Bosch Dishwasher Drain Pump Test

Bosch makes one of the best-selling dishwashers worldwide. They are known for the most advanced features, great cleaning power, and energy-saving designs. Homeowners prefer buying a Bosch dishwasher regardless of high price because it is reliable and durable.

However, like all the other dishwashers in the market, Bosch dishwashers can develop drainage problems. The best thing about troubleshooting the Bosch dishwasher not draining is that you can simply check if its pump is working or not in a few simple steps.

In this article, we will discuss how you can perform a drain pump test on a Bosch dishwasher.

Bosch Dishwasher Drain Pump Test

Please note that the following guidelines are for Bosch Ascenta series dishwashers. The steps can work for other series and models, too, but it is best to keep your user manual nearby while performing a drain pump test on your Bosch dishwasher.

What is a Drain Pump?

A drain pump is used to force the water out from your dishwasher and plays an important part in draining your machine properly. Any issues in the drain pump will result in water not being pushed out of the machine.

How to Test the Drain Pump

Luckily Bosch dishwasher users don’t need any tools or complex processes to check if the drain pump is working or not. Follow the steps below to test the drain pump in your dishwasher.

Step 1: Safety First

Turn off your dishwasher and remove the plug from the outlet. If the plug is hidden behind the wall, turn off the breaker powering the dishwasher. Please keep in mind that it will turn off other appliances on that breaker as well.

Step 2: Prepare your Dishwasher

Empty your dishwasher and remove the bottom rack.

Step 3: Remove the Filter

Step 3 Remove the Filter

Remove the water filter from your Bosch dishwasher and check for obstructions or food particles blocking the drainage system. Remove the clogs, if any. If the water starts draining, your pump is working fine.

Wash the filter if it needs cleaning. You can clean the filter and screen by placing it in a bowl of white vinegar and then washing it with warm soapy water. Use an old toothbrush to remove any stubborn particles.

Step 4: Testing the Drain Pump

Step 4 Testing the Drain Pump

You can check the drain pump by lifting the float. The floater is located near the base of the spray arm. Refer to the user manual if you can’t locate it.

When you lift the float, it causes the dishwasher to activate the drain pump. If the water starts to disappear from the bottom of your dishwasher, it means that the drain pump is working and the drain line is not clogged.

Step 5: General Cleaning

While you are at it, it is best to clean your dishwasher to remove any clogs and food particles that may be blocking the drainage system. Follow the steps below for clearing the drainage system of your dishwasher.

  • Add 4-5 tablespoons of baking soda to a glass container and make a paste with tap water.
  • Through the paste at the bottom of the dishwasher with the filter and screen removed.
  • Pour 1-2 cups of white vinegar over the baking soda.
  • Now add 1-2 liters of boiling water.
  • Let the contents sit for 20-30 minutes before inserting the filter back on.
  • Run a short rinse cycle to clean your dishwasher.
  • Make sure that you don’t add vinegar and boiling water to the container holding baking soda. These things must go in the dishwasher as per the sequence mentioned above.

Final Words

Testing the drain pump in this way saves a lot of time and lets you know that the drain system is working properly. It rules out drainage system errors from your troubleshooting checklist.


  • Stephen Powers

    Appliance repair guy from Washington. I am majorly experienced in dishwashers, water filters and refrigerators, AMA on my twitter account.

2 thoughts on “Bosch Dishwasher Drain Pump Test”

  1. I have done all of the above. There is no corrosion in our dishwasher. I even replaced the pump. We keep getting E-24 messages. I flushed water through all the drain pipes. Checked the return valve (looks okay). The filter/screen are clean. The little white drain pump cap clicks into place.

    I’m at a loss as to what else could be wrong.


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