A magnetic reluctance device includes a casing, an inner pipe, a lead screw, a magnet, at least a protruding unit, and at least a metallic element. The methods comprise administering to the patient an amount of a dendrimer composition effective to prevent absorption of substantial amounts of phosphate from the patient’s GI tract. Location information can include a street address, zip code, directional information, destination, velocity information, latitude andor longitude, etc. The method includes initiating a heating state of the fluid-heating apparatus, initiating a non-heating state of the fluid-heating apparatus, applying a voltage to the heating element during the non-heating state, sensing a leakage current of the heating element during the application of the voltage, and determining a degradation of the heating element with the sensed leakage current.