Bosch Dishwasher Not Draining: Troubleshooting Tips and Solutions

Do you have a Bosch dishwasher that’s not draining properly? If you’re dealing with standing water at the bottom of your dishwasher and dishes that come out still wet, we’re here to help you troubleshoot and find solutions to resolve the draining issue and restore the efficiency of your dishwasher.


If you own a Bosch dishwasher and are facing the frustrating issue of it not draining properly, you’re not alone. A dishwasher that fails to drain can be a major inconvenience, causing water buildup and preventing your dishes from getting clean.

In this comprehensive guide, we will delve into the common reasons why your Bosch dishwasher may not be draining and provide you with effective troubleshooting tips and solutions.

So, let’s roll up our sleeves and get your dishwasher back in working order!

Bosch Dishwasher Not Draining: Common Causes and Solutions

1. Clogged Drain Hose

A clogged drain hose is one of the primary culprits behind a Bosch dishwasher failing to drain. Over time, food particles, debris, and mineral deposits can accumulate in the hose, obstructing the water flow. To check if the drain hose is clogged:

  • Step 1: Turn off the dishwasher and disconnect it from the power source.
  • Step 2: Locate the drain hose, usually found at the back of the dishwasher.
  • Step 3: Detach the drain hose from the dishwasher and inspect it for any blockages.
  • Step 4: If you find a clog, use a plumber’s snake or a straightened coat hanger to gently remove the obstruction.
  • Step 5: Reattach the drain hose and test the dishwasher to see if it drains properly.

2. Blocked Dishwasher Filter

Another common reason for a Bosch dishwasher not draining is a clogged or dirty filter. The filter is responsible for trapping food particles and preventing them from entering the drain pump. Over time, the filter can become congested, impeding water flow.

Here’s how you can clean the filter:

  • Step 1: Locate the dishwasher filter, usually situated at the bottom of the dishwasher’s interior.
  • Step 2: Remove the filter by twisting or lifting it, depending on the model.
  • Step 3: Rinse the filter under warm running water to remove any debris and buildup.
  • Step 4: Inspect the filter for damages, such as cracks or tears. If necessary, replace it with a new one.
  • Step 5: Reinstall the clean filter and run a cycle to check if the dishwasher drains properly.

3. Faulty Drain Pump

If both the drain hose and filter are clear of any obstructions, the issue may lie with a malfunctioning drain pump. The drain pump is responsible for pumping out the water from the dishwasher during the drain cycle. If it fails to function correctly, water will accumulate in the dishwasher basin.

To troubleshoot a faulty drain pump:

  • Step 1: Turn off the dishwasher and disconnect it from the power source.
  • Step 2: Locate the drain pump, typically situated at the bottom of the dishwasher.
  • Step 3: Inspect the drain pump for any signs of damage, such as broken impellers or a burnt-out motor.
  • Step 4: If you notice any issues, it is advisable to replace the drain pump. Refer to the manufacturer’s instructions or seek professional assistance for a safe and accurate replacement.

4. Improper Dishwasher Installation

Sometimes, a Bosch dishwasher may not drain properly due to incorrect installation. If the drain hose is not installed correctly, it can lead to drainage problems.

Ensure the following during installation:

  • The drain hose should have a loop or high point to prevent backflow.
  • The drain hose should not be kinked or twisted.
  • The drain hose should be connected securely to the drain system.

5. Clogged Garbage Disposal

If your Bosch dishwasher shares a drain line with the garbage disposal, a clog in the disposal unit can cause drainage issues. The garbage disposal can become obstructed with food particles and grease over time, hindering water flow from the dishwasher.

To address this:

  • Step 1: Turn off the dishwasher and garbage disposal, and unplug them from their power sources.
  • Step 2: Check the garbage disposal for any clogs. If present, use a plunger or an Allen wrench to dislodge the obstruction.
  • Step 3: Once cleared, reconnect the dishwasher and garbage disposal and test the dishwasher to ensure proper drainage.

6. Insufficient Air Gap

An inadequate air gap can also lead to drainage problems in a Bosch dishwasher. The air gap prevents backflow of drain water into the dishwasher. If the air gap is blocked or installed incorrectly, it can disrupt the draining process.

Follow these steps to check and clean the air gap:

  • Step 1: Locate the air gap, usually positioned near the sink faucet or on the countertop.
  • Step 2: Remove the cap of the air gap and inspect it for any debris or obstructions.
  • Step 3: Clean the air gap thoroughly, ensuring the passage is clear and unobstructed.
  • Step 4: Replace the cap and run a dishwasher cycle to check if the drainage has improved.

FAQs about Bosch Dishwasher Not Draining

1: Why is my Bosch dishwasher not draining water?

If your Bosch dishwasher is not draining water, it could be due to a clogged drain hose, a blocked dishwasher filter, a faulty drain pump, improper installation, a clogged garbage disposal, or an insufficient air gap.

2: Can I use a plunger to unclog my Bosch dishwasher?

No, using a plunger to unclog your Bosch dishwasher is not recommended. The forceful plunging action can damage the delicate components of the dishwasher. It is best to address clogs by cleaning the drain hose, filter, or other dishwasher components.

3: How often should I clean the dishwasher filter?

To maintain optimal performance, it is advisable to clean the dishwasher filter once every two to three months. However, if you notice any signs of blockage or if your dishwasher is not draining properly, it is recommended to clean the filter immediately.

4: Can I install a Bosch dishwasher without an air gap?

While an air gap is not mandatory for Bosch dishwasher installation, it is highly recommended. The air gap prevents backflow of water into the dishwasher and helps ensure proper drainage. It is a safety feature that protects your dishwasher and the integrity of your home’s water supply.

5: When should I seek professional help for my Bosch dishwasher not draining?

If you have followed the troubleshooting steps mentioned in this article and your Bosch dishwasher still fails to drain, it is advisable to seek professional assistance. A qualified technician can diagnose the underlying issue and provide the necessary repairs or replacements.

6: How can I prevent future drainage issues with my Bosch dishwasher?

To prevent future drainage problems with your Bosch dishwasher, make sure to:

  • Regularly clean the drain hose and dishwasher filter.
  • Avoid overloading the dishwasher with excessive dishes.
  • Scrape off excess food particles before loading the dishes.
  • Run hot water in the sink before starting the dishwasher to ensure proper water temperature.


Dealing with a Bosch dishwasher not draining can be a frustrating experience, but with the right troubleshooting steps, you can resolve the issue and get your dishwasher back to its optimal functioning.

By addressing common causes like a clogged drain hose, a blocked dishwasher filter, or a faulty drain pump, you can restore proper drainage and ensure clean and spotless dishes every time.

Remember to follow the recommended maintenance practices and seek professional help when needed. Enjoy the convenience of a well-functioning Bosch dishwasher!

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