hot-water heating

Hot-water heating is a central heating system that uses hot water to transfer heat to rooms. In this system, a boiler heats water, which is then circulated through pipes to radiators or other heat emitters in the rooms. The heated water releases its warmth into the room, and the cooled water returns to the boiler to be reheated.

This method of heating became recognized around 1830 as an alternative to steam heating, offering a milder effect due to its lower surface temperature. Modern hot-water systems often use pumps to circulate the water, allowing for greater flexibility in boiler placement. This contrasts with earlier gravity-fed systems, which required the boiler to be located below the heat emitters. Hot-water heating is a popular choice in Great Britain and much of Europe.1