Abstract: A liquid level control device for monitoring the level of water in a steam generating tank between predetermined upper, intermediate, and lower levels, with the tank equipped with a valve for introducing water into the tank and heat energy valve means to generate steam to the water, comprising: a glass gauge tube adapted to be vertically mounted exteriorally of the tank; a top and bottom cover covering the ends of the glass gauge tube, with a bottom cover including an opening for communicating with a liquid in the tank and the top cover including an opening for communicating with steam generated in the tank; upper and lower magnetic float means mounted co-axially within the glass gauge tubes; the upper magnetic float means including means to activate the valve when the water is the region of the predetermined intermediate level so as to introduce water into the tank until the water is in the region of the predetermined upper level, and to deactivate the valve and stop the introduction of water when the water