SONOFF TRV Gen2 Zigbee Thermostatic Radiator Valve (TRV-ZBT)

Smarter Room-by-Room Heating with Zigbee 3.0

What is the SONOFF TRV Gen2?

The SONOFF TRV Gen2 (TRV-ZBT) is a Zigbee 3.0 smart thermostatic radiator valve designed to automatically regulate radiator heating. It features a high-resolution IPS color display, a temperature setting range of 5°C to 30°C, customizable weekly schedules, open-window detection and support for compatible external temperature sensors.

Its compact design is 38% smaller than the previous SONOFF TRVZB model. With Zigbee connectivity, the TRV Gen2 can integrate into compatible smart-home systems, including Home Assistant through Zigbee2MQTT, to provide room-by-room temperature control and heating automation.

Key Takeaways

• Zigbee 3.0 smart thermostatic radiator valve

• 38% smaller than the previous-generation TRVZB

• High-resolution IPS color display

• Four-way rotatable screen orientation

• Temperature setting range from 5°C to 30°C

• Three independent heating plans

• Seven-day scheduling with up to 12 temperature periods per day

• PID-based valve adjustment

• Open-window detection

• Compatible external temperature sensor support

• Automatic anti-calcification maintenance

• Frost protection

• Child lock

• Boost mode

• Temperature offset adjustment

• Low-battery notifications

• Historical temperature and heating activity data

• Home Assistant integration through Zigbee2MQTT

• M30 × 1.5 mm threaded radiator connection

• Powered by two AA alkaline batteries

Take Control of Your Radiator Heating

Traditional radiator valves often require manual adjustment, making it difficult to maintain comfortable temperatures throughout the day.

The SONOFF TRV Gen2 makes radiator heating more flexible by allowing you to set target temperatures, create schedules and automate heating based on your daily routine.

Instead of heating every room continuously, you can configure different temperatures for different times of day.

For example, you could maintain a comfortable temperature in the morning, reduce heating while everyone is away and warm the room again before bedtime.

The TRV Gen2 also supports temperature monitoring, smart-home integrations and automatic valve adjustments to help reduce unnecessary heating.

Because it uses Zigbee, connected functions require a compatible Zigbee gateway or coordinator.

Why Choose the SONOFF TRV Gen2?

Compact Second-Generation Design

The SONOFF TRV Gen2 is approximately 38% smaller than the original SONOFF TRVZB.

Its dimensions are:

50 × 50 × 82.9 mm

This compact housing makes installation easier in areas with limited clearance around radiator pipes, furniture or walls.

The smaller design is particularly useful for radiators positioned in narrow spaces or behind furniture.

Despite its reduced size, the TRV Gen2 includes an upgraded display and advanced heating-control features.

High-Resolution IPS Color Display

Unlike basic radiator thermostats with simple monochrome displays, the TRV Gen2 features an IPS color screen.

The display provides a clear view of:

• Current temperature

• Target temperature

• Operating mode

• Device status

• Heating settings

It also supports four-way screen rotation, allowing the display orientation to be adjusted according to how the radiator valve is installed.

This makes the screen easier to read on radiators with different valve positions.

Quiet Valve Operation

SONOFF designed the TRV Gen2 with a smooth valve-adjustment mechanism intended to minimize operating noise.

This is especially useful for:

• Bedrooms

• Children's rooms

• Living rooms

• Home offices

• Other quiet indoor spaces

The motor adjusts the radiator valve as required to regulate heating without requiring constant manual intervention.

Precise Temperature Control

The TRV Gen2 supports target temperatures between:

5°C and 30°C

You can adjust the desired room temperature directly through the device or through supported smart-home software.

The thermostat then regulates the radiator valve to work toward the selected temperature.

This makes it possible to maintain different heating settings in different rooms.

Three Independent Heating Plans

One of the most useful features of the SONOFF TRV Gen2 is its advanced scheduling system.

The device supports:

• Three independent heating plans

• Seven-day weekly schedules

• Up to 12 temperature periods per day

This allows you to create heating schedules for different routines.

Workday Heating Plan

Reduce heating during working hours and increase the temperature when you return home.

Weekend Heating Plan

Maintain comfortable temperatures for longer periods when more people are at home.

Holiday Heating Plan

Use lower target temperatures when the property is unoccupied while maintaining appropriate frost protection.

You can switch between supported plans rather than rebuilding your heating schedule every time your routine changes.

PID-Based Temperature Regulation

The SONOFF TRV Gen2 uses a PID-based control algorithm to adjust radiator valve openings.

Instead of relying entirely on simple fully open or fully closed operation, the valve can modulate its position according to heating demand.

This helps the thermostat respond more smoothly to temperature changes.

Potential benefits include:

• More consistent room temperatures

• Reduced temperature fluctuations

• Improved comfort

• More controlled radiator heating

• Reduced unnecessary heat output

Actual heating performance depends on the radiator, heating system, room conditions and selected settings.

Open-Window Detection

Heating a room while a window is open can waste energy.

The SONOFF TRV Gen2 includes open-window detection designed to reduce heating when ventilation is detected.

The valve supports two approaches.

Automatic Temperature-Drop Detection

The thermostat can detect a sudden decrease in temperature and temporarily reduce or stop heating.

Door and Window Sensor Integration

With supported Zigbee door/window sensors and compatible automation software, heating can be reduced when a window is opened.

This is particularly useful in bedrooms, kitchens and living rooms where windows are opened regularly for ventilation.

External Temperature Sensor Support

A radiator thermostat measures temperature near the radiator, which may differ from the temperature elsewhere in the room.

The TRV Gen2 supports external temperature sensing through compatible configurations.

For example, a supported SONOFF Zigbee temperature and humidity sensor can provide temperature readings from another location.

This can help improve temperature regulation by using measurements from a more representative part of the room.

For Home Assistant users, external temperature control can also be implemented through appropriate automation routines.

The available method depends on the Zigbee gateway and integration.

Smart Energy-Saving Features

The SONOFF TRV Gen2 includes several features designed to help reduce unnecessary radiator heating.

Energy-Saving Mode

Configure valve-opening behavior to limit unnecessary heat output.

Motion Sensor Automation

Use supported smart-home automations to reduce heating when a room is unoccupied.

Open-Window Detection

Automatically reduce heating when a window is opened or a rapid temperature drop is detected.

Weekly Scheduling

Lower the temperature during periods when a room is not in use.

Room-by-Room Control

Adjust heating independently in rooms with different schedules and temperature requirements.

These features can help reduce energy consumption, although actual savings depend on heating habits, building insulation and system configuration.

Historical Temperature and Heating Data

The TRV Gen2 supports historical data viewing for up to six months in supported configurations.

Available data includes:

• Target temperature

• Current temperature

• Heating activity

Heating activity represents the proportion of time the device was actively heating during a given period.

For example, 30 minutes of heating within one hour corresponds to 50% heating activity.

This information can help users understand their heating patterns and adjust schedules accordingly.

Frost Protection

The TRV Gen2 includes a frost-protection function.

This feature helps protect the heating system against excessively low temperatures by allowing the thermostat to respond when frost protection is needed.

It is particularly useful for:

• Bedrooms

• Guest rooms

• Holiday properties

• Rooms used infrequently

• Areas exposed to low indoor temperatures

Frost protection should not be treated as a substitute for proper winterization or building-level freeze protection.

Automatic Anti-Calcification Maintenance

Radiator valves can become stiff when they remain in one position for extended periods.

The SONOFF TRV Gen2 includes automatic anti-calcification maintenance designed to help prevent valve mechanisms from becoming stuck.

This function periodically operates the valve mechanism to support continued movement.

It can be particularly useful when radiator heating is used seasonally.

Child Lock

The built-in child lock helps prevent accidental adjustments to the thermostat.

When enabled, it restricts manual changes from the device controls.

This is useful in family homes, children's bedrooms and shared living spaces.

Boost Mode

Boost mode allows the radiator valve to temporarily prioritize heating.

This is useful when you want to warm a room more quickly without permanently changing the normal heating schedule.

After the boost period, the device can return to its previous heating settings according to the configured operating mode.

Temperature Offset Adjustment

The TRV Gen2 supports temperature offset adjustment.

This allows the measured temperature to be calibrated when readings near the radiator differ from the actual room temperature.

For example, if the thermostat consistently reports a temperature higher than a reference thermometer elsewhere in the room, the offset can help compensate for the difference.

This can improve the accuracy of temperature-based control.

Group Control and Multi-Room Heating

Multiple SONOFF TRV Gen2 devices can be used to create a room-by-room smart heating system.

For example:

• Bedroom: 19°C

• Living room: 21°C

• Home office: 20°C

• Guest room: 16°C

These are example temperature settings rather than fixed device presets.

With supported group controls or smart-home automations, multiple radiators can also be adjusted together.

This makes it easier to manage heating across several rooms without manually changing each valve.

Home Assistant Integration

The SONOFF TRV Gen2 supports Home Assistant through compatible Zigbee integrations.

For users who want broad device functionality, Zigbee2MQTT is the recommended integration to consider.

SONOFF specifies that Zigbee2MQTT version 2.12.1 or later is required for full TRV-ZBT feature support.

With a compatible Zigbee coordinator and Zigbee2MQTT, Home Assistant can manage supported functions including:

• Target temperature

• Current temperature

• Heating mode

• Heating status

• Battery status

• Child lock

• Open-window detection

• Frost protection

• Screen orientation

• Temperature calibration

• Valve position

• Weekly schedules

• External temperature inputs

• Heating activity data

The exact exposed controls depend on the installed Zigbee2MQTT version and device firmware.

Zigbee2MQTT Support

The TRV-ZBT has a dedicated Zigbee2MQTT device definition.

This is useful for advanced Home Assistant users who want to configure heating behavior, monitor radiator activity and build custom automations.

A typical setup is:

SONOFF TRV-ZBT → Zigbee Coordinator → Zigbee2MQTT → MQTT → Home Assistant

This arrangement allows the thermostat to participate in local Home Assistant automations without requiring the original SONOFF gateway for its Zigbee connection.

ZHA Compatibility

The SONOFF TRV Gen2 can also be used with Home Assistant's ZHA integration, but feature availability requires attention.

SONOFF's published compatibility information states that native full support was awaiting the merge of ZHA pull request #5234.

Until the relevant support is included in a user's installed ZHA version, some advanced functions may require manual configuration.

Users who want the complete documented feature set should consider the manufacturer's Zigbee2MQTT version recommendation.

Apple Home Integration

The SONOFF TRV Gen2 can be integrated into Apple Home through a compatible Matter Bridge.

Supported SONOFF bridging options include:

• SONOFF Bridge Max Bridge-M

• SONOFF Zigbee Bridge Ultra

• SONOFF iHost

• Supported eWeLink CUBE configurations

The thermostat itself is a Zigbee device, not a native Matter-over-Thread thermostat.

A compatible bridge exposes supported thermostat functionality to the Apple Home ecosystem through Matter.

The available controls depend on the bridge and the Matter platform.

Alexa and SmartThings Integration

The TRV Gen2 can work with supported Alexa and SmartThings configurations through compatible gateways and integrations.

SONOFF also documents direct integration paths using suitable ecosystem gateways.

Some advanced features may not be available in every platform.

For SmartThings, additional device configuration may be necessary to access the complete feature set.

Technical Specifications

Specification	Details
Product Name	SONOFF TRV Gen2
Model	TRV-ZBT
Product Series	SONOFF Thermo Series
Product Type	Zigbee Thermostatic Radiator Valve
Wireless Protocol	Zigbee 3.0
Zigbee Standard	IEEE 802.15.4
MCU	TLSR8258
Input	3V DC
Battery Type	2 × 1.5V LR6 alkaline AA
Expected Battery Life	Up to 6 months under normal conditions
Temperature Setting Range	5°C to 30°C
Threaded Connection	M30 × 1.5 mm
Display	IPS color display
Display Orientation	Four-way rotation
Heating Plans	3 independent plans
Weekly Scheduling	7 days
Temperature Periods	Up to 12 per day
Operating Temperature	-10°C to 50°C
Operating Humidity	5%–95% RH, non-condensing
Dimensions	50 × 50 × 82.9 mm
Net Weight	169 g with batteries
Housing Material	PC
Color	White
Operating Cycle	10,000 cycles
Certifications	CE, RoHS
Zigbee2MQTT	Supported
ZHA	Supported with feature limitations depending on version
Matter Bridge	Supported through compatible gateway

Compatibility

Platform / Function	Compatibility
Zigbee 3.0	Yes
SONOFF Zigbee Gateways	Supported models
Home Assistant	Yes
Zigbee2MQTT	Yes, version 2.12.1 or later recommended
ZHA	Yes, with possible feature limitations
Apple Home	Through compatible Matter Bridge
Alexa	Through supported gateways
SmartThings	Through supported gateway or integration
eWeLink	Through compatible SONOFF gateway
External Temperature Sensor	Supported
Weekly Scheduling	Yes
Open-Window Detection	Yes
Child Lock	Yes
Frost Protection	Yes
Boost Mode	Yes
Temperature Offset	Yes
Direct Wi-Fi	No
Native Thread	No
Standalone Matter Device	No
Zigbee Mesh Router	No, battery-powered end device

Radiator Valve Compatibility

The SONOFF TRV Gen2 uses an M30 × 1.5 mm threaded connection.

This is a common connection type used by many thermostatic radiator valves.

SONOFF also provides valve adapters for compatibility with additional heating systems.

Before installation, check:

• Existing radiator valve type

• Thread size

• Available installation clearance

• Required adapter

• Valve-pin movement

• Mechanical condition of the radiator valve

Not every radiator valve is compatible, even if it appears similar.

The TRV Gen2 controls the radiator valve mechanically. It does not replace the central heating boiler or the radiator itself.

What’s Included?

The SONOFF TRV Gen2 package includes the thermostatic radiator valve and compatible mounting accessories for supported radiator valve types, together with product documentation.

The device operates using two 1.5V AA alkaline batteries.

How to Set Up SONOFF TRV Gen2

Step 1: Install the Batteries and Mount the Valve

Insert two compatible 1.5V AA alkaline batteries and install the TRV-ZBT on an M30 × 1.5 mm radiator valve or use the appropriate compatible adapter. Follow the device's installation and valve calibration procedure.

Step 2: Connect to Your Zigbee Network

Place your compatible Zigbee gateway or coordinator into pairing mode and follow the TRV Gen2 pairing instructions. For Home Assistant, use a supported ZHA or Zigbee2MQTT configuration.

Step 3: Configure Your Heating Preferences

Set your target temperature, configure weekly heating schedules and enable useful features such as child lock, frost protection, open-window detection and external temperature control where supported.

Smart Heating Automation Ideas

Morning Heating Routine

Automatically increase the bedroom temperature shortly before your normal wake-up time.

Away-from-Home Heating

Reduce radiator heating when nobody is home.

Window-Open Automation

Use a supported door/window sensor to reduce heating whenever a window is opened.

Room Occupancy Heating

Combine the thermostat with a motion or presence sensor to adjust heating based on room occupancy.

Nighttime Temperature Control

Reduce heating overnight and return to a comfortable temperature before morning.

Multi-Room Heating

Use several TRV Gen2 devices to maintain different target temperatures throughout the house.

SONOFF TRV Gen2 vs SONOFF TRVZB

Feature	TRV Gen2 (TRV-ZBT)	Original TRVZB
Generation	Second	First
Dimensions	50 × 50 × 82.9 mm	59.4 × 59.4 × 95 mm
Relative Size	38% smaller by volume	Larger
Display	IPS color	Basic display
Display Rotation	Four-way	Not the same upgraded display
Batteries	2 × AA	3 × AA
Temperature Range	5°C–30°C	4°C–35°C
Zigbee	Yes	Yes
Open-Window Detection	Yes	Yes
Child Lock	Yes	Yes
Frost Protection	Yes	Yes
External Temperature Support	Yes	Yes, depending on gateway
Weekly Heating Plans	3 independent plans	Scheduling supported
M30 × 1.5 mm Connection	Yes	Yes

The TRV Gen2 is particularly attractive for users who want a smaller housing, upgraded display and more flexible scheduling.

Pros

• Compact second-generation design

• 38% smaller than the original TRVZB

• High-resolution IPS color display

• Four-way display rotation

• Zigbee 3.0 connectivity

• Supports Home Assistant

• Zigbee2MQTT integration

• Three independent heating plans

• Seven-day scheduling

• Up to 12 temperature periods per day

• PID-based heating regulation

• Automatic open-window detection

• Door/window sensor integration

• External temperature sensor support

• Boost mode

• Child lock

• Frost protection

• Anti-calcification maintenance

• Temperature calibration

• Historical heating activity data

• Quiet motor operation

• Group heating control

• M30 × 1.5 mm radiator compatibility

• Uses two AA batteries

• Matter Bridge integration for supported ecosystems

Cons

• Compatible Zigbee gateway required for connected functions

• Cannot connect directly to Wi-Fi

• Not every radiator valve is mechanically compatible

• Full ZHA functionality may require additional configuration

• Battery-powered device does not extend the Zigbee mesh

• Advanced features vary by smart-home platform

Who Should Buy the SONOFF TRV Gen2?

The SONOFF TRV Gen2 is suitable for homeowners and smart-home users who want more control over individual radiator temperatures.

It is especially useful for:

• Zigbee smart homes

• Home Assistant users

• Zigbee2MQTT installations

• Multi-room heating systems

• Bedrooms and living rooms

• Home offices

• Households with different heating schedules

• Users upgrading from manual radiator valves

• Users replacing the original SONOFF TRVZB

• Smart homes using compatible Matter Bridges

The TRV-ZBT is designed for compatible thermostatic radiator systems and is not a replacement for electric underfloor heating controllers or central boiler thermostats.

Frequently Asked Questions

What is the SONOFF TRV Gen2?

The SONOFF TRV Gen2 (TRV-ZBT) is a Zigbee 3.0 thermostatic radiator valve that automatically regulates radiator heating. It features an IPS color display, customizable heating schedules, open-window detection, child lock and frost protection.

Does SONOFF TRV Gen2 work with Home Assistant?

Yes. SONOFF TRV Gen2 works with Home Assistant through compatible Zigbee integrations, including Zigbee2MQTT. SONOFF recommends Zigbee2MQTT version 2.12.1 or later for complete feature support.

Does SONOFF TRV Gen2 work with Zigbee2MQTT?

Yes. Zigbee2MQTT supports the TRV-ZBT and exposes heating controls, temperature settings, battery status, schedules, valve information and other supported device functions.

Does SONOFF TRV Gen2 work with ZHA?

Yes, but some advanced features may require additional configuration depending on the installed ZHA version. SONOFF has documented pending native support improvements and provides setup guidance for users who need additional functionality.

Does SONOFF TRV Gen2 work with Apple Home?

Yes, through a compatible Matter Bridge such as SONOFF Bridge Max or Zigbee Bridge Ultra. The TRV-ZBT is a Zigbee thermostat and does not connect directly to Apple Home as a native Matter-over-Thread device.

What batteries does SONOFF TRV Gen2 use?

The TRV-ZBT uses two 1.5V LR6 alkaline AA batteries. SONOFF specifies up to approximately six months of operation under normal conditions, depending on usage, battery quality and Zigbee network stability.

What radiator valves are compatible with SONOFF TRV Gen2?

The TRV-ZBT fits M30 × 1.5 mm threaded radiator valves and supports additional compatible valve types using appropriate adapters. Check your radiator valve's mechanical compatibility before installation.

What is the difference between SONOFF TRV Gen2 and TRVZB?

The TRV Gen2 is 38% smaller than the original TRVZB, includes an upgraded IPS color display with four-way rotation, uses two AA batteries instead of three and provides three independent heating plans with detailed weekly scheduling.

Why Choose the SONOFF TRV Gen2?

The SONOFF TRV Gen2 Zigbee Thermostatic Radiator Valve combines compact hardware, flexible scheduling and smart-home integration to make radiator heating easier to manage.

Its upgraded IPS color display, three independent heating plans, PID-based valve regulation and support for external temperature sensors provide greater control over room comfort.

For Home Assistant users, Zigbee2MQTT integration makes it possible to incorporate radiator heating into broader smart-home automations, while compatible SONOFF Matter Bridges can expose supported controls to Apple Home and other Matter ecosystems.

The TRV Gen2 is a practical choice for anyone looking to upgrade compatible radiator valves with more precise, automated and room-specific heating control.