A compact smart TRV with a bright colour screen - heat the rooms you're using, not the ones you're not.
Fitting it is a quick and easy DIY job: just remove the existing plastic head from your radiator valve and pop this on in its place, no plumbing required. Once it's on, you can set temperatures and schedules from your smart home system, or adjust it using the dial.
The screen shows the target and current room temperature at a glance, and you can rotate it so it's the right way up however your valve is mounted. It's compact enough to fit around awkward pipework, quiet enough that you won't hear it at night, and runs for up to six months on two AA batteries.
This is a Zigbee device, so you'll need a compatible hub to use it with your smart home system - it won't connect directly to your Wi-Fi. If you don't have a Zigbee hub you can still adjust it using the dial (or over Bluetooth, using the eWeLink app).
What's New? ✨
Compared with the original Sonoff Zigbee Thermostatic Radiator Valve (TRVZB), this version is over a third smaller, has a colour screen and has Bluetooth.
When testing, we liked the clear screen, the metal thread and the remote recalibration. We especially liked being able to link it to an external temperature sensor, so it heats based on the actual room temperature rather than the air next to the radiator.
Get Smart, Automate!
This is a smart valve, so the fun really begins when you connect it to your home automation system.
Schedule rooms to warm up before you get home and cool off once you've left, or team it up with presence sensors so you're not heating empty rooms. It'll even stop heating when it spots an open window, either from a sudden drop in temperature or a linked door/window sensor.
Pair it with a Sonoff Zigbee hub such as the ZBBridge-P, NSPanel Pro or iHost and control your heating from anywhere with the eWeLink app. It also works with Home Assistant on a Raspberry Pi or Home Assistant Green (with a Zigbee adapter), and other Zigbee 3.0 hubs including SmartThings and some Amazon Echo devices.
Features
- Colour display: Bright, high-resolution IPS screen that rotates to suit how your valve is mounted.
- Compact and quiet: Just 50x50x83mm, with a low-noise mechanism.
- Smart scheduling: Up to three switchable heating plans, each with 7-day scheduling and up to 12 time periods per day.
- External sensor support: Use a temperature sensor positioned away from the radiator to heat based on the real room temperature.
- Open window detection: Stops heating when a window's open, and notifies you if it's left open.
- Remote calibration: Recalibrate the valve from the app, with no need to take it off the radiator.
- Built-in protection: Anti-calcification, frost protection, child lock and low battery alerts, and you can choose what the valve does when the batteries run low.
- Widely compatible: Robust metal M30 x 1.5mm fitting, plus adapters for most other valve types.
Tech Specs
| Model | TRV-ZBT |
| MCU | TLSR8258 |
| Input | 3V (2x 1.5V AA batteries) |
| Battery type | LR6 alkaline AA |
| Battery life | Up to 6 months |
| Display | IPS colour |
| Wireless connection | Zigbee 3.0 (IEEE 802.15.4), Bluetooth LE |
| Thread connection | M30 x 1.5mm |
| Temperature setting range | 5°C~30°C |
| Net weight | 169g (including batteries) |
| Colour | White |
| Dimensions | 50x50x82.9mm |
| Casing material | PC |
| Working temperature | -10°C~50°C |
| Working humidity | 5~95% RH non-condensing |
| Operating cycle | 10,000 cycles |
| Certification | CE/RoHS |
Resources
Check out the TRV-ZBT knowledge centre for installation instructions, setup tips and troubleshooting, and SONOFF's adapter selection guide if you're not sure which adapter you need.
Notes
- You'll need to fit the valve to your radiator before pairing it.
- Using Home Assistant? Full ZHA support is on its way - for now, some features need SONOFF's setup script (see the knowledge centre). Zigbee2MQTT supports everything from version 2.12.1. External temperature sensors are set up with an automation.
- Use alkaline AA batteries - rechargeable NiMH ones only provide 1.2V, which won't keep it going for long.
What is Zigbee?
Zigbee is a low-power wireless standard made specifically for smart home gadgets like sensors, switches and lights. It sips power so it's perfect for battery-powered devices that need to keep going for months (or years) between battery swaps.
Zigbee devices form a mesh network, with mains-powered devices like smart plugs and bulbs passing messages along for their neighbours. The more devices you add, the stronger and further-reaching your network gets.
It also works locally, so your devices keep chatting to your hub even if your internet decides to take the day off. That means snappier responses, better reliability and improved privacy. It's supported by loads of manufacturers too, so mixing and matching brands is no problem.
Want to learn more? Check out the official Connectivity Standards Alliance website.