A dual energy gas water heater is described and wherein a square flange, curved resistor style resistive heating element, is secured in a bottom portion of the tank of the water heater spaced above a top wall of the combustion chamber. A gas burner is secured in the combustion chamber and connected to a gas supply line through a gas valve. The curved resistive heating element is a low density, long life, element having a density in the range of about 20 to 80 watts/sq. inches. A switch is secured between the thermostat of the resistive heating element and the voltage supply line. A controller selectively operates the switch and the gas valve to disconnect the voltage supply line from the thermostat and/or shut-off the gas valve secured to the gas supply line depending on the desired source of energy. The controller is adapted to be optionally controlled by a utility/provider through a communication link. Renewable energy source may also be secured to an additional resistive heating element to improve the efficiency thereof.

A method of constructing a water heater includes the steps of providing a tank having a metal interior tank wall and a heat exchanger positioned within the tank, coating the interior tank wall and the heat exchanger with a first layer comprising glass enamel, and coating a portion of the first layer with a second layer comprising an organic polymer to protect the portion of the first layer from exposure to water in the tank.

A gas supply manifold has a nozzle forming member having a plurality of gas injection nozzles, a cover member configured to be overlapped on the nozzle forming member, and a caulking-fastening portion configured to fasten the nozzle forming member and the cover member. The caulking-fastening portion is configured such that a convex portion provided for one of the nozzle forming member and the cover member penetrates a hole provided for the other member, and a tip end portion of the convex portion has an engagement portion, the engagement portion having a larger diameter or a larger width than the hole and being engaged with a peripheral edge portion of the hole. A tip end face of the convex portion has a dent portion formed by pressing the tip end face into a base portion side of the convex portion and an area around the dent portion constitutes the engagement portion. Thus, the nozzle forming member and the cover member are appropriately caulked and fastened.

A pressure probe assembly for attachment to a venturi of a gas-fired appliance, where the venturi includes a body having an inlet end, an outlet end, and a wall defining a mixing chamber extending from the inlet end to the outlet end about an axis. A support member is detachably coupled to the mixing chamber. A first pressure probe is coupled to the support member and has a first pressure tap disposed substantially adjacent the axis. A second pressure probe is coupled to the support member and has a second pressure tap disposed substantially adjacent the mixing chamber wall. Also disclosed is a gas-fired appliance, such as a water heater, including the pressure probe assembly.

A gas fueled water heater appliance having a temperature control switch is provided herein. The gas fueled water heater appliance may include a tank for storage of water for heating, a chamber wall, a gas burner, a valve, the temperature control switch, and a conductive probe. The chamber wall may define a combustion chamber. The gas burner may be positioned adjacent to the tank and within the combustion chamber to heat the water in the tank. The valve may control a flow of gaseous fuel to the gas burner. The temperature control switch may be in operable communication with the valve. The conductive probe may extend through the chamber wall from a first end positioned on the temperature control switch to a second end positioned within the combustion chamber.

The present invention provides a boiler system, for example for use in heating a domestic hot water supply, and which is significantly more fuel efficient than existing boilers, the boiler system comprising a first reservoir and a second reservoir which together define a combustion enclosure, a storage tank positioned to define an upper wall or roof of the enclosure and being in fluid communication with the first water reservoir, a heat exchange tube located in the storage tank and being in fluid communication with the second water reservoir; and a burner arranged to directly heat atmospheric gases within the enclosure in order to indirectly heat the walls of the enclosure.

A gas fueled water heater appliance having a temperature control switch is provided herein. The gas fueled water heater appliance may include a tank for storage of water for heating, a chamber wall, a gas burner, a valve, the temperature control switch, and a conductive probe. The chamber wall may define a combustion chamber. The gas burner may be positioned adjacent to the tank and within the combustion chamber to heat the water in the tank. The valve may control a flow of gaseous fuel to the gas burner. The temperature control switch may be in operable communication with the valve. The conductive probe may extend through the chamber wall from a first end positioned on the temperature control switch to a second end positioned within the combustion chamber.

Aspects of the invention relate to water heaters including a water storage tank having a top wall, a bottom wall, and a side wall extending between the top wall and the bottom wall; a combustion chamber extending below the bottom wall of the water storage tank and a heat exchanger configured to receive combustion gases and to transfer heat to water in the water storage tank. The heat exchanger includes a first pass flue extending through the water storage tank and a plurality of second pass flues coupled to receive combustion gases from the first pass flue. The second pass flues extending through the water storage tank and having a straight top portion, a curved bottom portion, and a longitudinal axis residing in a plane. The curved bottom portion of the second pass flues exits the water storage tank through at least one aperture defined in the side wall of the water storage tank.

A fluid heating system for heating a production fluid using a thermal transfer fluid, the production fluid being contained in a vessel includes an electric blower configured to receive ambient air and electrical input power and to provide output source air, a combustion system configured to receive the source air from the electric blower and to receive fuel and to provide the thermal transfer fluid, a heat exchanger configured to receive the thermal transfer fluid from the combustion system and configured to be in thermal communication with the production fluid to provide convective heat exchange from the thermal transfer fluid to the production fluid, and to provide output exhaust gas, and wherein the electric fan provides a predetermined volume flow rate of the output source air at a predetermined blower efficiency such that the fluid heating system has a Bulk Heat Flux of at least about 14.7 kBTU/Hr/ft.sup.2 and a Pressure Drop of at least about 0.7 psi.

In a fuel-fired water heater with a standing pilot burner and a motorized flue damper, a specially designed controller is utilized to prevent overheating of water stored in the tank portion of the water heater caused by the hot combustion gases continuously generated by the pilot burner during standby periods of the water heater in which its main fuel burner is not being fired. The controller has a selectively variable water temperature control set point temperature and is operable to sense both ambient temperature and the tank water temperature and to open the flue damper and/or keep it open, after the main burner is off, in response to the presence for a predetermined continuous time period of a predetermined relationship of at least the selected temperature control set point temperature and the sensed ambient temperature.