Patent ID: 8097834

Claim:
A liquid heating vessel comprising a heater for heating liquid in the vessel provided on the underside of the base of the vessel, an electronic control, an electromagnetic switch for interrupting or reducing power to the heater, and a temperature sensor for providing a signal dependent on the temperature of liquid in the vessel to the control, the control being arranged to operate the electromagnetic switch to interrupt or reduce power to the heater in response to the control determining that a pre-determined temperature condition has been reached, wherein said electromagnetic switch comprises a pair of contacts configured to be normally open, and a coil arranged to hold the contacts in a closed position, after initial closure, when a predetermined current passes through the coil, and wherein the contacts are arranged to open upon the predetermined current to the coil being interrupted or reduced, and wherein a force produced by the predetermined current passing through the coil is adequate to maintain the contacts closed, but such force is inadequate to re-close the contacts when the predetermined current through the coil is restored.