Abstract: A rapid-heating electric water boiler includes a boiler vessel having an access opening at the lower portion thereof defined by a connecting flange. A boiler jacket surrounds the vessel but is spaced therefrom to provide a clearance filled with thermal insulation. A mounting flange is watertightly but removably attached to the connecting flange to close the access opening. A cold-water inlet pipe and a hot-water pass through the mounting flange into the vessel with the outlet pipe terminating in a free end adjacent the top of the vessel. A water-immersible metallic sheathed electric resistance heating element is attached to and in intimate thermal contact with the outlet pipe starting substantially from the lower end thereof at the flange and extending along at least a major portion of the length of the outlet pipe toward the free end thereof for simultaneously heating the water within the outlet pipe as well as the water in the vessel.