FixByModel
E23

Bosch E23: AquaStop leak protection has been triggered

The machine's AquaStop anti-flood system detected water where it should not be and shut the washer down to prevent a flood. Bosch treats this as a leak that needs professional attention.

May need a technician

By the FixByModel editorial team · Verified 2026-09 · Researched against manufacturer support & repair references (below)

Most likely causes

  1. Water collecting in the base tray from an internal leak, tripping the anti-flood float
  2. Leaking or damaged AquaStop inlet hose assembly
  3. Loose hose clamp, split sump hose, or worn door seal letting water into the base
  4. Excess suds from too much or wrong detergent overflowing into the base
  5. Faulty AquaStop valve or its safety switch
Where water escapes
1Door gasket
2Hoses & clamps
3Base tray
4Leak sensor

Schematic illustration of a typical washing machine — not your exact model.

Before you start — unplug the appliance and turn off the water supply. You'll be working near water and electrical parts, and drained water can be hot. If a step involves the pump, wiring, or opening the cabinet and you're unsure, stop and call a qualified technician.

Step-by-step fix

1Turn off the tapClose the water supply tap immediately, since AquaStop activates when it senses a possible active leak.
2Stop using the machineDo not run further cycles until the cause is found, to avoid an actual floor flood.
3Check for standing waterLook under and around the machine for signs of a leak, and confirm no water is pooling on the floor.
4Review detergent useUse only the correct type and dose of detergent, as heavy sudsing can overflow internally and trip the system.
5Call for serviceBecause the leak is inside the sealed base, contact Bosch support or a technician to trace and repair it before returning the washer to use.

Still showing E23?

If you’ve worked through every step and E23 keeps returning, an internal part likely needs testing and replacement. That’s a job for a qualified appliance technician, who can measure the suspect part against the service-manual spec before replacing it.

Which models this applies to

Bosch washing machines. Bosch washers fitted with the AquaStop / anti-flood leak-protection system; displayed as E23 or F23.

FAQ

What does Bosch E23 mean?

AquaStop leak protection has been triggered. The machine's AquaStop anti-flood system detected water where it should not be and shut the washer down to prevent a flood. Bosch treats this as a leak that needs professional attention.

What causes Bosch E23?

The most likely cause is water collecting in the base tray from an internal leak, tripping the anti-flood float. Other causes include Leaking or damaged AquaStop inlet hose assembly; Loose hose clamp, split sump hose, or worn door seal letting water into the base; Excess suds from too much or wrong detergent overflowing into the base; Faulty AquaStop valve or its safety switch.

Can I fix Bosch E23 myself?

Some checks are DIY, but this code often points to an internal component, so it may need a qualified technician.