f cooling plate fitting g triac h supply cord fitting i heat exchanger j thermostat k terminal l under casing enclosure m upper casing enclosure n circuit board o power setting button p shower head upper casing q shower head lower casing r shower bead connector s plastic plate t spring and u magnet flow sensor fig1 a and 1b illustrate a heat exchange fastener 1 heat exchange 2 circuit board 3 heat exchanger security bracket 4 terminal block 5 heating element electric terminals 6 triac cooling plate 7 triacs 8 air diverter 9 safety thermostat 10 shower lower enclosure 11 male adaptor for shower head 12 and laminate control panel 13 fig1 2 fig1 c illustrates an insulated heat exchanger 1 air vent diverter 2 heating element 3 heating element terminals 4 triac 5 triac cooling plate 6 terminal block 7 laminate circuit control board 8 and ground busbar 9 the system can be provided with a dry fire air eliminator air diverter 9 u2014 fig1 a and 1b and air diverter 2 u2014 fig1 c see also fig6 which can comprise a pipe that can be designed to eliminate or at least substantially reduce the chance of air or air bubbles in the incoming water pipe from entering the chamber and.