Bosch Dishwasher Not Draining? Causes and Solution

Hello Bosch Dishwasher owners! If you are facing a Bosch dishwasher not draining, don’t worry. This post will break down the various things that you can do to fix this issue and get it working again. Bosch is one of the best brands for dishwashers for many people because they are durable, long-lasting, and easy to maintain.

However, Bosch dishwashers also have a reputation for being difficult to repair if something goes wrong with them. Fortunately, there are several steps you can take before calling in a professional or buying a new dishwasher!

What Causes Bosch Dishwasher Not Draining? Troubleshoot and Diagnosis

Bosch Dishwasher Not Draining

Please check the below tips on how to fix a Bosch dishwasher that won’t drain.

Check Drain Hose

Bosch dishwashers are notorious for not draining properly. This might be because the hose is blocked or kinked, which could also mean that your Bosch dishwasher isn’t getting enough water to get all of the dishes clean. If the Bosch dishwasher not draining, first take a look and see if the drain hose is clogged. This will be one of the most common causes for Bosch dishwashers to stop draining water effectively.

If the hose is kinked, it can block the normal flow of water. To fix this problem, manually unkink or straighten out the hose to allow for a normal flow of water.

You’ll need to make sure that the drain hose doesn’t have any clogs or blockages. Disconnect it from your dishwasher and blow through, using a long wire coat hanger to check for debris too! Make sure there are no kinks in the line because these could stop water from flowing out of the machine. Double-check when you reattach it and ensure that its seal valve is securely fastened on again – this will make everything flow smoothly next time you use it.

Faulty Drain Valves

Most, but not all, dishwashers have a drain valve. This helps to keep water from draining back into the dishwasher. If the dishwasher has a bracket, then your dishwasher has this kind of valve.

See also  Bosch Dishwasher E22 Error Code [SOLVED] - Let's Fix It

Drain valves are not like most other parts in your home. They’re a one-way valve that makes sure water can flow out of the plumbing system when it needs to do so, but they actuate only when there is enough pressure from behind them and if debris hasn’t clogged up their way.

To ensure this function continues as smoothly as possible, clean out any residue or gunk that may have built upon the drain valve over time by removing its cover—it should be pretty easy with just an Allen wrench for assistance! If you’re still unable to activate it after cleaning it thoroughly without success, then don’t hesitate to replace what’s preventing drainage from happening.

Clogged Garbage Disposal

If your garbage disposal isn’t working at all, then something may have clogged it up from behind. This can happen when food waste such as leftover chicken bones is thrown into the disposer while still inside an un-rinsed container (or any other type of liquid). Or when too much grease has been put down the drain.

The drain hose from the dishwasher runs into your garbage disposal to empty water. If you have any food leftover in the sink that needs to be ground up or grease builds up in the pipe below it, this can prevent the dishwasher from draining properly. Some dishwashers don’t drain properly. You can try running your disposal to see if the problem clears up.

It is important to leave the faucet running and let your garbage disposal run for an additional 15 seconds after you are done with food to avoid getting clogs. This clears all the leftover food out from underneath the disposal.

See also  7 Reasons Why Dishwasher Soap Not Dissolving - DIY Solutions

Check Drain Pump

All dishwashers require drainage for the completion of a cycle. Most use a single motor to actuate two separate pumps, one that circulates water and one that drains it. Some dishwashers have an independent pump for draining, while the main circulating pump can assist others with a solenoid or flapper valve. On models that use a separate drain pump, you should check to see if there is any power getting to the pump during its draining portion. It’s also worth noting whether or not something has been inadvertently jammed in the input and output of the pump.

Check for damage to the drain impeller and replace if necessary. Make sure that the impeller can spin freely without binding.

Check to ensure the dishwasher’s motor is running in the appropriate direction. If the motor isn’t running at all, use a multi-meter to determine if electrical power is being sent out on that circuit. If there’s no power going out to that wire, one could check for malfunctioning door switches and/or an electronic control board that may not send electricity through those respective wires. Correct it, and it will help in resolving the Bosch dishwasher not draining issue.

If the dishwasher is making a loud humming noise, it might be that the motor has seized, or the drain impellor could be jammed. If that’s happened, you’ll need to replace either just the motor or get both a new motor and pump assembly.

Clean the Air Gap

The air gap located at the top of your sink should be clear in order to prevent water from backing up into your dishwasher. The air gap is Connected to the drain hose; this slotted cylinder is made of stainless steel and must remain free of blockage.

The air gap can be easily cleaned by first screwing the cap counterclockwise to remove it. Use water and brush to clean it out, then run the dishwasher cycle. If your dishwasher is filling up with water, this should correct the issue.

See also  Bosch Dishwasher Error Code E01 [SOLVED] – Let’s Fix It

Using the Wrong Detergent

Dishwashers are designed to work with dishwashing detergents that leave no suds. It’s all too easy to accidentally pour regular dishwashing soap into a dishwasher, where it can cause suds that obstruct the drain. If you run out of automatic dishwasher detergent and substitute laundry detergent, then the same problem can occur.

To fix this, clean the dishwasher tub until no water is left, and just run the cycle again with the correct type of detergent.


Some dishwashers may use a mechanical timer to control their cycles. The timing controls the main pump motor as well as the drain solenoid or even a separate drain pump if needed (depending on which style of dishwasher you have). 

The timer is usually in the control panel at the top of the dishwasher door. A wiring diagram and schematic can help you find out which contacts control the drain cycle. If the timer is defective, then you will get the Bosch Dishwasher Not Draining problem. Test the timer using a multimeter and if it fails the continuity test, then replace it.

Let me know if you need any help with your Bosch dishwasher. I’m happy to answer questions and provide guidance on troubleshooting the problem of not draining through a comment below!

Leave a Comment

Your email address will not be published. Required fields are marked *

Scroll to Top