Xiaomi robot vacuum cleaner requires water to be added, even though the tank is full: what to do?

You turned on wet cleaning on Xiaomi’s robot vacuum cleaner, but the device persistently signals the need to add water – even though the reservoir is clearly full? This error occurs in Mi Robot Vacuum-Mop 2 Pro models, Xiaomi Robot Vacuum-Mop 2 Lite, DreameBot D9 and other “smart” assistants with the function of floor washing.

In this article, we will look at all possible causes of a false alarm of the water level sensor, from improper installation of the tank to failure of electronic components. You will learn how to diagnose the problem yourself, which manipulations should be tried first, and in which cases you can not do without contacting the service center. We also collected current data on models of 2022-2026 and typical “jobs” of their firmware.

Spoiler: 60 percent of the time, the error is fixed in 5 minutes without disassembling the device, but there are also insidious exceptions, such as when the problem is disguised as a "water shortage," when the flow sensor or clogged supply valve is actually to blame. Next, a detailed analysis of the photo, video instructions and symptom chart.

1. Check the obvious: is the water tank properly installed?

To start with, the simplest thing is that the tank is not installed correctly, and even experienced users sometimes miss this point, especially if they have recently washed the tank or changed filters. Xiaomi and Dreame have three critical nuances:

• 🔹 Density of fit: the tank should stand with a characteristic click. If it dangles or sits crooked, the sensor contacts will not close.
• 🔹 Position «MAX»: Some tanks have a maximum level mark – if the water is above it, the sensor can work falsely.
• 🔹 The stub on the bottom: models with a system OZMO Pro (e.g. DreameBot) L10s Ultra) has a removable cap in the tank - if it is not closed, water does not enter the system.

What to do:

1. Remove the tank and install it again, pressing to the point.
2. Check if foreign objects interfere (such as the label or debris under the seal).
3. Make sure the water does not exceed the MAX mark (usually 200-250 ml).

Remove and re-install the tank before clicking |

Check the water level (not higher than MAX) |

Make sure the plug on the bottom is closed (for models with OZMO Pro)|

Check the seal for the presence of garbage-->

If after these manipulations, the robot still asks for water, we proceed to the next step.

Sensor pollution: how to clean contacts and sensors

Xiaomi’s robot vacuum cleaner water level sensor works on the principle of an infrared or capacitive sensor, and over time, its contacts accumulate deposits from hard water, dust and detergents, leading to false positives, especially in regions with high water hardness (Moscow, St. Petersburg, Yekaterinburg).

How to clean the sensor:

1. Remove the water tank and inspect its bottom. On most models, the sensor looks like a small round or rectangular hole (sometimes with metal contacts).
2. Take a cotton swab dipped in distilled water or alcohol, and clean the sensor carefully. Don't use abrasive materials!
3. To remove scale, a solution of citric acid (1 tsp per 100 ml of water) can be used, but only if the sensor does not have open contacts.

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If the sensor is covered with white plaque, soak the tank in a solution of vinegar (1:1 with water) for 15-20 minutes, then rinse with running water. This will help dissolve the lime deposits.

After cleaning, allow the tank to dry for 10-15 minutes and set it back. If the error persists, the problem may be deeper, such as oxidation of contacts on the board or damage to the wiring.

Once a month |

Once in 3 months |

Only when mistakes are made.|

Never cleaned.-->

Problems with the water supply valve: diagnosis and repair

In models with a wet cleaning system (for example, Xiaomi Mi Robot Vacuum-Mop P or DreameBot W10), an electromagnetic valve is responsible for supplying water. If it is clogged or malfunctioning, the robot may “think” that there is no water, although it is physically present in the tank.

• 💧 The robot makes a buzzing sound, but the water does not go to the napkin.
• 💧 The “pour water” error appears 5-10 seconds after cleaning starts.
• 💧 The display or Mi Home app displays error code 10, 12 or 36 (depending on the model).

How to check the valve:

1. Remove the bottom cover of the robot (usually mounted on 4-6 screws).
2. Find the valve - this is a small plastic block with tubes connected to the tank.
3. Blow into the tube -- if the air is flowing freely, the valve is in good condition. If not, cleaning or replacement is required.

Use a toothpick or compressed air to clean, if the valve does not respond to commands (does not click when cleaning is turned on), it will have to be replaced, and the cost of a new valve for popular models is from 800 to 1,500 rubles.

4. firmware failures: resetting settings and software updates

Sometimes the water-pump error is caused by software glitches, especially after a firmware update or power failure, which is common in models with a Wi-Fi module (Xiaomi Robot Vacuum-Mop 2S, DreameBot D10 Plus), where cleaning is controlled via an app.

Remedies:

• 📱 Software Update: Check the relevance of the firmware in the Mi Home application (section "Device settings" → Update»).

If the error persists after the reset, try rolling back the firmware to the previous version.

1. Download the firmware archive for your model from the official Xiaomi website or 4PDA forum.
2. Unpack the.pkg file on the microSD card.
3. Put the card in the robot, press the Spot Clean button and turn on the power. Hold the button 5-7 seconds until the beep.

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Before rolling back the firmware, make a backup copy of the cleaning card in the Mi Home app – after the reset, it will be deleted!

The table below shows the current firmware versions for popular models (data for June 2026):

Mechanical damage: cracks, leaks, wear of seals

If a robot vacuum cleaner fell, was hit, or was operated in high humidity, there could be microcracks in the tank or tubes, which leads to two problems:

1. Water leakage: The level in the tank drops unnoticed by the sensor, and the robot requires topping.
2. Air suction: The sensor detects "no water" due to depressurization of the system.

How to check:

• 🔍 Inspect the tank for cracks (especially in the places where the tubes are fastened).
• 🔍 Submerge the tank in water - if bubbles appear, there is a leak.
• 🔍 Check the sealing ring at the bottom of the tank - it should be elastic, without tears.

If damage is found:

• 🛠️ Cracks on the tank can be temporarily sealed with food silicone (but this is not a long-term solution).
• 🛠️ Seals and tubes are sold in remakes (for example, for Xiaomi Mi Robot Vacuum-Mop 2 kit is worth a lot). ~500 rubles).
• 🛠️ In case of serious damage to the tank case, replacement will be required (the price of a new one is from 1,200 to 2,500 rubles).

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To extend the life of seals, wipe them with a dry cloth after each cleaning and lubricate them with silicone lubricant once a month (for example, WD-40 Specialist).

⚠️ Warning: If the robot fell from a height of more than 50 cm, not only plastic parts, but also a gyroscope or accelerometer could be damaged.

6.Problems with power supply and charging

Insufficient voltage or unstable power sometimes leads to false alarms of sensors, including the water level sensor, which is true for models that have been on a charge for a long time or are connected to an unoriginal adapter.

Signs of nutritional problems:

• ⚡ The robot spontaneously shuts down during cleaning.
• ⚡ The “pour water” error only appears when the battery is low (less than 20%).
• ⚡ Mi Home app displays warning about 'unstable eating».

What to do:

1. Check the voltage on the power supply – it must match passport values (usually 20V 0.6A or 19.5V 1.5A).
2. Connect the robot to another adapter (preferably the original one).
3. Reset the battery settings: completely discharge the robot, then charge to 100% without interruptions.

If the problem persists, the battery or power control board may have malfunctioned, and only a diagnostic at the service center will help.

7.When you can not do without the service: symptoms of serious breakdowns

If you've tried all of these, but the robot vacuum cleaner still needs to refill the water, despite the water, it's probably a hardware malfunction.

• 🚨 The error appears immediately after the robot is turned on (even without starting cleaning).
• 🚨 The robot does not respond to resetting settings and flashing.
• 🚨 On the case or board, traces of oxidation, burnout or bloated capacitors are visible.
• 🚨 Mi Home shows error code 38, 42 or 99 (indicates a motherboard malfunction).

Average repair costs in official Xiaomi service centers (data for 2026):

⚠️ Warning: If the robot vacuum cleaner is warranty, don't disassemble it yourself! Opening the case will void warranty obligations. Contact the authorized Xiaomi service center with a check and warranty card.

FAQ: Frequent questions by mistake "pour water"