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ErrBase

Bosch Washer E23 Error: Fix the Aquastop Leak Detection

Quick Answer

The E23 error indicates a leak has triggered the safety float switch in the bottom pan of your Bosch washer. To fix it, you must unplug the machine, drain the water from the base tray, and identify the source of the leak, such as a torn door seal or a loose drain pump filter.

When I see E23 on a Bosch display, I know that safety float in the bottom pan got lifted by standing water. Nine times out of ten it's a torn door gasket or a loose pump filter cap. Ignore this and you risk shorting out the control board or pump, which turns a $40 gasket job into a $400 repair. The machine won't run again until that tray is completely dry.

BoschWasherSeverity: highDifficulty: intermediate92% DIY Success
Time to Fix
30–90 min
Difficulty
intermediate
Parts Cost
—
Tools Needed
Phillips #2 screwdriver, Torx T20 screwdriver

What Does the E23 Code Mean?

So here's the deal with E23: your Bosch isn't broken, it's scared. There's water somewhere inside the cabinet that doesn't belong there, and the machine is protecting itself. Bosch puts a little float switch in the drip tray at the bottom, and the second that float lifts up, everything shuts down. I see this one pretty regularly, and it's almost always something you can fix yourself without calling a tech.

Most Likely Causes

Based on aggregated repair data, here is the probability breakdown for this error code:

Torn or damaged door gasket45%
Loose or clogged drain pump filter25%
Internal hose failure or loose clamp20%
Faulty Aquastop float switch sensor10%

Symptoms You May Notice

  • E23 or F23 flashing on the display and the machine refuses to start a new cycle, or it stopped mid-cycle and won't do anything except run the drain pump continuously.
  • You hear the drain pump humming nonstop even though the drum is clearly empty. It just won't quit.
  • A wet floor or small puddle under the machine, sometimes barely a cup of water, sometimes a lot more depending on how long that leak went unnoticed.
  • Machine stops mid-cycle, drains everything out completely, then locks up with E23 on the screen.
  • When you pull the machine out from the wall, there are white mineral deposits or water stains on the cabinet floor underneath it.

Can you reset a Bosch washer to clear the E23 code?

Once the base tray is completely dry and you've fixed the leak, here's how to reset. Turn the program selector dial all the way to the Off position. Unplug the washer and leave it unplugged for at least 10 minutes so the control board fully resets. Plug it back in, turn the dial to a short wash cycle, and press Start. If the tray is truly dry and the float has dropped, the machine should fire right up without the E23 coming back.

Tools Required for Diagnosis

Phillips #2 screwdriverTorx T20 screwdriverFlashlightShop vacuum or dry towelsPliers for hose clampsSmall shallow pan or bucket for draining filter

Diagnostic Checklist

Follow these steps in order. We start with the easiest external fixes before opening up the machine.

Frequently Asked Questions

Can I just reset the E23 code without fixing the leak?
No, the code is triggered by a physical float switch. While you can clear the code temporarily by drying the tray, it will return as soon as water leaks back into the base. You must find the leak to stop the cycle from repeating.
Is E23 the same as the F23 error code?
Yes, on most Bosch models E23 and F23 are identical. They both refer to the Aquastop leak detection system being activated. Different generations of Bosch controllers use the E or F prefix interchangeably, so don't let that throw you off.
Why does my Bosch washer keep draining when E23 is displayed?
That's actually on purpose. When the float switch trips, the control board forces the drain pump to run continuously to prevent the drum from overflowing and flooding your laundry room. It'll keep running until the water is removed from the base tray and the float drops back down.
Where exactly is the float switch located?
It's at the very bottom of the machine, sitting in the plastic floor pan. Usually a small white plastic housing with a piece of styrofoam inside that rises when water fills the pan. You'll have to tilt the machine or remove the back panel to actually see it.
How much does it cost to fix E23?
Depends completely on what's leaking. A door gasket for a Bosch runs about $40-80 for the part and it's the most common fix by far. The pump filter O-ring is basically free. If the Aquastop inlet hose failed, that's around $30-60 for the part. If you've got a cracked tub or bad pump housing, now you're looking at $150+ in parts and honestly at that point you want a tech to diagnose it before you start spending money.
Can I prevent E23 from happening again?
Yeah, honestly you can. Check the pump filter every 3 months and make sure it's threaded back on properly. Inspect the door gasket once a year, run your fingers around the whole thing feeling for thin spots or hardness. Don't wash anything with loose metal hardware without securing it first. And if your Aquastop hose is more than 7-8 years old, just replace it proactively. They're not expensive and a failed Aquastop hose can dump a lot of water really fast.

Models Known to Experience E23 Errors

This repair applies to most Bosch washers with this error code. Common model numbers include:

WAT28401UC, WAW285H2UC, WAS24460UC, WFVC5400UC, WAT28402UC, WAS20460UC, WAE24169GB

MS

Written by

Mike Sullivan

Lead Appliance Repair Technician · 20 years experience

Last verified for technical accuracy on March 17, 2026