Abstract: Heat exchanger output control device in a one-pipe heating network characterized in that a first T-branch, which is connected to a second T-branch interconnected to a primary outlet pipe connection of a primary outlet pipe to a heat source through a primary outlet, is connected to the primary inlet pipe connection through a primary inlet. The first T-branch is connected to a secondary supply pipe connection through a secondary supply pipe with a secondary supply temperature sensor, and the second T-branch is connected to a secondary return pipe connection through a secondary return pipe with an additional secondary return temperature sensor. An impeller of a pump is connected to a secondary circuit to pump the heat-transfer medium from the first T-branch through a heat exchanger back to the second T-branch, and to connected to a electrical motor provided with a control unit connected to secondary supply and return temperature sensors.