Why Is My Dishwasher Not Cleaning the Top Rack?

If your dishwasher is leaving dishes on the top rack dirty while the bottom rack comes out sparkling, you’re not alone — this is one of the most common dishwasher complaints we hear from homeowners across Grand Rapids, Kalamazoo, and Lansing. The good news: in most cases, the fix is straightforward. The top rack not cleaning is almost always caused by a blocked or broken upper spray arm, low water pressure reaching the top of the machine, or a worn-out spray arm bearing. Here’s how to diagnose and fix it.

How Your Dishwasher Actually Cleans the Top Rack

Understanding why the top rack gets shortchanged starts with knowing how your dishwasher works. Most dishwashers have two or three spray arms — one at the bottom, one in the middle (aimed at the top rack), and sometimes one at the very top of the tub. Water is pumped up through the center of the machine and distributed through these spinning arms.

The top rack spray arm has to work harder. Water has to travel farther and fight gravity to reach it. That means any reduction in water flow, pressure, or spray arm function affects the top rack first.

7 Reasons the Top Rack Isn’t Getting Clean

1. Clogged Upper Spray Arm

This is the #1 culprit. The spray arm has small holes that can clog with mineral deposits (especially in West Michigan’s hard water), food debris, and detergent buildup. When those holes plug up, water doesn’t reach the top rack.

How to check: Pull out the top rack and locate the spray arm underneath it. Spin it — it should rotate freely. Remove it (usually a quick twist counterclockwise) and hold it up to the light. Are the holes clear? Rinse under hot water and use a toothpick to clear any blocked holes.

If your dishes have a white chalky residue, that’s hard water scale — soak the spray arm in white vinegar for 20–30 minutes to dissolve it.

2. Broken or Cracked Spray Arm

If the spray arm has a crack, water shoots sideways instead of upward toward your dishes. A damaged arm may still spin but won’t clean effectively.

How to check: Look carefully for hairline cracks while holding it under light. Also check the bearing cap where the arm attaches — if it’s cracked or loose, water pressure escapes at the base rather than through the holes.

Replacement spray arms are usually $15–$40 and easy to swap yourself.

3. Low Water Pressure or Insufficient Water Fill

If your dishwasher isn’t filling with enough water, the pump can’t push water up to the top rack with enough force. This happens when:

• The water inlet valve is partially failing
• Your home’s water pressure is low (common in older Grand Rapids neighborhoods)
• The door float switch is stuck, cutting the fill cycle short

How to check: Run your dishwasher and listen — you should hear water filling for about 90 seconds to 2 minutes. If it fills for only 30–60 seconds, the inlet valve may be restricted or the float is stuck. Check the float (a small cylinder or dome on the bottom of the tub) — it should move freely up and down.

4. Blocked Spray Arm Bearing or Tower

Many dishwashers have a center wash tower or spray arm tower running up the back of the machine. If that tower gets blocked with food debris or a piece of plastic, water can’t reach the top spray arm at all.

How to check: Remove the bottom rack and look at the tower. Run your hand along it — any hard obstructions? Check inside with a flashlight. Clear any debris and re-run a cycle.

5. Overloaded or Improperly Loaded Top Rack

This one’s embarrassing to hear, but it’s responsible for a surprising number of “broken dishwasher” service calls. If tall glasses, large bowls, or plastic containers are blocking the spray arm from rotating, or if they’re angled to block the water jets, the top rack won’t get clean — no matter how new your machine is.

Loading rules for the top rack:

• Cups and glasses angle downward (open side facing down and inward)
• No item should hang below the rack and block the spray arm
• Large plastic containers go on the edges, not the center
• Don’t jam the rack so full it can’t let water circulate

Give the spray arm a spin with the rack loaded. If it hits anything, rearrange.

6. Detergent Dispenser Not Opening Fully

If the detergent cup doesn’t open completely, or if it opens at the wrong time in the cycle, dishes don’t get the cleaning power they need. The top rack is most affected because soap-laden water tends to stay lower in the tub.

How to check: Look for detergent residue or a dried chunk inside the dispenser cup after the cycle. The spring-loaded door should snap open fully — test it manually. If the door sticks, clean it with a damp cloth and check the latch mechanism. Also make sure nothing in the bottom rack is blocking the dispenser door from opening.

We wrote a full guide on this: see our post on dishwasher detergent cup not opening.

7. Worn or Failing Circulation Pump

If the circulation pump is wearing out, it can’t push water with enough force to reach the top rack. You might notice:

• The bottom rack cleaning fine but the top rack always dirty
• A humming sound during the wash cycle but poor cleaning
• Dishes requiring pre-rinsing more than they used to

This is a professional repair — circulation pump replacement in West Michigan typically runs $150–$300 depending on the brand. For machines under 8 years old, it’s almost always worth fixing.

Quick Diagnostic Test

Here’s a fast way to narrow down the problem:

1. Run a short cycle and pause it mid-wash. Open the door carefully (steam will escape). Is there water in the bottom of the tub? If very little, suspect inlet valve or float.

2. After the cycle, check the spray arm holes. If some holes are plugged, that’s your culprit.

3. Put a cup in the top rack upside down. If it collects water after the cycle, water IS reaching the top rack — the issue is spray pattern (clogged holes or positioning). If it’s dry, water isn’t getting up there at all (pump, inlet, or tower blockage).

Does Brand Matter?

In our experience serving Grand Rapids, Kalamazoo, and Lansing homeowners, certain brands are more prone to top-rack problems:

• Bosch: Upper spray arm bearings wear over time — a known issue on older units. Parts are available but pricier.
• LG: The tower/rail system can accumulate debris — check it quarterly.
• Samsung: Water inlet valve failures are common at the 5–7 year mark.
• Whirlpool/Maytag/KitchenAid: Spray arm holes clog easily in hard water areas like West Michigan.

If you have a Bosch and the top rack is struggling, our Bosch dishwasher not draining troubleshooting guide has brand-specific tips that may help.

When to Call a Professional

Try the DIY steps first — many homeowners fix this problem in under 20 minutes. But call a technician if:

• The spray arm is cracked or the bearing is broken (replacement is inexpensive, but installation can be tricky on some brands)
• The machine fills with very little water (inlet valve replacement requires turning off water supply lines)
• You suspect a circulation pump issue (requires disassembly)
• You’ve cleaned the spray arm and checked loading, and the top rack still isn’t cleaning

Most top-rack cleaning issues are diagnosed and resolved in a single visit. Don’t put up with running dishes twice or hand-washing cups — it wastes your time and water.

Preventing the Problem

A little maintenance goes a long way:

• Monthly: Clean the spray arms and filter (yes, your dishwasher has a filter — most homeowners have never cleaned it)
• Quarterly: Run a cleaning cycle with a dishwasher cleaner or a cup of white vinegar on the top rack
• Annually: Inspect the spray arm bearing for wear; check the door gasket for cracks

Hard water is rough on dishwashers in Grand Rapids and across West Michigan. Using a rinse aid every cycle dramatically reduces mineral buildup in spray arm holes — it’s the single best preventive step you can take.

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HomeHalo Can Help

If cleaning the spray arm didn’t solve it, or if you’d rather have a pro take a look, HomeHalo Appliance Repair is ready to help. We serve Grand Rapids, Kalamazoo, and Lansing, Michigan — all brands, all models, residential and commercial.

Call us: (616) 367-5131 Book online: homehalorepair.com/booknow/

Most dishwasher repairs are completed same-day or next-day. If it can be fixed, we’ll fix it right the first time.