottom of the tub. Scrape off any melted plastic once the element has cooled completely.

• Call a Pro: If there is no plastic but the burning smell persists, shut off power to the unit immediately. This requires professional diagnosis to prevent an electrical fire.

5. Immediate Fixes & General Solutions (The "How-To")

If you are wondering how to remove bad smell from dishwasher units quickly, stop buying expensive deodorizers that just mask the odor. You need to neutralize it chemically.

Method 1: The Vinegar Cycle

This is the gold standard for how to get rid of smell in dishwasher with vinegar.

• Place a bowl of white vinegar (2 cups) on the top rack of an empty dishwasher.

• Run a hot water cycle (do not add detergent).

• The acid breaks down grease and neutralizes odors in the pump and hoses.

Method 2: The Baking Soda Scrub

If you want to know how to eliminate bad smell in dishwasher interiors that are stained:

• After the vinegar cycle, sprinkle a cup of baking soda across the bottom of the tub.

• Run a short hot cycle.

• The baking soda acts as a gentle abrasive to scrub away residue and freshen the steel.

Method 3: Commercial Cleaners

For those asking how to remove bad smell from dishwasher without vinegar, use a commercial cleaner like Affresh or Finish. These tablets use heavy-duty enzymes to break down biofilm inside the pump that vinegar might miss.

Preventing Future Smells

• Scrape, Don't Rinse: Remove solid food, but leave the sauce. Modern detergents need some grease to work, but solid chunks just rot in the filter.

• Hot Water Connection: Ensure your dishwasher is connected to the hot water line and that the water enters at 120°F. Cold water leaves grease behind, which turns rancid.

• Regular Maintenance: Run a cleaning cycle once a month to stop dishwasher from smelling bad permanently.

Frequently Asked Question: Common Questions About Dishwasher Odors

How do you get rid of bad smell in dishwasher immediately?

The fastest way to get rid of bad smell in dishwasher units is to check the drain filter for rotting food. Remove the debris, then place a bowl of white vinegar on the top rack and run the hottest cycle available to neutralize the odor.

Why does my dishwasher smell so bad like sewage?

A sewage smell indicates a drain issue. Either your garbage disposal is full of rotting food that is backing up into the dishwasher, or the drain hose is installed incorrectly without a "high loop," allowing sewer gases to travel back up the pipe.

What to do if dishwasher smells bad when drying?

If the dishwasher smells bad when drying, the heating element is likely baking dirty residue onto the bottom of the tub. Deep clean the interior floor of the dishwasher and use a Rinse Aid to prevent dirty water from clinging to surfaces during the heat cycle.

Why does my dishwasher smell bad when running?

If the odor appears specifically when running, it is often agitated water releasing gas from the drain, or a burning smell from a failing motor or melted plastic on the heating element. If it smells like burning electronics, shut the power off immediately.

Can a bad smell dishwasher make me sick?

Technically, yes. The smell is caused by bacteria (like Salmonella) and mold spores. While the heat of the drying cycle kills many pathogens, breathing in mold spores every time you open the door can be unhealthy for those with allergies