Electric immersion heater assembly

An electric immersion heater assembly for hot water heating boilers provided in one form as a single phase circuit with a central conductive reinforcing rod that is utilized as one electrode and a ceramic body surrounding said rod with a resistance heating wire spirally wound upon said ceramic body and connected at its other end with a second electrode, said electrodes extending out of the heater at the unimmersed end and said immersed portion glazed with a non-conductive coating. A further embodiment includes a multi-phase circuit and in which the central core includes three reinforcing conductive electrodes that are Delta connected to a multiphase power line.