Abstract: A draining system is disclosed for use in sanitary installation products such as basins, bathtubs and the like. The system has a hidden overflow system to save space. In the draining system the plug for collecting water in the sanitary installation is positioned above a waste water outlet for the sewage coming from the basin, which outlet may be positioned in a wall. Directly above the plug is the hidden overflow system having an inner and an outer duct, wherein upon closing the plug the water in parallel to the basin rises in the inner duct and, to prevent overflow, upon reaching a predetermined height is directed to the outer duct which leads directly to the waste water outlet.