How to Clean a Dishwasher Step by Step

Your dishwasher is meant to clean, but it can’t do its best work if it’s dirty inside. Food bits, grease, soap scum, and hard water minerals slowly build up, causing odors, cloudy dishes, and poor performance. The good news: with a simple routine and a deeper clean every few months, you can keep your dishwasher smelling fresh and running like new. This step-by-step guide uses beginner-friendly, affordable methods you can do with supplies you likely already have in your home.

Why Cleaning Your Dishwasher Matters

A clean dishwasher cleans better. When filters clog and spray arms gum up, water can’t flow properly. That means your dishes come out streaky or gritty, and your machine works harder than it should. Regular cleaning prevents odors, protects seals and moving parts, and helps your dishwasher last longer.

Signs Your Dishwasher Needs Cleaning

You notice a sour, musty, or fishy smell when you open the door. Dishes come out with grit, a cloudy film, or stuck-on food. The filter or sump area looks slimy. Spray arm holes are visibly blocked. There’s standing water in the bottom after a cycle. The door gasket (rubber seal) has dark spots or mold. If any of these sound familiar, it’s time to clean.

How Often to Clean

Light cleaning: once a month. Deep cleaning: every 2–3 months, or more often if you use your dishwasher daily, have hard water, or smell odors. The filter should be checked monthly and cleaned whenever you see debris.

What You’ll Need

White vinegar or citric acid powder, baking soda, mild dish soap, soft sponge or microfiber cloths, old toothbrush or small soft brush, toothpicks or a thin plastic skewer for spray arm holes, a small bowl or cup, warm water, paper towels or a dry cloth. Optional: a non-abrasive stainless steel cleaner for the exterior, hydrogen peroxide for mold, and a manufacturer-approved dishwasher cleaner if you prefer.

Safety and Prep

Before You Start

Turn off the dishwasher and let it cool if it just ran. Pull out the bottom rack to expose the filter and drain. Never mix vinegar and bleach. If your owner’s manual has special directions, follow those first. If your dishwasher has a stainless steel interior, avoid using bleach unless your manual clearly says it’s safe.

Protect Your Machine and Yourself

Use only soft cloths and non-abrasive cleaners inside the tub. Avoid harsh drain openers—these can damage hoses, pumps, and seals. If you’re sensitive to cleaners or dealing with mold, wear gloves and ventilate the area.

Step-by-Step Deep Clean

Step 1: Empty and Inspect

Remove all dishes and utensil baskets. Slide out both racks. Check the tub walls, corners, and the area around the drain for visible debris. Wipe out any loose food with a paper towel.

Step 2: Remove and Clean the Filter

Most modern dishwashers have a cylindrical or flat filter in the bottom. Twist or lift it out as the manual directs. Separate the coarse and fine screens if yours has both. Rinse under warm running water and gently scrub with a soft brush and a drop of dish soap. If grease is heavy, soak the filter in warm, soapy water for 10–15 minutes, then rinse well. Make sure the filter seats back snugly—an improperly installed filter can let debris into the pump.

Step 3: Clear the Drain and Sump Area

Shine a light into the drain opening and surrounding sump area. Remove seeds, shells, broken glass, or labels with a paper towel or tweezers. Wipe the surrounding floor of the tub to remove sludge. If there’s standing water after you remove the filter, bail it out with a cup and mop up with a towel so you can work safely.

Step 4: Clean the Spray Arms

Spray arms usually lift straight off or release with a clip. If removable, take them out. Rinse under warm water and use a toothpick to gently open clogged holes. Avoid metal skewers that could enlarge holes. If arms are greasy, wash with mild dish soap, then rinse. Reinstall them firmly so they spin freely.

Step 5: Wash Racks and Utensil Holders

Wipe down the racks and utensil baskets with warm, soapy water. Pay attention to the wheels, tines, and any clip-on accessories where food can hide. Rinse and set aside to dry. Check rack tines for rust; if you see bare metal, touch-up caps or a repair kit can prevent further damage.

Step 6: Clean the Door Gasket and Edges

Open the door and look closely at the rubber gasket around the frame. This area traps grime and can grow mildew. Dip a cloth in warm, soapy water and wipe the entire seal, folding it back gently to get in the folds. Use an old toothbrush in tight spots. For stubborn mold, lightly dampen a cloth with hydrogen peroxide and wipe, then follow with a clean water wipe. Dry thoroughly to protect the rubber.

Step 7: Scrub the Dispenser Area

Wipe the detergent cup and rinse aid cap with a damp cloth to remove dried detergent. If residue is heavy, use warm, soapy water and a soft brush. Make sure the dispenser door moves freely and the rinse aid cap is tight.

Step 8: Wipe the Interior Tub

Using a soft sponge and warm, soapy water, wipe the walls, ceiling, and floor of the tub. Pay extra attention to the corners, the lip at the bottom of the door, and the hinge area where grime collects. Rinse your sponge often and avoid abrasive pads that can scratch. Dry any pooled water with a towel.

Step 9: Run a Descaling Cycle (Vinegar or Citric Acid)

Option A: Vinegar. Place a dishwasher-safe cup filled with 1–2 cups of white vinegar upright on the top rack. Run a normal hot cycle with no detergent. Vinegar helps dissolve mineral deposits and soap scum and neutralizes odors.

Option B: Citric acid. If you have hard water or heavy white scale, citric acid can be more effective. Sprinkle 2–4 tablespoons of citric acid powder in the bottom of the empty tub and run a hot cycle. Alternatively, follow the directions on a manufacturer-approved descaler. Do not use vinegar and citric acid in the same cycle.

Step 10: Deodorize with Baking Soda

After the vinegar or citric acid cycle, sprinkle 1/2 cup of baking soda across the bottom of the tub and run a short hot cycle. This brightens the interior and absorbs odors. Skip this step if your manual advises against powders in an empty cycle, though most machines tolerate it well.

Step 11: Sanitize Carefully (Only If Needed)

If you’re dealing with persistent odors or recent illness and your manual allows it, run a sanitize cycle using the machine’s built-in sanitize setting. Avoid chlorine bleach in dishwashers with stainless steel tubs or interior components unless the manufacturer confirms it is safe. Never combine bleach with vinegar or citric acid, and never put liquid bleach directly in the rinse aid dispenser.

Step 12: Clean the Exterior and Controls

Wipe the outer door and handle with a damp cloth and a drop of dish soap. For stainless steel, wipe with the grain and dry to prevent streaks. Use a slightly damp cloth for the control panel; avoid soaking buttons or touchpads.

Step 13: Reassemble and Test

Reinstall spray arms, racks, and utensil baskets. Give the arms a spin to be sure they move freely. Run a quick rinse or short cycle to confirm smooth operation.

Special Situations and Stubborn Problems

Hard Water Scale and White Film

White haze on the tub or on glassware usually means mineral buildup. Run a citric acid cycle weekly for three weeks, then monthly. Use a rinse aid at every wash. If your home has very hard water, consider a water softener or a detergent booster designed for hard water.

Mold or Mildew Odors

Clean the filter, gasket, and drain thoroughly. Run a sanitize cycle if available. If your tub is plastic and your manual allows, you can sanitize by running a hot cycle with 1 cup of bleach placed in a measuring cup on the bottom rack, with no dishes and no detergent. Do not use bleach if your interior is stainless steel or if your machine’s manual warns against it. Alternatively, spray problem areas with 3% hydrogen peroxide, let sit 10 minutes, wipe, and rinse.

Grease and Soap Scum

Greasy buildup often comes from washing very oily pans or using too much detergent with cool water. Run the hottest cycle your machine has with vinegar or a dishwasher cleaner. Make sure your household hot water reaches at least 120°F (about 49°C) at the sink before starting a cycle; run the sink hot for 30–60 seconds first.

Cloudy Glasses: Film vs. Etching

If the cloudiness wipes off with vinegar, it’s mineral film. Fix with citric acid cycles and rinse aid. If it does not wipe off, it may be permanent etching from too much detergent, very soft water, or overly high heat. Use less detergent, avoid pre-rinsing (let enzymes work), and choose a gentler cycle for delicate glass.

Quick 15-Minute Monthly Clean

Simple Monthly Routine

Remove and rinse the filter under warm water. Wipe the gasket and door edges with a soapy cloth and dry. Sprinkle 1/2 cup baking soda on the bottom and run a short hot cycle, or place a cup of vinegar on the top rack and run a hot cycle. Wipe the exterior and control panel. Leave the door slightly open for an hour to air out.

Maintenance Habits That Prevent Buildup

Scrape, Don’t Pre-Rinse

Scrape off large food scraps but avoid a full pre-rinse. Modern detergents need some food soil to activate enzymes. Pre-rinsing can lead to oversudsing and residue if you still use a full detergent dose.

Use the Right Detergent and Dose

Use a high-quality dishwasher detergent. Pods are convenient and reduce overdosing, but if you have soft water, a half-dose of powder or gel can prevent etching. Follow the detergent maker’s dosage chart and your machine’s manual.

Always Use Rinse Aid

Rinse aid helps water sheet off dishes and the tub, reducing spotting and mineral deposits. Refill the reservoir monthly. If you see excessive foam or streaks, reduce the setting.

Run Hot Water First

Before starting your dishwasher, run the kitchen faucet on hot for 30–60 seconds to preheat the line. Hotter water improves cleaning and reduces greasy residue.

Load for Good Water Flow

Do not block the spray arms with oversized items. Face dirty sides of dishes toward the center. Keep tall items away from the detergent cup so it opens fully. Leave space between dishes for water to reach all surfaces.

Keep the Air Gap or Disposal Clear

If your sink has an air gap (a small cap on the counter), twist off the cap monthly and clean out any gunk. If your dishwasher drains into a garbage disposal, run the disposal with cold water for 20 seconds before starting a cycle to clear the drain path.

Let It Dry Out

After a cycle, crack the door open for an hour to vent steam. This reduces moisture that can feed mold and musty smells. Wipe the bottom lip of the door where water collects.

Troubleshooting After Cleaning

Standing Water After a Cycle

Check that the filter is correctly installed and not clogged. Inspect the drain opening and remove debris. Clean the air gap. Make sure the drain hose under the sink is not kinked and rises in a high loop before it connects to the disposal or drain. If the dishwasher shares a drain with a newly installed disposal, remove the knockout plug in the disposal inlet (this is often missed during installation).

Persistent Odors

Run a citric acid cycle followed by a baking soda short cycle. Clean the gasket folds thoroughly. Confirm the drain hose is not sagging (a sag can trap dirty water). If odor returns quickly, check for hidden leaks or standing water under the machine and address promptly.

Spray Arms Not Spinning

Make sure large items are not blocking movement. Remove arms and clear blocked holes. Verify water pressure by listening for strong spray sounds during a cycle. If weak, the inlet screen at the water valve may be clogged; consult a technician if you’re not comfortable checking it.

Leaks at the Door

Clean the gasket and door edge thoroughly and inspect for nicks or flattening. Ensure racks are not overfilled, which can deflect the door. Level the dishwasher so it does not lean forward. Replace a damaged gasket if cleaning does not help.

Too Many Suds or Foam

Do not use regular dish soap in the dishwasher. If suds overflow, sprinkle salt on the suds to help break them down and run a rinse cycle. Switch detergents if foaming persists and reduce the dose in soft water.

Eco and Safety Notes

Be Gentle with Cleaners

Avoid abrasive powders and scouring pads that can scratch the tub or dull stainless steel. Skip drain openers and strong acids—they can harm pumps and seals. Vinegar, citric acid, and baking soda are effective and safer when used properly.

Check the Manual for Restrictions

Some brands specify which cleaners are safe for their stainless steel interiors or rubber seals. When in doubt, use the mildest method first and test on a small area.

Frequently Asked Questions

Can I clean with vinegar every month?

Yes. A monthly hot cycle with 1–2 cups of white vinegar in a cup on the top rack is a simple way to prevent mineral buildup and odors. If your water is very hard, alternate with citric acid for better descaling.

Is bleach safe in my dishwasher?

Only if your manual says it is safe and your tub is plastic. Avoid bleach in dishwashers with stainless steel interiors or stainless components. Never mix bleach with vinegar or other acids.

Do I need special dishwasher cleaners?

Optional. Dedicated cleaners work well, especially for hard water. Vinegar, citric acid, and baking soda also do an excellent job when used as directed.

Why does my dishwasher smell musty?

Moisture plus trapped food equals odor. Clean the filter and gasket, run a hot sanitize or descaling cycle, use rinse aid, and leave the door slightly open after cycles to vent.

A Sample Deep-Clean Checklist You Can Follow

At a Glance

1) Remove racks and utensil basket. 2) Clean and reinstall the filter. 3) Clear the drain and sump. 4) Clean spray arms. 5) Wash racks and baskets. 6) Scrub gasket and door edges. 7) Clean dispenser area. 8) Wipe tub walls and corners. 9) Run a hot cycle with vinegar or citric acid. 10) Run a short cycle with baking soda. 11) Wipe exterior and controls. 12) Reassemble and test.

Conclusion

A dishwasher takes work off your hands, and with a little routine care it will keep doing that job beautifully. A clean filter, clear spray arms, and a monthly descaling cycle make the biggest difference. Keep the door gasket and drain area free of grime, use the right detergent and rinse aid, and let the machine dry out after runs. These simple steps boost cleaning power, prevent odors, and extend the life of your appliance. Start with the deep clean today, then follow the monthly quick clean—your dishes, and your dishwasher, will thank you.