How to Clean a Dishwasher (Start With the Filter Nobody Removes)

Your dishwasher has a filter in the floor of the tub that lifts out by hand. Most owners have never touched theirs.

That filter is the reason a dishwasher starts to smell. It is also why glasses come out gritty and why a dull film shows up on your dinnerware.

So this guide starts at the filter and works outward. Spray arms next, then the door seal, then the drain, and only after that the vinegar cycle everyone reaches for first.

The quick version: lift out the filter and rinse it under hot water. Clear any blocked spray arm holes. Wipe the rubber door seal. Then run an empty hot cycle with a cup of white vinegar or a cleaner tablet. The whole thing takes about 20 minutes, once a month.

Does Your Dishwasher Have a Filter You Can Remove?

Two designs exist, and the job is different for each one.

Manual filters sit in the floor of the tub, under the lower rack. You twist a plastic cylinder, lift it out, and a flat mesh plate comes out from under it. Nearly every quiet dishwasher built in the last 15 years works this way. Quiet running is the whole reason the design exists, because there is no grinder.

Hard food disposers chop debris instead of trapping it. They are noisy, and you mostly find them on older or budget machines. Nothing lifts out, but the grinder area still collects grease.

To check yours, pull out the bottom rack and look at the tub floor near the back wall. A round plastic cylinder with arrows or a slot on top means you have a manual filter. A flat metal plate with a small dome in the middle usually means a disposer.

If you are not sure, find your model number on the inside edge of the door and look up the manual. Filters vary a lot between brands, so the manual is worth two minutes of your time.

How to Clean a Dishwasher Filter

This is the step that fixes most complaints, so do it properly.

1. Empty the bottom rack and slide it out. You need clear access to the tub floor.
2. Twist the filter cylinder counterclockwise. On most machines it is a quarter turn. It should lift straight out.
3. Lift out the flat mesh plate underneath. Some models have it, some do not. It usually pulls forward and up.
4. Rinse both parts under hot running water. Turn the mesh so the water pushes debris back out the way it came in.
5. Work on the stuck bits with an old toothbrush. A drop of dish soap helps with the greasy film.
6. Look at the hole the filter came out of. Wipe the sump area around it with a paper towel and fish out anything solid.
7. Dry the parts and put them back. Drop the flat plate in first, then twist the cylinder until it locks.

Whirlpool’s own filter cleaning instructions say to clean the filter once a month, and every two weeks if the machine runs daily. The same page warns against wire brushes and scouring pads, because they tear the fine mesh. It also says never to run the machine with the filters out, since debris then goes straight into the pump.

What you will probably find: a grey paste of grease and starch, a few seeds, and one piece of something you cannot identify. That is normal. It is also exactly what has been sitting in warm water every time you ran a cycle.

Why a Blocked Filter Makes Dishes Dirtier

A dishwasher does not fill and drain over and over. It fills once, then pumps that same water around for most of the cycle. The filter is what keeps food out of that loop.

When the mesh clogs, water struggles through it. Pressure at the spray arms drops, so the top rack gets a weak rinse. Worse, the bits that do get through settle back onto clean plates. That is the grit you feel on a glass.

Cleaning the filter restores water pressure straight away. Many people who think their machine is failing just have a blocked filter.

Clear the Spray Arm Holes

Your dishwasher has two or three spray arms: one under the bottom rack, one under the top rack, and sometimes a small one at the roof. They spin because water pushes out of angled holes, like a lawn sprinkler.

Those holes are small, and they block. Hard water scale narrows them, and a stray fruit seed can plug one completely.

1. Spin each arm with your hand. It should turn freely with no grinding.
2. Hold the arm up and look through the holes toward the light.
3. Poke a blocked hole with a toothpick and wiggle gently.
4. If the arm unclips, take it off and rinse it under the tap so debris flushes out the other way.

Bosch’s cleaning and maintenance guide recommends the same toothpick trick and suggests checking the arms every few months. Do this at the same time as the filter and you will never think about it again.

One blocked hole changes the spray pattern for the whole arm. If one corner of the bottom rack always comes out dirty, check there first.

The Door Gasket and the Gunk Line

Open the door and run a finger along the rubber seal, especially the bottom lip where the door meets the tub. Most machines have a dark grey or pink line of buildup there.

Water never reaches that spot during a cycle, so it stays warm and damp for years. That makes it ideal for mold and bacteria. Maytag lists moldy gasket seals as one of the main causes of a smelly dishwasher, and the fix is simple.

• Dip a cloth in warm soapy water and wipe the full length of the seal.
• Use an old toothbrush in the folds and corners.
• Pull the gasket back gently where it is loose and wipe underneath.
• Dry it with a towel. Damp is what started this.

Do the same along the bottom edge of the door itself and the lip of the tub. Food slides in there and stays. Once a week keeps it from ever building up, and it takes under a minute.

While you are there, wipe the detergent dispenser. Powder cakes in the corners and stops the flap from opening. If your cookware comes out with a chalky coating, a stuck dispenser flap is one possible cause.

Check the Drain, the Sump and the Air Gap

Standing water in the bottom of the tub after a cycle means something downstream is blocked. Cleaning the inside will not fix that.

Work through these in order:

1. The sump. With the filter out, look down into the well. Feel around the edge for broken glass, labels or bones. Wear a glove.
2. The drain hose connection. Under the sink, the dishwasher hose connects to the garbage disposal or a drain tailpiece. If you just installed a disposal, check the knockout plug was removed. That single mistake blocks the drain completely.
3. The disposal. Run it for 20 seconds before any dishwasher cycle. A disposal full of scraps backs up into the machine.
4. The air gap. That small chrome cylinder on the counter beside the tap is an air gap. Twist off the cover and the plastic cap under it, then clear out the gunk. If water sprays from the air gap during a cycle, it is blocked.

A blocked air gap smells bad on its own, and people rarely think to check it. Your sink setup matters here too, because the hose and disposal share the same drain line.

Running a Cleaning Cycle: What Vinegar Really Does

Now for the step most articles put first. It works, but not for everything, and it is worth knowing which jobs it handles.

To run a vinegar cycle: empty the machine completely. Put a cup of plain white vinegar in a dishwasher-safe bowl on the top rack. Run the hottest cycle with no detergent. Wipe the tub dry when it finishes.

Vinegar is a weak acid, so it dissolves things acids dissolve. That means mineral scale, soap scum and the cloudy film on the tub walls. Maytag suggests exactly this method, using two cups of vinegar in a bowl with no detergent.

What vinegar does not do is break down grease or protein. Those need an alkaline detergent with enzymes, which is the opposite end of the pH scale. So a vinegar cycle will not clean a greasy filter, and it will not remove the paste from your door seal. You still have to do that by hand.

That is the honest limit of the trick. Vinegar is a descaler, not a degreaser.

Baking Soda Is for Odor, Not Scale

Baking soda is alkaline and mildly abrasive. Sprinkle a cup across the tub floor, run a short hot cycle, and it neutralizes sour smells and lifts light grease.

Do not run vinegar and baking soda in the same cycle. An acid and a base cancel each other out, fizz, and leave you with salty water. Run them on different days if you want both.

Never mix vinegar with bleach, or with any product containing bleach. The reaction releases chlorine gas, which burns your eyes, throat and lungs. This happens in minutes in a closed kitchen. If you have used a bleach cleaner anywhere near the machine, rinse it out fully before vinegar goes anywhere near it.

Bleach has a second problem. Samsung’s dishwasher cleaning guidance says not to use bleach in a dishwasher with a stainless steel interior, because it can damage or discolor the tub. Most modern machines have stainless tubs.

Cleaner Tablets, and Whether They Are Worth It

A purpose-made dishwasher cleaner is stronger than vinegar because it carries several active ingredients at once. Affresh tablets, for example, combine sodium carbonate to cut grease, plus citric acid and sodium bisulfate to attack limescale. That covers both jobs in one cycle.

You drop one in the empty tub and run a hot cycle, so there is nothing to measure or balance. A six-tablet box works out to six months of monthly cleaning. Affresh dishwasher cleaner tablets are the version appliance brands name most often. A pattern in owner reviews is that they help most with odor and hard water buildup. They do less for visible food debris, which is the filter’s job. You can read what buyers report and decide for yourself.

If your water is soft and your filter is clean, vinegar is enough. If you have hard water, a tablet does more per cycle.

Hard Water, Scale and the White Film on Your Glasses

Hard water is the single most common cause of a dishwasher that looks clean but leaves cloudy dishes.

Hardness is measured as calcium carbonate. The US Geological Survey classifies water hardness like this:

Classification	Calcium carbonate (mg/L)	What you notice
Soft	0 to 60	Clear glasses, detergent lathers easily
Moderately hard	61 to 120	Occasional spots, slow buildup on the heater
Hard	121 to 180	White film on glasses, scale on the tub floor
Very hard	Over 180	Heavy scale, cloudy dishes every cycle, shorter machine life

Your local water utility publishes an annual report with your hardness number. Look it up before spending money on fixes.

Here is what actually helps, in the order worth trying:

• Fill the rinse aid reservoir. Rinse aid lowers the surface tension of water so it sheets off instead of sitting in droplets. Fewer droplets means fewer spots. This is the cheapest fix and the most overlooked. A bottle of Finish Jet-Dry rinse aid lasts months.
• Add a citric acid booster. Lemi Shine detergent booster goes in the pre-wash cup alongside your normal detergent. Citric acid grabs the calcium before it can deposit.
• Run a monthly descaling cycle. Vinegar or a cleaner tablet, as above.
• Raise your water heater a little. Detergent enzymes work best in hot water. Most manufacturers want water arriving at about 120°F.

Scale is the same problem that wrecks kettles, and the method is the same too. Our guide to cleaning an electric kettle explains how acid breaks down limescale. And how electric kettles work shows why scale on a heating element wastes power.

One warning about cloudy glasses. If the film wipes off with vinegar, it is scale. If it does not, your glasses are etched, which is permanent damage from soft water plus too much detergent. Etching cannot be reversed, so switch to less detergent and check your glassware and dinnerware choices.

Why Your Dishwasher Smells, and What Actually Fixes It

Odor is a symptom. Match it to the cause instead of pouring in more vinegar.

What you notice	Likely cause	What fixes it
Sour, rotting smell	Food trapped in the filter or sump	Remove and rinse the filter, clear the sump
Musty, mildew smell	Mold on the door gasket	Scrub the seal with soapy water, dry it
Sewage smell	Blocked air gap or drain hose	Clear the air gap, check the hose loop under the sink
Burning plastic	Item touching the heating element	Stop the cycle, cool it, remove the item
Smell only at the start of a cycle	Stale water sitting in the sump	Run a hot empty cycle, then leave the door ajar
Smell that comes back in days	Drain clog you have not found yet	Check the disposal and drain line

Two habits prevent most of it. Leave the door open an inch after each cycle so the tub dries. And scrape plates properly instead of pre-rinsing them, since modern detergents need some soil to work against.

If the burning plastic smell keeps happening, check what you are loading. Lids from food storage containers slip off the top rack and land on the element. Anything not marked top-rack safe belongs in the sink.

When the Dishwasher Is Clean and Dishes Still Come Out Dirty

Cleaning the machine fixes a lot, but not everything. Run through these before you call a repair technician.

• Water temperature. Run the hot tap at the sink until it is properly hot, then start the cycle. Cold water at the start of a fill wastes the first several minutes.
• Detergent age. Powder and tabs lose enzyme activity over months. A box open since last year is weaker than you think.
• Loading. Bowls facing the spray, nothing blocking the arms, tall items at the sides. A single tall stockpot in the middle can block the whole upper arm.
• Overloading. Water has to reach every surface. Two half loads clean better than one crammed load.
• Cycle choice. Quick cycles are for lightly soiled dishes. Pots need a heavy cycle with a longer wash.

If your dishes come out clean but wet, that is usually rinse aid, not a fault. Plastic never dries well, because it does not hold heat the way ceramic and glass do.

What Should Never Go in the Dishwasher

Half of dishwasher damage is really cookware damage, and the dishwasher gets the blame. Keep these out:

• Cast iron. Detergent strips seasoning and the pan rusts within hours. Wash your Lodge skillet by hand and dry it on the stove.
• Good knives. Detergent is abrasive and the edge bangs against the rack. If you own a decent knife set, hand wash it. The difference between forged and stamped knives is mostly in the steel, and both edges dull faster in a machine. You will be reaching for a knife sharpener far sooner.
• Nonstick pans. Harsh detergent shortens the life of the coating. Read up on what nonstick cookware is and hand wash anything coated, including the pans in our nonstick pan guide.
• Ceramic-coated pans. Same rule. Our guide to cleaning a ceramic pan covers the gentler method.
• Hard anodized cookware. Detergent dulls and pits the finish. See how to clean hard anodized cookware instead.
• Wooden boards and handles. Wood swells, cracks and splits. An over-the-sink cutting board should be washed and dried by hand.
• Mandoline blades and air fryer parts. Check the manual first. Our guides on cleaning an air fryer basket and using a mandoline safely explain why.
• Probe thermometers. Electronics and water do not mix. Follow how to clean a meat thermometer instead.

Stainless steel pans are usually labeled dishwasher safe, but hand washing keeps the finish brighter. Our guide to cleaning stainless steel pans covers the stains a machine will never touch.

A Maintenance Schedule You Can Actually Keep

None of this is hard. The trick is doing small jobs often instead of a big job never.

Job	How often	Time it takes
Wipe the door gasket and bottom lip	Weekly	Under 1 minute
Run the hot tap before starting a cycle	Every cycle	20 seconds
Rinse the filter	Monthly, or every 2 weeks with daily use	3 minutes
Check the sump under the filter	Monthly	2 minutes
Run an empty cleaning cycle	Monthly	2 minutes plus the cycle
Check spray arm holes	Every 3 months	5 minutes
Clear the air gap	Twice a year	5 minutes
Top up rinse aid	When the light comes on	1 minute

Pin it inside a cabinet door if that helps. If your cabinets are already overflowing, these small kitchen cabinet organization ideas will free up the space to keep cleaning supplies near the machine.

Dishwasher Care in a Small Kitchen

A compact or countertop dishwasher needs the same care, with a few extra points.

• The filter clogs faster. Smaller sump, same amount of food. Check it every two weeks rather than monthly.
• Store cleaner tablets nearby. A box under the sink beats a box you forget about. If under-sink space is tight, our countertop organization ideas help you find a spot that is not the counter.
• Watch the drain hose on portable units. Portable models hook to the tap and drain into the sink. Rinse the hose end now and then so it does not go sour.
• Run full loads. A clean, efficient machine uses less water and power than washing by hand. Our guides to compact Energy Star appliances and the most energy-efficient small kitchen appliances cover what to look for. There is more on the same idea in how to reduce kitchen energy use in a small apartment.
• Dry and put away promptly. In a small space, a half-unloaded dishwasher blocks everything. These drawer organization ideas and tips for storing pots and pans make unloading faster.

When It Is the Machine, Not the Dirt

Cleaning fixes most problems. A few things it will not fix:

• Water still standing after you have cleared the filter, sump, hose and air gap. That points to the drain pump.
• Dishes cold and wet at the end of every cycle, with no heat inside the tub. That points to the heating element.
• The machine tripping the breaker or leaking from the door. Stop using it and call someone.
• Rust spreading from chips in the rack coating. Rack repair kits are cheap, and rust in the tub is a bigger issue.

If the machine is older than about ten years and needs an expensive part, replacing it often makes more sense. Newer models use far less water per cycle. That also changes what makes sense elsewhere in the kitchen, which our guide to energy-efficient cookware gets into.

And while you have the cleaning supplies out, your stovetop probably needs ten minutes too. If you cook on glass, read how to protect a glass top stove from cast iron before you put that skillet down.

Related Guides

• How to Clean Stainless Steel Pans
• How to Clean an Electric Kettle
• How to Protect a Glass Top Stove from Cast Iron
• How to Organize Pots and Pans
• Best Airtight Food Storage Containers
• Best Slide-In Electric Ranges Under $1000
• How to Clean Electric Griddle Fast

Frequently Asked Questions

How do I clean my dishwasher filter?

Pull out the lower rack and look at the floor of the tub. Twist the round filter cylinder counterclockwise, lift it out, then lift out the flat mesh plate underneath. Rinse both under hot running water and use an old toothbrush on any trapped food. Skip wire brushes and scouring pads, which damage the mesh. Dry the parts, drop the flat plate back in, then twist the cylinder until it locks.

How often should you clean a dishwasher?

Rinse the filter once a month. Whirlpool suggests every two weeks if you run the machine daily or cook for a large household. Wipe the door gasket weekly, since that takes under a minute. Run an empty cleaning cycle monthly, and check the spray arm holes every few months. If you have hard water, a monthly descaling cycle keeps film off your glasses.

Is vinegar or baking soda better for cleaning a dishwasher?

They do different jobs, so the answer depends on the problem. Vinegar is acidic, so it dissolves mineral scale, soap scum and cloudy film. Baking soda is alkaline and mildly abrasive, so it helps with odor and light grease. Do not run them together in one cycle. An acid and a base cancel each other out, and you end up with fizz and salty water.

Why does my dishwasher still smell after cleaning it?

The smell almost always comes from trapped food, so look for the food. Check the filter, the sump area under it, the spray arm holes, and the rubber seal along the bottom of the door. Also check the drain hose connection at the sink and the air gap on the counter. A cleaning cycle on its own will not fix a smell that comes from a clog.

Can you use bleach to clean a dishwasher?

Usually no. Samsung warns against bleach in any dishwasher with a stainless steel interior, because it can damage or discolor the tub. Bleach is also risky next to the vinegar most people reach for. Mixing bleach with vinegar or any acid releases chlorine gas, which is dangerous in a small kitchen. Use a citric acid cleaner tablet instead.

Why is my dishwasher leaving a white film on glasses?

A chalky white film is usually mineral deposit from hard water, not detergent failure. Water above 120 mg/L of calcium carbonate counts as hard, and the minerals stay behind when the water evaporates. Fill the rinse aid reservoir, add a citric acid booster to the detergent cup, and run a monthly descaling cycle. Etched, permanently cloudy glass is different and cannot be reversed.