Abstract: An auxiliary float chamber is provided for use in a cistern. A float operating in the chamber controls a valve allowing water into the cistern. In the floor of the chamber there is a syphonic tube. The chamber is held to the cistern wall by means of the valve which is of the type comprising a sliding tube sealing against a washer in a sealing cap so that the seal is not against the pressure of the inlet water. The auxiliary float chamber is mounted below the normal level of liquid in the cistern. As the cistern is discharged, the valve remains closed until water has drained from the auxiliary chamber. Water flowing into the cistern is thus not short-circuited through the discharge.