The LCN-AVN is an electrothermal actuator for radiator valves. It can be connected to valves from various manufacturers using an adapter. The actuator is designed for operation on LCN bus modules from model year 04/2008. All LCN actuators are closed when de-energized. The actuating mechanism works with a PTC-heated expansion element and a compression spring. The expansion element is heated by applying the operating voltage and the integrated tappet is moved as a result. The force generated by the movement is transferred to the valve tappet and opens or closes the valve. The LCN-AVN has a marking on the tappet that shows the opening width. The LCN-AVN is delivered from the factory in the first-open position, so that it is open when de-energized. This enables heating operation during the shell construction phase, even if the electrical wiring for the individual room control has not yet been completed. When the operating voltage is switched on (for more than 6 minutes), the first-open function is automatically unlocked and the drive is fully functional (closed when de-energized). The actuator snaps onto the valve adapter. It can be removed again by pressing the Plexiglas decorative cover. The decorative cover can be easily removed so that the actuator is secured against unlocking.