Bosch is widely known for its top-quality, German-engineered home appliances. The brand’s dishwashers are no exception. Still, if you have a Bosch dishwasher and find that it’s not cleaning as it should, we’re here to help.
When a Bosch dishwasher fails to wash the items inside, a clogged filter or a failed water inlet valve is the most likely reason. Both can cause a lack of circulating water inside, which reduces the effectiveness of the appliance. Besides that, incorrect loading and broken or clogged spray arms at the top, center, and bottom can isolate the problem to either the top or bottom racks.
Keep on reading to discover the most likely causes of your problem and what you can do to fix them.
Top Reasons Why Your Bosch Dishwasher Isn’t Washing
Here are some of the most likely general reasons why your Bosch dishwasher isn’t washing items on both the top and bottom racks.
What it is: At the bottom of your Bosch dishwasher’s interior is a filter. This part is designed to remove all food bits and other junk from the water before the appliance recirculates and continues using it to wash your dishes.
Ideally, this filter must be cleaned periodically. You can do this once a month or more often if you’re using the dishwasher more often than average.
How it fails: The dishwasher filter will continue catching food bits and dirt. As the filter becomes increasingly saturated with items, water flow through the filter will gradually become restricted. That will prevent water from being recirculated through the wash arms at a fast enough rate to wash all of the dishes effectively, resulting in dirty dishes at the end of the wash cycle.
How to fix: Fixing this is quite straightforward, as all you’ll need to do is remove and clean the filter at the bottom of your dishwasher. First, remove the bottom rack and the lower spray arm to gain access to the filter.
Next, take the filter out and wash it in your kitchen sink. Be sure to remove all visible dirt and food bits before you reinstall the filter.
Failed Water Inlet Valve
What it is: Your Bosch dishwasher has a component responsible for controlling the inflow of water at all times. That component is known as the water inlet valve, and it’s located where the water supply hose connects to the appliance.
Whenever you start a new wash cycle, the valve will open and allow the dishwasher to fill. As soon as there’s enough water inside, the valve will close, prevent overfilling of the machine, and prevent flooding of your kitchen floor.
How it fails: The water inlet valve is prone to two types of failures: mechanical and electrical failures. Mechanically, the valve itself could suffer from a buildup of minerals and dirt from the water, causing it not to open and close as it should.
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Besides that, an electrical failure could also cause similar problems, despite the valve receiving the correct signals from your dishwasher.
In either case, the dishwasher won’t fill up with enough water to wash your dishes thoroughly, leaving them dirty at the end of the wash cycle.
How to fix: The water inlet valve is a component that cannot be repaired, even on a Bosch dishwasher. Therefore, the only practical solution is to replace it entirely.
The position of the valve will depend on the precise model that you have. For example, some models have the valve on the front, right at the bottom, while others have it on the rear of the machine.
Firstly, identify and locate the water inlet valve on your dishwasher. Then, remove the valve and disconnect it from the water and electrical connections. Once that’s done, you can put the new one in its place and reconnect it the same way as the old one.
Reasons The Top Rack Isn’t Cleaning
Suppose you find that the lack of cleaning is isolated to items on the top rack only. If that’s the case, you’ll want to focus your attention on the upper or center wash arms in particular.
Upper Or Center Wash Arms Are Clogged Or Cracked
What it is: Your Bosch dishwasher has several wash arms, including those at the center and right at the top. The machine drives water through these wash arms and the jets (tiny holes) along each arm.
From there, the jets will spray water onto your dishes and remove all the food bits and dirt on them. Simultaneously, the force of that water will cause each spray arm to turn continuously.
How it fails: Wash arms are prone to clogging and cracking. Clogging happens when food bits and dirt get into the arm and prevent water from spraying out the jets. On the other hand, cracks form when the spinning arms hit hard objects like taller items loaded onto the racks.
Clogs prevent water from spraying, while cracks cause water to leak out of the spray arms instead of spraying out of those jets. In both cases, the dishes are left unwashed.
How to fix: Clogs are very easy to clear, as you can use a toothpick to clean out each jet on the spray arm. However, cracks or any other damage will require a total replacement of the affected spray arm.
Simply pull the spray arm out by hand and push a new one into place. You can perform this replacement without any tools.
Center Wash Arm Can’t Turn Freely
How this happens: As mentioned above, each spray arm must spin freely to do its job. Therefore, when the center wash arm is obstructed and can’t turn, that will prevent it from washing your kitchenware on the top rack.
This problem is caused by tall items loaded onto the bottom rack. For example, if you put a tall jug or bottle standing vertically in the bottom rack, that item will prevent the center wash arm from turning.
How to fix: This issue is easy to fix and prevent. Be mindful of how you load items onto the bottom rack and put tall items at an angle rather than standing vertically.
Reasons The Bottom Rack Isn’t Cleaning
Next, let’s look at the likely reasons the lack of cleaning is isolated to items on the bottom rack. Here, two things to consider are the bottom wash arm and how the bottom rack is loaded.
Bottom Wash Arm Is Clogged Or Cracked
How it fails: Just like with the center and upper wash arms, the bottom one is also prone to clogging and cracking. This arm, in particular, is focused on washing items on the bottom rack, which is why only those items are left dirty at the end of the wash cycle.
How to fix: Remove the bottom wash arm and inspect each jet for any clogs. You can clean them out with a toothpick and then wash off any excess dirt in your kitchen sink. Whenever you find a wash arm with cracks or other damage, you must replace it entirely.
Overloaded Bottom Rack
How this happens: Lastly, another likely cause is that your bottom rack is overloaded. When too many items sit on the bottom rack, many of them will not have water or detergent sprayed onto them. As a result, they don’t get washed thoroughly during the wash cycle.
How to fix: Firstly, refer to your user manual for tips on how your dishwasher model should be loaded correctly. As a rule of thumb, you must ensure there’s enough space between each item so water and detergent can reach all kitchenware surfaces. Plus, you must also angle each item slightly to ensure that the entire surface will be washed thoroughly by the spray arms.
How To Force A Bosch Dishwasher To Drain?
You can force your Bosch dishwasher by performing a reset on the appliance, following the steps below.
How To Reset A Bosch Dishwasher?
To reset your Bosch dishwasher, press and hold the Start button for three seconds, or until the display shows 0:01. Then, close the door.
Besides resetting the dishwasher, this procedure will also trigger a drain cycle to remove any remaining water in the appliance.
How To Run Diagnostics Mode On A Bosch Dishwasher?
The diagnostics mode on Bosch dishwashers is typically referred to as ‘program mode’. To enter this mode, follow these steps:
- Firstly, press and hold any two cycle keys. As you hold those buttons, press and release the power button on your dishwasher. You’ll see the display show “P0” if this step is done correctly.
- Next, identify the “Cancel-Drain” or “Cancel-Reset” button combination for your dishwasher. They are labelled on your control panel.
- From left to right, the button on the left of that combination is “Button A”, followed by the one in the middle, which is “Button B”, and the last one is “Button C”.
- Press Button B until the display shows “P1”.
- Lastly, press Button C to begin the test mode. The machine will begin running automated tests to identify any errors it might be experiencing.