What Does Error Code E23 Mean on a Bosch Washing Machine?
Tilt the machine gently forward to drain any pooled water from the base tray, then inspect the door seal and hose connections for visible leaks before restarting — this resolves the majority of E23 alerts caused by minor spillage or a loose hose connection (takes about 15 minutes).
Fault description
Error code E23 is triggered by Bosch's Aquastop or anti-flood protection system. A float sensor sits inside the plastic base tray beneath the drum. When water collects there — even a small amount — the sensor activates, the machine halts mid-cycle, and E23 is displayed on the control panel. The pump may run continuously in an attempt to clear the water.
This is a safety feature, not a nuisance fault. The machine is telling you that water has escaped from somewhere it shouldn't be. The source could be anything from a loose hose fitting to a cracked drum seal, so it's worth taking the fault seriously rather than simply resetting the machine and hoping it clears.
In most cases the water in the base tray is small in volume and the underlying cause is straightforward to identify. Working through the checks below in order will help you pinpoint the problem without needing specialist tools.
Causes
- Water pooled in the base tray from a previous minor leak — Even after the original leak source is fixed, residual water sitting in the base tray will keep the float sensor triggered. The machine cannot reset until that water is physically removed.
- Loose or damaged inlet or drain hose connection — Hoses can work loose over time due to vibration, especially at the point where they connect to the machine or to the wall supply. A slow drip from a loose jubilee clip or cracked hose end is enough to fill the base tray gradually.
- Worn or torn door seal (door gasket) — The rubber door seal can develop small tears, holes, or a build-up of mould that prevents it from forming a watertight contact with the door glass. Water then escapes around the door during the wash or spin cycle.
- Leaking detergent drawer or housing — Blocked detergent drawer channels can cause water to overflow and run down into the base of the machine rather than into the drum. This is more common when non-HE detergent or excessive amounts of detergent are used.
- Faulty or cracked pump housing or sump hose — The drain pump and the short rubber hoses connecting it to the drum and filter housing can develop cracks or loose clamps. A leak here drips directly into the base tray and is often only visible when the machine is running.
- Damaged or blocked pressure chamber or pressure hose — The pressure system that monitors water level uses a small rubber hose. If this hose splits or its connection weeps, water can track down into the base. A blocked pressure chamber can also cause overfilling, which leads to overflow.
Step-by-Step Fix
- 1
Switch off and unplug the machine
Before doing anything else, turn the programme dial to off and unplug the machine from the mains. Do not attempt to open the door or move the machine while it is still powered. Wait two minutes for any residual electrical charge to dissipate.
- 2
Drain the base tray
Carefully tilt the machine forward by about 15 degrees and hold it there for 30 seconds to allow water in the base tray to drain out through the ventilation slots at the bottom rear. Place old towels on the floor first. Once drained, stand the machine upright and leave it for 10 minutes to allow the float sensor to drop back to its resting position.
- 3
Inspect hose connections at the back of the machine
Pull the machine away from the wall and check both the cold water inlet hose and the drain hose. Feel along the full length of each hose for dampness. Tighten any loose jubilee clips with a screwdriver and look for cracks or splits in the hose body. Replace any hose that shows visible damage.
- 4
Check the door seal for damage
Open the door and run your fingers around the full circumference of the rubber door gasket. Look for tears, holes, or areas where the seal has pulled away from its retaining groove. Also check for a build-up of black mould, which can prevent the seal from sitting flush. A damaged seal will need to be replaced — it cannot be repaired with sealant reliably.
- 5
Clean and inspect the detergent drawer
Pull the detergent drawer fully out and rinse it under a tap to clear any blocked channels. Check the drawer housing inside the machine for limescale or detergent residue blocking the water jets. Blocked jets cause water to back up and overflow into the machine body. Wipe the housing clean with a damp cloth.
- 6
Run a short test cycle and observe
Once you have checked and addressed the above points, plug the machine back in and run a short 30-degree cotton cycle. Stay with the machine and watch for any drips from the door seal, hose connections, or beneath the machine. If you see water appearing, stop the cycle immediately and note exactly where it is coming from.
- 7
Check the pump filter area for leaks
If the test cycle triggers E23 again with no visible external leak, the source is likely internal — the pump housing or sump hose. Open the small access panel at the bottom front of the machine, place a shallow tray underneath, and slowly unscrew the filter cap to release residual water. Inspect the filter housing and the rubber seal on the cap for cracks or deformation. A damaged filter cap seal is an inexpensive fix.
Affected models
Select your model to see its full troubleshooting page.
When to call a service technician
If you have drained the base tray, checked all external hoses and the door seal, and the machine still triggers E23 within one cycle, the leak is most likely internal. Common internal sources include a cracked drum spider, a split sump hose, or a leaking pump body — all of which require the machine to be partially dismantled to access safely.
You should also call a service technician if you notice water staining or corrosion on the base tray itself, if the float sensor appears physically damaged, or if the machine is still under warranty and you do not want to risk voiding it by opening the casing. A technician can pressure-test the system and identify the exact source quickly.
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Frequently Asked Questions
Can I reset the E23 error without fixing the leak?
You can clear the error temporarily by unplugging the machine and draining the base tray, but if the underlying leak is still present the sensor will trigger again as soon as water re-enters the base. Resetting without fixing the cause risks water damage to your floor and the machine's electrical components.
How do I drain the water trapped inside the machine when E23 is showing?
Use the emergency drain procedure: place a shallow tray under the small access panel at the bottom front of the machine, then slowly unscrew the filter cap to release the water in a controlled flow. Have plenty of towels ready. Once empty, you can open the door safely.
Is E23 the same as the Aquastop system activating?
They are related but not identical. The Aquastop system refers specifically to the valve in the inlet hose that cuts off the water supply when it detects a leak in the hose itself. E23 is triggered by the float sensor in the base tray, which responds to any water in the machine's base — regardless of where it came from.
How much does it typically cost to repair a Bosch washing machine showing E23?
If the fault is a door seal or a hose, parts are generally inexpensive and the repair is straightforward. A door seal for a Bosch machine typically costs between £20 and £50 depending on the model. If the pump or internal hoses need replacing, a service technician call-out including parts and labour is likely to fall in the £80–£150 range, though this varies by region.
Why does my Bosch washing machine keep showing E23 even after I've dried out the base?
If the error returns quickly after drying the base, there is an active leak that has not been identified yet. The most common overlooked sources are a pinhole tear in the door seal that is only visible when the seal is stretched, a weeping connection on the pressure hose at the back of the drum, or a hairline crack in the pump housing that only leaks under pressure during a cycle. A service technician with a torch and experience of the machine layout can usually find this within a single visit.