How to Clean a Dishwasher: Filter, Spray Arms, and an Empty Cycle Step by Step
updated 11 July 2026
Quick answer
To clean a dishwasher, remove the filter and rinse it under running water, then clear the spray arm nozzles with a toothpick. Next, wipe the door seals and run an empty cycle at the highest temperature with citric acid or vinegar. Check the filter weekly and do a full clean once a month.
Step by step
- 1
Remove and rinse the filter
You'll find the filter at the bottom of the tub, under the lower spray arm - twist it counterclockwise and pull it out. Rinse it under warm running water and remove food residue and grease with a soft brush or an old toothbrush. If it's heavily greased, soak it for a few minutes in water with dish soap, and rinse the metal mesh screen underneath as well.
- 2
Unclog the spray arms
Remove the lower and upper spray arms - usually you just unscrew a nut or pull them upward - and check the holes the water sprays through. Clear clogged nozzles with a toothpick and rinse the whole arm under the tap to flush out limescale and crumbs. Clear spray arms are the foundation here, because they're what distributes water around the entire tub.
- 3
Clean the seals and door edges
Wipe the rubber seals around the door and the bottom edge of the tub with a damp cloth and a splash of vinegar. These are the spots where mold, grease, and food scraps collect, because the water can't reach them during a wash cycle. Look under the seal and into the grooves too, since that's where bad odors usually start.
- 4
Run an empty cycle with citric acid or vinegar
Pour 3-4 tablespoons of citric acid into the detergent compartment, or place a bowl with a cup of vinegar on the bottom rack. Run the hottest program, usually 60-70°C (140-158°F), with no dishes inside. The acid dissolves limescale and grease from the heating element, hoses, and walls you can't see with the naked eye.
- 5
Top up the dishwasher salt and rinse aid
Unscrew the cap of the salt reservoir at the bottom of the tub and add dishwasher salt if the level is low - it softens the water and protects against limescale buildup. Pour rinse aid into the separate dispenser in the door until the indicator shows full. Even with all-in-one tablets, salt and rinse aid make sense if the water in your area is hard.
- 6
Wipe the interior and leave the door ajar
After the cycle finishes, wipe the walls and bottom with a dry cloth and put the filter back in place. Leave the door slightly ajar for a few hours so the interior can dry out. Moisture trapped inside is the main reason a dishwasher starts to smell bad over time.
How often to clean your dishwasher
The filter gets dirty fastest, so check and rinse it once a week, especially if you load dishes without scraping off leftovers first. It takes a minute and prevents most problems with odors and poor washing results.
Do a full clean with an empty cycle and a spray arm check once a month. Wipe the seals and door edges every two weeks. Check the salt and rinse aid levels when the indicator lights up on the panel, or whenever you happen to open the dispenser.
Where the bad dishwasher smell comes from
An unpleasant smell almost always comes from food scraps rotting in the filter, on the mesh screen, and under the seals. The second source can be a clogged or kinked drain hose with dirty water sitting in it. Start by cleaning the filter thoroughly and running a hot cycle with citric acid.
If the smell keeps coming back despite cleaning, check whether the drain hose is connected too low, because water from the sink can flow back into the machine. Leave the door ajar after every wash so the interior dries out. Every now and then, wipe around the detergent dispenser too, because detergent drying up there can also start to smell.
Frequently asked questions
›Citric acid or vinegar - which cleans a dishwasher better?
Both dissolve limescale and grease, so either will work. Citric acid is gentler on rubber seals and hoses, which makes it the safer choice for regular cleaning. Use vinegar less often, because frequent use can speed up seal wear.
›How much citric acid should you put in a dishwasher?
For a single cleaning, 3-4 tablespoons poured into the detergent compartment or straight onto the bottom of the tub is enough. Then run an empty, hot program. Don't overdo the amount - a bigger dose doesn't clean any better, it just puts needless strain on the seals.
›What temperature should you clean a dishwasher at?
Pick the hottest available program, usually 60-70°C (140-158°F). High heat dissolves grease and limescale better and is more effective at killing the bacteria responsible for odors. Eco and short programs do a poor job here.
›How do you get rid of a bad smell from a dishwasher?
Start by removing and thoroughly rinsing the filter and mesh screen, because that's where most food scraps rot. Then run an empty cycle with citric acid at a high temperature and wipe the seals. If that doesn't help, check whether the drain hose is clogged or connected incorrectly.
›Do you need to rinse dishes before loading them into the dishwasher?
You don't need to rinse them under water - just scrape larger leftovers, bones, and peels into the trash. Oversized scraps clog the filter and spray arms, and that's the most common cause of poor washing and odors. Detergents handle dried-on grime fine, as long as the filter is clear.