HEATER UNIT FOR ELECTRIC WATER HEATER

PROBLEM TO BE SOLVED: To make a heater unit compact and to reduce cost, by putting a thin plate exothermic body between a heater case upper plate and a heater pressing plate, and mutually fixing both plates at peripheries of the heater case upper plate abutting on the lower face of the heater pressing plate and the heater case upper plate. SOLUTION: A soak heating plate 27 and the lower face of a mica heater 26 are overlapped and put between a heater case upper plate 25 and a heater pressing plate 28, and an outer periphery welding part 42 and an inner periphery welding part 44 of the heater pressing plate 28 are spot-welded to the lower face of the heater case upper plate 25. Next, the pressing part 58 of a heater case lower plate 29 is pressed against the lower face of the heater pressing plate 28, a flange 54 of the outer periphery is forcibly fit into the inside of a flange 33 of the heater case upper plate 25 with a required interference, the fitting part is welded by air tight welding such as TIG welding, etc., to fix the heater case upper plate 25 and the heater case lower plate 29 together to constitute the heater case.