Water heater

Abstract

A water heater according to the present invention comprises: a combustion chamber; a burner provided to cause a combustion reaction in the combustion chamber; a plurality of circulation pipes that communicate with the combustion chamber so that combustion gas generated by the combustion reaction flows through the inside; a circulation housing that surrounds the plurality of circulation tubes and the combustion chamber so that circulating water flows to the surroundings of the plurality of circulation tubes and the combustion chamber; a pre-stage heat exchanger that communicates with the plurality of circulation tubes to exchange heat between direct water and combustion gas passing through the plurality of circulation tubes to generate pre-stage hot water; and a main heat exchanger that is connected to the pre-stage heat exchanger and the circulation housing, to generate hot water by exchanging heat between the hot water received from the pre-stage heat exchanger and the hot water delivered from the circulation housing.

Dependencies are inferred from the claim text.