Water-bearing domestic appliance comprising a drainage pump and corresponding drainage pump

A water-bearing domestic appliance includes a retainer for retaining items to be subjected to a liquid treatment and a drainage pump having an inlet through which liquid enters the drainage pump. The drainage pump also includes an outlet through which liquid exits the drainage pump, a pump impeller for conveying liquid along a passage through the drainage pump extending from the inlet to the outlet, and a separate chamber located upstream of the pump impeller relative to the direction of flow of liquid through the passage. The separate chamber has an internal diameter and an external diameter and has respective radial bores on its external diameter and in the vicinity of its internal diameter.