This radiator thermostat is only designed to work alongside an existing Wiser Smart Heating System with a Wiser Heat Hub. Replace your existing radiator TRV valves to give room-by-room heating control. Simply screw off/on existing TRV radiator valves and replace with Wiser smart thermostats to expand your current system. Works with 90% of existing valves. An adaptor to fit the Danfoss RA valve is included in every box. Add up to 32 smart radiator thermostats in up to 16 different rooms/zones. Begin with 1 radiator thermostat and add more over time. 1 Thermostat required per radiator for maximum comfort and energy saving. Full heating control can be monitored and schedules updated via the Wiser App (IOS and Android). Use voice commands to check the status and make changes to individual rooms or groups of rooms. Fully compatible with Alexa, Google Assistant and IFTTT. Open window detection turns off heating if a window is open. Twist top allows manual override of the schedule via the radiator thermostat. Average connectivity range is 25-40 feet but will depend on location of Heat Hub and thickness of walls. For larger houses or houses with thick walls, we recommend the Wiser Smart Plug to help extend the range. Wiser is not suitable for gravity fed systems. Smart radiator thermostat is powered by 2 x AA Batteries (Batteries Included). Expected to last around 12 months, dependent on battery type and the amount of interactions with each device. Wiser is not suitable for gravity-fed systems Radio Equipment Directive (RED) 2014/53/EU, Batteries Directive 2006/66/EC, RoHS Directive 2011/65/EU