Early central heating seems to have developed along several lines that included hearths and fireplaces, stoves, and underfloor systems. Fixed central hearths date as far back as 2500 B.C. They were excavated in Greece.
Crude fireplace heating was used as early as the 800s A.D., and was widespread in Europe by the 13th century. Castles built at that time had fireplaces that had a short flue to the outside, a crude form of chimney. All of the early fireplaces were constructed entirely of stone, but casting technology improvements led to the introduction of cast iron firebacks designed to protect the stone from direct fire heat.
Louis Savot of France invented the raised grate and designed a circulating fireplace in the early 1600s. Savot used a hollow iron bottom and back in the hearth, through which cold room air entered at the bottom, was warmed, and entered the room through openings above the mantle.
In England, another improvement was to provide combustion air through a duct from the outside. A French priest (actually a Cardinal) wrote the first comprehensive manual on fireplace design, Mechanique du Feu, in 1713. The science of fireplace construction reached its zenith with Benjamin Thompson, Count Rumford, who published Chimney Fireplaces in 1796.
Like fireplaces, stoves also first appeared in the 800s as crude devices made from clay bricks. Masonry stoves became common in northern Europe by the 1500s. The stoves, called Russian or Swedish stoves, were very large. Later versions were very ornate, with tile coverings.
The earliest metal stoves, appearing after 1400, were made of cast iron hearth firebacks connected together. Later, cast iron sections were designed specifically for stove construction, and Holland and Germany became leading centers for iron stove manufacturing.