Abstract: A filter cartridge for use in the interior of a water tank of a household appliance, the wall of which separates a housing internal side from a housing external side. A filter inlet opening which in the operation of the filter cartridge is open in relation to the external environment of a filter housing. A device for water conduction comprises at least one filter chamber having at least one filter medium and terminates in a filter outlet opening for suctioning water from the filter cartridge in the interior of the filter housing, downstream of the filter inlet opening relative to the flow direction of the water during operation. A filter port has an annular filter sealing face for the connection of the filter cartridge in a water tank. The filter sealing face has a separately disposed filter-proximal guide structure for receiving a centering element for centering the filter cartridge.

Abstract: A water tank for a household appliance having a connection for a filter cartridge, wherein an annular tank sealing face is provided on the tank bottom for the tight connection of the filter cartridge and the tank sealing face encloses a tank passage opening for the water from the filter cartridge to flow through the wall of the tank bottom to the household appliance, characterized in that the tank sealing face along its circumference has a variable radius in relation to a central axis, so that the tank sealing face comprises radial concavities and/or radial convexities, wherein the convexities and/or concavities have a round profile, and wherein the concavities and/or convexities are configured to periodically oscillate around a circular line.