LG dishwashers have many modern advantages but, when it comes down to it, cleaning power is still what matters most. What can you do when your LG dishwasher leaves dishes dirty? A thorough cleaning of the interior components can improve performance. Use these LG dishwasher troubleshooting tips for cleaner dishes every time.
LG Dishwasher Leaves Dishes Dirty? Here’s How to Pinpoint The Problem.
While a part failure is always possible, there’s usually a DIY fix when your LG dishwasher leaves dishes dirty. From improper loading to detergent problems, here’s how to determine what’s really going on.
1. Dishes Not Loaded Correctly
One of the most common reasons an LG dishwasher leaves dishes dirty is overloading. Placing too many items in the dishwasher restricts their access to detergent and water, leaving food particles behind. Always leave space between dishes and avoid overlapping bowls and cups. However, loading the dishwasher correctly involves more than just leaving adequate space.
Try these LG dishwasher loading tips for cleaner dishes:
- Don’t block the spray arms: Load large platters along the perimeter of the bottom rack and lay long utensils on the top. This will prevent them from blocking the spray arms, ensuring that all items have access to water.
- Alternate silverware: Avoid the nesting that leaves silverware dirty by alternating forks, spoons and knives next to each other.
- Load plates facing inward: This ensures optimum access to water and detergent. If possible, alternate large and small plates next to each other to further improve water flow.

2. Dishwasher Interior is Dirty
Detergent residue, water, and food particles can leave your dishwasher’s interior dirty with mold, mildew, and clogs, impacting performance. Regularly cleaning the dishwasher’s interior can remove these byproducts and ensure cleaner dishes.

Here’s how to clean LG dishwasher filter, spray arms, and tub:
- Filter: Remove the bottom rack and turn the mesh filter counterclockwise to remove. Lift up on the STS filter to remove it as well. Rinse both components under running water and replace the STS filter, followed by the mesh filter, turning the latter clockwise to secure.
- Spray arms: Consult your user manual to determine how to detach the spray arms on your model dishwasher. If you find your LG dishwasher not spraying water, use a toothpick to unclog spray arm holes. Rinse under running water to remove dirty buildup.
- Tub: Place 2 cups of white vinegar in a dishwasher-safe bowl in the top rack of an empty dishwasher. Run a complete wash cycle with hot water and an extra rinse.
3. Problem With Dishwasher Detergent
While dishwasher detergent is essential in getting dishes clean, improper use can leave them dirty.
The following detergent problems can result in dirty dishes :
- Improper amounts: Too little detergent will leave grease and food particles behind. However, if you notice your LG dishwasher leaves residue on dishes, you’ve likely used too much. When adding detergent, use the amount recommended on the package or in your dishwasher’s user manual.
- Poor quality: Always use the highest quality detergent available. Those that include a combination of enzymes and rinse aid can pack a more powerful cleaning punch.
- Broken dispenser: If the dispenser is clogged with residue or doesn’t open properly, detergent won’t discharge at the appointed time. While clogs can be cleaned with a damp cloth, a broken dispenser must be replaced.

4. Water Supply Not Sufficient
You’ll find that your LG dishwasher leaves dishes dirty if it has an insufficient supply of hot water.
The following issues can affect the dishwasher’s water supply and cleaning power:
- Low temperature: A dishwasher’s water temperature should be between 130-140℉ to penetrate grease and activate detergent. Running the hot water in the kitchen sink before starting a wash cycle can ensure that it’s readily available. However, you may need to increase the temperature on your home’s water heater if the temperature remains low.
- Low water pressure: The dishwasher’s water inlet valve requires 20-120 psi of water pressure to operate properly. Without adequate pressure, it won’t open and allow water to flow to the dishwasher from your home supply. If the valve is receiving adequate pressure and still doesn’t open, it’s faulty and requires replacement.
- Clogged or broken spray arm: Is your LG dishwasher not cleaning top rack items effectively? The spray arm may be cracked or improperly assembled, or the ports could simply be clogged. Check both the top and bottom spray arms to make sure they’re properly secured. Use a straightened-out paperclip (not a wooden toothpick) to gently clear out the individual spray arm jets. If either arm appears cracked or damaged, it must be replaced.
If your dishwasher still leaves dishes dirty after these troubleshooting tips, a professional dishwasher repair service should take a look. Schedule your appointment with AlphaTek Appliance Repair today.