A water heater includes a water tank having an inlet and an outlet, and a flue extending through the tank. A nozzle is positioned near a first end of the flue, arranged so as to emit a fuel stream into the flue, and a flame holder is located within the flue in a position to receive the fuel stream and to hold a flame entirely within the flue.

A water heater includes a water tank having an inlet and an outlet, and a flue extending through the tank. A nozzle is positioned near a first end of the flue, arranged so as to emit a fuel stream into the flue, and a flame holder is located within the flue in a position to receive the fuel stream and to hold a flame entirely within the flue.

A water heater includes a water tank having an inlet and an outlet, and a flue extending through the tank. A nozzle is positioned near a first end of the flue, arranged so as to emit a fuel stream into the flue, and a flame holder is located within the flue in a position to receive the fuel stream and to hold a flame entirely within the flue.

Disclosed herein are connectors for a tankless water heater. The connectors can comprise a flange, an aperture extending through the flange having a first diameter, one or more slots extending through the flange, a connector portion substantially surrounding the aperture and extending outward from the flange away from the tankless water heater. The aperture can correspond to an air inlet extending into the tankless water heater, and the air inlet can have a second diameter that is larger than the aperture. To keep the flange in place, the one or more slots can correspond to one or more fastening holes in the tankless water heater. The one or more slots can be substantially parallel and on opposite sides of the aperture. The connector can be in a secured state when the one or more slots are fastened to the one or more fastening holes.

The present application discloses a combustion apparatus including: an air supply/exhaust port formed such that an air supply passage surrounds the outside of an exhaust passage; and an air supply port in which an air supply passage is formed. This combustion apparatus is configured such that in a case where this apparatus is installed in the double-pipe system, the air supply passage of the air supply port is closed, whereas in a case where it is installed in the separate-pipe system, the air supply passage of the air supply/exhaust port is closed. The combustion apparatus includes: a supplied-air temperature sensor; and a guide member, which is located near the air supply passage of the air supply/exhaust port or the air supply passage of the air supply port, and by which air flowing into the space in the housing is guided to the supplied-air temperature sensor.

The disclosure discloses a condensing heat exchanger and a water heating/heating device thereof. The condensing heat exchanger includes: a housing including a first end portion and a second end portion opposite to each other, and a side wall arranged between the first end portion and the second end portion, the second end portion being provided with a mounting portion for mounting a combustor; a smoke outlet arranged on the housing; a heat exchange component arranged inside the housing; and a first heat insulating member arranged close to the first end portion. A first gap is provided between the first heat insulating member and the first end portion, and at least part of smoke which has exchanged heat with the heat exchange component can flow through the first gap and be discharged from the smoke outlet. This application improves reliability of the condensing heat exchanger and the water heating/heating device thereof and reduces the cost by optimizing an internal structure of the condensing heat exchanger on the premise of ensuring the heat insulating and cooling effect.

The present application discloses a combustion apparatus including: an air supply/exhaust port formed such that an air supply passage surrounds the outside of an exhaust passage; and an air supply port in which an air supply passage is formed. This combustion apparatus is configured such that in a case where this apparatus is installed in the double-pipe system, the air supply passage of the air supply port is closed, whereas in a case where it is installed in the separate-pipe system, the air supply passage of the air supply/exhaust port is closed. The combustion apparatus includes: a supplied-air temperature sensor; and a guide member, which is located near the air supply passage of the air supply/exhaust port or the air supply passage of the air supply port, and by which air flowing into the space in the housing is guided to the supplied-air temperature sensor.

A gas water heater includes a water tank, a combustion chamber, a burner, a heat exchanger tube at least partially within the water tank, and a fan. The burner receives fuel gas and primary air from a first air-supply channel to create a primary air-fuel mixture for combustion in the combustion chamber with secondary air. The primary air-fuel mixture has a gas concentration above the upper explosive limit of the fuel gas. Secondary air is supplied through a second air-supply channel to the combustion chamber. The secondary air creates a low excess air ratio (e.g., below 1.5) for combustion in the combustion chamber. A totally sealed channel is defined from the air inlet of the fan to the heat exchanger tube.

A vent attachment for a tankless water heater is provided. The vent attachment includes a first conduit and a second conduit. The first conduit includes a first exhaust pathway and a first air intake pathway. The first air intake pathway includes an adjustable portion having a first adjustable length and a first adjustment mechanism. The second conduit includes a second exhaust pathway and a second air intake pathway. The second air intake pathway slidably engages with the first air intake pathway. The second air intake pathway includes a projecting portion having a second adjustable length equal to or greater than the first adjustable length and a second adjustment mechanism. The first adjustment mechanism and the second adjustment mechanism slidably couple the second conduit with the first conduit for a desired length of the vent attachment.

A heat-exchanger unit according to the present invention comprises: a sensible-heat heat-exchange portion arranged in a sensible-heat heat-exchange area for receiving sensible heat generated by a combustion reaction and thereby heating water, the sensible-heat heat-exchange portion having a sensible-heat heat-exchange pipe for receiving the water and causing same to flow through the interior thereof, thereby forming a sensible-heat channel along which the water flows; and a latent-heat heat-exchange portion positioned downstream of the sensible-heat heat-exchange area with reference to a first reference direction along which combustion gas generated during the combustion reaction flows, the latent-heat heat-exchange portion being arranged in a latent-heat heat-exchange area for receiving latent heat generated during a phase change of the combustion gas and thereby heating the water, the latent-heat heat-exchange portion having a latent-heat heat-exchange pipe for receiving the water and causing same to flow through the interior thereof.