Dishwasher Not Cleaning Dishes Properly – Causes & Solutions

Dishes coming out of the dishwasher still dirty, greasy, or with food residue is a frustrating problem. Most dishwasher cleaning problems are caused by a few common issues you can fix yourself without calling a technician.

✓ Common Causes of Poor Dishwasher Cleaning

1. Clogged or Damaged Spray Arms

Spray arms distribute water throughout the dishwasher. If the holes are clogged with mineral deposits or food debris, or if the arm is cracked, water won't reach all the dishes properly.

2. Dirty or Clogged Filter

The dishwasher filter catches food particles. If not cleaned regularly, it becomes clogged and recirculates dirty water onto your dishes.

3. Low Water Temperature

Dishwashers need water at 120-140°F to properly dissolve detergent and clean dishes. If your water heater is set too low, cleaning performance suffers.

4. Wrong Detergent or Too Little Detergent

Using the wrong type or amount of detergent significantly impacts cleaning performance. Use fresh dishwasher detergent (not dish soap) and the correct amount for your water hardness.

5. Failed Wash Pump or Pump Motor

The wash pump circulates water through the spray arms. If it fails or is weak, water pressure is insufficient to clean dishes properly.

6. Failed Diverter Valve

The diverter valve routes water between the upper and lower spray arm circuits. When it fails, one rack gets full water pressure while the other gets little to none — causing uneven cleaning. Replace the Bosch Dishwasher Diverter Valve 00751950 if dishes on one rack are consistently cleaner than the other.

7. Improper Loading

Overloading, blocking spray arms, or placing items incorrectly prevents water from reaching all surfaces.

✓ Troubleshooting Steps (Do These First)

1. Clean the filter - Remove and rinse the filter under running water. Clean monthly
2. Clean the spray arms - Remove spray arms and clear clogged holes with a toothpick or wire
3. Check water temperature - Run hot water at the sink before starting the dishwasher
4. Use fresh detergent - Old or clumped detergent doesn't dissolve properly
5. Check loading - Make sure spray arms can rotate freely and dishes aren't blocking each other
6. Test the diverter valve - If one rack cleans well and the other doesn't, the diverter valve is the likely culprit

✓ Find Your Dishwasher Cleaning Parts

We stock Spray Arms & Spray Arm Assemblies, Wash Pump Motors, Filters & Filter Assemblies, Water Inlet Valves, and Diverter Valves for all major brands.

✓ Why Choose XPart Supply

• 30+ years experience helping Canadians fix their appliances
• Expert support – call us to verify part compatibility for your dishwasher model
• Fast shipping across all provinces and territories
• Genuine OEM parts – guaranteed fit and quality

Still having dishwasher cleaning problems? Contact our expert support team and we'll help you diagnose the problem and find the right replacement part for your dishwasher.