Patent ID: 8087388

Claim:
A water heater comprising: a cylindrical main body; a hot water storage chamber arranged above a mirror plate that includes an upwardly protruding first restriction part having a first predetermined length in the axial direction of the water heater, wherein the upwardly protruding first restriction part is continuously inwardly tapered towards a center axis of the water heater; the hot water storage chamber positioned above the mirror plate and in the cylindrical main body; a combustion chamber having a burner positioned below the mirror plate such that hot water in the hot water storage chamber is heated by combustion of the burner; and a second restriction part protruding outwardly in a curved ring shape and having a second predetermined length in the axial direction of the water heater that is less than the length of the first restriction part, wherein the second restriction part includes, a peripheral edge of the minor plate that smoothly merges with and abuts an inside cylindrical surface of the cylindrical main body, and a protrusion part protruding inwardly in a ring shape toward a center side of the mirror plate, said protrusion part continuously extending between the first restriction part and said peripheral edge; wherein the burner is positioned such that a combustion surface of the burner directly radially faces said protrusion part and said peripheral edge.