# How to Fix Bosch Error E23 (AquaStop Leak)
Error code E23 on a Bosch washing machine specifically relates to the **AquaStop System** detection. This guide will help you understand the error and walk through the necessary steps to diagnose and resolve the leak.
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## 1. Explanation: What is Error E23?
The Bosch E23 error code signals that the washing machine has detected water leaking into its base pan (the sealed bottom tray beneath the drum).
### What is the AquaStop System?
Bosch washing machines are equipped with an anti-flood system called AquaStop. This is a crucial safety feature. When water pools in the base pan, a small polystyrene float rises and triggers a micro-switch (the AquaStop sensor).
**When E23 appears, the machine immediately:**
1. Stops the water inlet.
2. Activates the drain pump to prevent further flooding.
3. Displays the E23 error and locks the cycle.
**The most likely culprits for this water accumulation are:**
* A leak from the main door seal or bellows.
* A cracked internal hose or tub seal.
* **The AquaStop Inlet Hose itself (the solenoid valve assembly is leaking).**
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## 2. Step-by-Step Fix and Diagnosis
To resolve E23, you must first drain the water from the base pan to reset the float switch, and then identify the source of the leak.
⚠️ **SAFETY FIRST:** Always unplug the washing machine from the wall outlet before attempting any repairs or moving the unit. Turn off the water supply taps.
### Step 1: Drain the Base Pan and Reset the Sensor
The E23 error will not clear until the water is removed from the pan, allowing the float switch to drop.
1. **Preparation:** Place thick towels or a shallow pan behind the machine to catch the spilled water.
2. **Tilt the Machine:** Carefully tilt the machine forward by about 45 degrees. You may need a second person for this.
3. **Release Water:** Hold the machine in this position for 30–60 seconds. You should hear and see water pouring out from the bottom rear of the unit. This is the water that was collected in the base pan.
4. **Stand Upright:** Gently set the machine back down.
5. **Restart:** Plug the machine back in. If the error clears, the sensor has reset.
### Step 2: External Inspection (Find the Source)
If the error clears, run a quick, empty rinse cycle and observe the machine closely to find the source of the leak.
1. **Inspect the Door Seal:** Look for visible tears, especially at the bottom of the rubber door gasket (bellows).
2. **Check Hoses:** Feel around the connections where the hot and cold fill hoses attach to the rear water valves. Ensure they are tight and not dripping.
3. **Examine the AquaStop Hose:** If your machine has a thick, specialized AquaStop Inlet Hose (with a plastic block/box near the tap connection), inspect the plastic housing for cracks or moisture, as the solenoid valve inside can sometimes fail and leak internally.
### Step 3: Advanced Diagnosis (Internal Access)
If the leak is not visible externally, you will need to open the machine panels to check the internal components.
1. **Remove the Top Panel:** Unscrew the two or three screws at the back of the machine holding the top lid in place, and slide the lid off.
2. **Check Internal Hoses:** Look down inside the unit, focusing on the large drain pump hoses, the small hoses running from the soap dispenser, and the connections to the tub itself. Look for white mineral deposits or fresh water that indicates a leak point.
3. **Inspect the Tub:** Check the large rubber boots and seals around the drum for signs of splitting or detachment.
### Step 4: The AquaStop Hose Failure
If the leak only happens when the machine is filling with water, and no internal hoses appear to be split, the fault may lie directly in the specialized **AquaStop Hose.**
This hose contains a safety solenoid valve designed to cut off water flow if the primary valve fails. If the solenoid or the outer casing of the AquaStop mechanism is cracked, it can drip water constantly into the base pan, triggering the E23 error.
**Resolution:** The AquaStop Hose is a sealed unit and must be replaced entirely if it is the source of the leak. It cannot be repaired. Ensure you purchase a genuine Bosch replacement hose designed for your specific model series.
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## 3. Replacement Part
If your diagnostics point to a failure within the inlet hose system, a full replacement is required.
Check the price for a replacement AquaStop Hose here: https://www.amazon.com/s?k=Bosch+AquaStop Hose&tag=trivian-20