Sonoff AirGuard TH SNZB-02DR2 - Zigbee Temperature and Humidity Sensor with LCD

Temperature and Humidity at a Glance Humid bathrooms, stuffy bedrooms, a wine cellar that's a bit too warm... you only notice when it's too late. The Sonoff AirGuard TH (SNZB-02DR2) measures temperature and humidity with laboratory accuracy and displays the values clearly on a large 3.6-inch LCD screen. No phone needed for a quick check. Power and Connectivity The sensor communicates via Zigbee 3.0 (IEEE 802.15.4) and runs on 2 AAA batteries. A Zigbee coordinator is required for smart home integration; the sensor functions as an EndDevice in the Zigbee network. In addition to Zigbee, the sensor features a Bluetooth Proximity mode for direct pairing with the eWeLink app on your smartphone, without a hub. Functionality and Settings The 3.6-inch LCD display shows current temperature, humidity, 24-hour minimum and maximum values, and a comfort index. Measurement accuracy is ±0.2 °C over a range of -20 °C to 60 °C and ±2% RH over 0 to 100% RH, based on the Sensirion SHT40 sensor. The display switches between °C and °F. Via Zigbee2MQTT, comfort limits for temperature and humidity can be set; the display shows an icon if these limits are exceeded. Temperature and humidity calibration is adjustable via an offset. Pairing with other sensors In Zigbee mode, the AirGuard TH can display live readings from another Sonoff Zigbee sensor (SNZB-02, SNZB-02P, SNZB-02WD, SNZB-02D or SNZB-02LD) on its display. This allows you to see indoor and outdoor temperatures at a glance, without opening the app. Data History and Analysis The eWeLink app stores measurement history for approximately 6 months and displays graphs and long-term statistics. Additionally, the app calculates dew point and VPD (Vapour Pressure Deficit), useful for plant growers and terrariums. Threshold notifications can be set per sensor. Home Assistant The SNZB-02DR2 is fully supported in Home Assistant via Zigbee2MQTT and ZHA. Pairing procedure via Zigbee2MQTT: Put the coordinator in pairing mode in Zigbee2MQTT. Press the reset button on the back of the sensor until the display responds. The sensor will automatically appear as SONOFF SNZB-02DR2 in Zigbee2MQTT. After pairing, the entities sensor.temperature, sensor.humidity, sensor.battery, and sensor.voltage will be available. Comfort limits can be set via Zigbee2MQTT after waking up the sensor with the button on the back. Operation is entirely local, no cloud required. OTA firmware updates are supported via Zigbee2MQTT. No Zigbee coordinator at home? You can find one at slimhuisje.nl. Homey At the time of writing, the SNZB-02DR2 is not yet officially supported in the Sonoff Zigbee app for Homey. Check the Homey App Store for the current status. Pairing as a generic Zigbee device is possible via the Zigbee controller on Homey Pro, but with limited entities. Other platforms Compatible with Amazon Alexa, Google Home and Apple Home (via Matter-bridge) via the eWeLink app or a compatible Zigbee hub. The eWeLink app provides direct access via Bluetooth Proximity without a hub. Automation examples Ventilation schedule based on humidity Trigger: sensor.bathroom_humidity rises above 70% RH. Condition: time window 06:00–23:00. Action: turn on smart plug with bathroom fan. Second trigger: humidity drops below 60% RH, turn off fan. Night frost notification for conservatory or outdoor area Trigger: sensor.conservatory_temperature drops below 4 °C. Condition: time after 20:00. Action: push notification to phone: "Conservatory temperature below 4 °C — risk of night frost." Optional: turn on smart plug with hot air fan. Points of Attention Requires a Zigbee coordinator for smart home integration; not included. Functions as an EndDevice; does not extend the Zigbee network as a router. Homey support via the official Sonoff app has not yet been confirmed; check the app store for the current status. Setting comfort limits via Zigbee2MQTT requires the sensor to be active (press the button). Not moisture resistant; not suitable for outdoor use or direct moisture exposure. 2× AAA batteries are included. Contents of the box Sonoff AirGuard TH SNZB-02DR2 2× AAA batteries Mounting materials Quick start guide Compatibility Works with: Home Assistant (Zigbee2MQTT / ZHA) · eWeLink app (Zigbee + Bluetooth Proximity) · Amazon Alexa · Google Home · Apple Home (via Matter-bridge) · Sonoff Zigbee Bridge Pro · SONOFF NSPanel Pro · SONOFF ZBDongle-P/E. Specifications Model SNZB-02DR2 EAN 6920075743593 Protocol Zigbee 3.0 (IEEE 802.15.4) + Bluetooth Proximity Zigbee chipset TLSR8656F512ET32 Zigbee role EndDevice Sensor Sensirion SHT40 Display 3.6 inch LCD Temperature range -20 °C to 60 °C Temperature accuracy ±0.2 °C Humidity range 0–100% RH Humidity accuracy ±2% RH Response time 5 seconds (upon value change) Power supply 2× AAA 1.5V (included) Dimensions 95 × 70 × 18.2 mm Weight 99.3 g (with batteries) Certification CE / FCC / RoHS Warranty 2 years Frequently Asked Questions How do I pair the Sonoff AirGuard TH with Home Assistant? Put your Zigbee coordinator in pairing mode via Zigbee2MQTT or ZHA. Then press the reset button on the back of the sensor until the display responds. The sensor will automatically appear as SONOFF SNZB-02DR2 and after pairing, entities for temperature, humidity, battery, and voltage will be immediately available. Do I need a hub or bridge? For Zigbee integration with Home Assistant or the eWeLink app via Zigbee, you need a Zigbee coordinator. Via Bluetooth Proximity mode, you communicate directly with the eWeLink app on your smartphone, without a hub. Does the sensor also work outdoors? The sensor is not moisture-resistant (no IP rating) and not suitable for direct exposure to rain or condensation. However, its measurement range extends down to -20 °C, so use in a covered outdoor area or conservatory is possible, provided it stays dry. Can I combine two sensors on one display? Yes. In Zigbee mode, you can pair a second Sonoff Zigbee sensor (such as the SNZB-02P) to the AirGuard TH. The display will then show the values of both sensors live, which is convenient for monitoring indoor and outdoor temperatures at a glance. Does the sensor work with Homey? At the time of writing, the SNZB-02DR2 is not yet officially supported in the Sonoff Zigbee app for Homey. Please check the Homey App Store for the current status. Pairing via Homey Pro as a generic Zigbee device is possible. How long do the batteries last? Sonoff does not specify an exact battery life for the SNZB-02DR2. In practice, battery life depends on the reporting interval and ambient temperature. With comparable Sonoff Zigbee sensors without a display, you typically get 1 to 2 years on 2 AAA batteries; the display consumes extra power, so expect a shorter lifespan. ✅ slimhuisje.nl delivers the Sonoff AirGuard TH directly from stock. Connect it to your existing Zigbee network in minutes and keep a close eye on every room.