Abstract: A freeze protection system is provided that includes a first valve configured to be coupled with an inlet of a water heater, such as a tankless water heater; a second valve configured to be coupled with an outlet of the water heater; and a valve actuator configured to automatically actuate the first valve and the second valve to permit water to drain from the water heater when (1) electric power is lost to the water heater, and (2) a temperature of a fluid in or around the water heater is less than or equal to a predetermined low temperature threshold.

Abstract: A combustion system includes a premix blower system and the premix blower system includes an additional air inlet with an adjustable opening which includes an additional reversibly pluggable air intake. The adjustable opening of the additional air inlet can be opened at higher elevations to compensate for thinner air.

Abstract: A combustion system includes a premix blower system and the premix blower system includes an additional air inlet with an adjustable opening which includes an additional reversibly pluggable air intake. The adjustable opening of the additional air inlet can be opened at higher elevations to compensate for thinner air.

Abstract: The disclosed technology includes an air distribution baffle for distributing a flow of air from an air moving device to a burner assembly within a fluid heating device. The air distribution baffle can include a substantially flat portion and a raised portion extending upwardly from the substantially flat portion. The raised portion can include one or more faces having one or more apertures. The apertures can be arranged in a predetermined pattern or arrangement designed to provide a more uniform distribution of air flow and thus increase the combustion efficiency of the fluid heating device.

Abstract: A combustion system includes a premix blower system and the premix blower system includes an additional air inlet with an adjustable opening which includes an additional reversibly pluggable air intake. The adjustable opening of the additional air inlet can be opened at higher elevations to compensate for thinner air.

Abstract: A high efficiency downfired gas water heater is provided which has a tank for storing water to be heated, a combustion chamber extending downwardly through a top end of the tank, and a gas burner operative to create hot combustion products within the combustion chamber. At the bottom end of the tank is a transfer chamber coupled to an external discharge conduit and to a single pass heat exchanger, in the form of multiple flue tubes. extending vertically through the tank and connected to the combustion chamber. In one embodiment of the water heater the burner is a power burner which forces the combustion products sequentially through the combustion chamber, heat exchanger, transfer chamber and discharge conduit. In another embodiment of the water heater a draft inducer fan is used to draw the combustion products through this path from the combustion chamber.

Abstract: A high efficiency downfired gas water heater is provided which has a tank for storing water to be heated, a combustion chamber extending downwardly through a top end of the tank, and a gas burner operative to create hot combustion products within the combustion chamber. At the bottom end of the tank is a transfer chamber coupled to an external discharge conduit and to a single pass heat exchanger, in the form of multiple flue tubes. extending vertically through the tank and connected to the combustion chamber. In one embodiment of the water heater the burner is a power burner which forces the combustion products sequentially through the combustion chamber, heat exchanger, transfer chamber and discharge conduit. In another embodiment of the water heater a draft inducer fan is used to draw the combustion products through this path from the combustion chamber.

Abstract: A high efficiency downfired gas water heater is provided which has a tank for storing water to be heated, a combustion chamber extending downwardly through a top end of the tank, and a gas burner operative to create hot combustion products within the combustion chamber. At the bottom end of the tank is a transfer chamber coupled to an external discharge conduit and to a single pass heat exchanger, in the form of multiple flue tubes. extending vertically through the tank and connected to the combustion chamber. In one embodiment of the water heater the burner is a power burner which forces the combustion products sequentially through the combustion chamber, heat exchanger, transfer chamber and discharge conduit. In another embodiment of the water heater a draft inducer fan is used to draw the combustion products through this path from the combustion chamber.

Abstract: The efficiencies of illustrative embodiments of vertical center flue type fuel-fired base water heaters are improved by installing in the water heaters variously configured tubular condensing type secondary heat exchangers of smaller diameters than the associated center flues. The efficiency increases are achieved with components and manufacturing processes similar to those utilized in the base water heaters and secondary heat exchanger materials similar to those in the tank portions of the base water heaters.

Abstract: A high efficiency downfired gas water heater is provided which has a tank for storing water to be heated, a combustion chamber extending downwardly through a top end of the tank, and a gas burner operative to create hot combustion products within the combustion chamber. At the bottom end of the tank is a transfer chamber coupled to an external discharge conduit and to a single pass heat exchanger, in the form of multiple flue tubes. extending vertically through the tank and connected to the combustion chamber. In one embodiment of the water heater the burner is a power burner which forces the combustion products sequentially through the combustion chamber, heat exchanger, transfer chamber and discharge conduit. In another embodiment of the water heater a draft inducer fan is used to draw the combustion products through this path from the combustion chamber.

Abstract: The efficiencies of illustrative embodiments of vertical center flue type fuel-fired base water heaters are improved by installing in the water heaters variously configured tubular condensing type secondary heat exchangers of smaller diameters than the associated center flues. The efficiency increases are achieved with components and manufacturing processes similar to those utilized in the base water heaters and secondary heat exchanger materials similar to those in the tank portions of the base water heaters.