Electrode phase transition boiler- inside which heat storage and transfer were carried out by certain se­lected medium's phase transition, mainly composes of electrode tube, medium tube ,heat exchanger and its control device. The idea is originally proposed and achieved by Runpaq-Liju. Three-phase electrode is fixed in the tube which immersed in heating medium-usually, water with certain conductivity; when electri­fied, the medium vaporizes rapidly into high-temp steam- which tunneled to the heat exchanger; Heat transfer between the high-temp steam and cold water take place in the exchanger and after that, cold water is heated to hot water or steam for end users, meanwhile, the cooled medium back to medium tube. In elec­tric heating cycle, heating medium vaporizes and liquefies in enclosed chamber. The heating power is pre­cisely controlled by electrode immersion depth, and proportional control ranges from 1-100%.