LG dishwasher not cleaning well

Fix it in order

1. Filter — clean it monthly.
2. Spray arms — remove the upper and lower arms (and QuadWash arms), clear the nozzles with a toothpick, soak in vinegar to dissolve scale.
3. Hard water — Las Vegas water is very hard. Set rinse aid to 3–4, use a quality detergent (pods or powder with a hard-water booster) and run a dishwasher cleaner every 1–2 months.
4. Hot water — run the kitchen tap until it is hot before starting.
5. Loading — nothing tall blocking the arms; dirty sides facing the center.

When to call

Weak spray with clean arms, nE or LE codes, or a hum without spraying. See LG dishwasher repair.