SONOFF SNZB-02 – Zigbee Temperature and Humidity Sensor – ZigBee 3.0

SONOFF SNZB-02 ZigBee wireless temperature and humidity sensor is the third step in our smart home project. We’ll be able to use it to control humidity (we’ll know when to dehumidify, automate) or as another component of our system to serve as an external thermometer, well placed to control our heating system.

Buy it at Sonoff / Itead official store:

What’s in the box, what do you need to know?

The SNZB-02 zigbee wireless temperature and humidity sensor is a tiny 43mm * 43mm plastic device. It uses a Zigbee network, so you can expect a long battery life, but very cold weather (around 0 degrees) is not recommended for the CR2450 button cell.

It requires a Zigbee hub to connect to the eWelink application. Of course, if you have a Zigbee hub from another manufacturer that works through the Smart life app, you should be fine there too.

There’s not much in the box, just what you need: a short quick start guide for installation, a SNZB-02 zigbee wireless temperature and humidity sensor and a 3M sticky base to fix it anywhere. I use it freely and place it in a quieter part of the room.

What is Zigbee?

Zigbee is a communication solution specifically designed for low-power devices where high data bandwidth is not required, but where it is important to minimise the time delay. Zigbee is a good choice for battery-powered sensors, for example, where the uptime is several times that of WiFi. Zigbee devices are capable (under certain conditions) of mesh networking and can reach huge distances between two endpoints.

The Zigbee sensors cannot be used on their own, they need a Zigbee hub to connect them to your home/office network. One per system is sufficient, taking advantage of the above options.

zigbee mesh network

What it can be used for, automation ideas

The SNZB-02 zigbee wireless temperature and humidity sensor has a lot of applications, but of course we can make the most of them with automation. Let’s look at some ideas:

  • If the temperature is higher than X, turn on one of our smart plugs that controls a fan
  • If the temperature is lower than x, turn on your boiler (here it also depends on the heating system, but almost all of them can be automated with smart relays)
  • You can get a continuous temperature and humidity value with a look back with a graph. It can be useful if you’re using it in a sensitive area, like a wine cellar…just an example, but it’s great to leave it there and check from a distance from time to time that everything is working properly.
snzb 02 ewelink


  1. Launch your eWelink or Smart Life app where the Zigbee hub is already active and ready.
  2. Find the add button and click on it in the app
  3. Remove the back of the sensor, check that the battery is not protected with a thin film, remove it
  4. There is a small button at the bottom of the device. Press and hold it for a few seconds.
  5. After a few seconds the top grid will flash red, indicating that it is in Pairing mode
  6. In 5-15 seconds they will find each other and your phone screen will display the relevant information

That’s it 🙂

🆓 – I was interested in the product, I received it for testing
💵 – I got it for free, 100% my own opinion

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