Bosch Dishwasher Not Draining [How To Fix]

By: Talen Quire

Is your Bosch dishwasher not draining? It’s a common issue that can turn a simple clean-up into a major headache. When water pools at the bottom of the dishwasher, it signals a problem that needs immediate attention. One fact to keep in mind: a clogged filter or drain pump is often the culprit.

Many Bosch dishwasher owners face this problem, and the frustration is understandable. Imagine opening your dishwasher to find dirty water and soaked dishes. It’s not just inconvenient; it can also lead to unpleasant odors and potential water damage.

If you’re in a hurry you can also force out the drain from the Bosch dishwasher. But to resolve the issue by root, you’ll need to fix the cause of it.

Don’t worry, though. We’ll walk you through the steps to fix this issue. By the end of this guide, you’ll have your Bosch dishwasher running smoothly again. Let’s get started!

Bosch dishwasher standing water at the bottom

What Signs Indicate That the Bosch Dishwasher Is Not Draining Properly?

Here are the signs that indicate that your dishwasher isn’t draining properly:

  • Standing Water: After the wash cycle, if you notice water pooling at the bottom of the dishwasher, it’s a clear indication of a drainage issue. This water should have been pumped out during the cycle.
  • Dirty Dishes: If your dishes come out dirty or with food particles stuck to them, the dishwasher may not be draining. Proper drainage is crucial for rinsing off soap and food debris.
  • Slow Drain: If you hear your dishwasher trying to drain but it seems sluggish or takes longer than usual, there might be a blockage.
  • Error Codes: Bosch dishwashers often display error codes like E24, indicating a draining problem. This code suggests a blockage in the filter, hose, or pump.
  • Unpleasant Odors: Stagnant water can lead to bad smells. If you open your dishwasher and are met with a foul odor, it’s likely due to drainage issues.
  • Noise During Drain Cycle: Unusual sounds during the drain cycle, such as gurgling or grinding, can indicate that the pump is struggling to remove water.

If you notice any of these signs, it means your dishwasher is experiencing some drainage issues that need attention.

Why My Bosch Dishwasher Is Not Draining?

There are several reasons that can cause your Bosch dishwasher not to drain properly. Some of the most common reasons are as follows:

Dirty Filter Unit

Dishwasher filter unit

The filter in your Bosch dishwasher plays a crucial role in preventing food particles from circulating back onto your clean dishes and blocking the drainage system. As water and detergent circulate during a wash cycle, they rinse off food debris from your dishes. This debris is then trapped in the filter at the base of the dishwasher.

When the filter becomes clogged with this debris, it obstructs the water from passing through it. As a result, your dishwasher will not drain.

How to Fix It?

To address this, you’ll need to clean the filter:

  1. Remove the Bottom Rack: Take out the bottom dish rack to access the filter.
  2. Remove the Filter: Twist and lift out the filter unit. It’s usually a circular tube at the base of the dishwasher.
  3. Separate and Clean: Untwist the cylinder from the filter, then use a small brush to scrub off any debris.
  4. Reassemble and Replace: After cleaning, reassemble the filter and cylinder, making sure the arrows align, and then place it back into the dishwasher.

Most probably this will fix the drainage issue. If it doesn’t, follow the next mentioned method.

Incorrect Detergent Usage

Detergent plays a critical role in the cleaning process, but using the wrong type can cause issues. Some Bosch dishwashers are specifically designed to use powder detergent. When you use liquid detergent instead, it can create excessive suds that the dishwasher isn’t equipped to handle. These suds can overflow and clog the drainage system, causing water to pool at the bottom of the machine.

How to Fix It?

Always use the detergent recommended by the manufacturers. You can check the recommended detergent type in the user manual.

Kinked Drain Hose

The drain hose, connecting your dishwasher to the sink’s drainage system, is crucial for removing wastewater during the cleaning cycle. When this hose becomes kinked or twisted, the water flow is restricted, leading to improper drainage.

How to Fix It?

To fix this issue, inspect the drain hose for any kinks or twists. Gently straighten any bends and ensure the hose runs smoothly from the dishwasher to the sink drain. If necessary, disconnect the hose and flush it with water to remove any internal blockages.

Blocked Drain Line

Drain line of the dishwasher

The drain line, responsible for channeling wastewater away from the dishwasher, can become clogged with food particles, grease, and other debris. When this happens, the water cannot exit the dishwasher efficiently, leading to standing water at the bottom of the appliance.

How to Fix It?

To address this issue, inspect the drain line for any clogs. Disconnect the drain line and clear any visible blockages using a mixture of baking soda and vinegar. Pour about a cup of each into the drain line, followed by hot water to flush out the debris. Regularly cleaning the drain line can help prevent clogs and ensure your Bosch dishwasher drains properly.

Clogged Garbage Disposal

If you have a garbage disposal unit connected to your dishwasher, it can also cause the culprit.

Dishwashers connect to the garbage disposal via a hose, a blockage in the disposal can cause obstruction in the drainage path. When the garbage disposal is clogged, it restricts the water flow from the dishwasher. As a result, the dishwasher stops draining.

How to Fix It?

To address this issue, check and clear any visible clogs in the garbage disposal. Run the disposal to ensure it’s working properly and flush it with water. 

Clogged Air Gap

An air gap is a small device installed on the sink or countertop, designed to prevent dirty water from siphoning back into the dishwasher. When the air gap gets clogged, it disrupts the water flow, leading to a non-draining dishwasher.

How to Fix It?

To clear a clogged air gap, follow these steps:

  1. Locate the Air Gap: Usually found on the sink or countertop near the dishwasher.
  2. Remove the Cover: Unscrew or pop off the air gap cover.
  3. Clean the Air Gap: Use a brush or a straightened paper clip to clear any debris inside the air gap.
  4. Flush with Water: Run water through the air gap to ensure it’s clear.

Blocked Drain Pump

Drain pump of the Bosch dishwasher

The dishwasher pump is located at the bottom of the appliance and has two main functions: forcing water into the spray arms during the wash cycle and directing water into the drain hose during the drain cycle. When the pump is blocked or malfunctioning, it can’t effectively remove water, leading to the non-draining Bosch dishwasher.

How to Fix It?

To unblock or troubleshoot a dishwasher pump, follow these steps:

  1. Remove the Bottom Dish Rack: Slide out the lower rack to access the filter and pump area.
  2. Remove the Filter Unit: Lift out the cylindrical filter unit located at the base.
  3. Drain Residual Water: Use a sponge to soak up any remaining water in the bottom of the dishwasher.
  4. Remove the Pump Cover: Wearing protective gloves, use a small spoon to pry off the white, plug-like pump cover below the filter unit.
  5. Clean the Pump: Clear out any debris inside the pump to ensure smooth operation.
  6. Reassemble: Replace the pump cover, ensuring it clicks into place, then reinsert the filter unit, aligning the arrows.

How Do I Reset My Bosch Dishwasher After a Draining Issue?

After addressing a draining issue, you may need to reset your Bosch dishwasher to clear any error codes and restore normal operation.

To reset your Bosch dishwasher:

  • Turn Off the Dishwasher: Press the power button to turn off the dishwasher. Wait a few seconds to ensure it has completely powered down.
  • Open the Door: Open the dishwasher door fully. This helps in resetting the control board.
  • Press and Hold the Reset Button: Depending on your model, locate the reset button, often labeled “Start” or “Reset.” Press and hold it for about 3 to 5 seconds until the display changes or the machine beeps.
  • Close the Door: Close the door firmly. The dishwasher should start draining any residual water and reset the control board.
  • Wait for Completion: Allow the dishwasher to complete its reset process. You may hear the pump running as it clears out water.

For models without a dedicated reset button:

  • Turn Off the Dishwasher: Press the power button to turn off the dishwasher.
  • Open the Door: Open the door fully.
  • Press and Hold the “Cancel/Drain” Button: Press and hold the “Cancel/Drain” button for about 3 seconds. This will initiate a drain cycle to clear any remaining water.
Bosch dishwasher cancel/drain button
  • Wait for Completion: Close the door and let the dishwasher complete the drain cycle. The control board will reset once this is done.

When Should You Call the Professional for Help With the Drainage Issue?

If you’ve tried all the troubleshooting steps and your Bosch dishwasher still isn’t draining, it might be time to call a professional.

  1. Persistent Drainage Issues: If the dishwasher consistently fails to drain despite clearing the filters, drain hose, and air gap, a professional technician can diagnose and repair more complex issues.
  2. Error Codes: When your dishwasher displays persistent error codes even after a reset, it often indicates a more serious problem that requires specialized tools and expertise to resolve.
  3. Water Damage: If you notice water pooling around your dishwasher, this could signify a leak or internal malfunction. Professional help can prevent further damage to your kitchen.
  4. Electrical Problems: Any signs of electrical issues, like tripping breakers or flickering lights on the dishwasher panel, necessitate professional intervention to avoid safety hazards.
  5. Pump Replacement: If the dishwasher pump is faulty, replacing it involves intricate work that is best handled by someone with experience in appliance repair.
  6. Unusual Noises: Strange sounds coming from the dishwasher, especially during the drain cycle, can indicate deeper mechanical issues that a technician can accurately identify and fix.
  7. Warranty Concerns: Attempting DIY repairs might void your warranty. If your dishwasher is still under warranty, it’s advisable to contact authorized service providers.

What Are the Consequences of Ignoring a Bosch Dishwasher That Won’t Drain?

Ignoring a Bosch dishwasher that won’t drain can lead to several negative consequences.

1. Water Damage: If water remains in the dishwasher, it can overflow and cause damage to your kitchen floor and cabinets. This can lead to costly repairs and potential mold growth.

2. Mold and Mildew: Standing water creates an ideal environment for mold and mildew to grow, which can lead to health issues and unpleasant odors in your kitchen.

3. Appliance Damage: Continually running a dishwasher that doesn’t drain properly can strain the appliance’s components, such as the pump and motor, leading to premature wear and expensive repairs or replacement.

4. Inefficient Cleaning: A dishwasher that doesn’t drain can’t clean dishes effectively. Dirty water can recirculate, leaving dishes grimy and requiring extra washing by hand.

5. Increased Utility Bills: Running a malfunctioning dishwasher multiple times in an attempt to get clean dishes wastes water and electricity, increasing your utility bills.

6. Electrical Hazards: Persistent water issues can lead to electrical problems, posing a risk of short circuits or even electrical fires.

7. Voided Warranty: Ignoring the issue and continuing to use the dishwasher may void any existing warranty, leaving you responsible for all repair costs.

How Can I Prevent My Bosch Dishwasher From Not Draining in the Future?

Tips to prevent dishwasher drainage issues

To prevent your Bosch dishwasher from not draining in the future, follow these steps:

1. Regularly Clean the Filter: The filter traps food particles and debris, preventing them from clogging the drain. Clean the filter weekly to ensure it remains clear.

2. Inspect the Drain Hose: Make sure the drain hose is free of kinks and blockages. Periodically check it for any debris that might hinder water flow.

3. Use a Rinse Aid: A rinse aid helps water flow off dishes more effectively, reducing the chances of residue buildup in the dishwasher’s components.

4. Run Hot Water Before Starting: Run hot water in your kitchen sink before starting the dishwasher. This helps to ensure the water entering the dishwasher is hot, improving cleaning efficiency and reducing residue buildup.

5. Avoid Overloading: Do not overload the dishwasher, as this can impede water flow and result in poor drainage. Follow the manufacturer’s guidelines for loading dishes properly.

6. Clean the Air Gap: If your dishwasher has an air gap, clean it regularly. This device prevents the backflow of water and can become clogged with debris.

7. Use the Right Detergent: Use a detergent recommended by Bosch, and avoid using too much detergent, which can cause suds and impede drainage.

8. Run a Cleaning Cycle: Periodically run an empty dishwasher with a cup of vinegar or a dishwasher cleaner to remove buildup and ensure the drain system remains clear.

9. Check the Garbage Disposal: If your dishwasher drains through a garbage disposal, ensure the disposal is clear and clean. Run the disposal before starting the dishwasher to prevent clogs.

10. Regular Maintenance: Schedule regular maintenance checks with a professional technician to ensure all components are functioning correctly and to address any potential issues before they become major problems.

Frequently Asked Questions

Can I Fix a Bosch Dishwasher That Won’t Drain Myself?

Yes, you can attempt to fix a Bosch dishwasher that won’t drain by checking for common issues such as a blocked drain line, clogged garbage disposal, or a faulty pump. Regular maintenance and basic troubleshooting steps can often resolve the problem.

Can I Use a Drain Cleaner to Fix a Bosch Dishwasher That Won’t Drain?

It’s not recommended to use drain cleaners in your Bosch dishwasher. These chemicals can damage the dishwasher’s components. Instead, manually inspect and clean the filter, drain hose, and pump to address the drainage issue safely.

Why Is There Water Left in the Bottom of the Dishwasher?

Water left in the bottom of the dishwasher can occur if the cycle is interrupted before draining or due to a clog in the drain line or garbage disposal. Regular maintenance and clearing of obstructions can prevent this issue.

Can I Fix a Bosch Dishwasher Not Draining Myself?

Yes, you can often fix a Bosch dishwasher not draining by performing basic troubleshooting. Check and clear the filter, drain hose, and pump for clogs. If these steps don’t resolve the issue, professional assistance may be necessary.

Conclusion

A non-draining Bosch dishwasher can be caused by various issues, including a blocked drain line, a clogged garbage disposal, and a faulty dishwasher pump. Each of these problems can disrupt the dishwasher’s ability to drain water properly.

Resetting your Bosch dishwasher can often resolve minor drainage issues. Ignoring drainage problems can lead to more severe consequences, including water damage and mold growth.

To prevent future drainage issues, regularly clean the filter, inspect the drain hose, and use a rinse aid. Proper loading, running hot water before starting, and using the right detergent also help. 

This was all from my side. If you have any questions, comment below. I would love to help you further.

About Talen Quire

Talen Quire is a seasoned mechanical engineer with 20 years of industry experience. He earned his engineering degree from the University of Michigan and holds certifications in research and prototype development. Talen has collaborated with top brands like KitchenAid, GE, and BOSCH. Currently, he works at a leading research and development company. Passionate about technology, Talen actively shares the latest tech updates online, engaging a community of enthusiasts and professionals. Outside of work, he's an amateur astronomer and enjoys woodworking, creating detailed furniture and gadgets in his workshop.

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