If your E28 robot emits an audible error stating "Wastewater Extraction Error: Please check the app for troubleshooting" and stops its operation, it is likely due to an air leak during the wastewater extraction process, which prevents the dirty water tank from being drained.

Please refer to the following troubleshooting steps to resolve the issue：

Verify that the latch of the dirty water tank at the base station is tightly fastened. Additionally, check if the dirty water tank contains any water.

1. Please refer to the video link listed below for visual assistance: https://d3pkbgk01oouhl.cloudfront.net/upload_file/prod/Dirty-water-tank-latching.mp4

Ensure that the foam pad located between the Portable Deep Cleaner and the base station has been removed. If the foam pad has not been removed, please remove it and make sure the dirty water tank is properly positioned.

2. Please refer to the video link listed below for visual assistance: https://d3pkbgk01oouhl.cloudfront.net/upload_file/prod/Foam-interference.mp4

3. Inspect the E28 robot’s wheels, side brushes, roller brush, and roller mop for any obstructions, and verify that the wheels, roller brush, and roller mop are properly positioned.

4. Check for any water accumulation at the bottom of the Portable Deep Cleaner and ensure that it is correctly positioned.

5. Ensure that the cleaning tray of the base station is properly positioned, with the sewage pipe clearly visible.

Gently shake the robot's dirty water tank to check if the float can rise and fall freely. If the float is still, empty the water tank, invert the water tank (with the bottom facing down), and gently tap the bottom of the water tank to verify if the float can move freely.

6. Please refer to the video link listed below for visual assistance: https://d3pkbgk01oouhl.cloudfront.net/upload_file/prod/Dirty-water-reservoir-float-ball.mp4

7. If the base station is currently placed on a carpet, consider moving it to a hard surface, as an uneven surface may lead to tilting and cause water extraction failure.

Inspect the water extraction port for proper rebound action, and check whether the sewage outlet remains securely in place without signs of any looseness.

Please refer to the video links listed below for visual assistance, and provide a video for eufy Support Engineers to analyze the issue:

Water inlet inspection: https://d3pkbgk01oouhl.cloudfront.net/upload_file/prod/Water-inlet-inspection.mp4

8. Sewage outlet inspection: https://d3pkbgk01oouhl.cloudfront.net/upload_file/prod/Sewage-outlet-inspection.mp4

9. Verify if there is any water in the cleaning tray of the base station. If the water looks murky, it is likely due to a defective seal at the sewage outlet, which allows wastewater to seep into the cleaning tray. Please try the following steps:

   1. Clean the cleaning tray thoroughly.

   2. Manually place the E28 robot at its base station, and gently push it until it is completely docked.

   3. Start the Roller Self-Cleaning feature in the app and check for any water leaks in the cleaning tray. The issue is completely resolved if water stops leaking into the cleaning tray.

If you have any other questions about the E28 robot, please don't hesitate to contact us for further assistance.