Abstract: A liquid flow activated switch is operative to effect completion of an electrical circuit and energizing of an electrical power using device, such as an electric water heater, upon commencing of liquid flow through a liquid inlet of a housing having walls defining a chamber therein. A switch member is pivotally mounted in the chamber and has a first portion positioned between the liquid inlet and a liquid outlet so that liquid entering the chamber impinges upon the first portion of the switch member to move a second portion of the switch member and a magnet thereon to a second position energizing magnetically operated components mounted on the housing and electrically connected to the electrical circuit.