Bosch Dishwasher Not Draining: Causes and Fixes

When a Bosch dishwasher leaves water in the bottom of the tub, the usual cause is food debris clogging the filter or the drain pump. Bosch's own support pages say to clean the filter first, then take off the drain pump cover and clear anything caught underneath. If that does not fix it, the drain hose, the high loop or the disposer connection is the next place to look.

Bosch dishwashers often flag a drain problem with a code. E24 and E25 both point to drain trouble, and E22 points to a clogged filter. Our Bosch dishwasher error codes guide covers the full list.

Start with safety

Before you reach into the tub or under the sink, turn off power to the dishwasher at the circuit breaker or unplug it. If you will be working anywhere near the water line, or if water is on the floor, close the dishwasher's water supply valve. It is usually under the kitchen sink on the branch line that feeds the dishwasher, and it closes clockwise. If there is no working valve for the dishwasher, shut off the main water supply to the house.

Keep a towel and a shallow pan or cup handy. You will likely need to bail standing water out of the tub before you can get to the filter.

What you can check yourself

1. Clean the filter

Bosch uses a manually cleaned, multi-stage filter (coarse, fine and micro) at the bottom of the tub. It does not clean itself, so it fills up over time. Twist the filter out, rinse it under running water with a little mild soap and a soft brush, and lock it back in place. Bosch suggests doing this about every two months with normal use, and more often if you load dishes with a lot of food left on them.

2. Clear the drain pump cover

With the filter out, you will see the small drain pump cover in the sump. Bosch says to remove it and clear any debris. Glass shards, fruit pits, labels and bits of bone are common culprits. Remove anything you find, check that the pump's impeller turns freely, and put the cover back so it clicks into place.

3. Check the drain hose

Follow the drain hose from the back of the dishwasher to the sink. Look for kinks, crushed spots or a hose that got pinched when the unit was pushed back into the cabinet. A kinked or clogged hose is one of the causes Bosch lists for drain codes.

4. Confirm the high loop or air gap

Bosch's installation instructions call for a high loop in the drain hose, so dirty sink water cannot flow back into the dishwasher. A missing high loop is a listed cause of a not-draining code. If your sink has an air gap (the small cap on the countertop or sink deck), clear any debris inside it.

5. Check the disposer and sink drain

If the dishwasher drains into a garbage disposer, run the disposer to clear it. On a new disposer, the knockout plug at the dishwasher inlet must be removed. If it was left in, the dishwasher will not drain at all. A slow or clogged kitchen sink drain can also back up into the dishwasher.

Likely failed parts and what a technician tests

If the filter, pump cover, hose and sink drain are all clear and the tub still holds water, a part has probably failed. A technician will usually check:

• Drain pump. Bosch's E23 code points to a drain pump that is blocked, clogged or faulty. A tech checks whether the pump hums but does not move water, tests its winding, and looks for a cracked or seized impeller.
• Drain hose and connections. A hose clogged inside, or a check valve stuck shut, can stop water from leaving even when the pump runs.
• Wiring and connectors. A loose or corroded connector at the pump can make it look dead when the pump itself is fine.
• Control board. Less common, but if the pump never gets a signal to run, the electronics may be at fault.

Bosch dishwashers with Home Connect support Remote Diagnostics, which lets Bosch customer service look at a connected unit at the owner's request. That can help narrow things down before anyone opens the machine.

Water in the base is a different problem

If the display shows E15, water has reached the base pan under the tub and tripped Bosch's leak protection. That is not a drain clog. Shut off the water supply and get the leak found before running the dishwasher again. Our guide to a leaking dishwasher explains where that water usually comes from.

When to stop DIY and call a pro

Call a technician if:

• The filter and pump cover are clean, the hose is clear, and the tub still will not drain.
• You hear the pump hum or buzz with no water moving, or you hear grinding.
• E23 or E15 shows up, or the same drain code keeps coming back.
• Water is leaking onto the floor or into the cabinet.
• Fixing it would mean pulling the dishwasher out from under the counter or taking off the kick panel to reach the pump.

You can find local technicians who work on these machines through our Bosch dishwasher repair directory, including pages for Houston and Chicago. This site is an independent directory and is not affiliated with Bosch or BSH.

What a Bosch drain repair costs

Fixr puts a typical dishwasher service call fee at about $35 to $100, and that fee is often credited toward the repair if you go ahead with it. Fixr lists drain pump replacement at roughly $150 to $400, and a drain pump repair at about $100 to $250. If the problem turns out to be the control board, Fixr's range for replacement is about $200 to $500.

Fixr's rule of thumb is that if a repair costs more than about half the price of a new dishwasher, replacing it is usually the better value. Our dishwasher repair cost guide has more detail, and how long dishwashers last can help with the repair or replace call.

How to keep it draining

• Scrape food off plates before loading. You don't need to pre-rinse, but large scraps end up in the filter.
• Clean the filter about every two months, or more often with heavy use.
• Run a dishwasher cleaner and a descaler a few times a year on the hottest, longest cycle, as Bosch suggests.
• Run the disposer before starting the dishwasher.
• Keep stored items under the sink from pressing on the drain hose.

For drain problems on other brands, see our general guide to a dishwasher not draining, or browse all dishwasher guides.