LG Dishwasher: Not Cleaning Dishes
Quick answer: Dishes coming out with food, grit or a film means water is not reaching them with enough force, heat or detergent.
- Turn off power before removing the spray arms, sump cover or heating element connections.
- Let the tub cool before touching the heating element or the water after a cycle.
- Use only automatic dishwasher detergent; hand dish soap will foam out of the machine.
Why is my dishwasher not cleaning dishes?
Dishes coming out with food, grit or a film means water is not reaching them with enough force, heat or detergent. The most likely causes are a clogged filter recirculating dirty water, blocked or non-rotating spray arms, a weak or failed circulation pump, a low fill from a restricted inlet valve, a detergent dispenser that does not open, and water that never gets hot because the heating element has failed.
Our fitment data covers 119 LG dishwasher models and 428 LG dishwasher parts, so the part links below are filtered to this brand; always confirm your model number before ordering.
Most Likely Causes, in Order
1. Filter assembly
Modern dishwashers recirculate the same water throughout the wash. When the filter is coated with food and grease, dirty water is sprayed back onto the dishes and grit settles on glasses.
How to check: Remove the lower rack and lift out the cylindrical and flat filters. Look for a coating of sludge or a clogged mesh and check the sump opening for debris. If the water in the tub looks cloudy or smells at the end of a cycle, the filter is overdue for cleaning.
Fix: Scrub the filters with hot water and a brush, clear the sump, and clean them monthly from then on. Replace the filter if the mesh is torn. (Difficulty: Easy)
No LG part for this cause is in our catalog yet; search by your model number.
2. Spray arms
Water pressure through the small nozzles is what spins the arms and scrubs the dishes. Mineral scale, seeds or bits of label plug the nozzles, and a cracked hub lets pressure escape, so the arm barely turns.
How to check: Pull each spray arm off and hold it to the light; every nozzle should be open. Spin the arms on their mounts; they should turn freely with a fingertip. Place a bowl upside down on a rack, run a cycle, and check whether water reached the inside; if it is dry, the arm did not spin.
Fix: Clear the nozzles with a toothpick and soak the arm in white vinegar to dissolve scale. Replace the arm or its mounting hub if it is cracked or wobbles. (Difficulty: Easy)
Matching LG parts:
- Dishwasher Middle Spray Arm Manifold 4975DD1002A — $38.03 – $43.19 · 52 models
- Dishwasher Spray Arm Assembly, Lower AGB32598301 — $46.16 – $58.25 · 52 models
- LG Dishwasher Spray Arm, Lower AGB73932401 — $93.71 – $190.80 · 43 models
3. Circulation pump
The wash pump forces water up through the spray arms. A worn impeller, a jammed motor or a burned winding gives weak spray or none at all, so dishes come out exactly as they went in even though the cycle ran.
How to check: Start a cycle, wait for the fill to finish, and open the door: you should hear a strong rush of water and see wet dishes. Silence or a faint hum after the fill means the pump is not running. With power off, remove the filter and sump cover and spin the wash impeller by hand; if it is seized or the blades are broken, the pump is done.
Fix: Clear a jammed impeller, or replace the circulation pump and motor assembly if it hums, is seized, or tests open on a multimeter. (Difficulty: Advanced)
No LG part for this cause is in our catalog yet; search by your model number.
4. Water inlet valve
The dishwasher needs a specific amount of water in the sump to build spray pressure. A valve screen clogged with sediment or a weak solenoid allows only a partial fill, so the pump sucks air and the spray is weak.
How to check: Start a cycle and open the door when the fill stops; the water should just reach the bottom of the heating element or the lip of the sump. If it is well below that, or the fill takes several minutes, shut off the water and check the inlet screen on the valve for sediment. Confirm the supply valve under the sink is fully open.
Fix: Clean the inlet screen or replace the water inlet valve if flow is still weak with full supply pressure. (Difficulty: Moderate)
Matching LG parts:
- Dishwasher Water Inlet Valve 5221DD1001E — $79.12 – $103.35 · 78 models
- Dishwasher Water Inlet Valve 5221DD1001A — $55.14 – $63.45 · 37 models
- Water Inlet Valve 5221DD1001F — $47.06 – $69.25 · 37 models
5. Detergent dispenser
If the dispenser door never opens, or opens after the main wash, the detergent stays in the cup or is rinsed away with no cleaning power. A gummed latch, a broken spring or a failed wax motor is usually to blame.
How to check: Look in the cup after a cycle; a lump of wet detergent or an unopened lid means the dispenser failed. Close the lid on an empty cup and run a cycle, then check whether the lid is open at the end. Make sure no tall item in the lower rack blocks the lid from swinging open.
Fix: Clean the latch and lid edge of caked detergent, and replace the dispenser assembly if the spring or actuator no longer releases the lid. (Difficulty: Moderate)
No LG part for this cause is in our catalog yet; search by your model number.
6. Heating element
Grease and dried food need water above about 120 degrees Fahrenheit to dissolve, and detergent enzymes work best when hot. A burned-out element leaves the wash lukewarm, so greasy film remains and dishes come out wet.
How to check: Open the door partway through the main wash; the steam and water should feel hot, not merely warm. Inspect the element in the bottom of the tub for blisters or a break. With power off and the wires disconnected, a multimeter reading of open circuit across the element terminals confirms it has failed.
Fix: Replace the heating element; it is held by two nuts under the tub and pulls up from inside. (Difficulty: Moderate)
Matching LG parts:
- Dishwasher Water Heating Element 5301DD1001A — $115.56 · 37 models
Other LG parts the catalog tags for this symptom
- Dishwasher Water Inlet Guide Assembly 4975DD1001A — $126.00 – $133.30 (no water; slow fill; won't fill)
- Dishwasher Sump Gasket MDS58387601 — $65.85 – $76.11 (leaking; won't drain; won't pump)
- Dishwasher Drain Hose AEM69493807 — $34.95 – $54.95 (clogged; drain; leaking; won't drain)
- Circulation Pump Motor 4681ED1004B — $178.89 – $274.17 (leaking; won't drain; won't pump)
- Dishwasher Circulation Pump AJH31248608 — $331.81 – $400.29 (drain; leaking; won't drain; won't pump)
- Dishwasher Pump Housing Seal MFZ32863101 — $10.57 – $15.54 (leaking; won't drain; won't pump)
Popular LG dishwasher models
Confirm the model number on the rating plate before ordering. Each model page lists every compatible part.
Frequently Asked Questions
Should I rinse dishes before loading the dishwasher?
Scrape off solid food but do not pre-rinse. Detergent enzymes need some soil to work on, and most models sense the dirt level to set wash time. Do clean the filter regularly, since that is where the scraped food ends up.
Why are my glasses cloudy after the dishwasher?
A cloudy film that wipes off with vinegar is hard-water scale; use rinse aid and more detergent. A film that will not come off is etching from soft water and too much detergent; use less detergent and skip the heated dry.
Why is only the top rack coming out dirty?
The upper spray arm is fed through a tube or docking port at the back of the rack. If the rack is not pushed in fully, the tube is clogged, or the middle arm nozzles are blocked, the top rack gets little water.
When to Call a Professional
Call a technician if the filter and spray arms are clean but there is no wash action after the fill, if the circulation pump must be replaced from underneath, or if an electrical test of the element or pump is beyond your comfort level.