Dishwasher Not Cleaning: Causes & Fixes (2026)

Cause 1: clogged spray arm jets

The spray arms spin and blast water at the dishes through tiny holes. When food debris, scale, or a stray sticker blocks those holes, the spray weakens and dishes come out dirty.

Fix: pull the bottom rack out, twist the spray arms off (they typically unscrew or unclip — check your model’s manual), and inspect the holes. Poke out clogs with a toothpick or pipe cleaner, then rinse under running water. Check both the bottom and top spray arms.

Cause 2: detergent problems

Dishwashers need dishwasher detergent — hand dish soap creates a suds flood, and old or clumped detergent loses its cleaning power. Pods are convenient but must go in the dispenser (not the silverware basket) and the dispenser door must open during the cycle.

Fix: use fresh dishwasher detergent, fill the dispenser properly, and run a hot rinse cycle to clear any residue. If your machine has a pre-wash cup, add a little detergent there too for the pre-wash stage.

Cause 3: hard water and water temperature

Hard water leaves mineral film on dishes and reduces detergent effectiveness. And if your water heater is set below 120°F, the dishwasher can’t get hot enough to cut grease.

Fix: check the water heater is set to at least 120°F. For hard water, use rinse aid (fills the compartment next to the detergent) and run a dishwasher cleaner through an empty cycle once a month.

Cause 4: loading problems

You can’t just cram dishes in. If large plates or bowls block the spray arms, or if bowls face up and hold water, the cycle can’t reach everything.

Fix: face soiled surfaces toward the center where the spray arms are, angle bowls downward so water drains off, and don’t nest cups or bowls together. Leave space so the arms spin freely — you should be able to rotate them by hand.

Cause 5: clogged filter (link to the draining issue)

A dishwasher that can’t drain properly leaves dirty water sitting on the dishes. The filter at the bottom of the tub traps food debris — when it’s clogged, both cleaning and draining suffer.

Fix: pull and rinse the filter (see our full dishwasher-not-draining guide for details).

The 3-step process (works for any brand)

1. Clean the spray arms (do this first — it’s free)
2. Check detergent + water temp (fresh detergent, 120°F+, rinse aid for hard water)
3. Fix the loading (face dirt inward, angle bowls, clear the spray path)

Parts & tools you’ll need

• Rinse aid (for hard water film)
• Dishwasher cleaner (monthly deep clean)
• Replacement spray arm (if the old one is cracked)
• Replacement filter (if cracked or warped)

FAQ

Q: Why is my dishwasher not cleaning but the spray arms spin? A: Check the water temperature (needs 120°F+) and detergent freshness. Hard water film is also a common hidden cause — try rinse aid.

Q: Why do my glasses come out cloudy? A: A common cause is hard water or too much detergent. Add rinse aid, reduce detergent, and run a cleaner cycle.

Q: Can a clogged filter cause poor cleaning? A: Yes — a clogged filter can leave dirty water in the tub during the cycle, which re-deposits food on the dishes. Clean it first, always.

Related guides

• Dishwasher Not Draining — Causes & Fixes
• Appliance Repair Cost vs Buy New (2026)

Part locations vary by model — check your manual before ordering parts. When in doubt, a licensed appliance tech is worth the call.