Dishwashers are among the most practical large appliances found in modern kitchens. According to the U.S. Energy Information Administration (EIA), over 80 million American homes have a dishwasher, and over 54% of homeowners use the appliance at least once per week. While dishwashers help homeowners save time and manual labor, these appliances can also emit foul odors that can alter the atmosphere of your kitchen. Although it’s easy to tell when something smells bad, it’s often harder to pinpoint the exact source. A look at the top causes of dishwasher odors can provide guidance for choosing the best way to address these unpleasant smells.
Why Does Your Dishwasher Smell?
There are several reasons your dishwasher may smell. Common reasons include clogged filters, food residue, hard water, unit damage, or an aging appliance. Each source can result in a different smell that ranges in severity.
Clogged Filter
Most dishwashers have a filter that helps trap food scraps. By trapping food particles, the filter helps prevent loose debris from circulating throughout the unit and redepositing on clean dishes. If the filter becomes clogged with old food residue, however, the entire unit can start to stink. While some dishwashers have self-cleaning cycles to tackle the filter, others require you to remove and clean the filter at least once per month. Consult with a plumbing professional if you’re unsure about the type of model you have or if you suspect the obstruction may have resulted from something more serious like broken dishes or glass.
Trapped Melting Plastic
A burning smell is often a sign of melting plastic. For example, a plastic utensil or piece of non-dishwasher-safe cutlery can start to melt if it comes in contact with the appliance’s heating element. In more serious instances, problems with the dishwasher’s wiring can cause the plastic casing to melt and emit a burning odor as it disintegrates. Since wiring problems can constitute a safety hazard, be sure to turn off the unit and contact a professional for repairs.
Greasy Residue
If you never clean or sanitize your dishwasher, the interior can become coated with greasy residue and soap scum. This residue can coat the walls as well as components like the spray nozzles or utensil baskets. The accumulation of buildup often produces a rancid odor. Since this residue can trap and harbor bacteria, experts recommend pre-rinsing dishes and using a dishwasher cleaning cycle to reduce the occurrence of greasy buildup.
Clogged Drain
If your dishwasher is connected to kitchen sink pipes, the gray wastewater usually exits the dishwasher through the garbage disposal before draining outside. While this system is highly efficient, it also means that any clog or obstruction near the drain can result in bad smells. These odors are often similar to sewage and can emanate from your wall plumbing. This interior plumbing issue is a job for professionals. A plumber can identify potential clogs within your garbage disposal or wall plumbing and can provide suggestions to help prevent recurrence.
Hard Water
Hard water contains a high concentration of minerals, like calcium carbonate or magnesium carbonate. The consistent flow of hard water through your dishwasher can leave behind mineral deposits that result in limescale buildup. Excessive limescale can give your dishwasher a metallic or sulfuric odor. The limescale can also clog functional components within the unit. In the worst instances, it can result in corrosion. Since mineral deposits are hard to remove with store-bought dishwasher cleaners, solving the issue may require professional descaling to eliminate the odor and improve the performance of your unit. A plumber may also install a water softener to reduce the concentration of carbonates within your pipe water.
Mold or Mildew
Mold thrives in damp and dark environments. If there is trapped water or improper drainage in the hard-to-reach areas of your dishwasher, the appliance may become the perfect breeding ground for mold spores. Similar biological contaminants like mildew, algae, or other fungi can grow in areas like the door gasket or drain tubes. Mold tends to produce a musty or earthy odor, and mold spores can cause health problems or exacerbate respiratory issues. The last thing anyone wants is for mold to contaminate freshly washed dishes. A plumber can inspect your dishwasher for mold and conduct repairs if there are culprits like drainage issues.
Leaking Unit
If there are no obvious problems but you notice persistent or sour smells coming from your dishwasher, a hidden leak might be to blame. Leaking dishwasher elements can seep beneath your appliance and result in bacteria growth. In the worst-case scenarios, these leaks can rot the wooden flooring beneath the unit. Many homeowners may not realize there is a leak until they notice dampness on nearby cabinets or beneath the sink. Reach out to a professional about sour or rotting odors to rule out plumbing leaks.
Damaged Hose
Damaged hoses, sprayers, or nozzles can also cause unpleasant dishwasher smells. Without a functional hose, your dishwasher will be unable to remove odor-causing food waste or debris from pots and dinnerware. This under-performance means that the organic waste can remain trapped within the appliance and eventually start to stink. Plumbers can repair or replace damaged hoses so that your unit performs as intended.
Poor Initial Installation
Bad dishwasher smells can also result from poor initial installation. The most common installation errors include misalignment or loose connections among drain hoses. These errors can cause dirty dishwater to flow backward into your appliance and emit unhygienic odors. If your dishwasher is pretty new but you notice a bad stench and gray water pooling at the bottom of the unit, poor installation is typically the culprit. An expert plumber may be able to correct installation problems.
Aging Dishwasher
Although dishwashers are reliable, all major appliances have a finite lifespan. If your dishwasher is over 10 years old and constantly smells, it may simply be time to pick out a new unit. Older dishwashers gradually become less efficient and can emit stronger odors while completing each cleaning cycle. Upgrading to a new dishwasher can restore efficiency, improve the ambiance of your kitchen, and may even help you save money. For example, the Department of Energy reports that a standard-sized ENERGY STAR-certified dishwasher costs only around $50 per year to operate and can save between 3,870-5,800 gallons of water over the course of its lifetime.
What Can You Do About Dishwasher Smells?
Experts recommend smart practices when using your dishwasher. Try to pre-rinse dishes before loading them into the appliance, and remember to routinely use the cleaning cycle if it is available on your model. You should also practice good plumbing habits in general. For example, dishwasher inspections are often included in annual plumbing inspections or maintenance. Plumbers can check for any defective components or leaks and fix these issues as needed. A professional plumber is also best equipped to handle serious repairs, like problems with the drain line or mold removal. In addition, a plumber can also install water-efficient or ENERGY STAR models that help save money on utility bills.
How We Can Help
Foul dishwasher odors can turn your kitchen’s time-saving appliance into a smelly and unhygienic nightmare. But if you are struggling with bad dishwasher smells, there’s no need to panic. The experts are here to help. Pilgrim Plumbing, Inc. offers dishwasher services for homes in Norwell, MA and the surrounding areas. We offer inspection and troubleshooting of this major kitchen appliance and can conduct repairs as needed.
Our plumbers can also install new dishwashing units and help you upgrade to energy-efficient models to benefit the whole household. In addition to dishwashers and kitchen plumbing, we also work with boilers and gas lines. Our plumbers can service your existing water heater or help you upgrade to an efficient tankless water heater. We can address water quality issues and can even help you customize a plan for kitchen remodeling. No matter the issue, we can help. Contact Pilgrim Plumbing, Inc. today for all plumbing needs.
