Abstract: A hot water apparatus includes a heat exchanger and a housing. A case of the heat exchanger has a circumferential wall portion, a lower opening, and a flange portion. A case of the housing has a flange portion, a circumferential wall portion, and an upper opening. The circumferential wall portion includes a downwardly-extending wall portion inserted into the inside of the circumferential wall portion through the upper opening. In a state where the downwardly-extending wall portion is arranged inside the circumferential wall portion, the lower opening is located below an upper surface of the flange portion, and a flange connection is formed between the heat exchanger and the housing.

Abstract: A fin has a plurality of insertion holes in an elliptical shape through which a heat transfer tube is inserted and contains stainless steel as a material. The plurality of insertion holes are disposed as being aligned in a single row in a first direction. The fin has a first slit extending from a first end portion toward a second end portion and a second slit extending from the second end portion toward the first end portion. The second slit has a first edge portion where a cut and raised wall portion is disposed and a second edge portion where no cut and raised wall portion is disposed.

Abstract: A latent heat recovery heat exchanger includes a case, a heat exchange portion, and a straightening vane. The heat exchange portion includes a plurality of heat transfer plates surrounded by a peripheral wall portion of the case and layered on one another, each of the plurality of heat transfer plates extending in a direction from an inlet toward an outlet. The straightening vane includes a top plate portion covering the plurality of heat transfer plates so as to close a space between the plurality of heat transfer plates in end portions of the plurality of heat transfer plates in a direction intersecting with a direction of layering of the plurality of heat transfer plates when the heat exchange portion is viewed from the inlet toward the outlet.

Abstract: A water heater includes: a burner; a heat exchanger; a fan for supplying air to the burner and emitting combustion gas having passed through the heat exchanger to outside of the water heater; and a drainage water discharge path connected to the heat exchanger. The drainage water discharge path has a water-sealing structure that is water-sealed by drainage water. The water heater further includes a control unit: having a water-seal determination unit giving permission that the water heater can operate in a normal mode based on a condition that the drainage water discharge path has been water-sealed; and issuing an instruction to cause the burner to intermittently operate for a time period until the water-seal determination unit gives the permission.

Abstract: A fin-and-tube type heat exchanger includes: a plurality of plate fins arranged in a case side by side in a fore-and-aft direction of the case; and a heat transfer tube including a plurality of straight-type tubular bodies each passing through these plurality of plate fins. First and second plate fins arranged side by side in the right-and-left width direction of the case are provided as a plurality of plate fins. The heat transfer tube has a connection tubular body connecting the straight-type tubular bodies passing through the first and second plate fins. The heat transfer tube passes through areas in which the first and second plate fins are arranged.

Abstract: A hot water apparatus includes a heat exchanger and a housing. A case has a circumferential wall portion, a lower opening, and a flange portion. A case has a flange portion, a circumferential wall portion, and an upper opening. The circumferential wall portion includes a downwardly-extending wall portion inserted into the inside of the circumferential wall portion through the upper opening. In a state where the downwardly-extending wall portion is arranged inside the circumferential wall portion, the lower opening is located below an upper surface of the flange portion.

Abstract: A fin has a plurality of insertion holes in an elliptical shape through which a heat transfer tube is inserted and contains stainless steel as a material. The plurality of insertion holes are disposed as being aligned in a single row in a first direction. The fin has a first slit extending from a first end portion toward a second end portion and a second slit extending from the second end portion toward the first end portion. The second slit has a first edge portion where a cut and raised wall portion is disposed and a second edge portion where no cut and raised wall portion is disposed.

Abstract: A latent heat recovery heat exchanger includes a case, a heat exchange portion, and a straightening vane. The heat exchange portion includes a plurality of heat transfer plates surrounded by a peripheral wall portion of the case and layered on one another, each of the plurality of heat transfer plates extending in a direction from an inlet toward an outlet. The straightening vane includes a top plate portion covering the plurality of heat transfer plates so as to close a space between the plurality of heat transfer plates in end portions of the plurality of heat transfer plates in a direction intersecting with a direction of layering of the plurality of heat transfer plates when the heat exchange portion is viewed from the inlet toward the outlet.

Abstract: In a primary heat exchanger, a heat conduction pipe is arranged as one connected pipe in a lower stage and an upper stage in a manner extending back and forth through a plurality of fins. The heat conduction pipe is arranged such that a pitch between the heat conduction pipes in the upper stage is shorter than a pitch between the heat conduction pipes in the lower stage. In addition, the heat conduction pipe is arranged such that a position in a center of each heat conduction pipe in the upper stage in a second direction orthogonal to a first direction in which the heat conduction pipe extends and a position in a center of each heat conduction pipe in the lower stage in the second direction are displaced from each other.

Abstract: A fin includes a cut and raised slit and a cut and raised wall portion. The cut and raised slit is formed in a region adjacent to at least one through hole of a plurality of through holes in a first direction and has a tunnel-shaped hole extending in a second direction intersecting the first direction. The cut and raised wall portion is located in the second direction of the cut and raised slit, protrudes toward a main surface of the fin, and extends along the first direction. Thus, a heat exchanger and a water heater capable of sufficiently conducting an amount of heat of a combustion gas to a heat conduction pipe even in a blind spot of a flow of the combustion gas of the heat conduction pipe and suppressing noise can be realized.

Abstract: A fin-and-tube type heat exchanger includes: a plurality of plate fins arranged in a case side by side in a fore-and-aft direction of the case; and a heat transfer tube including a plurality of straight-type tubular bodies each passing through these plurality of plate fins. First and second plate fins arranged side by side in the right-and-left width direction of the case are provided as a plurality of plate fins. The heat transfer tube has a connection tubular body connecting the straight-type tubular bodies passing through the first and second plate fins. The heat transfer tube passes through areas in which the first and second plate fins are arranged.

Abstract: A fan serves to suction combustion gas which has passed through a secondary heat exchanger and emitting combustion gas to the outside of a water heater. A drainage water discharge pipe is connected to the secondary heat exchanger in order to discharge the drainage water produced as a result of recovery of latent heat in the secondary heat exchanger to the outside of the secondary heat exchanger. An air passage pipe is connected to an exhaust box. A Y-shaped pipe joint has a flow path allowing merging of the drainage water discharge pipe and the air passage pipe, and the flow path after merging leads to the outside of the water heater.

Abstract: A water heater includes: a burner; a heat exchanger; a fan for supplying air to the burner and emitting combustion gas having passed through the heat exchanger to outside of the water heater; and a drainage water discharge path connected to the heat exchanger. The drainage water discharge path has a water-sealing structure that is water-sealed by drainage water. The water heater further includes a control unit: having a water-seal determination unit giving permission that the water heater can operate in a normal mode based on a condition that the drainage water discharge path has been water-sealed; and issuing an instruction to cause the burner to intermittently operate for a time period until the water-seal determination unit gives the permission.

Abstract: A fan serves to suction combustion gas which has passed through a secondary heat exchanger and emitting combustion gas to the outside of a water heater. A drainage water discharge pipe is connected to the secondary heat exchanger in order to discharge the drainage water produced as a result of recovery of latent heat in the secondary heat exchanger to the outside of the secondary heat exchanger. An air passage pipe is connected to an exhaust box. A Y-shaped pipe joint has a flow path allowing merging of the drainage water discharge pipe and the air passage pipe, and the flow path after merging leads to the outside of the water heater.