The T3 enables automatic time and temperature control of heating systems in homes and apartments. The T3 saves energy - the advanced self-learning Honeywell Home TPI algorithm ensures that boiler control is more efficient than ever before. This thermostat is easy to use and features precise temperature control that makes the operation of boilers more efficient. It stands out with its modern design, clear, backlit temperature displays that are visible from a distance, and large temperature buttons that are easy to operate. Its simple programming philosophy makes installation straightforward and extremely user-friendly. The wired T3 thermostat offers a simple two-wire installation option and has a lifespan of 2 years (2 x AA batteries included), simplifying the installation and replacement of your current thermostat. This thermostat is compatible with 24 - 230 V on/off devices such as gas boilers, combi boilers, and heat pumps. It also works with zone valve applications. Not suitable for electric heating.