Abstract: A water mixer for a sink, the water mixer comprising a mixing chamber having a hot water tap pillar and cold water tap pillar for controlling a supply of hot and cold water to respective inlets of a mixing chamber. Outlets from the mixing chamber supply water to the hollow interiors of the hot and cold water tap pillars which are interconnected by a mixer conduit joined with a nozzle for discharging water to the sink. The mixing chamber is provided with a shuttle valve formed by a truncated conical poppet valve receivable in a valve seat in response to water pressure from hot and or cold mixing chamber acting of a plate member connected by shaft to the poppet valve. The pressure on the plate develops when a spray head valve is operated to cause a flow of water from the mixing chamber to the spray head.