Abstract: A water heater of a latent heat recovery type includes: a combustion apparatus including a burner having a plurality of burner port portions and generating combustion gas from openings at ends of the plurality of burner port portions; a heat exchanger heating water that flows through inside by heat exchange with combustion gas generated in the combustion apparatus; and a fan suctioning the combustion gas that has passed through the heat exchanger and emitting combustion gas to outside of the water heater. The fan includes a fan case, an impeller housed within the fan case, and a drive source connected to the impeller. At least a part of an upper surface of a bottom wall of the fan case is inclined with respect to a reference plane including the openings of the plurality of burner port portions.

Abstract: A row of rich-side flame holes of a combustion burner is arranged in center. Two rows of lean-side flame holes are arranged respectively on sides of the rich-side flame hole row. Two rows of rich-side flame holes are arranged respectively on the outsides of the two lean-side flame hole rows. Supply of lean-side mixture is provided to the lean-side flame hole rows from a tubular part. A lower end part of a central rich-side burner part is projected into a tubular part, into which the rich-side mixture is introduced, to establish lateral fluid communication, with its lower end edge placed in a state of non-contact with the inner surface of the tubular part. First communication holes in fluid communication with an internal space are opened in the lower end part. Communication holes in fluid communication with the outer rich-side flame holes are opened in the inside of the tubular part.

Abstract: A row of rich-side flame holes is centrally arranged. Two rows of lean-side flame holes are arranged on both sides of the rich-side flame hole row, respectively. In addition, two rows of rich-side flame holes are arranged on the outsides of the two lean-side flame hole rows, respectively. A lower end part of a central rich-side burner part is projected into a tubular part into which the rich-side mixture is introduced, and communication holes in fluid communication with an inner space are formed in walls on both sides so as to pass completely therethrough in alignment with each other. Each communication hole has a larger diameter than an inner width P and is disposed at a portion situated nearer to the upper of the tubular part and nearer to the front so as to leave, at the rear, a space in which dust p particles are accumulated.

Abstract: A combustion apparatus (1) is generally composed of a principal part (5), a supplementary part (6) and a burner port assembly (3). Four metal plates (7,8,10,11) constituting the principal and supplementary parts (5,6) are pressed to have in them several protuberances and recesses. These metal plates are laid one on another to form in them some hollow spaces and sealed regions. These hollow spaces communicate with each other to form a thin gas passage (22) together with a thick gas passage (73) in this combustion apparatus (1) in such a manner that its condition of thick and thin fuel combustion is rendered more stable.

Abstract: A combustion apparatus (1) with a burner port assembly (3) comprises an elongated first array of main burner ports (53) for jetting and burning a fuel gas mixture of a concentration to make main flames. The combustion apparatus (1) comprises at least one second arrays of auxiliary burner ports (63) for jetting and burning a further fuel gas mixture of a different concentration to make auxiliary flames, wherein the second arrays of said auxiliary burner ports (63) extend along the first array of said main burner ports (53). The burner port assembly (3) is constructed using inner and outer wall segments (52) together with outermost wall segments (52a,52f) or bands (58). One of the bands (58) faces the corresponding one of said outermost segments (52a,52f) so as to define between them collateral burner ports (61a,61b).

Abstract: A combustion apparatus (1) is generally composed of principal part (5), a supplementary part (6) and a burner port assembly (3). Four metal plates (7,8,10,11) constituting the principal and supplementary parts (5,6) are pressed to have in them several protuberances and recesses. These metal plates are laid one on another to form in them some hollow spaces and sealed regions. These hollow spaces communicate with each other to form a thin gas passage (22) together with a thick gas passage (73) in this combustion apparatus (1) in such a manner that its condition of thick and thin fuel combustion is rendered more stable.

Abstract: A combustion apparatus (1) with a burner port assembly (3) comprises an elongated first array of main burner ports (53) for jetting and burning a fuel gas mixture of a concentration to make main flames. The combustion apparatus (1) comprises at least one second arrays of auxiliary burner ports (63) for jetting and burning a further fuel gas mixture of a different concentration to make auxiliary flames, wherein the second arrays of said auxiliary burner ports (63) extend along the first array of said main burner ports (53). The burner port assembly (3) is constructed using inner and outer wall segments (52) together with outermost wall segments (52a,52f) or bands (58). One of the bands (58) faces the corresponding one of said outermost segments (52a,52f) so as to define between them collateral burner ports (61a,61b).