An object of the present invention is to provide a plate-shaped heat insulator with good workability during construction and less susceptible to damage after construction. Provided is a plate-shaped heat insulator including a plate-shaped papermaking product containing inorganic fibers, wherein the plate-shaped heat insulator is intended to be disposed in a combustion chamber.

The present disclosure provides an outdoor support-type water heater, including a gas water heater main body and a water-heater bracket. By arranging at the bottom of the gas water heater main body a bracket which includes two separate brackets that are arranged at both sides of the gas water heater main body to support the gas water heater main body, the gas water heater main body may be fixed outdoors, the user just needs to connect a fuel gas vessel carried by the user to the gas inlet to complete the supply of fuel gas, and connect an outdoor water pipe to the water inlet pipe to complete the supply of water; therefore, supply of hot water is enabled outdoors with the gas water heater and a wider application scope is enabled for the water heater.

Provided are a boiler and a method for stage change control of the boiler. The boiler includes a burner to generate a calorie necessary for producing hot water by burning air and gas, and a controller to perform a stage change control operation, when the number of times, in which the stage is changed, is equal to or greater than a reference number of times, for a predetermined time, based on information on occurrence of the change of the stage in the burner, while hot water is used.

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.

In a combustion apparatus that includes a heat exchanger which is disposed in a combustion box, on a premise that a direction from a burner to the heat exchanger is defined as a Z-axis plus direction, a direction opposite to the Z-axis plus direction is defined as a Z-axis minus direction, and an orthogonal direction to a Z-axis direction, which is along fins of the heat exchanger is defined as a X-axis direction, a thermal insulation material is arranged on an inner surface of a swelling part that is formed at a side plate part of a combustion box and outwardly swells in the X-axis direction so as to be sandwiched from both sides in the Z-axis direction by a step that is outwardly bent in the X-axis direction, which is positioned an end, in the Z-axis plus direction, of the swelling part and a structural member of a burner, which inwardly protrudes in the X-axis direction from an end, in the Z-axis minus direction, of the side plate part. A vicinity portion of an end, in the Z-axis plus direction, of the thermal insulation material is held from an inside in the X-axis direction by a side edge portion, on each side in the X-axis direction, of the fins.

A modulating burner apparatus includes a burner and a blower placed upstream of the burner. A venturi is placed upstream of the blower. A damper valve is placed upstream of the venturi. The damper valve has an open position and a restricted position. A smaller gas valve and a larger gas valve are communicated with the venturi. A controller is operably associated with the system to select a position of the damper valve and to select the appropriate one of the gas valves so as to provide a low output operation mode and a high output operation mode, which in combination provide an overall turndown ratio of at least 25:1.

A premixing flow path forming member of a premixing device includes a member whose attachment mode can be changed, and flow path resistance of a fuel gas flow path can be changed when the attachment mode of the member is changed.

A method controls an air handler that generates heated air from hot water generated by a water heater. The method includes generating a signal in the presence or absence of an indicia of water flow associated with the water heater; initiating operation of a pump associated with the air handler when the signal indicates that water flow associated with the water heater is at least at a selected level to supply hot water to the air handler sufficient to generate heated air; and/or terminating operation of the pump and/or a blower/fan associated with the air handler when the presence or absence signal indicates that the water flow associated with the water heater is less than the selected level.

The present disclosure discloses a gas mixing device and a gas water heating device. In which, a gas mixing device, comprises: a shell provided with a fuel gas channel for inputting fuel gas, an air channel for inputting air and a gas mixing channel, the fuel gas channel being provided with a first cut-off portion capable of changing a flow area, and the air channel being provided with a second cut-off portion capable of changing a flow area; a moving part movable in the shell, the moving part simultaneously changing the flow areas of the first cut-off portion and the second cut-off portions by moving. The gas mixing device and the gas water heating device can provide a higher regulation ratio, thereby solving the problem that the water temperature is too high in summer.

A gas fueled water heater appliance may include a tank for storage of water, a chamber wall, a gas burner, a gas conduit, a support post, and a guide bracket. The chamber wall may define a combustion chamber and a conduit hole. The gas burner may be positioned adjacent to the tank and within the combustion chamber. The gas conduit may extend from the gas burner and through the conduit hole. The support post may be fixed to the gas burner within the combustion chamber. The guide bracket may be mounted within the combustion chamber and define a mounting point. The guide bracket may be in selective engagement with the support post at the mounting point. The guide bracket may include a pair of lateral arms extending outward from the mounting point toward the chamber wall to guide the support post to the mounting point.