Cleaning the sensor air purifier Xiaomi: when, how and why to do it

Why Xiaomi Air Purifier Sensor Needs Cleaning and When to Do It

Xiaomi air purifiers (Mi Air Purifier, Smartmi, Deerma series) are equipped with high-precision air quality sensors that become polluted over time. Dust, tobacco smoke, fat particles and even ordinary household dirt settle on the sensor, distorting the readings. PM2.5, TVOC And so the device starts to work incorrectly, turns on for no reason, doesn't react to real pollution, or ignores it.

The first signs that the sensor needs cleaning:

• 🔴 The cleaner is often turned on at maximum power for no apparent reason (e.g., in a clean room after wet cleaning).
• 📉 Testimonies. PM2.5 Mi Home is overstated or understated (compare with other sensors or weather stations).
• 🔄 The device is cyclically restarted or gives an error E1/E2 (sensor codes).
• 🕒 The operating time at one speed was reduced by 2-3 times (the sensor falsely fixes "clean air" and turns off the fan ahead of time).

The manufacturer recommends cleaning the sensor every 3-6 months, but the actual interval depends on the operating conditions. For example, in homes with animals, smokers or after repairs, cleaning may be required after 1-2 months. Neglect of care leads not only to inaccurate readings, but also to accelerated wear of the fan due to suboptimal operating modes.

What sensors are installed in Xiaomi cleaners and where they are located

Depending on the model of the air purifier Xiaomi can use different types of sensors. in most devices (for example, Mi Air Purifier). 3/4 Pro, Smartmi Air Purifier P1) A combined sensor module is installed that measures:

• 🌫️ PM2.5/PM10 — concentration of fine particles (dust, smog, pollen).
• 🧪 TVOC — Volatile organic compounds (formaldehyde, benzene, acetone).
• 🌡️ Temperature and humidity (in some models).

The sensor is usually located under the front panel (behind a bar or plastic cover) or at the top of the case (in models with a round display, for example, Mi Air Purifier). 3C). To get to him, you will need to remove:

1. Filter (usually held by latches or magnets).
2. Front / top panel (can be mounted on clips or screws under rubber plugs).
3. A protective mesh or plastic sensor casing (sometimes glued to a double-sided tape).

Look carefully at the sensor, if you see a gray or yellowish coating on the surface, and dust accumulates inside the case, cleaning is mandatory. DEM-F600) The sensor is integrated into the control board and cleaning requires special care.

Preparation for cleaning: tools and safety measures

Before starting work, disconnect the cleaner from the network and wait for the fan to stop completely (1-2 minutes).

What can't be done:

⚠️ Warning: Do not use cotton swabs – the pile may remain on the sensor and further distort the readings. Also avoid abrasive materials ( sandpaper, hard brushes), acetone or other solvents – they will damage the protective coating of the sensor.

If your model of cleaner is under warranty, note: self-disassembly can lead to loss of warranty service. In this case, it is better to contact the Xiaomi service center (the list of addresses is available on the site mi.com).

Turn off the socket cleaner|Prepare tools and materials|Take a picture of the disassembly process (for reverse assembly)|Check for spare clips/screws (they are often lost)-->

Step-by-step: how to disassemble the cleaner and get to the sensor

The disassembly process depends on the model, but the overall scheme is the same for most Xiaomi cleaners.

1. Take the filter off. Pull the handle or press the latches on the sides. In some models (like the Smartmi). P1) The filter is attached to magnets - just pull it on yourself.
2. Unscrew the screws or snap the front panel. The screws can be hidden under rubber plugs (plastic blades). 3H panel is held on 4 clips - gently squeeze them around the perimeter.
3. Remove the sensor's protective grid, which can be screwed or pasted onto double-sided tape, in the latter case, put a mediator on it and tear it off carefully so that the plumes are not damaged.
4. Disconnect the sensor plume (if required). In some models, the sensor module is connected to the board with a flexible plume. Don't pull the wires - gently press the lock.

The photo below shows the Mi Air Purifier 3 sensor after the lid is removed:

The sensor is a small board with a hole in the middle (through which air passes for analysis). PM2.5) and gas sensors (for the purpose of TVOC).

If you're not sure about your abilities, take a picture of each stage of disassembly, which will help you to properly assemble the device back. 3C) Be careful: the screen plume is easily damaged.

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If the screws don’t unscrew, don’t put too much effort into it – they may have a special head (like Torx). T5 Buy a suitable screwdriver or contact the service.

How to Clean the Sensor: Dry and Wet Methods

There are two main ways to clean the sensor: dry (for mild contaminants) and wet (for heavy deposits), starting with a safer option.

Dry cleaning (dust, light plaque)

1. Remove the dust with a brush. With gentle movements, sweep away the dirt from the sensor surface and the surrounding body. Move from center to edge so you don't drive the dust inside the sensor.
2. Blow the sensor with compressed air. Use a compressed air can (for example, to clean keyboards) or a dryer in cold blow mode. Keep the balloon vertical to avoid moisture.
3. Walk through the sticky electronics wipe. It will remove the remaining small particles. Don't press hard. The sensor is fragile!

Wet cleaning (fat, sticky deposits, persistent plaque)

This method requires caution, as moisture can damage electronics.

1. Moisten the lilac-free napkin with isopropyl alcohol. Alcohol must be at least 70%, it evaporates quickly and leaves no stains. Do not pour alcohol directly on the sensor!
2. Wipe the surface of the sensor. Move from the edges to the center, avoiding heavy pressure. For hard-to-reach areas, use a paintbrush soaked in alcohol.
3. Remove the dirt residues with a cotton swab (metal contacts only!).If there is oxidation on the board, gently wipe the contacts with alcohol.
4. Dry the sensor. Use the dryer in cold mode (keep at a distance of 10-15 cm) or leave the device disassembled for 2-3 hours for natural drying.

⚠️ Warning: If after wet cleaning the sensor stopped working (does not turn on, it gives an error) E3), Disconnect the device immediately and dry it for at least 12 hours in a warm, dry place (e.g., near the battery).

For models with laser sensor PM2.5 (For example, Mi Air Purifier Pro H, avoid direct light hitting the sensor during cleaning, which can interfere with calibration. Once assembled, allow the device to operate for 10-15 minutes automatically for self-diagnosis.

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After cleaning, the sensor can show inflated values for 1-2 hours, which is normal. After a few cycles of operation, the readings are stabilized.

What to do if cleaning didn’t help: Diagnostics and alternative solutions

If the sensor still works incorrectly after cleaning, the following problems may occur:

In some cases, resetting the cleaner to the factory settings helps.

1. Hold the power button for 5-10 seconds (until the beep).
2. In the Mi Home app, go to Device Settings → Reset.
3. Turn off and reconnect the cleaner to the network.

If the sensor is physically fit but the readings are inaccurate, try manual calibration (not available on all models).

1. Place the cleaner in a room with an open window (outdoors without wind).
2. Turn on Auto mode and wait for the stabilization of the readings (10-15 minutes).
3. Compare data with an external source (e.g. a service) WAQI).
4. If the difference is more than 20%, contact the service for professional calibration.

In extreme cases, you can turn off the automatic mode and manually control the cleaner through the application, but this is a temporary solution - a faulty sensor will eventually lead to overloading of the fan.

Prevention: how to extend the life of an air purifier sensor

To lessen the need to clean, follow these tips:

• 🌿 Change the filters regularly. HEPA-filter causes the fan to work at the limit, which accelerates the contamination of the sensor. The optimal interval of replacement is every 6-12 months (or according to the indicator in the application).
• 🚫 Avoid kitchens (fat, steam), smoking areas or close to furniture with L chipboard (formaldehyde). The optimal distance is 1-1.5 meters from walls and objects.
• 💨 Use a cleaner in a well-ventilated room. If the room is sealed (for example, after installing plastic windows), the sensor will record high values. CO₂ and turn on the fan more often than necessary.
• 📱 Update your firmware. The manufacturer regularly releases updates that improve the algorithms of the sensors.
• 🔄 Periodically turn on the maximum mode. Once a month, run the cleaner at full power for 10-15 minutes - this will help to "blown" the internal components from dust.

If your area has high dust levels (such as during seasonal fires or sandstorms), consider buying a prefilter — it traps large particles before they hit the sensor. It is also useful to use an ionizer (if your model has one) — it reduces the amount of dust in the air.

The average life of the sensor in Xiaomi cleaners is 3-5 years. With careful care and regular cleaning, this period can be extended to 7 years. However, if the sensor begins to “lie” even after cleaning, it will most likely need to be replaced (cost from 1,500 to 3,000 rubles depending on the model).

Frequent questions about cleaning Xiaomi air purifier sensor