Electronic thermostatic head BT-SRT03-RF

Discover the BT-SRT03 RF, the wireless electronic smart radiator thermostat by WATTS Vision®. Control your water-based radiators room by room, save energy and boost home comfort with precise PID regulation and bidirectional 868.3 MHz RF communication.

The BT-SRT03 RF is a programmable electronic thermostatic head for water-based radiators. Designed for both residential and collective housing, it can operate as a standalone device or be fully integrated into the WATTS® Vision® smart home ecosystem alongside the BT-CT03 RF central control unit, the BT-ST03 RF smart thermostat, and BT02/03-RF Series room thermostats.

Thanks to its wireless 868.3 MHz bidirectional RF communication, the BT-SRT03 RF enables seamless, multi-zone heating control — ideal for modern smart homes seeking energy efficiency and comfort.

Key Features

• Wireless 868.3 MHz bidirectional RF communication — compatible with WATTS Vision® ecosystem
• Easy programming via the Watts Vision+ app (iOS & Android)
• Weekly programming with customisable comfort and reduced temperature modes
• Temporary override (Boost) function for instant temperature adjustment
• Anti-freeze protection down to 5°C
• Anti-grip valve function to prevent valve seizure
• PID regulation for precise and energy-efficient temperature control
• Heating & cooling modes
• Non-volatile EEPROM memory — settings retained after battery removal
• Compatible with AA rechargeable batteries (LR6 1.5V)
• Adjustable actuator force: 70N or 90N — suitable for most radiator valve brands
• Extra valve opening function for specific valve types (e.g. Heimeier)
• 6 universal adaptor types: M30x1.5, Danfoss RA, Danfoss RAV, Danfoss RAVL, Giacomini, M28x1.5 (Comap), Watts TRV
• Open window detection function
• ERP Class IV (2%) energy efficiency rating

Installation Types

Type 1 — Standalone Mode

Perfect for collective housing where users do not control the central heating system. The BT-SRT03 RF independently opens or closes the radiator valve based on room temperature, operating whenever the collective boiler is active.

Type 2 — Multi-Zone Water Radiator System

Enables precise room-by-room temperature control for water radiator installations. Pair the smart radiator thermostat with a BT-ST03 RF smart thermostat, which in turn controls the boiler or heat pump via a wall receiver.

Type 3 — Combined Underfloor Heating & Water Radiators

Advanced multizone installation combining underfloor heating with water radiators. Managed through the BT-CT03 RF central control unit for complete building-wide climate control.

Compatibility & Adaptor Types

The BT-SRT03 RF fits most radiator valves on the market thanks to its 6 included adaptor types:

• M30×1.5 (pre-mounted thread)
• Danfoss RA
• Danfoss RAV
• Danfoss RAVL
• Giacomini
• M28×1.5 (Comap)
• Watts TRV