Abstract: In a water heater provided with an inlet pipe a downstream end of which is connected with an upstream end of a water heating channel of a heat exchanger for producing hot water, an outlet pipe an upstream end of which is connected with a downstream end of the water heating channel, and a bypass pipe branching at a part of the inlet pipe, which is positioned at an upstream-end part away from an upstream end, and is connected with a part of the outlet pipe, which is positioned at a more downstream part than at an upstream end, a connecting part of the bypass pipe with the outlet pipe and another connecting part of an inlet pipe and the upstream end of the water heating channel are arranged at a same height in a setting state of the water heater.

Abstract: A heat exchanger having a drainage member (1) mounted on an open end (322) of a heat-transfer tube (32), wherein the drainage member (1) contains a flow guide portion (11) including an insertion portion (11a) configured to be inserted into the heat-transfer tube (32) from the open end (322), and a projecting portion (11b) projecting toward an outside of the heat-transfer tube (32) from the open end (322) and extending downward.

Abstract: A turbulence member is made of a flat plate member configured to be inserted into a heat-transfer tube having a substantially elliptical cross-sectional shape. The flat plate member is a generate turbulence in a fluid flowing inside the heat-transfer tube by a plurality of projected pieces projected on both front and back surfaces. A rotation preventing piece configured to prevent rotation of the flat plate member inside the heat-transfer tube is provided in at least one of both side edges along the flow passage direction in the flat plate member. The rotation preventing piece is provided at a predetermined angle to the flat plate member so that a forefront comes into contact with a tube wall inner circumferential surface of the heat-transfer tube. A space through which the fluid can circulate is formed between the rotation preventing piece and the tube wall inner circumferential surface.

Abstract: A turbulence generator includes a flat plate member (1) having a plurality of through holes (10a), (10b), and pairs of projecting pieces (11, 12) and (13, 14) projecting respectively from upstream-side edges and downstream-side edges of the through holes (10a), (10b), wherein the pairs of projecting pieces (11, 12) and (13, 14) project alternately to front and back surface sides of the flat plate member (1).

Abstract: The heat exchanger including a plurality of fluid flow paths (401), (402), (403) arranged in a plurality of stages in a height direction, wherein a fluid inlet port (13a) and a fluid outlet port (13b) of the fluid flow path (403) located at a lowermost stage among the plurality of fluid flow paths (401), (402), (403) have larger flow path cross-sectional areas than a fluid inlet port (11a) and a fluid outlet port (11b) of the fluid flow path (401) located at an uppermost stage.

Abstract: A heat exchanger having a drainage member (1) mounted on an open end (322) of a heat-transfer tube (32), wherein the drainage member (1) contains a flow guide portion (11) including an insertion portion (11a) configured to be inserted into the heat-transfer tube (32) from the open end (322), and a projecting portion (11b) projecting toward an outside of the heat-transfer tube (32) from the open end (322) and extending downward.

Abstract: A turbulence member is made of a flat plate member configured to be inserted into a heat-transfer tube having a substantially elliptical cross-sectional shape. The flat plate member is a generate turbulence in a fluid flowing inside the heat-transfer tube by a plurality of projected pieces projected on both front and back surfaces. A rotation preventing piece configured to prevent rotation of the flat plate member inside the heat-transfer tube is provided in at least one of both side edges along the flow passage direction in the flat plate member. The rotation preventing piece is provided at a predetermined angle to the flat plate member so that a forefront comes into contact with a tube wall inner circumferential surface of the heat-transfer tube. A space through which the fluid can circulate is formed between the rotation preventing piece and the tube wall inner circumferential surface.

Abstract: A turbulence generator includes a flat plate member (1) having a plurality of through holes (10a), (10b), and pairs of projecting pieces (11, 12) and (13, 14) projecting respectively from upstream-side edges and downstream-side edges of the through holes (10a), (10b), wherein the pairs of projecting pieces (11, 12) and (13, 14) project alternately to front and back surface sides of the flat plate member (1).