Dishwasher smells bad? A deep-clean routine that actually works
Maintenance
Photo: Wendelin Jacober / Pexels If opening the dishwasher greets you with a swampy smell, the good news is that the machine is almost certainly fine. Odor comes from food film feeding bacteria in the spots that never get scrubbed. Set aside about an hour and work through all four zones, because cleaning only one rarely fixes it.
The filter assembly comes first
Twist out the cylindrical filter and lift the flat screen beneath it. Wash both in hot soapy water with a soft brush, paying attention to the fine mesh where grease bridges the openings. Wipe the sump cavity underneath with a paper towel. This is where the majority of dishwasher odor originates and it should be cleaned every two to four weeks.
Door gasket and the bottom lip
Run a damp cloth with a little dish soap all the way around the door seal, then along the flat ledge below the door where the tub does not drain. That ledge collects standing water, food particles, and mold, and it is completely invisible when the door is closed. An old toothbrush reaches into the gasket folds where a rag cannot.
Spray arms and the detergent cup
Remove the lower spray arm and rinse debris from the jets. Wipe out the detergent dispenser cup, where softener residue and gel buildup collect and can eventually keep the door from opening. Also pull the silverware basket and rinse it, since the closed bottoms of basket cells hold sludge.
Run an acid cleaning cycle
With the tub empty, place a dishwasher-safe bowl with two cups of white vinegar on the top rack, or use a citric acid tablet designed for the purpose, and run the hottest cycle available. Acid dissolves the mineral scale that odor-causing residue clings to. Follow with a rinse cycle. Do this monthly if your water is hard.
Check the drain hose and air gap
A drain hose without a high loop lets sink water sit in the line and smell. A clogged countertop air gap does the same. If the odor is strongest right when the dishwasher starts, suspect the drain path rather than the tub, and check that the disposal side of the sink is clean too since they share plumbing.
Habits that keep it fresh
Scrape plates well, run the machine at least every two or three days so water does not stagnate in the sump, and leave the door cracked open after a cycle so the tub dries. If odor returns within a week of a thorough cleaning, there may be standing water from a partial drain restriction that needs a technician to trace.
Frequently asked questions
Is bleach safe in a dishwasher?
Avoid bleach in any dishwasher with a stainless interior or stainless parts, as it corrodes them. Vinegar or a dedicated dishwasher cleaner is safer.
Why does my dishwasher smell like sewer gas?
A sewer odor usually points to the drain path or an unvented sink trap rather than the machine, and it is worth having the plumbing checked.
Can I put the filter in the dishwasher to clean it?
Hand washing is better. The fine mesh needs mechanical scrubbing to release grease that a wash cycle will not lift.