Abstract: A domestic plumbing installation of a generally simple design which is easy to manufacture, is obtained in the following manner: a connecting end of the water-conduit element is merely pushed into a connection-receiving part and includes at least one locking notch, which extends generally perpendicularly to the direction of insertion, preferably approximately tangentially, the valve housing includes at least one locking bore extending generally perpendicularly to the direction of insertion preferably approximately tangentially to the connection-receiving part and ending in the connection-receiving part. To this end the locking notch is aligned with the locking bore; a locking pin preferably a tangential pin of solder material can be inserted into the locking bore and further into the locking notch for temporary assembly, when the tangential pin is inserted the water-conduit element is permanently secured to the valve housing by causing the solder material to melt.