Vaso di espansione da 7 litri per le caldaie Themaclassic e Thematek.

Saunier Duval was founded in 1907, but its origins date back to 1850. In 1907, Charles Saunier was director of Bengel Frères, a company specialising in gas-fired heating and appliances. The company was sold to him and he went into partnership with an industrialist, Maurice Duval. Saunier Duval was born. Unfortunately, Charles Saunier was killed in action in 1916. Henry Frisquet replaced him, and the company became Saunier Duval Frisquet. Reconstruction enabled the partners to sell thousands of street lamps and candelabras. It was Saunier Duval Frisquet that equipped the Alexandre III bridge, the Place de la Concorde, the Banque de France, etc. In 1922, the takeover of Établissements Farge developed the "hot water/heating" business, with its gas-fired water heaters: Vesuvio and Stromboli, among others. In the 50s and 70s, once again Saunier Duval, the company experienced strong growth and developed its wall-mounted combi boilers, an innovation that provided both hot water and heating; then came solar water heaters and heat pumps. In 1979, Saint-Gobain became a majority shareholder. In the 2000s, Saunier Duval was bought out by the Vaillant Group, a German company founded in 1874 and now Europe's second-largest heating manufacturer. Saunier Duval continues to innovate with its IsoDyn process (instantaneous and accumulated power) and its 1st intelligent hybrid system, Genia Hybrid.