the self-cleaning mop feature isn't working, the station just makes a humming noise and the pads stay dirty.

Diagnosis

The humming noise you hear is the pump attempting to engage the water cycle, but a failure in the fluid loop is preventing the water from actually moving into the mop washing tray. This is typically caused by a "false full" reading from the Dirty Water Tank (DWT). The X1 Omni uses a physical float sensor—a small plastic bobber—inside the dirty water tank. If this float becomes stuck due to slime, hair, or detergent buildup, the station believes the tank is full and triggers a safety cutoff to prevent overflow, even if the tank is empty. Alternatively, the issue may be a vacuum seal failure. If the DWT is not seated with a perfect airtight seal, the pump cannot create the necessary suction to pull the dirty water out of the mop tray. You can confirm this by checking the Ecovacs Home app; if you see a "Dirty Water Tank Full" notification despite the tank being empty, the float sensor is the culprit. If there is no error message but no water movement, the issue is likely a blockage in the internal drainage ports or an airlock in the clean water line.

How to Fix It

To restore the self-cleaning functionality, follow these precise steps to reset the fluid sensors and clear the lines:

1. Remove the Dirty Water Tank (DWT) from the Omni station. Empty all contents into a sink.
2. Locate the small rectangular chamber on the side of the DWT. Inside, you will see a small plastic float. Pour a small amount of warm water into the tank and shake it vigorously. Ensure the float moves freely up and down. If it is stuck, use a cotton swab to clear any debris from the edges of the chamber.
3. Inspect the rubber gasket on the top of the DWT. Wipe it clean with a damp cloth to ensure no hair or dust is preventing a vacuum seal.
4. Remove the Clean Water Tank (CWT) and ensure the filter at the bottom is not clogged with mineral deposits. If you use tap water, soak the filter in white vinegar for 10 minutes to dissolve calcium buildup.
5. Clear the mop tray. Remove the mop pads and check the drainage holes at the bottom of the station's tray for any clumps of hair or debris that may be blocking the suction.
6. Reinsert both tanks firmly. You should hear a distinct "click" as the tanks lock into place.
7. Run a "Customized Cleaning" cycle via the app to test the mop washing sequence.

If That Didn't Work

• Perform a Hard Reset of the Station: Power down the Omni station by unplugging it from the wall for at least 60 seconds. This clears the temporary logic errors in the pump controller that may be causing the humming loop without water flow.
• Clear the Internal Airlock: If the pump hums but no water enters the tray, an air bubble may be trapped. Fill the Clean Water Tank to the absolute maximum line and manually press down on the tank lid to increase pressure, then trigger the wash cycle.
• Deep Clean the Mop Tray: Remove the plastic mop tray (if your specific regional model allows) or use a vacuum to suck out any sludge from the drainage port. If the port is blocked by a "plug" of wet dust, the pump will hum but the water will not drain.
• Check for Tank Leaks: Inspect the bottom of the tanks for hairline cracks. Even a microscopic leak can prevent the station from achieving the vacuum pressure required to pull water from the tray into the DWT.

Heads Up

• Avoid using third-party floor cleaners or highly sudsy soaps in the Clean Water Tank. These create micro-bubbles that trick the float sensor and can cause the pump to cavitate, leading to the humming noise.
• Always empty the Dirty Water Tank immediately after a cleaning cycle. Leaving dirty water to sit creates a biofilm (slime) that is the primary cause of float sensor failure.
• If you live in a hard-water area, use distilled water in the Clean Water Tank to prevent calcium carbonate from clogging the narrow internal tubing and the pump head.
• Periodically wipe the gold-colored electrical contact points on the tanks and the station with a dry microfiber cloth to ensure the station can communicate with the tank sensors.