LG Dishwasher Not Cleaning Dishes: Causes and DIY Fix Guide
If your LG dishwasher finishes a cycle but dishes come out with food residue, greasy film, or dried-on spots, you can fix most of these problems yourself. Nine times out of ten, the issue is a clogged filter, blocked spray arms, or low water temperature. Here’s exactly what to check and how to fix it in under an hour.
Likely Causes and Quick Decision Guide
Before you pull out tools, run through this fast assessment. Each item below is a pass/fail check that tells you where to focus your effort.
- Spray arm rotation: Does the lower spray arm spin freely by hand? If stuck, food debris is blocking it.
- Filter assembly: Is the coarse filter and fine mesh screen visibly clogged with food particles? A clogged filter is the #1 cause of poor cleaning.
- Water temperature: Does your incoming hot water reach at least 120°F at the kitchen sink? LG dishwashers need hot water to activate detergent and dissolve grease.
- Detergent dispenser: Does the dispenser lid open fully during the cycle, or is the detergent still caked inside after the wash?
- Drainage: Does standing water remain in the bottom of the tub after a cycle? If yes, your machine has a draining issue that affects cleaning performance.
If you hit a fail on any of these, start with the fix steps below. If you get all passes and dishes are still dirty, move to the deeper mechanical checks.
Step-by-Step Fix Process
Step 1: Deep Clean the Filter Assembly
LG dishwashers use a two-part filter system. Pull out the bottom rack and remove the lower spray arm by twisting the retaining nut counterclockwise. The filter assembly sits in the center of the tub floor – twist the handle to unlock and lift it out.
Rinse the coarse filter under running water. Use a soft brush or old toothbrush on the fine mesh screen to dislodge trapped particles. Pay special attention to the center cylinder where the mesh meets the plastic housing – that spot collects grease and small seeds that cause recirculation issues.
Reassemble: Lock the filter back into place, reinstall the spray arm, and run a rinse cycle before loading dishes again.
Step 2: Clear the Spray Arm Nozzles
Even if the filter is clean, clogged spray arm nozzles can starve your dishes of water pressure. Remove both the upper and lower spray arms. Hold them under bright light and look through each nozzle hole. If you see a blockage, use a paperclip or small wire to gently poke it through.
Flush each arm with tap water until water streams evenly from every hole. Spin the arm on its mounting hub to confirm it rotates freely without sticking.
Step 3: Verify Water Temperature and Detergent
Your LG dishwasher heats its own water, but it starts with whatever is in the supply line. Run the kitchen sink faucet on hot until the water feels hot to the touch, then start the dishwasher. If your water heater is set below 120°F, the dishwasher will struggle to dissolve detergent and break down food soils.
Detergent check: Use only fresh, high-quality dishwasher detergent pods or powder. Avoid gel detergents in hard water areas – they leave film that blocks the spray action. Make sure the dispenser door isn’t blocked by a large dish or utensil handle.
Step 4: Check the Drain Pump and Hose
If you saw standing water in the tub during the decision guide, you need to address the drain issue before the cleaning problem will improve. Remove the bottom rack and scoop out any standing water. Check the drain impeller (located under the filter assembly) for broken glass, toothpicks, or small bones that can jam the pump.
Disconnect the drain hose from the sink drain or garbage disposal and run water through it over a bucket. If the hose is clogged with grease or debris, replace it. A dishwasher that can’t drain properly recirculates dirty water across your dishes.
For a detailed walkthrough of drain-related issues, see our lg dishwasher not draining fix guide.
Success Check
After completing Steps 1–4, run a normal cycle with a cup of white vinegar in a dishwasher-safe container on the top rack. If dishes come out clean and free of residue, the fix worked. If problems persist, move to the mechanical checks below.
Common Error Codes and What They Mean
LG dishwashers display error codes on the control panel or floor light. These codes can point you directly to the problem without guesswork.
| Error Code | Meaning | What to Do |
|---|---|---|
| nE (or nE1) | Water temperature sensor failure | Check wiring connections on the thermistor; replace if faulty |
| oE (or oE1) | Overfill or drain issue | Clear drain pump and hose; check float switch movement |
| IE (or IE1) | Water supply problem | Verify water inlet valve is open and supply hose isn’t kinked |
| LE | Drain pump motor locked | Remove debris from pump impeller; replace pump if motor is seized |
| dE | Door switch error | Ensure door closes fully; check latch alignment |
If your model shows a code not listed here, write it down and consult the manual. Most LG models also display a blinking pattern on the floor light below the door – count the blinks and match them to your owner’s manual chart.
Deeper Mechanical Checks
If you’ve cleaned the filter, cleared the spray arms, and confirmed hot water and drainage, but dishes still aren’t clean, the issue is likely a mechanical component failure.
Wash motor. The wash motor circulates water through the spray arms. If it runs but sounds weak or hums without spinning, the motor windings may be failing or the impeller might be broken. This requires multimeter testing and usually a replacement motor assembly.
Circulation pump. On some LG models, the circulation pump is a separate unit. A failing pump will produce low water pressure even when the filter is clean. Listen for a grinding or rattling noise during the wash cycle – that’s a telltale sign of a worn pump bearing or broken impeller.
Control board. If the dishwasher runs through a cycle but skips wash phases or doesn’t advance, the main control board might have a failed relay or capacitor. This is a less common cause but worth checking if all other components test good. Board repairs are best left to a technician unless you’re comfortable with electronics soldering.
FAQ
Q: Why does my LG dishwasher leave white spots on glasses?
Hard water minerals cause white film when the rinse aid dispenser is empty or the water softener setting is incorrect. Fill the rinse aid reservoir and adjust the water hardness setting in the control panel menu.
Q: Can I use vinegar to clean my LG dishwasher?
Yes, but only in small amounts. Place a cup of white vinegar in a dishwasher-safe container on the top rack and run a hot water cycle without detergent. For a detailed guide, see how to clean your lg dishwasher with vinegar. Do not mix vinegar with bleach or commercial dishwasher cleaners.
Q: How often should I clean the filter?
Clean the filter assembly every two to four weeks, depending on use. If you rinse dishes before loading, you can stretch to monthly. If you never pre-rinse, clean the filter every two weeks.