Frequently asked questions

• I want a sensor in every room — how many can one hub handle?

  Dozens: the limit comes from the hub, not the sensor. For a flat with 4–6 SNZB-02P units an iHost, NSPanel Pro or ZBDongle-E has plenty of headroom; in eWeLink each sensor is assigned to its room, so scenes stay tidy.
• Does the sensor relay other Zigbee devices' signals?

  No. Running on a battery, the SNZB-02P sleeps most of the time and acts as an end node — only mains-powered devices (plugs, relays) extend the mesh. If the hub is far away, any of those becomes the repeater.
• Four years on a single battery — is that realistic?

  It is SONOFF's lab estimate for typical use; real life depends on how often the room climate changes and on link quality. Inside sits a 3 V CR2477; the level shows in eWeLink and swapping it takes a minute.
• Will the SNZB-02P work in Home Assistant via Zigbee2MQTT or ZHA?

  Yes, it is a standard Zigbee 3.0 device: with a coordinator such as the ZBDongle-E or ZBDongle-P it is picked up by both Zigbee2MQTT and ZHA, reporting temperature, humidity and battery. No eWeLink cloud required.
• Can it drive a TRVZB radiator head directly, without a hub?

  There is no direct radio link — both join the same Zigbee hub and a scene ties them together: the SNZB-02P reading is the condition, the TRVZB acts on it. That way the head heats by the room's temperature, not the valve's down by the floor.
• I'm on iPhone — will the readings show in the Home app?

  The sensor itself is not a Matter device, but the official bridge solves it: a SONOFF ZBBridge-U or eWeLink CUBE exposes the SNZB-02P to Apple Home as a bridged device, and temperature and humidity appear in the app.
• The internet is down — do alerts still arrive, do scenes still run?

  Push alerts travel through the eWeLink cloud, so they will not arrive offline. Local scenes on an iHost or NSPanel Pro, however, run inside your network: the TRV or humidifier still fires even with the ISP down.
• How do I get an alert when the nursery drops below 20 °C?

  In eWeLink you set upper and lower thresholds for temperature and humidity: give the nursery sensor a 20 °C lower bound and a push arrives the moment it is crossed. The same condition can switch heating on through a scene.