How to Clean the Sensors of the Xiaomi Roborock S5

The Roborock S5 is a sophisticated device that relies on multiple sensors to navigate and prevent falls. When these components become contaminated, the machine begins to behave inadequately: bumps into obstacles, falls off carpets or loses a map of the room. Owners often face a situation where maintenance is ignored before critical errors appear.

Properly cleaning the sensors can restore the robot to its previous accuracy and speed without having to visit a service center. In this article, we will discuss in detail which sensors require attention, how to wipe them, and how to avoid the typical errors that can lead to failure of electronics.

Before disassembling or cleaning, you need to completely disconnect the device from the network and remove the main brush to safely access the bottom of the case, and it is strictly forbidden to use alcohol-containing liquids or aggressive household chemicals to wipe the optical lenses of sensors, which can cause clouding of the plastic or destroy the protective coating.

The main types of sensors in the Roborock S5

The Xiaomi Roborock S5 navigation system is built on a combination of a laser rangefinder and a host of auxiliary sensors. The Lidar, located in the top turret, scans the room, creating a digital copy of it. However, infrared sensors located at the bottom of the housing are used to move safely around the floor.

It's critical to understand the difference between gradients and impact sensors: the first one is responsible for keeping the robot from falling down stairs or getting stuck on a thick carpet, the second one is fixing touch with furniture, and contamination of any of these elements leads to different types of errors in the application.

The design also uses optical sensors that track distance traveled, and if they get wool or dust, the robot may mistakenly believe that it has already removed a particular area, skipping entire cleaning areas, and the accuracy of positioning depends on the transparency of the protective glass of these modules.

⚠️ Warning: When cleaning the bottom panel, do not turn the robot over abruptly if there is water or dust inside the container.

Tools and workplace preparation

You don't need a complex engineering toolkit to maintain the quality, you just need to prepare a clean, well-lit surface where nothing is lost, and small parts like screws or lids are better folded into a separate container so that they don't roll under the furniture.

As a cleaning product, special wipes for screens or microfibre, slightly moistened with distilled water, are ideal. The use of paper towels is not recommended, as they can leave villi, which will subsequently fall into the rotation mechanisms.

Some users try to use compressed air to blow dust out of hard-to-reach areas, which is acceptable, but only at low pressure, so as not to damage the senses of the sensor membrane, the jet of air should be directed at an angle, not perpendicular to the surface of the sensor.

Cleaning of height difference sensors

The most common problem that Roborock S5 owners face is the “lift the main unit” error when the robot is standing on a flat floor, culprits are elevation sensors located around the perimeter of the bottom, their task is to read the reflected IR signal from the floor.

When a layer of dust or a greasy film accumulates on the lens, the signal doesn't reflect correctly, and the robot thinks there's a void underneath. To clean, you flip the vacuum cleaner over and find the black plastic windows. Gently wipe them with a dry microfiber in circular motions.

• 🧹 Remove visible dust lumps with a dry brush before wiping.
• 💧 Use a minimum amount of moisture so that water does not leak into the body.
• 👀 Check if the sensors are sealed with stickers or protective film (a common mistake of new users).
• 🔄 After cleaning, run the sensor test in the engineering menu or just watch the bumper reaction.

If the problem persists after wiping, it may be that the contamination has been injected through microcracks or that the emitter itself has worn out, in which case a more thorough diagnosis or replacement of the module may be required.

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If you have dark carpets or black floors, the height difference sensors may not work properly even in their pure form, and in such cases, sticking special light labels or using virtual walls in the application helps.

Maintenance of laser rangefinder (Lidar)

The top turret with the laser is the eyes of your robot, and inside it is a rapidly rotating mechanism that makes a distinctive whistling sound when it's working, and if that sound gets louder, if it clicks, or if the robot starts to crash into the walls, it's time to service the laser head.

First, wipe the transparent window at the end of the turret, often hit by a small suspension that creates a fog for the laser, then carefully remove the turret lid (it holds on the latches, act carefully) to access the rotating module.

Inside, you'll see a horizontal slot where the beam comes from, often wool and dust that interfere with rotation, carefully remove the contamination with tweezers or dry cotton swabs, don't oil the mechanism, it'll only attract more dust.

Bumper sensors and wheelbase

The front movable part of the body is a bumper, which also has infrared sensors inside it, which help the robot determine proximity to objects before physical contact, and dirt on the front can cause the robot to be "scared" by non-existent obstacles.

And you also need to look at the sensors that are placed next to the wheels, which help the system understand if the robot is standing on the surface or raised, and if those contacts are contaminated, the robot may not start cleaning after it's installed on the floor, requiring a manual start.

To clean, remove the side brush and wipe the area around the wheels. Make sure that the gaps between the wheel and the body are not filled with compressed coat, which can block the course and distort the readings of position sensors.

⚠️ Warning: Don't try to remove the bumper completely unnecessarily.There are plumes underneath that are easily damaged when assembled sloppy, leading to bumper error.

Cleaning of the optical motion sensor

The bottom panel of the Xiaomi Roborock S5 also features an optical sensor that reads the texture of the floor to determine the distance traveled (odometry), a critical element for building an accurate map and returning to base.

It's usually a small hole, often covered by a safety net or glass. If the robot passes the same place several times or loses position, check this particular node, and the dirt here accumulates quickly because of the proximity to the main roller.

Use a dry cotton swab for delicate cleaning. Don't press hard to keep the sensor from pushing inside the case. After the procedure, be sure to blow the hole to remove the leftover pile from the stick.

Frequent errors and troubleshooting

Even after careful cleaning, there can be nuances in the operation of the device, and often the problem lies not in the sensor itself, but in the operating environment, for example, the bright sun falling on the elevation sensors can blind them, because the infrared spectrum of the sun contains a powerful component.

Another common situation is the use of floor-conditioned detergents, which create a greasy film that sticks quickly onto the lenses, and in such cases dry cleaning won't help, you'll need a slightly damp wipe followed by dry polishing.

• ☀️ Avoid cleaning in direct sunlight if sensors are not working properly.
• 🧼 Do not use film-leaving products to wash floors in robot vacuum mode.
• 🔋 Keep an eye on battery power, as at low voltage, sensors can be unstable.

If none of these methods worked, and the robot continues to make sensor errors, it may be a hardware problem, which could be a plume break, contact oxidation, or the module itself.

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Regular preventive cleaning of sensors every 2-3 weeks prolongs the life of the robot and prevents 90% of navigation errors.

FAQ: Frequently Asked Questions