While Bosch dishwashers are known for their reliable cleaning ability, a day may come where it just doesn’t perform like it used to. Why is my Bosch dishwasher not cleaning dishes? The spray arms, filter, and tub require regular maintenance to perform optimally. Use these Bosch dishwasher troubleshooting tips to restore its cleaning power.
Help! Why Is My Bosch Dishwasher
Not Cleaning Dishes Like It Should?
Just because your dishwasher no longer performs as expected doesn’t mean it needs a repair or (gasp!) replacement. Oftentimes, some regular maintenance or change to your use and care can improve performance.
1. Loading Too Many Items
Overloading the dishwasher leaves little space for water and detergent to reach every item. It also increases the chance that an item will protrude from a rack and block the spray arms’ rotation.
Try these loading tips when your Bosch dishwasher leaves dishes dirty:
- Leave adequate space between each item: This means placing one dish per slot and alternating forks and spoons next to each other to avoid nesting. Make sure bowls don’t overlap each other to improve water and detergent access.
- Don’t block the spray arms: Make sure loaded items don’t hang below the rack, where they can block the spray arms. Load taller items along the perimeter of the bottom rack so they don’t impede the spray arms’ rotation.
- Place large utensils in the top rack: This will ensure that they don’t block spray arms or overcrowd the silverware basket.

2. Dishwasher Maintenance Required
Is your Bosch dishwasher leaving food residue behind and emitting a bad odor? It may be in need of a thorough cleaning. Cleaning the filter, spray arms and tub every 3-6 months can result in cleaner dishes and eliminate bad smells.
Here’s how to clean Bosch dishwasher components and improve performance:
- Filter: Remove the filter and its mesh screen and rinse both separately under running water. Scrub away stubborn debris with a soft toothbrush before reconnecting both components and replacing.
- Spray arms: Remove the top and bottom spray arms and rinse both under running water to remove mold or mildew. Use a toothpick to remove debris from spray arm holes before replacing.
- Tub: Add one box of Bosch Dishwasher Cleaner to the base of your empty dishwasher and run the longest cleaning cycle with hot water. Alternatively, pour 3 cups of white vinegar in the base of the empty dishwasher and run a complete cleaning cycle with hot water.
3. Detergent Dispenser Not Working
Detergent issues could also be responsible for a Bosch dishwasher not cleaning dishes sufficiently. Always use a quality dishwasher detergent that utilizes a blend of enzymes, soap, and rinse aid to dissolve food particles and lessen hard water stains.
However, even a high-quality detergent won’t help if the dispenser doesn’t open during a wash cycle. Check the dispenser and remove any accumulated residue that can clog it or prevent it from opening. If dishes remain dirty and the dispenser is still closed after a wash cycle, it may have malfunctioned and requires replacement.
4. Water Supply Malfunction
A dishwasher needs adequate amounts of hot water to not only remove food particles but rinse away detergent residue. If you notice your Bosch dishwasher not rinsing soap and leaving dishes dirty, a water supply malfunction could be the cause.

These water supply issues can impact cleaning performance:
- Low water temperature: Dishwasher performance improves when its water temperature is at least 120β. Check your home’s hot water heater to make sure it heats water to this optimal temperature. Running the hot water in your kitchen sink can ensure that it’s readily available at the start of a wash cycle.
- Water pressure is too low: The dishwasher’s water inlet valve requires at least 20 psi of pressure to fully open, allowing water to flow from your home supply. If the pressure is too low, the water inlet valve may not open sufficiently, reducing water flow and cleaning power. If your kitchen sink exhibits low water flow, your home’s water pressure should be assessed by a professional service.
- Defective water inlet valve: Even if the valve has adequate pressure, a malfunction can prevent it from opening, reducing water flow to the dishwasher. If the water inlet valve shows visible damage or a lack of continuity with multimeter testing, it should be replaced by a dishwasher repair service.
- Broken spray arm: A malfunctioning spray arm won’t distribute water evenly or at all, leaving dishes dirty. In this case, the spray arm must be replaced.
Is your Bosch dishwasher not cleaning dishes even after these troubleshooting tips? Let the team at Apex Appliance Service help with a fast and professional repair!