Troubleshooting guide
Why Does My Dishwasher Smell Bad?
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- ✓ 45-day parts & labor warranty
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Quick answer
A smelly dishwasher almost always has food trapped in the filter, sump or door gasket, or dirty water flowing back in from the sink drain. Clean the filter, wipe the gasket and the bottom of the door, and run a hot cycle with a dishwasher cleaner. If it smells like sewage or keeps coming back, check that the drain hose has a high loop or air gap. A burning or electrical smell is different: turn the dishwasher off and get it checked.
Dishwashers are warm, wet and full of food scraps, so a smell builds up fast if anything is trapped. In a Florida kitchen that stays warm most of the year, bacteria grow even faster.
The type of smell tells you a lot. Musty or sour is old food and grease. Sewer or rotten egg usually means drain water is getting back in. Burning plastic or a hot electrical smell is a safety issue, not a cleaning issue.
Causes, from most to least likely
1.Dirty filter
The filter catches food so it doesn't recirculate. If it isn't cleaned, that food sits in warm water and rots between cycles. It's the most common source of dishwasher odor by a wide margin.
- Check it yourself
- Remove the bottom rack, twist out the filter and lift out the flat mesh. Scrub them with hot soapy water and a soft brush. Wipe out the sump area below.
- The fix
- Clean the filter every two to four weeks. If the smell doesn't go away, the sump or drain path may be partly clogged.
2.Grime in the door gasket and door bottom
The lower edge of the inner door and the gasket fold trap a surprising amount of food and grease. Spray arms don't reach them well.
- Check it yourself
- Open the door fully and look along the bottom edge and under the lip. Wipe with warm soapy water and an old toothbrush. Check the corners of the tub too.
- The fix
- No part needed unless the gasket is torn or moldy deep in the fold. A damaged gasket is replaced.
3.Drain water flowing back in
The drain hose should rise to a high loop under the counter, or pass through an air gap, before it connects to the disposal or drain. Without that, sink and disposal water can siphon or back up into the dishwasher. This causes the classic sewer smell.
- Check it yourself
- Look under the sink. Is the drain hose fastened up high under the counter? If it lies on the cabinet floor, it doesn't have a high loop. If you have an air gap on the sink deck, pull the cap off and clear any debris.
- The fix · typical $120 – $190
- Lifting and fastening the hose is often all it takes. If the hose itself is coated with sludge, it's cleared or replaced.
4.Standing water from a partial drain
If the dishwasher isn't draining fully, dirty water sits in the tub between cycles and goes stale. A stuck check valve can also let drained water slide back into the sump.
- Check it yourself
- Look in the tub after a cycle ends. A little water in the sump is normal on many models; water across the tub floor is not. Follow the steps in our dishwasher-not-draining guide.
- The fix · typical $170 – $290
- We clear the sump and drain path, and replace the drain pump or check valve if one has failed.
5.A dishwasher or sink that sat unused
Homes that sit empty for weeks — seasonal residents, vacation rentals between guests, homes waiting on a sale — come back to a stale dishwasher. Water left in the sump goes sour. The sink drain's trap can also dry out, letting sewer gas into the kitchen, which people blame on the dishwasher.
- Check it yourself
- Run hot water in the kitchen sink for a minute to refill the trap. Clean the filter, then run an empty hot cycle with a dishwasher cleaner. Before leaving for a long stretch, run a rinse and leave the door cracked open.
- The fix
- Usually no repair. If the sewer smell persists after the trap is refilled, have a plumber check the sink drain and vent.
6.Burning smell from the heater or wiring
A plastic lid or utensil that drops through the rack onto an exposed heating element melts and smells strongly. A failing wire connection at the junction box or a shorting part can also give off a hot electrical smell.
- Check it yourself
- With the dishwasher off and cool, look at the heating element for melted plastic. Don't remove panels or touch wiring.
- The fix · typical $170 – $290
- Melted plastic can sometimes be removed from a cool element. If the element is damaged, it's replaced. Burned wiring is repaired before the dishwasher is used again.
When to call a technician
Call us if the smell comes back after cleaning the filter and running a cleaner, if water is standing in the tub, or right away if you smell burning. We'll find where the odor starts, fix the drain path or part involved, quote you in writing before work begins and credit the $79 diagnostic to the repair.
45-day parts & labor warranty
Every repair carries a 45-day warranty on the parts we install and on our labor.
What the warranty covers →Common questions
Can I use bleach in my dishwasher?
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Not as a routine cleaner. Bleach can damage stainless tubs, seals and some plastics, and it should never be mixed with other cleaners. A dishwasher cleaner made for the job is a safer choice.
Does vinegar get rid of dishwasher smells?
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It can help with light odors and mineral film. Some manufacturers advise against frequent vinegar use because it may wear rubber seals over time, so check your manual. Cleaning the filter matters more than anything you add.
Why does my dishwasher smell like rotten eggs?
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Usually food decaying in the filter or sump, or drain water backing up from the sink. Clean the filter and check the drain hose for a high loop.
How do I keep my dishwasher from smelling while I'm away?
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Clean the filter, run an empty hot cycle, and leave the door cracked open so the tub dries out. When you come back, run hot water at the sink before using the dishwasher.
Is a burning smell from the dishwasher dangerous?
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It can be. Stop the cycle and turn off the breaker. If it's melted plastic on the heater, it's usually minor. If the smell came from the controls or under the dishwasher, have it inspected before using it again.
Related guides
Last reviewed 2026-10-07 by Mako Appliance Repair, Clearwater FL.
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