Abstract: An arrangement for measuring a quantity of heat given off by a heating body to a space and for simultaneously controlling a fluid stream passing through the heating body and serving as a heat carrier for regulating of the space temperature, has a volume stream regulator for allowing a constant fluid stream. An on-off valve is controlled by a signal generator for example a space thermostat via a control valve and switched by the energy of the fluid stream to block or unblock the fluid stream. A temperature sensor cooperating with the heating body and an electronic element determine the quantity of heat by integration of temperature difference values converted into an electrical value during opening times of the on-off valve.