How To Deep Clean A Dishwasher

Prep checklist

What you will need

• owner's manual (for filter type, spray arm removal, and tub material specifics)
• soft brush or old toothbrush
• microfiber cloth
• warm water
• mild dish soap
• the model-approved machine cleaner, only if the manual calls for one
• thin pick or toothpick (for spray arm nozzle clearing)

Normal vs not normal

What a deep clean fixes versus what it cannot

It is normal for a dishwasher that has been running for a few months without a deep clean to have a slightly sour smell when you open the door, minor food debris stuck in the filter mesh, and faint white mineral film on the tub walls near the spray arm openings. Those issues resolve completely with the deep cleaning steps below.

What a deep clean cannot fix is a pump that has failed, a drain hose that is physically kinked or partially collapsed, a heating element that no longer heats, or a spray arm that is cracked and leaking pressure. If your machine throws error codes, makes grinding noises that persist after you clear debris from the spray arms, or leaves standing water that does not drain even after a clean filter, those symptoms point to a component problem that routine cleaning will not solve.

Start here

Deep cleaning steps — from easiest to most thorough

1. Remove and scrub the filter. Take out the filter assembly from the bottom of the tub. Rinse it under warm running water to remove loose debris. Use a soft brush to scrub the mesh screens, the cylindrical fine filter if your model has one, and the flat coarse screen. Wash the filter well itself—the cavity where the filter sits—with warm water and mild dish soap, scrubbing any slime or food paste that has accumulated on the bottom and walls of the well. Reseat the filter firmly. See How To Clean Dishwasher Filter for model-specific guidance.
2. Clear the spray arms nozzle by nozzle. Remove both the upper and lower spray arms according to your manual. Hold each arm up to the light or a window and look for blocked nozzle holes. Clear each blockage with a thin pick or toothpick, then rinse the arm under warm water to flush out any loosened debris. Check the arm body for cracks or warping; a cracked arm needs replacement, not cleaning. Reinstall both arms. See How To Clean Dishwasher Spray Arms for the full process.
3. Wipe the door gasket, inner door panel, and lower edge. Run a damp microfiber cloth along the full length of the rubber gasket around the door opening. Pay special attention to the bottom edge and the two bottom corners where moisture, mold, and food debris collect most heavily. Then wipe the inside of the door panel—the plastic or metal surface that faces the tub when the door is closed—because detergent splatter and rinse aid residue build up there over months. Finally, wipe the lip at the bottom of the door opening where water settles between cycles.
4. Flush the drain area. Pour warm water directly into the filter well and the drain opening to flush any remaining food sludge or mineral grit down the drain path. If you see visible debris that does not flush away, use a soft brush to loosen it and pour another cup of warm water to carry it down.
5. Run only an approved cleaning cycle. Use the cleaner type, dose, placement, and programme in the exact appliance manual. Never mix cleaners or assume acid is compatible with every tub, seal, dispenser, or internal softener.
6. Do not add a second household cleaner. One approved product and cycle is enough for the test; mixing or sequencing acids, alkalis, bleach, or detergent creates avoidable compatibility risk.
7. Inspect detergent and rinse-aid settings. Match them to the model manual, product label, measured hardness, and load soil rather than a universal spoonful or dial position.

Common cause pattern

Why dishwashers accumulate hidden buildup that monthly wiping misses

Monthly maintenance catches visible debris on the filter surface and gasket edge, but it does not reach the filter well cavity, the interior of spray arm passages, the inner door panel, or mineral scale inside the tub walls and drain plumbing. Over three or four months, food paste hardens inside the filter well, mineral scale narrows spray arm nozzles from the inside, detergent and rinse aid residue coat the inner door surface, and fine grit collects in the drain opening just below the filter. Those hidden accumulations are invisible during a quick monthly wipe but they gradually reduce spray pressure, slow drainage, feed odor bacteria in dark crevices, and leave residue on dishes.

Use the model’s inspection and cleaning schedule, and respond sooner when visible soil or performance changes appear. A cleaning cycle cannot confirm or clear a concealed restriction; unchanged symptoms need targeted diagnosis.

Branch selection

If odor persists after the deep clean

When a sour or musty smell returns within a few days of a full deep clean, the source is likely in the drain plumbing rather than inside the tub. Check whether the drain hose has a proper high-loop or air gap that prevents wastewater from siphoning back into the machine after each cycle. If the hose sits flat or dips below the drain connection, wastewater can flow back and feed odor inside the tub even when the filter and gasket are perfectly clean. See Dishwasher Smells Bad After Wash and Dishwasher Smells Like Sewer After Cycle for drain-related odor troubleshooting.

Branch selection

If residue on dishes returns quickly after the deep clean

Residue that returns can reflect hardness, detergent, rinse aid, loading, filter condition, or wash performance. Measure hardness, follow the model and product settings, and change one variable at a time. See Dishwasher White Residue On Dishes.

Avoidable issues

Mistakes that make deep cleaning less effective or risky

• Mixing household or commercial cleaners. Use one model-approved product exactly as labeled.
• Putting an unapproved cleaner into the dispenser, tub, or rinse-aid reservoir.
• Using abrasive scrub pads on the filter mesh or spray arm surfaces. Abrasive pads damage fine mesh screens and can scratch spray arm nozzles, creating new blockage points.
• Forcing spray arms off when they are designed to twist gently free. Cracked arms leak spray pressure and must be replaced, not just cleaned.
• Skip the inner door panel wipe. Detergent splatter and rinse aid residue on that surface feed odor and can drip back onto dishes during future cycles.
• Running a maintenance product with dishes inside unless both the appliance instructions and cleaner label explicitly allow it.
• Jumping to chemical drain cleaners when the drain area has food sludge. Chemical drain cleaners are not designed for dishwasher internals and can damage the drain pump, hose, and gasket.

Know when to stop

When a deep clean cannot solve the problem and service is appropriate

• Odor, residue, or standing water persists after a full deep clean followed by two regular wash loads.
• The dishwasher throws error codes, leaks, trips a breaker, or makes grinding or humming noises that do not improve after spray arm clearing.
• The next step would require disassembly beyond routine filter and spray arm access, electrical testing, plumbing modification, or part replacement.
• A spray arm is cracked or warped and needs replacement rather than cleaning.

At that point, a professional technician can test the drain pump, inspect the heating element, check internal hose routing, and diagnose electronic or mechanical failures that fall outside maintenance scope.

Common questions

FAQ

• How is a deep clean different from routine inspection? It may cover more user-accessible surfaces and an approved machine-clean cycle, but it does not extend into concealed parts.
• How often should I deep clean my dishwasher? Use the interval and symptom guidance in the exact model manual.
• Which cleaner should I use? Use only the type, dose, placement, and cycle approved by the appliance manual, and never mix products.
• What if the filter smells bad even after scrubbing? Check the filter well underneath the filter. Food paste and slime accumulate in the cavity where the filter sits, and that hidden layer feeds odor even when the filter mesh itself looks clean. Scrub the well with warm water and dish soap.
• Do I need to remove both spray arms for a deep clean? Yes. The upper arm is just as prone to nozzle blockage as the lower one, and you cannot see or feel internal scale without removing it and holding it up to the light.
• When should I stop deep cleaning and call for service? Stop when the next step would require disassembly beyond routine filter and spray arm removal, when you encounter broken parts, or when symptoms like standing water, error codes, or loud grinding persist after a full deep clean.

Fact check

Sources and scope notes

• Whirlpool Product Help: Cleaning the Removable Filtration System — running-water, soft-brush, and filter-reinstallation guidance.
• Whirlpool Product Help: Spray Arm Not Working — blocked-arm, loading, cleaning, and model-option checks.
• Filter and spray-arm removal varies by model; follow the owner manual before removing either part.

Keep reading

Related guides

• How To Clean Dishwasher Filter
• How To Clean Dishwasher Spray Arms
• Monthly Dishwasher Maintenance Checklist
• Dishwasher Smells Bad After Wash
• Dishwasher Musty Smell When Not Used
• Dishwasher White Residue On Dishes
• Dishwasher Standing Water After Cycle
• Dishwasher Cloudy Glasses After Cycle