Sonoff TRV Gen2 Review: A Compact Zigbee Radiator Valve With a Colour Screen
An IPS display with 4-way rotation, three switchable 12-slot schedules and external sensor support, on a Zigbee radio that needs a hub.
The Sonoff TRV Gen2 (TRV-ZBT) is a Zigbee thermostatic radiator valve built for people who already run a Zigbee network and want per-room heating control they can script. Its standout is the interface: a colour IPS screen that rotates in four directions so it stays readable whichever way the valve points, backed by three switchable weekly plans of up to 12 time slots each and the option to take the room temperature from a separate Sonoff sensor instead of the hot air next to the radiator. The trade-off is that it is an end device, not a standalone thermostat: it needs a Zigbee coordinator, and Apple Home and Matter only see it once a Sonoff bridge republishes it. At this price tier it is one of the better equipped valves for a hub-based home rather than an app-only one.
- Zigbee homes
- Home Assistant users
- Room-by-room heating
- Budget buyers
Pros
- Colour IPS screen with 4-way rotation, readable whichever way the valve is mounted
- Three switchable weekly plans with up to 12 time slots per day
- Can take its reference temperature from a separate Sonoff sensor, plus an offset for calibration
- Smart Scene automations triggered by open-window detection, status or temperature
- Frost protection with an adjustable threshold, and a child lock that disables the knob
- Works with Alexa, Google Home, SmartThings and Home Assistant via Zigbee2MQTT or ZHA
- Compact 50 x 50 x 82.9 mm body for tight pipework
- Two year warranty
Cons
- Zigbee end device: a coordinator or hub is required, it does not work alone
- Apple Home and Matter only through a Sonoff bridge, there is no Matter radio in the valve
- ZHA needs the quirk script Sonoff publishes until its pull request is merged
- No humidity sensor
- No geofencing and no schedule learning, the plans are the ones you write
- Around six months on two AA batteries, less if the valve adjusts often
Who is the Sonoff TRV Gen2 for?
This valve suits a home that already has a Zigbee coordinator running, whether that is a Sonoff bridge or dongle, a SmartThings hub, an Echo with a Zigbee radio, or a Zigbee2MQTT or ZHA setup inside Home Assistant. It replaces the manual head on a radiator with an M30 x 1.5 mm thread and turns that radiator into its own heating zone, which is the point of a TRV: instead of one thermostat deciding the temperature of the whole house, each room follows its own plan. The compact 50 x 50 x 82.9 mm body helps where pipework is tight and a taller head would not clear the wall or the sill.
What stands out on paper
The display is the clearest upgrade over a typical valve head. It is a colour IPS screen rather than a segment LCD, it shows the current temperature next to the target, and it rotates in four directions so the reading stays upright on a valve mounted sideways or upside down. Scheduling is unusually deep for the category: three independent plans, each covering all seven days with up to 12 time slots per day, plus manual and anti-freeze modes and a boost timer. Two features fix the classic TRV accuracy problem: the valve can read its reference temperature from a separate Sonoff sensor placed away from the radiator, and it exposes a temperature offset for calibration. Smart Scene automations can trigger on open-window detection, device status or the current temperature and switch the valve between auto, anti-freeze, manual and boost. Frost protection with an adjustable threshold and a child lock that disables the knob round out the practical side, and Sonoff backs the unit with a two year warranty.
What to know before you buy
It is a Zigbee 3.0 end device, so it does nothing on its own: a coordinator has to host it. Sonoff lists its own ZBBridge-P, ZBBridge-U, NSPanel Pro, iHost and ZBDongle coordinators, and the valve also pairs directly with Alexa, SmartThings and Google Home through the eWeLink account or a compatible Zigbee hub. Apple Home and Matter are indirect: the valve has no Matter radio of its own and reaches both only when a Sonoff bridge republishes it over Matter. On the Home Assistant side, Zigbee2MQTT has a device page for the TRV-ZBT and Sonoff asks for version 2.12.1 or later, while ZHA needs the quirk script Sonoff publishes until its pull request is merged, so expect a little setup work there. Feature-wise the valve has no humidity sensor, no geofencing, and no learning: it follows the plans you write rather than inferring a schedule from your habits. Power is two AA alkaline cells, rated at around six months, and that figure drops when the valve adjusts often or the network is unstable.
Is the Sonoff TRV Gen2 worth it?
For a Zigbee household it is good value. The colour screen, the three switchable schedules, the external temperature reference and the automation hooks are the parts that actually change how a radiator behaves day to day, and they sit at the budget end of the category. What you give up against a pricier valve is autonomy: no cellular or Wi-Fi fallback, no occupancy learning, no location-based control, and a hub in the chain for every ecosystem beyond eWeLink. If the plan is one valve and a phone app with no hub in the house, this is not the right purchase; if the plan is six radiators driven by a hub or Home Assistant, it is a sensible per-room unit to standardise on.
Frequently asked questions
Does the Sonoff TRV Gen2 need a hub?
Yes. It is a Zigbee 3.0 end device, so it has to join a Zigbee coordinator. Sonoff lists its ZBBridge-P, ZBBridge-U, NSPanel Pro, iHost and ZBDongle coordinators, and the valve also works through a SmartThings hub, an Echo with a Zigbee radio, or a Zigbee2MQTT or ZHA coordinator in Home Assistant.
Does the Sonoff TRV Gen2 work with Home Assistant?
Yes. Zigbee2MQTT publishes a device page for the TRV-ZBT and Sonoff asks for Zigbee2MQTT 2.12.1 or later for full feature support. With ZHA it also works, but some entities need the quirk script Sonoff distributes until its pull request is merged upstream.
Does it work with Apple Home?
Indirectly. The valve speaks Zigbee, not Matter, so Apple Home sees it once a Sonoff bridge (Bridge-M, ZBBridge-U, iHost, NSPanel Pro or eWeLink CUBE) republishes it into Matter. Alexa, Google Home and SmartThings are also supported through the eWeLink account or a compatible Zigbee hub.
Can it use the temperature of the room instead of the air next to the radiator?
Yes. The Temp. Display from External Sensor setting lets the valve use another Sonoff sensor on the same eWeLink account as its control reference, including the SNZB-02, SNZB-02P, SNZB-02D, SNZB-02WD, SNZB-02LD, SNZB-02B and SNZB-02M. There is also a temperature offset if you only want to calibrate the built-in reading.
How long do the batteries last?
Sonoff rates two 2,000 mAh AA alkaline cells at around six months of normal use. How often the valve adjusts, the ambient temperature and network stability all shorten it, and an unstable Zigbee link that makes the valve keep searching for the network is the biggest drain.
Will it fit my radiator?
It mounts on the standard M30 x 1.5 mm valve thread. Note that the Thread Connection line on the Sonoff spec sheet refers to that mechanical thread, not to the Thread wireless protocol, which the valve does not use.
