SONOFF SNZB-02D - Zigbee 3.0 Temperature and Humidity Sensor with LCD Screen

General Overview

The SONOFF SNZB-02D is a smart Zigbee 3.0 temperature and humidity sensor distinguished by its large 2.8" high-definition LCD display that continuously shows the climate data of your room. Featuring a precision sensor made in Switzerland, it guarantees exceptional accuracy with a tolerance of only ±0.2°C for temperature and ±2% for relative humidity, rivaling professional measuring instruments while remaining accessible to the general public.

Designed for proactive climate monitoring, the SNZB-02D refreshes its measurements every 5 seconds, allowing for immediate responsiveness to environmental changes. Its LCD displays not only precise numerical values but also includes intuitive visual comfort level indicators (dry, humid, cold, hot) as well as the battery status, making reading immediate and accessible to all family members without needing to consult the mobile app.

Beyond local display, this sensor offers complete remote monitoring via the eWeLink app with Zigbee range reaching up to 120 meters in open field. The system keeps up to 6 months of history in the cloud for free, with hourly granularity allowing analysis of trends, identification of daily peaks and troughs, and data export in file format for in-depth analyses. Customizable push alerts instantly notify you on your smartphone as soon as a predefined temperature or humidity threshold is crossed, enabling you to react quickly to protect your sensitive belongings, your health, or your plants.

The SNZB-02D seamlessly integrates into any home automation ecosystem thanks to its standard Zigbee 3.0 compatibility with SONOFF gateways (ZBBridge, NSPanel Pro, iHost), Amazon Echo (4th Gen, Echo Plus 2nd), Home Assistant, and any other certified Zigbee 3.0 gateway. Its compact design (59.5x62.5x18.5mm) and lightweight (69.5g) come with three installation options: foldable stand with adjustable angle up to 120°, magnetic base for fixing on metal surfaces, or 3M double-sided adhesive for permanent wall mounting. Powered by an easily replaceable standard CR2450 button cell battery, it operates autonomously for months without needing electrical wiring.

Key Features

• Instant reading without a smartphone: Check temperature and humidity at a glance on the large LCD screen, ideal for baby rooms, wine cellars, greenhouses, or offices without taking out your phone
• Professional metrological reliability: Swiss reference sensor used in the industry, guarantees trustworthy measurements for demanding applications like food preservation, musical instruments, or sensitive collections
• Real-time responsiveness: Detects changes in 5 seconds compared to 30-60 seconds for competitors, crucial for fire alerts, water leaks, or automatic ventilation
• Smart comfort indicators: Automatic visual pictograms (water drop, snowflake, flame) to instantly understand if the atmosphere is too dry, humid, cold, or hot according to comfort standards
• Customizable preventive alerts: Set your critical thresholds based on usage (cellar 10-15°C, bedroom 18-22°C, greenhouse 24-28°C) and receive push notification before the problem worsens
• In-depth historical analysis: Access the last 6 months of data for free with hourly resolution, identify problematic patterns, validate the effectiveness of your modifications (insulation, heating, dehumidifier)
• Data export for expertise: Download the full history in file format for advanced statistical analyses, compliance reports, or sharing with professionals (allergy doctor, building expert)
• Advanced conditional automations: Trigger dehumidifier if >60%RH, activate heating if 25°C - unlimited scenarios via eWeLink or Home Assistant
• Hands-free voice control: Ask "Alexa, what's the temperature in the room?" or "OK Google, what's the humidity level in the basement?" without interrupting your activity
• Tool-free and drill-free installation: Choose from three methods according to your need - magnet for metal radiator, adhesive for wall, or self-stable stand for shelf with adjustable angle 0-120°
• Extended battery life: Common CR2450 button cell battery available in supermarkets, months of autonomy, low battery indicator with sufficient notice for planned replacement
• Extended range via mesh network: Coverage up to 120m in direct line, extendable via Zigbee routers (smart plugs, bulbs) for multi-story homes or annex buildings
• Apple Home integration via Matter: Add the sensor to HomeKit using a compatible Matter Bridge (iHost, NSPanel Pro) for total smart home centralization
• Multi-room without extra cost: Add as many sensors as needed to your existing gateway, monitor all sensitive areas (rooms, cellar, attic, garage) simultaneously from one app
• Installation compliant with regulations: Certified installation up to 2m maximum height for safety standards compliance, guaranteed absence of accidental fall even in the presence of children

Technical Specifications

Hardware Specifications

• Model: SNZB-02D
• MCU: Silicon Labs EFR32MG22
• Sensor: Sensirion (Swiss made)
• Color: White
• Dimensions: 59.5 x 62.5 x 18.5 mm
• Net weight: 69.5g (with battery and stand)
• Case materials: PC (polycarbonate) + LCD
• LCD Screen: 2.8-inch high definition
• Display resolution: Temperature 0.1°C/°F, Humidity 0.1%RH

Measurement Performance

• Temperature range: -9.9°C to +60°C / 14°F to 140°F
• Temperature accuracy: ±0.2°C / ±0.4°F
• Humidity range: 5% to 95% RH (non-condensing)
• Humidity accuracy: ±2% RH
• Refresh frequency: 5 seconds (if change detected)
• Automatic report interval: 60 minutes minimum (if no change)
• Measurement resolution: 0.1°C and 0.1%RH

Wireless Connectivity

• Protocol: Zigbee 3.0 (IEEE 802.15.4)
• Frequency: 2405-2480 MHz
• Transmission power: ≤10 dBm
• Free field range: Up to 120m / 400 feet
• Typical indoor range: 30-50m depending on obstacles
• Network topology: Mesh via Zigbee routers

Power Supply

• Nominal voltage: 3V (button cell)
• Battery type: CR2450 (standard)
• Battery life: Several months depending on use
• Battery indicator: Icon on LCD screen + app alert
• Rechargeable battery: No (single-use disposable battery)

Display and Interface

• Screen: 2.8" permanent LCD without backlight
• Displayed data: Temperature, humidity, Zigbee signal icon, battery
• Comfort indicators: Automatic dry/humid/cold/hot pictograms
• Temperature units: °C or °F (switchable via button)
• Physical button: 1 multifunction button on the back

Physical Button Functions

• Long press 5 seconds: Zigbee pairing mode (180s)
• Single press: Wake device / Reconnect network
• Double press: Toggle °C ↔ °F
• Status LED: Slow blinking (pairing), solid (connected), off (not connected)

Comfort Level Indicators

• Dry: Humidity ≤40% RH
• Humid: Humidity ≥60% RH
• Cold: Temperature ≤19°C / 66.2°F
• Hot: Temperature ≥27°C / 80.6°F
• Optimal comfort: 19-27°C and 40-60% RH (no indicator)

Installation and Mounting

• Integrated foldable stand: Adjustable angle 0-120°
• Magnetic base: Fixation on metal surfaces (radiator, cabinet)
• 3M double-sided adhesive: Permanent wall mounting included
• Max installation height: ≤2 meters (safety standard)
• Installation: Tool-free, drill-free, no wiring

Environmental Conditions

• Operating temperature: -9.9°C to +60°C
• Operating humidity: 5-95% RH (non-condensing)
• Maximum altitude:
• Usage: Indoor only
• Protection: IP20 (not waterproof)

Zigbee Gateway Compatibility

• SONOFF Gateways: ZBBridge, ZBBridge-P, ZBBridge-U, NSPanel PRO, iHost, ZBDongle-P, ZBDongle-E
• Amazon Echo: Echo Plus 2nd Gen, Echo 4th Gen, Echo Show 2nd Gen
• Other gateways: Any certified Zigbee 3.0 gateway
• Compatibility check: Exhaustive list on manufacturer’s website

Platform Compatibility

• eWeLink App: iOS and Android (native monitoring)
• Home Assistant: Native integration via ZHA or Zigbee2MQTT
• Amazon Alexa: Voice commands and routines
• Google Home: Voice commands and scenarios
• Apple Home: Via Matter Bridge (iHost, NSPanel Pro)
• SmartThings: Via Matter Bridge
• openHAB, Jeedom, Domoticz: Via compatible gateways

eWeLink App Features

• Real-time monitoring: Current temperature and humidity
• Free cloud history: 6 months with hourly resolution
• Trend graphs: Daily/weekly/monthly evolution curves
• Min/max values: Records by hour, day, or period
• Data export: CSV/Excel file download
• Customizable push alerts: Configurable temperature and humidity thresholds
• Home automation scenarios: Conditional multi-device triggers
• Family sharing: Multi-users on the same account
• Grouping: Organization by rooms and floors

Possible Automations

• Humidity management: Dehumidifier ON if >60%RH, OFF if
• Heating control: Smart thermostat based on measured temperature
• Automatic ventilation: Ventilation system or motorized window as needed
• Collection protection: Alerts for wine cellar, musical instruments, artworks
• Baby room comfort: Parent notification if conditions are inadequate
• Smart greenhouse: Watering + ventilation based on temperature/humidity
• Presence detection: Combination with motion sensor for smart heating

Certifications and Standards

• European compliance: CE (RED Directive 2014/53/EU)
• US compliance: FCC (Part 15 Class B)
• Canada compliance: ISED (ICES-003)
• Environment: RoHS (free from hazardous substances)
• Electrical safety: EN IEC62368
• Radio: EN 300 328, RSS-247

Battery Safety

• Battery type: CR2450 lithium 3V (non-rechargeable)
• Warning: Ingestion hazard (severe chemical burns in 2h)
• Storage: Keep out of reach of children
• Replacement: Unscrew rear cover, respect +/- polarity
• Recycling: Do not dispose of with household waste, drop off at collection point
• Do not: Recharge, disassemble, heat >60°C, incinerate

Factory Reset

• Method: Delete device from eWeLink application
• Effect: Complete erasure of history and settings
• Re-pairing: Necessary after reset

Package Contents

• 1x SONOFF SNZB-02D temperature/humidity sensor
• 1x Integrated foldable stand
• 1x Removable magnetic base
• 1x 3M double-sided adhesive
• 1x Pre-installed CR2450 battery with protection tab
• 1x Multilingual quick start guide