It doesn't stop with boilers.
Radiators have improved over the years, which are made with more metal surface area and less volumes of water making them efficient too. Also, the use of controls will help make the whole of the central heating system more efficient. Controls such as Thermostatic Radiator Valves will automatically shut off the heat to the radiator when the room has reached temperature.
These, however, only work for each individual room. To control the whole system, a main room thermostat should be fitted to control the temperature and for the times where your home is vacant whilst at work, for example, a programmer should be fitted to control the times when the boiler is in operation.
