Dishwasher Not Cleaning? Troubleshooting Guide and Common Causes

A dishwasher that runs a full cycle but leaves your dishes dirty is a frustrating problem. You expect to open the door and find clean, spotless dishes, but instead you find food residue, cloudy glassware, or greasy plates. The good news is that most dishwasher cleaning problems can be diagnosed and fixed without replacing the machine.

Table of Contents

• Common Causes of a Dishwasher Not Cleaning
• 1. Clogged or Damaged Spray Arms
• 2. Faulty Wash Pump or Circulation Pump
• 3. Low Water Temperature
• 4. Wrong Detergent or Not Enough Detergent
• 5. Overloading or Improper Loading
• 6. Clogged Filter or Fine Mesh Screen
• 7. Failed Heating Element
• 8. Hard Water or Mineral Buildup
• Brand-Specific Dishwasher Not Cleaning Issues
• How to Troubleshoot a Dishwasher Not Cleaning: Step by Step
• When to Call a Professional for Dishwasher Repair
• Dishwasher Repair Costs in San Diego
• Preventing Future Dishwasher Cleaning Problems
• Frequently Asked Questions

911 Appliance Repair has been fixing dishwashers in San Diego since 1991. This guide walks through the most common reasons a dishwasher stops cleaning properly, how to troubleshoot each one, and when to call a professional.

TL;DR: The most common causes of a dishwasher not cleaning are clogged spray arms, a faulty wash pump, low water temperature, improper loading, or a clogged filter. Most of these can be diagnosed in under 30 minutes. If your dishwasher is not cleaning dishes, call 911 Appliance Repair at 800-929-1192 for same-day service in San Diego.

Common Causes of a Dishwasher Not Cleaning

1. Clogged or Damaged Spray Arms

The spray arms, also called wash arms, distribute water throughout the dishwasher tub. If the small holes in the spray arms become clogged with food particles, mineral deposits, or debris, water cannot spray with enough force to clean the dishes. This is the most common cause of a dishwasher not cleaning properly.

How to check: Remove both the upper and lower spray arms. Most snap or screw off. Inspect each spray hole for blockages. Use a toothpick, wire, or small brush to clear any debris. Rinse the spray arms under running water. If an arm is cracked or damaged, replace it. Reinstall and run a test cycle.

Important: Check the spray arm for free rotation. If an arm is hitting a dish or utensil during the cycle, it cannot spray properly. Make sure tall items do not block the spray arm.

2. Faulty Wash Pump or Circulation Pump

The wash pump, also called the circulation pump, pushes water through the spray arms. If the pump motor is weak or the impeller is worn or damaged, water pressure drops and the dishwasher cannot clean effectively. You may hear the motor running but notice that the spray arms are barely turning or not turning at all.

How to check: Open the dishwasher during the wash cycle (most models allow this briefly). Check whether the spray arms are rotating and whether water is spraying with force. If the arms are not rotating or the water pressure is weak, the wash pump may be failing. Access the pump from the bottom of the dishwasher and test the motor with a multimeter for continuity. Inspect the impeller for wear or damage.

Cost to replace: A wash pump typically costs $80 to $200 for the part, plus labor. Total repair cost is usually $200 to $400.

3. Low Water Temperature

Dishwasher detergent needs hot water to dissolve and work effectively. The FDA and most detergent manufacturers recommend a water temperature of at least 120 degrees Fahrenheit for proper cleaning. If the water entering the dishwasher is too cold, the detergent will not dissolve completely, and grease and food residue will not be removed from dishes.

How to check: Run the kitchen sink faucet until the water is hot, then start the dishwasher. This ensures hot water is in the supply line. If your dishwasher has a built-in water heater or heating element, it should heat the water further. If your home’s water heater is set below 120 degrees, raise the temperature. If the dishwasher is not heating the water at all, the heating element may have failed.

4. Wrong Detergent or Not Enough Detergent

Using the wrong type of detergent or too little detergent is a surprisingly common cause of poor cleaning. Dishwasher detergent is specifically formulated for dishwashers, and using dish soap or hand soap creates excessive suds that interfere with cleaning. Using too little detergent leaves food and grease on dishes, while using old or expired detergent that has absorbed moisture will not clean effectively.

How to check: Make sure you are using dishwasher detergent, not dish soap. If you have hard water, you may need more detergent or a rinse aid. Check the detergent packaging for the recommended amount. If your detergent is clumpy or has been open for more than a few months, replace it with a fresh package.

5. Overloading or Improper Loading

How you load the dishwasher has a major impact on cleaning performance. If dishes are stacked too tightly, placed over each other, or blocking the spray arms, water cannot reach all surfaces. Large items like pots and baking sheets can block the spray arms entirely, preventing water from reaching the upper rack.

How to check: Make sure dishes are not touching each other. Face the dirtiest side of each dish toward the spray arms. Do not place tall items in the center of the lower rack where they block the upper spray arm. Place glasses and cups upside down on the upper rack. Make sure utensils are mixed in the basket, not nested together.

6. Clogged Filter or Fine Mesh Screen

The filter at the bottom of the dishwasher tub catches food particles and debris. If the filter is clogged, water flow is restricted and the dishwasher cannot clean effectively. A clogged filter can also cause food particles to be redeposited on dishes during the wash cycle.

How to check: Remove the lower dish rack. Twist and lift the filter assembly at the bottom of the tub. Rinse it under running water and scrub with a soft brush. Check the area underneath the filter for debris. Reinstall the filter and run a test cycle.

7. Failed Heating Element

The heating element heats the water during the wash cycle and dries the dishes at the end of the cycle. If the heating element fails, the water may not get hot enough to dissolve detergent and remove grease. Dishes may come out wet and greasy. Some dishwashers will not start the wash cycle at all if the heating element has failed.

How to check: Access the heating element at the bottom of the dishwasher tub. Test it with a multimeter for continuity. If the element shows no continuity, it has failed and needs replacement. If the element tests good but the water is still not heating, the thermostat or control board may be the problem.

Cost to replace: A heating element typically costs $40 to $100 for the part, plus labor. Total repair cost is usually $150 to $280.

8. Hard Water or Mineral Buildup

Hard water leaves mineral deposits on dishes, glassware, and the internal components of the dishwasher. Over time, mineral buildup can clog the spray arms, coat the heating element, and reduce the effectiveness of detergent. If your glassware comes out cloudy or spotted, hard water is likely the cause.

How to check: If your glasses have a white, cloudy film that does not wipe off with your finger, it is likely etching from hard water. If the film wipes off, it is soap scum. Run a cleaning cycle with a dishwasher cleaner or a cup of white vinegar placed in the top rack. If your home has very hard water, consider installing a water softener or using a dishwasher detergent formulated for hard water.

Brand-Specific Dishwasher Not Cleaning Issues

Whirlpool Dishwasher Not Cleaning

Whirlpool dishwashers commonly fail to clean due to a clogged chopper blade assembly. The chopper blade chops food particles before they reach the pump, and if it becomes jammed, water flow is restricted. The spray arms can also clog. Check the chopper assembly first, then clean the spray arms.

Bosch Dishwasher Not Cleaning

Bosch dishwashers commonly fail to clean due to a clogged fine mesh filter or blocked spray arms. Bosch models use a very fine filter that clogs more easily than other brands. The spray arm jets on Bosch models are also small and prone to mineral buildup. Clean the filter thoroughly and clear the spray arm holes.

Samsung Dishwasher Not Cleaning

Samsung dishwashers commonly fail to clean due to a weak wash pump or clogged spray arms. Samsung models also have a water softener system on some models that can fail. Check the spray arms first, then the filter, then the wash pump.

LG Dishwasher Not Cleaning

LG dishwashers commonly fail to clean due to a faulty wash pump or a clogged filter. LG models use a direct-drive pump that can weaken over time. Check the filter first, then the spray arms, then test the wash pump.

GE Dishwasher Not Cleaning

GE dishwashers commonly fail to clean due to a clogged spray arm or a faulty wash pump. GE models with a piston and nut assembly in the drain path can also have cleaning problems if the assembly is clogged. Check the spray arms first, then the filter, then the wash pump.

KitchenAid Dishwasher Not Cleaning

KitchenAid dishwashers, manufactured by Whirlpool, share the same cleaning issues. The chopper blade assembly, spray arms, and filter are the most common culprits. Check the spray arms first, then the chopper, then the filter.

Frigidaire Dishwasher Not Cleaning

Frigidaire dishwashers commonly fail to clean due to a clogged filter or a weak wash pump. The spray arms on Frigidaire models can also clog with mineral deposits. Check the filter first, then the spray arms, then the wash pump.

Maytag Dishwasher Not Cleaning

Maytag dishwashers, also manufactured by Whirlpool, share the same cleaning issues. The chopper assembly and spray arms are the most common culprits. Check the spray arms first, then the chopper, then the filter.

How to Troubleshoot a Dishwasher Not Cleaning: Step by Step

1. Check loading: Make sure dishes are not blocking the spray arms or touching each other. Rearrange if needed.
2. Clean the spray arms: Remove both spray arms and clear any blockages in the holes with a toothpick or wire.
3. Clean the filter: Remove the filter at the bottom of the tub and clean it thoroughly under running water.
4. Check water temperature: Run the kitchen faucet until hot before starting the dishwasher. Make sure your water heater is set to at least 120 degrees.
5. Check detergent: Use fresh dishwasher detergent and the correct amount. Add rinse aid if you have hard water.
6. Run a cleaning cycle: Run an empty cycle with a dishwasher cleaner or a cup of white vinegar to remove mineral buildup.
7. Check spray arm rotation: Open the dishwasher during the wash cycle and verify the spray arms are rotating freely.
8. Test the wash pump: If the spray arms are not rotating and the filter and spray arms are clean, test the wash pump with a multimeter.
9. Test the heating element: If the water is not getting hot, test the heating element with a multimeter for continuity.

If you are not comfortable working with electrical components or disassembling your dishwasher, call a professional. Dishwasher repair involves water and electrical components in close proximity, which requires safe handling.

When to Call a Professional for Dishwasher Repair

Call 911 Appliance Repair if:

• You have cleaned the spray arms, filter, and checked loading but dishes still come out dirty
• The spray arms are not rotating during the wash cycle
• You do not have a multimeter or are not comfortable testing electrical components
• The dishwasher is not heating the water
• You suspect a wash pump or heating element failure
• You want the repair done quickly with a warranty

Dishwasher Repair Costs in San Diego

Part	Part Cost	Total Repair Cost (Parts + Labor)
Spray arm cleaning	$0	DIY
Filter cleaning	$0	DIY
Spray arm replacement	$20 to $60	$100 to $180
Heating element	$40 to $100	$150 to $280
Chopper blade assembly	$20 to $50	$130 to $250
Wash pump / circulation pump	$80 to $200	$200 to $400
Control board	$100 to $300	$250 to $500

At 911 Appliance Repair, our $49.95 house call is free when you approve the repair. We provide upfront pricing before any work begins, and every repair is backed by a 1-year warranty on parts and labor.

Preventing Future Dishwasher Cleaning Problems

• Scrape plates before loading. Large food particles can clog the filter, spray arms, and chopper blade. Scrape food into the trash before loading dishes.
• Clean the filter monthly. Remove the filter and rinse it under running water. Use a soft brush for stubborn buildup.
• Clean the spray arms every 3 months. Remove the spray arms and clear the holes with a toothpick or wire to prevent clogs.
• Run hot water before starting the dishwasher. Run the kitchen faucet until hot, then start the dishwasher to ensure hot water is in the supply line.
• Use the right detergent and rinse aid. Use dishwasher detergent, not dish soap. Use a rinse aid to prevent spotting and film, especially if you have hard water.
• Run a cleaning cycle monthly. Use a dishwasher cleaner or run an empty cycle with a cup of white vinegar in the top rack to remove grease and mineral buildup.
• Do not overload the dishwasher. Leave space between dishes so water can reach all surfaces. Do not block the spray arms with tall items.

If your dishwasher is not cleaning dishes and you need professional repair in San Diego, call 911 Appliance Repair at 800-929-1192. Same-day service is available for most calls, and we stock common dishwasher cleaning parts in our service trucks for single-visit repairs.

Frequently Asked Questions

Why is my dishwasher running but not cleaning dishes?

The most common causes are clogged spray arms, a clogged filter, a weak wash pump, low water temperature, or improper loading. Start by cleaning the spray arms and filter, then check that the spray arms are rotating freely during the wash cycle. If they are not, the wash pump may be failing.

How do I know if my dishwasher spray arms are clogged?

Remove the spray arms and inspect the small holes for food particles or mineral deposits. Clear any blockages with a toothpick or wire. If the spray arms are not rotating during the wash cycle, they may be clogged or the wash pump may be too weak to spin them.

Can low water temperature cause a dishwasher not to clean?

Yes. Dishwasher detergent needs water at least 120 degrees Fahrenheit to dissolve and work effectively. If the water is too cold, the detergent will not dissolve completely and grease and food residue will remain on dishes. Run the kitchen faucet until hot before starting the dishwasher.

How much does it cost to fix a dishwasher that is not cleaning?

Most dishwasher cleaning repairs cost between $100 and $400, depending on the part. A spray arm replacement is the least expensive at $100 to $180, while a wash pump replacement costs $200 to $400. A heating element costs $150 to $280. At 911 Appliance Repair, our $49.95 house call is free with repair.

Is it worth fixing a dishwasher that is not cleaning?

In most cases, yes. The most common fixes (spray arm cleaning, filter cleaning, spray arm replacement) cost $0 to $180. Even a wash pump or heating element replacement costs $150 to $400, which is far less than buying a new dishwasher ($400 to $1,200). If your dishwasher is less than 10 years old, repair is the better choice.