Abstract: The meter forms part of a heating system supplied with thermal energy in the form of hot water from a heat generator, and serves to determine the amount of heat supplied to a consumer, for the purpose of appropriately charging the consumer for incurred heating costs. The meter includes a computer, operating on the analog principle, a volumeter and connection elements for connection to signal processing devices. The volumeter is formed by a first tubular body through which the hot water flows to the consumer, and this first tubular body is surrounded coaxially, at a definite radial spacing therefrom, by a second tubular body so that the two tubular bodies define a completely closed annular space. The cooled hot water returns through a return line. The supplied hot water in the first tubular body constitutes a primary medium flowing therethrough, and the completely closed annular space receives a secondary medium which is heated by the primary medium.