Abstract: A pump having a three-way valve has a motor for generating a turning effect by an electric power applied thereto. The pump pressurizes a fluid by using an impeller. The three-way valve is installed to the inlet side of the pump. A magnetic plate and ball swing between the first inlet and second inlet by means of load switches as many as a predetermined angle. The pump and three-way valve are integrally formed to require no separate piping between the three-way valve and pump. Thus, the manufacturing processing of the boiler is reduced while enhancing productivity. An installation space is shrunken to decrease the external dimensions of a product such as boilers.

Abstract: As a heat exchanger for a hot-water storage type gas boiler, the present invention provides an easily assembled stacked-up type heat exchanger eliminating the installation of a separate hot-water pipe so that the thermal efficiency of the heat exchanger can be improved and the size thereof can be reduced. The stacked-up type heat exchanger comprises a bottom plate including one or more combustion gas flues for carrying combustion gas from a burner, a return heating-water outlet for collecting and delivering heating-water, and a cold-water inlet; a first plate disposed over the bottomplate; fourth plate disposed over the first plate; and a top plate disposed over the fourth plate.