Abstract: A fuel-fired water heater has a draft inducer fan assembly with a housing having an inlet for receiving hot combustion gases discharged from the water heater, and an outlet for discharging the combustion gases. A normally closed damper member within the housing is openable by fluid pressure force created by operation of a draft inducer fan portion of the assembly. With the damper in its open position the fan exhausts the received combustion gases through a housing outlet. When the damper closes it prevents convective outflow through the housing outlet of flue-heated air. In alternate embodiments of the assembly the fan is operative to also draw in dilution air that cools the fan motor and the discharged combustion gases, with the assembly having an internal configuration preventing convective outflow of flue-heated air through the housing dilution air inlet during standby periods of the water heater.

Abstract: A water heater is provided with monitor/diagnostic display apparatus that selectively provides a user with visual or other type of indicia of the recovery time for the water heater. The apparatus includes a monitoring unit that may be mounted on the water heater, and a display unit that may be mounted either on the water heater or remotely therefrom.

Abstract: A fuel-fired water heater has a draft inducer fan assembly with a housing having an inlet for receiving hot combustion gases discharged from the water heater, and an outlet for discharging the combustion gases. A normally closed damper member within the housing is openable by fluid pressure force created by operation of a draft inducer fan portion of the assembly. With the damper in its open position the fan exhausts the received combustion gases through a housing outlet. When the damper closes it prevents convective outflow through the housing outlet of flue-heated air. In alternate embodiments of the assembly the fan is operative to also draw in dilution air that cools the fan motor and the discharged combustion gases, with the assembly having an internal configuration preventing convective outflow of flue-heated air through the housing dilution air inlet during standby periods of the water heater.

Abstract: A water heater is provided with monitor/diagnostic display apparatus that selectively provides a user with visual or other type of indicia of the remaining hot water availability of, the recovery time for, and the overall efficiency of the water heater. The apparatus includes a monitoring unit that may be mounted on the water heater, and a display unit that may be mounted either on the water heater or remotely therefrom.

Abstract: An instantaneous type fuel-fired water heater has a variable speed blower that discharges combustion air into a fuel burner utilized to heat water flowing through a heat exchanger portion of the water heater. A portion of the air discharged from the blower bypasses the burner and associated heat exchanger, flows around the heat exchanger, and then mixes with flue gases being discharged from the heat exchanger portion into the flue portion of the water heater. In this manner, such flue gases are cooled by the bypassing blower discharge air to an extent permitting the flue portion to be formed from a low cost plastic material instead of a high temperature metal material such as stainless steel.

Abstract: A representatively pumpless water heater system has an instantaneous water heater coupled in series with a storage water heater by piping circuitry incorporating a bypass valve and a mixing valve and useable to route pressurized incoming cold water sequentially through the instantaneous and storage type heaters. A control system (1) operates the bypass valve to cause a selectively variable portion of the incoming cold water to bypass the instantaneous heater and flow to the mixing valve, and (2) operates the mixing valve to blend the bypassed cold water with hot water exiting the storage heater to maintain a predetermined temperature of heated water exiting the system. Another system embodiment adds a directional bypass valve operable by the control system to selectively divert to the mixing valve a portion of the heated water exiting the instantaneous heater for delivery to the storage heater.

Abstract: An instantaneous type fuel-fired water heater has a variable speed blower that discharges combustion air into a fuel burner utilized to heat water flowing through a heat exchanger portion of the water heater. A portion of the air discharged from the blower bypasses the burner and associated heat exchanger, flows around the heat exchanger, and then mixes with flue gases being discharged from the heat exchanger portion into the flue portion of the water heater. In this manner, such flue gases are cooled by the bypassing blower discharge air to an extent permitting the flue portion to be formed from a low cost plastic material instead of a high temperature metal material such as stainless steel.

Abstract: A transistor used as a normally open switch is connected in the millivolt electrical circuit of a fuel-fired natural draft water heater in series with a thermopile device impinged upon by a standing pilot flame, and the solenoid coil portion of the pilot fuel valve. A variable resistance type flammable vapor sensor is connected in a control circuit which is powered by a DC battery and is coupled only to the transistor portion of the millivolt circuit. In the absence of flammable vapor detection by the sensor the control circuit outputs an electrical signal to the transistor that holds it in a closed position to thereby maintain the standing pilot flame. In response to sensor detection of flammable vapor, the control circuit output signal terminates to cause the transistor to return to its normally open switch position, thereby shutting off the pilot flame.

Abstract: Electrical components projecting outwardly from the storage tank portion of an electric water heater are shielded from foam insulation material being injected into an insulation space between the tank and an outer jacket portion of the water heater by a hollow, open sided foam dam structure extending through a jacket opening and circumscribing the electrical components. Force exerting projections on the dam engage the interior side surface of the jacket and forcibly hold the inner side of the dam structure in sealing engagement with the tank. The projections also hold an outer side peripheral lip of the dam in a an outwardly and resiliently deflected orientation in which it is sealingly pressed inwardly against the outer side surface of the jacket around the periphery of the opening therein to prevent injected foam from being forced outwardly through the jacket opening.

Abstract: A specially configured fuel-fired water heater production platform may be used as a natural draft water heater. Alternatively, by modifying an upper end portion of the production platform using associated conversion apparatus, the same platform may be converted to a power vented water heater subassembly, a natural draft direct vent water heater subassembly, or a powered direct vent water heater subassembly to thereby lower the overall production costs for these different types of fuel-fired water heaters.

Abstract: Various embodiments of fuel-fired low NOx water heaters are provided with burners having built-in venturi inlet sections for receiving fuel from a source thereof and combustion air from outside of the water heater. The burners are integrated in various manners with flammable vapor ignition resistance (FVIR) platforms to thereby reduce the tooling costs necessary to provide the water heaters with both lowered NOx emissions and flammable vapor ignition resistance.

Abstract: Electrical components projecting outwardly from the storage tank portion of an electric water heater are shielded from foam insulation material being injected into an insulation space between the tank and an outer jacket portion of the water heater by a hollow, open sided foam dam structure extending through a jacket opening and circumscribing the electrical components. Force exerting projections on the dam engage the interior side surface of the jacket and forcibly hold the inner side of the dam structure in sealing engagement with the tank. The projections also hold an outer side peripheral lip of the dam in a an outwardly and resiliently deflected orientation in which it is sealingly pressed inwardly against the outer side surface of the jacket around the periphery of the opening therein to prevent injected foam from being forced outwardly through the jacket opening.

Abstract: Electrical components projecting outwardly from the storage tank portion of an electric water heater are shielded from foam insulation material being injected into an insulation space between the tank and an outer jacket portion of the water heater by a hollow, open sided foam dam structure extending through a jacket opening and circumscribing the electrical components. Force exerting projections on the dam engage the interior side surface of the jacket and forcibly hold the inner side of the dam structure in sealing engagement with the tank. The projections also hold an outer side peripheral lip of the dam in a an outwardly and resiliently deflected orientation in which it is sealingly pressed inwardly against the outer side surface of the jacket around the periphery of the opening therein to prevent injected foam from being forced outwardly through the jacket opening.

Abstract: A foam dam in the insulation cavity of an electric water heater comprises a plastic bag into which liquid foam insulation is injected, the bag having an essentially closed top edge portion with only a small opening for receiving the injected insulation. A small portion of the insulation injected into the bag is forced outwardly therefrom via small metering holes to form external protrusions on the bag that mechanically interlock with a second batch of insulation subsequently injected into the cavity and prevent the hardened second insulation batch from pulling away from the bag. The substantially closed top edge of the bag permits the insulation injected into the bag to pack therein and increase the top-to-bottom hardened foam density uniformity. Side edges of the bag may be pleated to increase the sealing area of the foam dam.

Abstract: A foam dam in the insulation cavity of an electric water heater comprises a plastic bag into which liquid foam insulation is injected, the bag having an essentially closed top edge portion with only a small opening for receiving the injected insulation. A small portion of the insulation injected into the bag is forced outwardly therefrom via small metering holes to form external protrusions on the bag that mechanically interlock with a second batch of insulation subsequently injected into the cavity and prevent the hardened second insulation batch from pulling away from the bag. The substantially closed top edge of the bag permits the insulation injected into the bag to pack therein and increase the top-to-bottom hardened foam density uniformity. Side edges of the bag may be pleated to increase the sealing area of the foam dam.

Abstract: Electrical components projecting outwardly from the storage tank portion of an electric water heater are shielded from foam insulation material being injected into an insulation space between the tank and an outer jacket portion of the water heater by a hollow, open sided foam dam structure extending through a jacket opening and circumscribing the electrical components. Force exerting projections on the dam engage the interior side surface of the jacket and forcibly hold the inner side of the dam structure in sealing engagement with the tank. The projections also hold an outer side peripheral lip of the dam in a an outwardly and resiliently deflected orientation in which it is sealingly pressed inwardly against the outer side surface of the jacket around the periphery of the opening therein to prevent injected foam from being forced outwardly through the jacket opening.

Abstract: Electrical components projecting outwardly from the storage tank portion of an electric water heater are shielded from foam insulation material being injected into an insulation space between the tank and an outer jacket portion of the water heater by a hollow, open sided foam dam structure extending through a jacket opening and circumscribing the electrical components. Force exerting projections on the dam engage the interior side surface of the jacket and forcibly hold the inner side of the dam structure in sealing engagement with the tank. The projections also hold an outer side peripheral lip of the dam in a an outwardly and resiliently deflected orientation in which it is sealingly pressed inwardly against the outer side surface of the jacket around the periphery of the opening therein to prevent injected foam from being forced outwardly through the jacket opening.

Abstract: Electrical components projecting outwardly from the storage tank portion of an electric water heater are shielded from foam insulation material being injected into an insulation space between the tank and an outer jacket portion of the water heater by a hollow, open sided foam dam structure extending through a jacket opening and circumscribing the electrical components. Force exerting projections on the dam engage the interior side surface of the jacket and forcibly hold the inner side of the dam structure in sealing engagement with the tank. The projections also hold an outer side peripheral lip of the dam in a an outwardly and resiliently deflected orientation in which it is sealingly pressed inwardly against the outer side surface of the jacket around the periphery of the opening therein to prevent injected foam from being forced outwardly through the jacket opening.

Abstract: Convective heat traps are installed at the cold water inlet and hot water outlet of a water heater. Each heat trap has a tubular body with two axially spaced apart resilient flapper members transversely extending across the interior of the body and being hinged on opposite sides thereof. The heat trap at the cold water inlet is coaxially disposed within a dip tube. In one alternate structure, flapper members are mounted directly on the dip tube, and in another alternate structure an external annular seal element is mounted on the dip tube or heat trap body, with a flapper member being integrally formed with the seal element.

Abstract: A water heater is provided with a specially designed molded bottom pad/foam dam member formed from a crushable material, such as polystyrene, which is received in a metal bottom pan and has concentric circular grooves formed in its top side to receive circular bottom end edge portions of the tank and outer jacket portions of the water heater. A circumferentially spaced plurality of rigid support members are imbedded in the bottom pad/foam dam member and underlie its tank groove to prevent the tank from crushing the member one of the support members is formed from an electrically conductive material and defines an electrical grounding path between the tank and the bottom pan, and the other support members are formed from a thermally insulative material to inhibit heat loss from the tank to the bottom pan.