Bosch E23 fault codewhat it means and how to fix it
Water has been detected in the base of the machine and the AquaStop system has cut in. Bosch say to turn the tap off immediately and stop using it until it is repaired.
Stop — this needs an engineer
Get a qualified appliance engineer to look at your Bosch E23
We do not pass enquiries to a repair firm, so there is no form here. When you book a qualified appliance engineer, tell them the make, the model and the exact code or message on the display, and ask whether they carry parts for this make — that is what turns one visit into a repair rather than a quote.
What E23 means
E23 is the one Bosch code where the manufacturer uses genuinely urgent language, and it deserves to be taken at face value. It means water has collected in the base of the machine and the leak protection has triggered. Bosch UK’s page says the washing machine is leaking or there is water in the base plate, and that if you suspect a leak you should turn off the supply tap immediately. Their instruction manual is blunter still: there is water in the base trough, the appliance is leaking, turn off the tap and call after-sales service.
BSH’s Bosch-branded article says it is "unfortunately a problem that you cannot resolve by yourself" — turn off the water tap, call customer service — and Bosch’s US index adds that you should not use the washing machine until it has been fixed.
Two things make this worth stopping for rather than working around. The first is obvious — a leak inside a cabinet that also contains mains electronics is the one hazard a washing machine genuinely has, and the base tray is where a leak collects before it reaches your floor. The second is that AquaStop is a protective system doing its job. Resetting it to get one more wash out of the machine overrides the thing that is currently containing the problem. The immediate actions are simple and you should do them now: turn off the water tap behind the machine, switch it off at the wall and unplug it, and leave it until somebody has looked at it.
What causes it
| Cause | What is actually happening | How likely |
|---|---|---|
| Internal hose or connection leaking | A perished sump hose or a loosened clip letting water into the base tray. Common on older machines and one of the more straightforward repairs. | Common |
| Pump or sump seal failed | Water escaping at the bottom of the tub where the pump connects. Tends to worsen steadily rather than suddenly. | Occasional |
| Door seal split at the bottom | A perished boot leaking down the front of the cabinet and collecting underneath. Sometimes visible from outside if you fold the seal back. | Occasional |
| Heavy foaming overflowing the tub | Not a cause Bosch list for this code, but enough excess detergent can push foam out of the tub and into the base, tripping the sensor without any component having failed. | Occasional |
| Leak sensor faulty | The protection system reporting water that is not there. Real, but assumed only after a leak has been ruled out rather than before. | Rare |
Can you fix it yourself?
Stop — this needs an engineer
What it costs to fix
Typical repair cost
£90–£260
A hose or clip repair is typically £90 to £160. A pump or tub seal is more, at £150 to £260, because more has to come apart to reach it.
Typical UK prices including parts and labour, updated September 2026. Your quote may differ.
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Related Bosch fault codes
- E18Get it checkedThe machine could not pump out in the time allowed. Bosch point at the filter and the drain hose, and warn that the water you are about to release may be scalding.Related: same brand
- E17Get it checkedProblems with the water connection: tap, kinked hose, blocked inlet filter or low pressure. Bosch’s AquaStop hose has a filter at the tap end most owners do not know about.Related: same brand
- E32Usually simple to fixAn unbalanced load, and Bosch headline it as the machine flashing "end" at the end of the programme. They state outright that this is not a fault.Related: same brand
- E06Get it checkedThe pump is blocked by something that got into it, or the outlet hose was kinked when the machine was last moved. Both are owner jobs.Related: same brand
- E16Get it checkedThe door is not locked properly. Bosch’s US index groups this with E34, F16 and F34 as one fault, and washing caught in the seal is the usual reason.Related: same brand
- E19Get it checkedA fault in the heating circuit. BSH offer nothing to try and send it straight to service, and they give E20 the same one-line answer.Related: same brand
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Related guides
Common questions about Bosch E23
What should I do right now?
Three things, in this order. Turn off the water tap behind the machine — Bosch’s first instruction in every document. Switch it off at the wall and pull the plug. Then leave it alone and book someone. Bosch’s manual says call after-sales service, and their US page says not to use the machine until it has been fixed; that is a straightforward instruction rather than a legal disclaimer.
There is no water on my floor. Is it really leaking?
Very possibly, and that is the point of the base tray — it catches the leak before it reaches your kitchen. A dry floor means the protection is working, not that there is nothing wrong.
Can I just tip the machine to drain the tray and carry on?
No. That is a widely shared trick and it defeats the safety system without addressing the leak. You would be running a machine that is putting water into its own base with the sensor emptied so it cannot tell you again.
Could too much detergent have caused it?
It can. Heavy foaming can push suds over the top of the tub and into the base, which trips the same sensor. It is worth mentioning to the engineer if you have had a foaming problem, but it does not change what to do now.
Is this worth repairing?
Frequently yes — a hose or a clip is a modest job. What makes it unpredictable is that the leak has to be found before it can be priced, so expect a diagnosis first and a figure after.
Technical review
Not reviewed by an engineer
No engineer has read this page. Severity follows what the manufacturer publishes, and we would rather tell you that than let a byline imply a sign-off.
Sources and how we verified this
We establish the facts from the sources below and then write the explanation ourselves. We do not copy manufacturer wording and we do not host their manuals.
- Manufacturer support portal
- Manufacturer technical and service documentation
This page has not been reviewed by an engineer, and we would rather tell you that than imply otherwise. The severity rating follows what the manufacturer publishes: where they say isolate the appliance and call someone, so do we.