A tankless water heater includes a scale control module (SCM). The SCM is mounted inside or outside of a cabinet which encloses a heat exchanger and source of heat of the water heater. The SCM may include a connector and a cartridge removably attaching to the connector or may only include a cartridge permanently affixed to the tankless water heater. The tankless water heater includes a continuous water pathway inside the cabinet to supply water to all components of the tankless water heater, including the SCM. The tankless water heater receives supply water at its inlet, treats the supply water in the SCM to generate treated water having reduced scale-forming characteristics compared to the supply water, and heats the treated water in the heat exchanger to generate heated treated water.

A tube profile (1), in particular for manufacturing a heat exchanger for a condensing boiler, wherein the cross-section (10) of the tube profile (1) comprises: a rectangular portion (20) having two greater sides (21, 22) parallel to each other and two smaller sides (31, 32) parallel to each other and orthogonal to the greater sides (21, 22), and an ogival portion (40) defined by a convex flat figure formed by a base (41) and two curved sides (42, 43) connected to each other in an apical zone (48) opposite to said base, wherein said base (41) coincides with a first side (31) of said two smaller sides (31, 32) of the rectangular portion (20), wherein said two curved sides (42,43) are symmetrical to an axis of symmetry (S-S) parallel to said greater sides (21, 22) and passing through the central points (33, 34) of said smaller sides (31, 32), wherein one end of each of said two curved sides (42, 43) joins to one end of a respective one of said two greater sides (21, 22)) in a first joining point (PH1), said each of said two curved sides (42, 43) being tangent to said respective one of said two greater sides (21, 22) in said first joining point (PH1), and wherein an overall dimension of said ogival portion (HO) measured along said axis of symmetry (S-S) is greater than the length of said base (41); wherein the two greater sides (21, 22), a second side of said two smaller sides (32), and said two curved sides (42, 43), define the outer surfaces (50) of the walls of said tube profile (1).

A condensate trap apparatus according to the present invention comprises: an inlet hole for inflowing a condensate; a storage space for storing the condensate introduced from the inlet hole; an outlet unit including a discharge hole for discharging the stored condensate from the storage space; and a buoyant body including a closing portion which is convex vertically downward so as to close the discharge hole by being seated on the outlet unit, and a support of a pillar type extending vertically upward from the closing portion.

A heat pump boiler is disclosed. The heat pump boiler includes a compressor. The heat pump boiler further includes an exterior heat exchanger that is configured to transfer heat between refrigerant and exterior air. The heat pump boiler further includes an interior heat exchanger that is configured to transfer heat between refrigerant and water. The heat pump boiler further includes a channel change valve that is configured to provide refrigerant compressed by the compressor to the exterior heat exchanger or the interior heat exchanger. The heat pump boiler further includes a first boiler heat exchanger that is configured to heat water that has passed through the interior heat exchanger from heat generated through combustion. The heat pump boiler further includes a second boiler heat exchanger that is configured to transfer heat between refrigerant and gas discharged from the first boiler heat exchanger.

A heat pump boiler is disclosed. The heat pump boiler includes a compressor. The heat pump boiler further includes an exterior heat exchanger that is configured to transfer heat between refrigerant and exterior air. The heat pump boiler further includes an interior heat exchanger that is configured to transfer heat between refrigerant and water. The heat pump boiler further includes a channel change valve that is configured to provide refrigerant compressed by the compressor to the exterior heat exchanger or the interior heat exchanger. The heat pump boiler further includes a first boiler heat exchanger that is configured to heat water that has passed through the interior heat exchanger from heat generated through combustion. The heat pump boiler further includes a second boiler heat exchanger that is configured to transfer heat between refrigerant and gas discharged from the first boiler heat exchanger.

A heat exchanger with a tube bundle wound in a helical manner about a longitudinal axis. The tube bundle includes at least two tube sections which are placed beside each other in the direction of the longitudinal axis. The tube sections each include a helically wound tube with has an internal cross-section which is constant over the helical winding thereof.

A heat exchanger with a tube bundle wound in a helical manner about a longitudinal axis. The tube bundle includes at least two tube sections which are placed beside each other in the direction of the longitudinal axis. The tube sections each include a helically wound tube with has an internal cross-section which is constant over the helical winding thereof.

[Problems to be Solved] An exhaust duct (4) for assembly into a combustion apparatus has: a burner (1) to eject air-fuel mixture downward; and a combustion box (3) disposed on a lower side of the burner (1). The exhaust duct includes: a riser duct section (42) elongated in a vertical direction and having, at a lower portion thereof, an inlet port (41) connected to an exhaust port (35) for combustion gas which is opened in a lower portion of the combustion box (3); and a flat horizontal duct section (43) bent at an upper end of the riser duct section (42) so as to be elongated forward. By restraining the resonance of an upper wall part (431) and a lower wall part (432) of the horizontal duct section (43), noises due to resonance sounds are reduced.

[Solving Means] The natural frequencies in an upper wall part (431) and the lower wall part (432) of the horizontal duct section (43) are varied from each other. For example, the lower wall part (432) is fixed to a burner body (11) in order to vary the natural frequencies of the upper wall part (431) and of the lower wall part (432) from each other.

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.

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.