This self-learning Nest thermostat is compatible with most central heating systems, including

combination boilers
system and solo boilers
domestic boilers
underfloor heating systems with hot water
heat pumps with air heat and geothermal heat (heating only)
zone systems (1 Nest thermostat per zone)
heating systems with OpenTherm technology
Characteristics

diameter: 8.4 cm
screen diameter: 5.3 cm
width: 3.1 cm
LCD screen with 24 bit colours
resolution 480x480 and 229 PPI
Sensors: temperature, humidity, far and near activity, ambient light
Built-in rechargeable lithium-ion battery
Remote control requirements:

Wifi connection with internet access
Nest app on mobile or tablet with iOS 8 or later, or Android 4.1 or later
Latest version of Safari, Chrome, Firefox or Internet Explorer on Mac OS
Sensors:

Temperature
Humidity
Activity nearby
Remote activity
Ambient light
The Nest learning thermostat is also suitable for voice control using a compatible home assistant.