The DuoFern radiator actuator will attempt to perform reference runs after registration. If you do not install the radiator actuator directly, this will cause the battery to discharge quickly. If you do not install the radiator actuator immediately after registration, you should remove the batteries and reinsert them just before installation. It is then not necessary to log on again. After the batteries are inserted, three dashes first appear in the display, after a few seconds the display automatically jumps to POS, press the menu key once to start the installation drive. The display jumps to InS. Subsequently, the last set temperature is displayed.