A boiler heating system heats water and pushes either hot water or steam through a series of pipes and radiators to provide heat. Specifically, steam is distributed through pipes to the radiators, and hot water is distributed through radiant floor systems, a heat coil or baseboard radiators.
Steam boilers operate at a much higher temperature than water boilers, making them less efficient. In the hot water system, the boiler heats the water and the circulator pushes the water through the pipes. In the steam system, there is no circulator, and the steam rises naturally through the pipes. Steam radiators can build up pressure that needs to be released through a valve. Boilers allow homeowners to choose radiant floor heating, which means that small pipes under the floor can warm cold surfaces such as tile or wood.