The 
Honeywell Home T3R
 is a wireless, 7-day programmable thermostat designed for automatic time and temperature control of domestic heating systems. It includes a battery-powered thermostat unit and a separate wireless receiver box that wires directly to the boiler. 
Key Features
Wireless Connectivity: The thermostat communicates with the receiver box via a robust RF signal, allowing the main unit to be placed anywhere in the home (it comes with a table stand or can be wall-mounted).
Programmable Scheduling: Users can set a 7-day or 5/2-day heating schedule with up to 4 or 6 independent time and temperature changes per day to suit their comfort needs and help save energy.
Compatibility: It works with a wide range of 24-230V on/off heating systems, including gas boilers, combi boilers, heat pumps, and zone valve applications. It also supports OpenTherm appliances.
User-Friendly Display: The device features a large, clear, backlit LCD screen with easily recognized icons and simple buttons for operation and programming.
Energy-Saving Features: It utilizes an advanced TPI (Time Proportional & Integral) self-learning algorithm for efficient boiler control, a "Holiday mode" to set a constant temperature while away, and frost protection (maintains a minimum 5°C).
Installer-Friendly Design: The receiver box is designed for easy installation with clear, labelled terminals and an override button for system checks, which helps shorten installation time.