A dishwasher that leaves food behind is usually telling you that water, spray or detergent is not reaching the dishes in the way the cycle expects. Start with the dirty pattern: one rack, one corner, a film on every item, or loose food left across the whole load. That pattern points to the next safe check.
Turn the dishwasher off before removing a filter or touching a spray arm. Filter edges can be sharp. Do not remove panels or test a heating or pump component from inside the tub.
The dirty pattern is your first clue
If only one rack is dirty, look first at loading and the spray path serving that rack. If every item has a film, consider filter condition, water temperature, detergent or water hardness. If food is left in the same corner, check whether a rack, tall pan or utensil is blocking the spray path.
In one typical report, the upper spray arm was not moving while the upper rack stayed dirty. That observation does not identify a failed pump, but it does tell you to check for blocked jets, an obstruction or a model-specific spray-arm instruction before changing detergent.
Give the spray arms room to work
Spray arms need to rotate and send water through their openings. A tall plate, pan handle or utensil can stop an arm or shield part of the rack.
Load plates with their dirty faces toward the spray, keep tall items from blocking the center path, and spin each visible arm by hand only when the dishwasher is off. If an arm has blocked openings, follow the owner’s cleaning instructions. Do not force a cap or remove a part that the manual does not identify as user-removable.
Clean the filter before changing the detergent
A dirty filter can return food particles to the wash water. It can also reduce the amount of clean water reaching the spray system.
Switch off power, remove the filter as the manual shows, and rinse the permitted parts. Be careful around the filter edge. If glass or hard debris is below the filter, do not reach into the pump area; arrange service instead.
Water temperature and detergent change the result
The wash needs enough hot water to dissolve detergent and loosen grease. For the LG guidance linked below, 120°F is the recommended water temperature. Follow the requirements for your dishwasher rather than treating that figure as a universal setting.
Run the hot-water tap until it is hot before starting if your installation and owner instructions allow that practice. Use the detergent amount and type listed for your machine. In hard-water areas, follow the manual’s instructions rather than adding more detergent at random.
More soap is not always more cleaning. It can leave a film.
If the machine fills but the dishes stay dirty
When the tub fills and the cycle completes but the dishes remain dirty, compare the spray pattern, filter condition and water temperature before assuming the motor or heater has failed. A dishwasher can sound normal while a blocked jet, overloaded rack or poor detergent match reduces the cleaning result.
If the display shows an inlet or water-related message, use the exact-model support page. Do not treat a generic cleaning checklist as an explanation for an error code.
What the pattern can—and cannot—tell you
| What you observe | Possible explanation | What it cannot prove | Next step |
|---|---|---|---|
| Only one rack is dirty | Spray path or loading may be blocked | That the pump has failed | Recheck rack clearance and visible spray movement |
| Food is left in one corner | A pan, utensil or blocked jet may shield that area | That the detergent is the problem | Rearrange the load and inspect the permitted spray openings |
| Film remains on most dishes | Filter, water temperature, detergent or hardness may be involved | That more detergent will fix it | Clean the filter and follow the manual’s water and detergent guidance |
| Spray arm does not move freely when power is off | Debris or a load obstruction may be present | That the arm or motor must be replaced | Clear only what the manual allows; stop if resistance remains |
| Cycle completes with an inlet or water message | Water supply or fill conditions may need attention | That poor loading caused the issue | Use the exact-model support instructions |
A practical no-disassembly check
- Turn the dishwasher off and wait until the spray arms stop.
- Check whether tall dishes or utensils block either arm.
- Rotate the visible arms gently with power off.
- Remove and rinse the user-cleanable filter according to the manual.
- Note whether the dirty pattern is limited to one rack or spread across the load.
- Check the water-temperature and detergent guidance for the exact model.
- Run a normal cycle with a lighter, correctly placed load.
If the same pattern returns, record it for support. Do not open the machine to test a hidden component.
When to stop checking on your own
Stop when the spray arm is cracked, the filter will not release, glass is lodged below the filter, the dishwasher leaks, a breaker trips, or the next step would require removing a panel. Heating, pump and wiring faults need model-specific service.
Save the cycle name, the dirty rack or corner, the filter condition and any display message. Those details are more useful than simply saying that the dishwasher “does not clean.”
FAQ
Why does my dishwasher clean the bottom rack but not the top rack?
Check the upper rack’s loading and the spray path serving it. A blocked jet or an arm that cannot move can leave one rack dirty while the rest looks acceptable.
Should I add more detergent if dishes have a film?
Not automatically. Water temperature, filter condition and water hardness can all affect the result. Follow the detergent amount in the model’s instructions.
Can I clean the spray-arm holes with a sharp object?
Use only the cleaning method allowed by the owner’s manual. Do not enlarge the openings or force debris deeper into the arm.
Why are food particles still on every dish after a full cycle?
Check the filter, loading, spray clearance and water temperature first. If the whole load remains dirty after those checks, use model-specific support instead of replacing a part based on the symptom alone.
Sources and verification
These official pages support the spray, filter, loading, water and error-message checks described here. The permitted steps and temperature guidance can vary by model.
Sources checked September 19, 2026.