As soon as the water reaches a certain level, the sensor transmits the switch signal to the SHT-12 FS fixed transmitter. In seconds the command is sent wirelessly to the SHR-12 K1 transmitter over a large distance. When it arrives, the receiver starts the water pumping station and fills the tank to the required water level again. A specific time can be set for this or a second signal can switch the pumping station off again. The control system can therefore be operated reliably at all times without personnel.