A central-heating system provides warmth to the whole interior of a building from one point to multiple rooms. When combined with other systems in order to control the building climate, the whole system may comprise a HVAC.

Central heating differs from local heating in that the heat generation occurs in one place, such as a furnace room in a house or a mechanical room in a large building.

The most common method of heat generation occurs through combustion of fossil fuel in a furnace or boiler. The resultant heat then gets distributed: typically by forced air through ductwork, by water circulating through pipes, or by steam fed through pipes. Increasingly, buildings utilize solar powered heat sources, in which case the distribution system normally uses water circulation.

In the UK, in much of northern Europe and in urban portions of Russia, where people seldom require air-conditioning in homes due to the temperate climate, most new housing comes with central heating installed. Such areas normally use gas-fired heating, or, where no ready supply of gas exists, oil-fired systems.

In the west and south U.S natural-gas-fired central forced-air systems occur most commonly; these systems and central boiler systems both occur in the far northern regions of the USA. Steam-heating systems, fired by coal, oil or gas, feature in the USA, Russia and Europe: primarily for larger buildings. Electrical heating systems, far less energy-efficient, occur less commonly.

Gas heater

A gas heater is a device used to heat a room by burning natural gas or liquefied petroleum gas.

The first gas heater made use of the same principles of the Bunsen burner invented in the previous year. It was first commercialized by the English company Pettit and Smith in 1856. The flame heats the air locally. This heated air then spreads by convection, thus heating the whole room.

Beginning in 1881 the burner's flame was used to heat a structure made of asbestos, a design patented by Sigismund Leoni, an English engineer. Later, fire clay replaced the asbestos because it is easier to mould. Modern gas heaters still work this way although using other refractory material.