Abstract: A boiling water heater incorporating a tank with electrical heating element and water level control wherein the supply of current to the element is controlled by the temperature in an inclined condenser tube extending upwardly from the top of the tank. The condenser tube incorporates a steam exhaust flue, a temperature sensing bulb and a cold water inlet. The temperature sensing bulb is located with its lower end adjacent the cold water inlet into the condenser tube but below the steam exhaust flue outlet from that tube. The thermostat controls the operation of the heating element and the water level control valve so that the element is disconnected from the electricity supply and the control valve opened in response to the temperature in the condenser tube being above a predetermined lower limit when the water level in the tank as sensed by the water level control is above a predetermined lower limit.

Abstract: An automatic continuous boiling water heater unit has a water heating tank incorporating an electric heating element near the bottom thereof and a float operated valve for feeding water to the heating tank from a level control tank mounted alongside the heating tank through a constricted conduit designed to allow a water flow rate substantially equal to the boiling water heating rate capacity of the element. A temperature control device, including a temperature sensitive probe surrounded by a metal gauge and positioned in a conduit communicating the level control tank with the heating tank above the water level therein maintained by the float operated valve, is provided for deenergizing the heating element when the water in the heating tank reaches boiling temperature.