What this error means
Aquastop triggered — flood protection system has activated
The E23 error means the machine's Aquastop flood protection system has detected water in the base of the machine and has automatically shut off the water supply to prevent flooding. This is a safety feature, not a machine malfunction. The most common causes are a leaking hose, a dripping door seal, a failed pump seal, or an overfilling fault that has allowed water to collect in the base tray.
What you'll need first
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Step-by-step
Symptoms to look for
- Machine stops mid-cycle and will not fill again
- Water visible on the floor around the base of the machine
- Machine completes a drain but then will not take on new water for the next phase
- Aquastop indicator light or fault code displayed on the control panel
What to check
Turn the water supply tap fully clockwise (closed) and unplug the machine from the mains socket. Both steps are essential before any inspection begins.
Using a torch, inspect the area around the base of the machine for signs of where the water entered. Look around the door seal, the pump area, the drum shaft at the rear, and all hose connection points at the back.
With the machine pulled carefully away from the wall, examine the full length of the inlet hose from the tap to the back of the machine. Some Siemens models use an Aquastop safety hose with a built-in shutoff valve and a separate outer casing. Check the full length for bulges, cracks, splits, or damp areas on the outer sleeve. Check that both hose end fittings are firmly attached with no drips.
Open the door and examine the rubber door seal around its full circumference. Look for cracks, tears, holes, or areas where the seal has pulled away from its retaining groove. Press gently into the fold of the seal and feel for soft or damp areas.
With the rear panel removed and the machine unplugged, shine a torch into the lower base area. Look for water staining, mineral deposits (white or brown marks indicating dried water), or active drips around the pump housing, the pump body, and where the sump hose connects to the pump.
Once the source of the leak has been identified and fixed, dry the base tray as thoroughly as possible using dry cloths or a sponge. The Aquastop float switch is a small buoyant component that rises on the water surface — it must return to its resting position before the machine will allow water to enter again. If necessary, carefully tilt the front of the machine upward by 10 degrees to allow remaining water to run toward the drain point.
When to call an engineer
- Leak is internal — from the pump seal, drum shaft seal, or a cracked internal hose
- Aquastop float switch remains raised even after the base tray has been thoroughly dried
- Door seal has a visible tear or has separated from the machine body
- Aquastop inlet hose is bulging, cracked, or shows water on the outer sleeve — must be fully replaced
Frequently asked questions
Does E23 mean the machine is broken?
Will the Aquastop reset itself automatically?
Is it safe to run the machine again after drying the base?
Can the Aquastop float switch itself become stuck?
🎯 What is likely causing this fault?
⚠️ Estimates based on common faults — not a guaranteed diagnosis. Always verify before ordering parts.
Parts you may need
Enter your model number to filter results to your exact machine
Usually found on a label inside the door frame or on the back panel of the machine.
| Part | Approx. UK Cost | Find it |
|---|---|---|
| Aquastop Hose | £10 - £20 | 🏷️ eBay UK → |
| Aquastop Hose | £20 - £30 | 🛒 Amazon UK → |
ℹ️ Prices are approximate. Always check the part number matches your model before ordering. Not sure of your model number? Find out how to locate it here.