Founded in 1984, the first orders of HEAT wärmetechnische Anlagen crossed already the borders of Austria. In 1991 HEAT Germany was set up and has today its headquarters in Kassel. Premaberg, which is a specialist in the gas and oil exploration/processing, is part of the group since 1995. The company R+I Rohr- und Industrieanlagen joins since 1996 the HEAT Group and offers competency in assembly. HEAT-Gázgép is one of the largest manufacturers of household regulators in Europe and turned to a group member in 1997. In the years 1999 and 2000 the companies HEAT Romania and HEAT Bulgas, located in Romania and Bulgaria, were established.

HEAT Holding became the parent company of the whole group in 2002, which ensured a tight structure. HEAT Hungary was founded in 2006, followed by HEAT Refrigeration and HEAT Bioenergy in 2007. 2009 the company LOG Oiltools was taken over and HEAT Casting merged with HEAT-Gázgép. HEAT Poland and PSC Personalmanagement were set up in 2010. In 2011 E.U.T. Anlagenbau was taken over and the internationalization continued in 2012, with the foundation of HEAT Czech Republic.