The backwater valve for wastewater without sewage is equipped with two mechanical flaps which close automatically in the event of backwater. One flap serves at the same time as an emergency closure to be closed by hand. The battery-operated warning unit in the lockable cover generates an optical and acoustic warning if backwater occurs. Optionally, the warning message can control a remote signal generator in the living area via the EnOcean protocol or automatically disconnect a switched socket from the mains.
