Which one is more economic; central heating boiler or central system?

Central heating boiler provides individual heating comfort and economy. Thus, you can warm yourself up for any time and as much as you want. Besides, there is no need for use of an additional device (geyser, water heater, boiler etc.) for hot water thanks to the central heating boilers, which are also used in heating of hot domestic water. However, use of central boiler is more advantageous than central heating boiler regarding fuel consumption in apartments having 4 or more flats.