Abstract: A system and method for measuring the heat emission of space heaters includes an input device for selectively inputting special heater constants Q.sub.N and n, which are characteristic space heaters associated therewith. The device is coupled to a processor which, in operation, receives the temperature values T.sub.V, T.sub.R and T.sub.i sensed by a supply temperature sensor, a return temperature sensor, and an ambient temperature sensor. A timer provides the clock signal for the processor. The processor develops an output representing a quantitative measure for the heat consumption of the associated heater from the preadjusted characteristic constants, Q.sub.N and n, and the sensed temperature values, T.sub.V, T.sub.R and T.sub.i. The processor is programmed so as to also serve as correction device for automatically correcting any throttle states of the heater in operation.