A hydronic heating system consists of a boiler, water pipes, heat exchanger, water and valves. The boiler raises the temperature of water to boiling point while the water pipes carry hot water to heat exchangers/radiators located in different parts of the house. The valves are controlled by the thermostat. They are used to stop hot water from getting into the radiator when the preferred room temperature has been reached. In these systems, heat is distributed around the room naturally through convection currents.
The main advantage of these systems compared to other forms of heating is that they are highly efficient since water is a better heat transfer medium than air. Secondly, the system operates much more quietly than forced air systems, so they are much more comfortable to have at home. Thirdly, they are much safer for people who have allergies, asthma and sinusitis among other types of respiratory problems.