Bosch Dishwasher E20 Error Code — What It Means & How to Fix It

What Does This Error Mean?

E20 on a Bosch dishwasher means there is a problem with the drain pump — the dishwasher cannot drain the water after washing. You will likely see water standing in the bottom of the dishwasher tub at the end of a cycle. The most common cause is a blocked filter, clogged drain hose, or debris jamming the drain pump impeller. In most cases, this error can be resolved without professional help.

Affected Models

Bosch Serie 2 SMS25
Bosch Serie 4 SMV46
Bosch Serie 6 SMS68
Bosch Serie 8 SMV88
Most Bosch freestanding and built-in dishwashers

Common Causes

Clogged dishwasher filter preventing water from reaching the drain pump
Drain hose is kinked, blocked, or improperly installed preventing water from leaving
Drain pump impeller is jammed by broken glass, a bone, or other debris
Drain pump motor has failed and cannot run
Blocked sink drain or garbage disposal connection preventing dishwasher water from exiting

How to Fix It

Remove, clean, and reinstall the dishwasher filter. This is the most common cause of E20. Twist the cylindrical filter counterclockwise to remove, rinse under the tap, and scrub with a soft brush.

If there is standing water in the tub, use a sponge or small bowl to remove it before accessing the filter.
Check the drain hose for kinks. The drain hose runs from the dishwasher to the sink drain under the counter. It should have a smooth curve with no sharp bends.

Also check the connection at the sink drain or garbage disposal — food buildup at the connection point is a common blockage location.
If you have a garbage disposal, ensure the knockout plug was removed when the dishwasher was installed. A missed knockout plug completely blocks drainage. Check this if the dishwasher is newly installed.

New garbage disposals come with a plastic plug over the dishwasher connection inlet — it must be punched out before connecting the dishwasher.
Carefully reach into the sump area (after removing the filter) and feel for debris around the drain pump inlet. Remove any glass, food, or objects that you find.

Broken glass in the sump is common — use gloves and feel carefully rather than grabbing blindly.
Run a short drain-only cycle or reset the dishwasher and run a quick wash to test whether E20 has cleared. If water still does not drain, the drain pump motor has likely failed and needs professional replacement.

Bosch drain pumps typically cost £40 to £90 / $50 to $110 for the part.

When to Call a Professional

If cleaning the filter and drain hose does not clear the blockage, the drain pump may need to be accessed and cleared or replaced. Accessing the drain pump requires removing the lower panels of the dishwasher. An appliance technician can do this quickly and also test whether the pump motor has failed.

Frequently Asked Questions

There is water at the bottom of my Bosch dishwasher — is that the E20 error?

Standing water in the tub at the end of a cycle is the main symptom of E20. A small amount of water (a cup or less) below the filter is normal on many dishwashers. But if the tub has inches of water that clearly was not drained, E20 is the likely error code.

Can I use my Bosch dishwasher while it has the E20 error?

The dishwasher will likely refuse to start a new cycle if it detects standing water from the last cycle. You must clear the blockage and drain the water before the machine will run again. Do not add dishes and try to force a cycle — you may make the blockage worse.

How often should I clean my Bosch dishwasher filter?

Bosch recommends cleaning the filter at least once a month — or more often if you use the dishwasher daily. A clean filter is the best prevention for E20 and most other drainage errors. It takes less than 5 minutes to remove, rinse, and reinstall.