What does the Bosch E23 error code mean?
The Bosch E23 error code indicates that the machine has detected water in the base of the appliance, triggering the built-in anti-flood protection system (also known as Aquastop).
When this happens, the washing machine will usually stop mid-cycle and may refuse to start again until the issue is resolved. The purpose of this system is to prevent water leaks from causing damage to your home.
In most cases, E23 is caused by a leak inside the machine or excess water collecting in the bottom tray. This can sometimes be a one-off issue, but it can also indicate a developing fault that needs attention.
Common symptoms of the E23 error
If your machine is showing the E23 error, you may notice the following:
- The washing machine stops suddenly during a cycle.
- The pump may run continuously even when the machine is off.
- The machine may not start a new programme.
- You may hear a constant humming noise from inside the appliance.
- In some cases, there may be visible water underneath or around the machine.
These symptoms are all linked to the anti-flood system being activated.
How to fix the Bosch E23 error code
Start by switching off the machine and unplugging it from the mains.
Carefully pull the appliance forward so you can access the sides and back. You may need help, as washing machines are heavy.
Tilt the machine slightly backwards at around a 30 to 45 degree angle. This allows any water trapped in the base tray to drain out. You may see water coming from underneath, so keep towels ready.
Once drained, return the machine to its normal position and leave it unplugged for several hours to fully dry out.
After drying, plug the machine back in and run a short cycle to check if the error has cleared.
If the E23 code does not return, the issue was likely caused by a temporary leak or excess water buildup.
Why the E23 error happens
Bosch washing machines use a float switch in the base of the appliance to detect water leaks. If water collects in this tray, the switch is triggered and the machine activates its anti-flood protection.
This immediately stops normal operation and may activate the drain pump to prevent further water buildup.
Even a small amount of water in the base can trigger this system, which is why E23 can sometimes appear suddenly.
When to call an engineer
If the E23 error keeps returning after you have drained and dried the machine, there is likely an ongoing leak inside the appliance.
Common causes include a worn door seal, a leaking hose, a faulty pump, or a cracked internal component.
At this point, further inspection usually requires removing panels and accessing internal parts, so it may be best to contact a qualified engineer.
Related Bosch error codes
Some Bosch washing machine error codes are closely linked to leak and drainage issues.
E18 indicates a drainage problem, often caused by blockages.
E21 indicates slow draining, which can develop into more serious faults.
If your machine is showing a different code, it’s worth checking those as well.
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