It may sometimes irritate you to open a bad dishwasher and smell something awful while its interior looks perfectly clean. It goes without saying that despite the fact that the interior of the dishwasher is perfectly clean, even when the tub appears spotless, leftover food particles, grease, and dirty water stay hidden in areas the spray arms never reach.
A regular wash cycle will never clear the filter, clean the drain sump, unfold the door gasket, or unblock the drain hose. Therefore, if your dishwasher smells bad after running its cycles, then you should inspect its hidden elements.
Why Does My Dishwasher Smell Bad Even After Cleaning?
Nevertheless, normal cleaning cannot ensure that all dirty spots are cleansed. The mesh filter, for example, is placed apart from the water flow; hence, decaying food pieces make the dishwasher smell bad.
Food particles get into the drain filter area, so they cannot be washed off during the rinsing process with water.
Also, poor drainage will result in the formation of stagnant water, which provides a good environment for the bacteria responsible for emitting bad odors. Besides, the drain hose has a column of dirty water even without any residue being left behind in the bathtub.
Moreover, the rubber door seal retains some food and moisture in its crevices, out of reach of the water flow. Clogged spray arm holes circulate dirty water over the dishes again. Finally, external factors, such as a clogged garbage disposal, may cause the odors to get into the dishwasher.
8 Reasons Your Dishwasher Smells Bad
Here are the most common reasons behind your persistent dishwasher issues:
1. Dirty or Clogged Dishwasher Filter
A blocked filter will be the main reason for a bad smell in your dishwasher. Food particles will be captured in the mesh of the filter after each wash to keep the pipes from getting clogged.
Nevertheless, improper cleaning of the filter causes the odor in your dishwasher to become even stronger. The filter will usually be located under the lower spray arm. Please check our useful dishwasher cleaning tips for your dishwasher.
2. Food and Grease Trapped in the Drain or Sump
However, if the odor coming from your dishwasher remains after cleaning the filter, you should examine the area of the sump further. Food particles make their way through the filter and into the bottom of the dishwasher.
As a consequence, over time, grease will accumulate in the basin where bacteria that cause odors will remain trapped. Cleaning the surface does not help reach this part of the dishwasher, and thus, food smells reappear after 24 to 48 hours.
- How to diagnose it: Remove the filter assembly and inspect the inner chamber. Dirty water or sludge indicates trapped debris inside the sump.
- Will cleaning the filter fix it? Not always. Persistent odors usually mean debris sits deep in the drain sump rather than the filter screen.
3. Standing Water at the Bottom of the Dishwasher
All it takes is a few drops of water in the drain cup to ensure that the seals are moist. It, however, is unnatural to have water everywhere on the bottom surface of the tub.
Since water is the most conducive breeding ground for bacteria, any bad smell in your dishwasher will pose an even bigger threat. Bacteria thrive in warm and confined places.
4. Dirty Door Gasket or Seal
These flexible door gaskets seal food particles in deep crevices of rubber, through which water cannot reach. Consequently, moisture, along with poor air circulation, leads to the formation of mold.
The mold creates the typical musty odor in the dishwasher, not that of decaying food. Dark spots and mold can be observed in the rubber folds. Preventing this from happening is easy by following these dishwasher door gasket cleaning tips.
5. Clogged Spray Arms
Food bits, hard water minerals, and paper labels often clog spray arm nozzles. Because of these blockages, water pressure drops and impairs overall cleaning performance.
Unwashed food residues then bake onto plates and collect inside the machine. To check this, remove the spray arms and hold them up to a light source to inspect the holes.
6. Drain Hose, Air Gap, or Garbage Disposal Problem
Most odors from sewage indicate that there is something wrong with the drain line, not inside.
As a case in point, a low drain hose with no high loop makes it easy for the water to come back into the bathtub. An air gap stops any siphoning, yet debris buildup may prevent it. In the same way, a clogged garbage disposal connection causes backups, hence a smelly dishwasher.
- High Loop: Position the hose above the height of the sink drain pipe before connecting the hose to the garbage disposal or drain pipe.
- Testing: Look beneath the sink to see whether there is an arch-shaped flexible hose before the drain pipe connection.
- Does a clean tub stink of sewage? Yes. Plumbing problems will let sewer gas into the device despite the tub being clean.
7. Mold, Mildew, or Bacteria Buildup
The growth of molds is stimulated by heat, moisture, and organic material. More specifically, molds tend to grow in cracks within gaskets, door crevices, low shelves, and drains.
- Musty odor: Indicates that there is mold/mildew caused by the presence of moisture.
- Wet odor: Indicates that there is biofilm, which is bacterial slime created due to water.
A closed door right after the heat cycle means that there will be trapped moisture inside. Therefore, it is essential to leave the door partially open for one hour after every cycle.
8. Dishwasher Isn’t Draining Properly
An incomplete drain cycle leaves dirty water behind to breed bacteria. This stagnant water creates repeating smell cycles with every load.
A failing drain pump leaves dirty water behind without always forming an obvious pool. Consequently, you will notice the dishwasher smells bad within hours of running a wash.
What Does Your Dishwasher Smell Mean?
Knowing the particular smell helps in finding the root cause faster:
Dishwasher Smells Like Rotten Eggs
- Decaying matter from food caught in the filter or sump
- Bacteria producing sulfur in the still water
- Gas from sewers backing up through the drain line
Dishwasher Smells Like Sewage
- Incorrect drain hose routing without a high loop
- Clogged or missing countertop air gap
- Back-siphoning from a blocked garbage disposal
Dishwasher Smells Like Wet Dog
- Biofilm coating on interior walls and under the tub
- Saturated food debris sitting inside an uncleaned filter
- Stagnant water residing inside the lower sump cavity
Dishwasher Smells Musty
- Mold growing inside rubber door gasket folds
- Trapped humidity from closing the door immediately after hot cycles
- Hidden mildew growth along the unwashed bottom door ledge
Dishwasher Smells Burnt or Like Plastic
- Melted Plastic: A plastic item fell onto the heating element.
- Component Malfunction: The heating element is overheating.
- Electrical Burning: Damaged wiring or a failing control board.
Warning: A strong burning odor indicates a possible fire risk. Consequently, you should discontinue use of the machine, switch off the circuit breaker, and contact a technician.
How to Get Rid of a Bad Smell From Your Dishwasher
Follow these actionable dishwasher cleaning tips in order to clear persistent odors:
- Filter Cleaning: Remove, disassemble, and wash the entire filter assembly using warm water and a soft brush.
- Sump Cleaning: This task requires examining the chamber below the filter, wiping off any seeds, grease, and excess water collected there using a paper towel.
- Rubber Seal Cleaning: Use a damp cloth with detergent to clean the rubber seal folds and the bottom portion of the door.
- Nozzle Cleaning: Unfold the spray arms and clear the clogged nozzles using a toothpick or wire.
- Standing Water Check: Do a short cycle and check the drain point to identify any standing water problem.
- Drain Pipe Connection Check: Ensure that the drain hose located under the sink is arranged in such a way as to form a high arch before being attached to the drain pipe.
- Dishwasher Clean-Up: Lastly, do a hot cycle using the appropriate dishwasher cleaning tablets.
Why Does My Dishwasher Smell Again After Cleaning?
If a bad smell from dishwashing cycles resurfaces after a cleaning effort, it may be a sign that you have only treated the symptom rather than the actual source of the problem:
- Decomposed food waste is lodged in the filter assembly.
- Food sludge is present deep in the sump basin beneath the filter screen.
- Dirty water pools in the drain hose and recirculates at the start of a cycle.
- A malfunctioning drain pump results in stale wash water.
- Back-pressure in the garbage disposal causes wastewater to enter the tub.
- Food particles are concealed deep in the rubber door seals.
- Inappropriate plumbing connections result in sewer gas circumventing the P-trap.
In the event of a re-emergent bad smell in the dishwasher within 24 to 48 hours, consider sources other than the visible parts of the tub.
Dishwasher Cleaning Mistakes That Cause Odors
- Wiping Only Surface Areas: Disregarding folds in the gasket, bottom of the door, and filter assembly.
- Disregarding the Filter: Failure to clean the filter frequently is the most common reason for a bad smell from your dishwasher.
- Neglecting Food Scraping: Large chunks of food build up rapidly in the sump and get stuck on the filter screen.
- Closing the Door Too Soon: This traps the steam inside and causes the formation of mold and biofilm.
- Neglecting the Standing Water: Believing that the water will dry off by itself.
- Loading Dishwasher Racks Too Much: Obstructing spray arms leads to poor water flow and leaves food behind.
- Starting New Cycles in Dirty Water: Performing new cycles while leaving the dirty water inside.
- Using Strong Chemicals: Strong chemicals damage rubber seals and create places for bacteria to grow.
When Should You Call a Repair Technician?
Many dishwasher odor problems are caused by mechanical issues rather than by the machine being dirty. Contact a technician in case you have any of these:
- The bad smell comes back shortly after a deep manual cleaning.
- Standing water remains in the tub after a full cycle completes.
- Sluggish or no draining occurs.
- Sewage odors persist after confirming proper high loop setups.
- Grinding or clicking noises come from the drain pump.
- Water leakage from under the cabinet or near the door gasket.
- Dishes are still dirty even when the spray arms work well.
- Your dishwasher stops the cycles randomly.
- You have burning or electrical smells while using the appliance.
Conclusion: Get Professional Dishwasher Service
While a badly smelling dishwasher can be solved simply by manual scrubbing because of surface dirt, some deeper dishwasher odors may need an inspection of the hidden parts of the machine.
Dishwasher cleaning tip recommendations state that cleaning your dishwasher’s filter, drain sump, door seals, and ensuring proper function of the drain hose high loop would get rid of virtually all the smells. However, if a very strong smell from the dishwasher occurs within 24 to 48 hours after the above-mentioned procedure, you can be sure that there is something wrong with your drain pump or drain line.
Do not ruin the air in your kitchen with the presence of stinky water and sewer gases because of your bad-smelling dishwasher. Call our professionals from Appliance Care of Atlanta and get your problem sorted out!
Our professionals can offer you fast and reliable services for repairing your dishwasher, which include diagnosis of drainage issues and repair of drain pump problems, among others. You can learn more about our dishwasher repair services.
Frequently Asked Questions
Why does my dishwasher smell bad even after cleaning?
If your dishwasher smells bad after washing following its cleaning cycle, it’s highly possible that surface cleaning was not enough to remove any food residues trapped in the filter, sludge in the sump, mold in the gasket folds, or dirty water in the drain hose.
What is causing the unpleasant smell in my dishwasher, a sulphuric smell similar to that of rotten eggs or sewage?
Without an air gap in the drain hose, the air gap and the garbage disposal pipe get blocked, resulting in sewer gas entering the dishwasher.
Why does my dishwasher smell worse after running a cycle?
Since there is already heat in the water and steam, they raise the temperatures of the food debris, greasy material, and bacteria in the filters and drainage lines, which makes your dishwasher odor worse.
How do I get rid of a bad smell from my dishwasher?
For a smelly dishwasher, clean the filter, the sump basin, the folds of the door seal, the spray arm nozzles, and follow the dishwasher cleaning tips we provide.
When should I call a technician for a dishwasher smell?
If you smell bad odors during the dishwashing cycles, have standing water after the cycles, hear any noise coming from the drain pump, or smell a burning electrical odor, please contact a technician. This service is available at Appliance Care of Atlanta.
