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Bosch E23 on a washer dryer

Aquastop triggered — water has been detected in the base of the machine.

The same code appears on Neff and Siemens machines — they share the same control platform.

Verdict

Needs an engineer

Mains electrical, gas or sealed-system work

Urgency
Urgent

About 37 min to work through

Typical cost

£75–£220

DIY: £18–£60 in parts

What E23 actually means

Bosch machines have a float switch sitting in the base tray. If water collects under the appliance the float rises, the machine shuts everything down and locks out to stop a flood. This code is telling you the machine is leaking internally, so unlike a blocked filter it is not something to keep resetting and ignoring.

Before you start

  • Electrical safety: There is standing water inside an appliance that is connected to the mains. Unplug it at the wall before doing anything else, and do not run it again until the leak is found.

  • Water: Turn off the water supply tap. Left running, a slow internal leak will damage flooring and, in a flat, the ceiling below.

What causes it, most likely first

  1. Split door seal or bellows

    Most likely

    The rubber boot between the door and the tub perishes and splits, usually in the lower half where water sits. It leaks only when the drum is full or spinning, which is why the floor may look dry between cycles.

    Door seal / bellows£18–£50 for the partDIY with care

  2. Leaking pump filter housing or sump hose

    Common

    A cross-threaded or perished filter cap seal drips steadily into the base tray. So does a sump hose whose clip has relaxed or whose rubber has hardened with age.

  3. Detergent drawer or its housing overflowing

    Common

    A scaled-up drawer housing backs up on fill and overflows down the inside of the cabinet. Often accompanied by visible detergent residue down the front left of the machine.

  4. Failed tub-to-pump hose or a cracked sump

    Occasional

    Hoses inside the cabinet harden and crack with age and vibration. Finding which one needs the lid and often the front panel off.

  5. Drum bearing seal failure

    Occasional

    A failed shaft seal lets water past the bearings and down the back of the tub. This usually comes with a roaring noise on spin, and at this point replacement often beats repair.

    Drum bearing kit£25–£70 for the partEngineer

  6. False trigger from a tilted machine or condensation

    Rare

    A machine that is not level, or one moved with water still in the base tray, can trip the float without an active leak. Worth ruling out, but never assume it without looking.

How to fix it, step by step

  1. Isolate the machine immediately

    Unplug it at the wall and turn off the water supply tap. Do not keep resetting the code to squeeze another wash out — the anti-flood system is doing exactly the job it exists to do.

    2 min

  2. Drain the drum down and empty the base tray

    Use the emergency drain hose behind the bottom hatch to empty the drum. Then tilt the machine gently backwards onto its rear feet, with a helper, and let the base tray empty onto towels. Note roughly how much comes out.

    15 minTowels, Shallow tray

  3. Inspect the obvious leak points

    Peel back the outer lip of the door seal and run a finger round the lower half feeling for splits and grit. Check the filter cap seats squarely and its seal is intact. Pull out the detergent drawer and look for scale and backed-up sludge in its housing.

    15 minTorch

  4. If you found nothing obvious, stop and book an engineer

    Anything past this point means removing panels with the machine plumbed in and live testing to find the source. That is engineer territory. Tell them it is an E23 or F23 aquastop trip — it saves them diagnostic time and usually saves you money.

    5 min

Need an engineer for this E23?

We list 4 washer dryer repair businesses across the UK, 3 of which are Bosch-authorised. Diagnostic callouts typically start around £55, and many will put that towards the repair if you go ahead.

Find washer dryer engineers near you

Parts you might need

Typical UK prices for the part alone, before fitting. Worth knowing before you accept a quote — the part is often a small share of what a repair is priced at.

  • Door seal / bellows

    The flexible rubber boot between the door and the tub. Splits in the lower half leak only on fill or spin, which makes them easy to miss.

    £18–£50

  • Drum bearing kit

    The bearings the drum spins on, plus the shaft seal. Replacing them is a full strip-down and is often the point at which a repair stops being worth it.

    £25–£70

Worth repairing, or replace it?

At the top of this range the repair costs a significant share of a graded replacement, which typically starts around £280. Worth getting the quote first, then deciding — on a machine under about five years old a repair usually still wins.

Work out if it's worth fixingCompare graded washer dryers

Related problems

Other Bosch washer dryers codes

All Bosch washer dryers fault codes