Abstract: A thermal cut-off circuit for a gas-fired device and method of operating the circuit. The thermal cut-off circuit includes a thermal cut-off switch and an ambient thermal switch. The thermal cut-off switch is positioned in a combustion chamber and the ambient thermal switch is preferably positioned in a flow of air entering the combustion chamber. The thermal cut-off circuit ensures a gas valve is closed upon detecting a possible incomplete combustion in the combustion chamber.

Abstract: A secondary safety circuit for a gas-fired device and method of operating the circuit. The secondary safety circuit includes a low-voltage direct current power source, a valve, and at least one sensor. The valve can be positioned in a pilot burner gas line. The secondary safety circuit ensures the valve is closed upon detecting an unsafe condition with the sensor.

Abstract: An original equipment manufacturer water heater including a water tank including an inlet and an outlet, means for heating water in the water tank, a base pan at least partially supporting the water tank such that water leaked from the water tank collects in the base pan, a valve closable to prevent water from entering the water tank through the inlet, and a sensor positioned in the base pan, the sensor configured to close the valve upon detecting water.

Abstract: A water heater adapted to be positioned outside of a building and to interface with the plumbing system of the building. The water heater includes a water storage tank adapted to store water outside of the building, a means for heating the water in the tank, a base member supporting the tank outside of the building, and a plurality of water pipes communicating with the water tank. The water heater also includes a manifold that is mounted to the base member and includes a plurality of pipe unions adapted to interface between the plumbing system and the plurality of pipes to provide cold water to the tank and to remove heated water from the tank for use in the building.

Abstract: A fluid-heating apparatus for heating a fluid and method of operating the same. The fluid-heating apparatus includes a heating element for heating a fluid surrounding the heating element and a control circuit connected to the heating element and connectable to a power source. The control circuit includes a current path from the power source to the heating element back to the power source, a switch connected in the current path, and a current sensor. The method includes initiating a heating state of the fluid-heating apparatus, initiating a non-heating state of the fluid-heating apparatus, applying a voltage to the heating element during the non-heating state, sensing a leakage current of the heating element during the application of the voltage, and determining a degradation of the heating element with the sensed leakage current.

Abstract: A water heater including a water inlet line having an inlet opening that introduces cold water to a tank, a water outlet line having an outlet opening that withdraws heated water from the tank, and a heating element. The water heater further includes a control circuit. The heating element can be an electrical resistance heating element, a gas heating element, or a combination thereof. In one construction, the gas heating element includes a first combustive section and a second combustive section separately controlled from the first combustive section.

Abstract: A fluid-heating apparatus for heating a fluid and method of operating the same. The fluid-heating apparatus includes a heating element for heating a fluid surrounding the heating element and a control circuit connected to the heating element and connectable to a power source. The control circuit includes a current path from the power source to the heating element back to the power source, a switch connected in the current path, and a current sensor. The method includes initiating a heating state of the fluid-heating apparatus, initiating a non-heating state of the fluid-heating apparatus, applying a voltage to the heating element during the non-heating state, sensing a leakage current of the heating element during the application of the voltage, and determining a degradation of the heating element with the sensed leakage current.

Abstract: A fluid-heating apparatus for heating a fluid and method of operating the same. The fluid-heating apparatus includes a heating element for heating a fluid surrounding the heating element and a control circuit connected to the heating element and connectable to a power source. The control circuit is configured to determine whether a potential dry-fire condition exists for the heating element. The method includes applying a first electric signal to the heating element, detecting a first value of an electrical characteristic during the application of the first electric signal, applying a second electric signal to the heating element, applying a third electric signal to the heating element, detecting a second value of the electrical characteristic during the application of the third electric signal; and determining whether a potential dry-fire condition exists based on the first and second values.

Abstract: A water heater includes a sealed combustion chamber and one or more fans for raising pressure in the combustion chamber to increase efficiency of the water heater. The pressure permits a more restrictive baffle to be used in the flue compared to baffles used in atmospheric water heaters. The water heater may include a water temperature sensor that activates the fan without activating the burner if water temperature raises above a desired temperature. The water heater may also include pressure and vapor sensors to ensure the combustion chamber is properly sealed and there are no flammable vapors present prior to igniting the burner. The fans are relatively small and run off the same DC power that runs an electric gas valve. The fans may be, for example, 12 or 24 Volt fans with power inputs of about 10 Watts or less.

Abstract: A method, and a system using the method, of controlling a heating device. The method includes combusting a mixture of fuel and air in a sealed combustion chamber thereby forming a reaction zone in which the fuel reacts with the air, and also forming outside of the reaction zone an ion zone in which ions are formed as a result of combustion. The method also includes positioning an ion detecting member in the ion zone, and generating an electrical signal at the ion detecting member in response to an ion concentration in the ion zone. The method also includes detecting a direction reversal of the electrical signal at the ion detecting member, and stopping combusting the mixture in response to the reverse of the direction of the electrical signal.

Abstract: A water heater includes a sealed combustion chamber and one or more fans for raising pressure in the combustion chamber to increase efficiency of the water heater. The pressure permits a more restrictive baffle to be used in the flue compared to baffles used in atmospheric water heaters. The water heater may include a water temperature sensor that activates the fan without activating the burner if water temperature raises above a desired temperature. The water heater may also include pressure and vapor sensors to ensure the combustion chamber is properly sealed and there are no flammable vapors present prior to igniting the burner. The fans are relatively small and run off the same DC power that runs an electric gas valve. The fans may be, for example, 12 or 24 Volt fans with power inputs of about 10 Watts or less.

Abstract: A blower for a water heater having a flue defining a flue axis. The blower includes a housing at least partially defining a first chamber and a second chamber and having an inlet opening into the first chamber and an outlet communicating between the second chamber and atmosphere, the inlet being alignable with the flue, a ramp extending through the second chamber and having a surface, the surface being oriented at an acute angle with respect to the flue axis, and an impeller positioned in the second chamber and being operable to draw exhaust from the flue into the first chamber through the inlet and being operable to direct the exhaust through the second chamber and across the surface of the ramp, the surface of the ramp directing the exhaust through the outlet in a direction substantially parallel to the flue axis.

Abstract: An apparatus for heating a medium includes a combustion chamber; a burner within the combustion chamber and operable to create products of combustion for heating the medium to be heated; a conduit for the exhaust of the products of combustion; and an airflow apparatus capable of creating airflow in the absence of any opposition to the airflow, the airflow having a pressure, the airflow apparatus communicating with the conduit and operable such that the pressure of the airflow resists standby convection flow of gases out of the conduit when the burner is not operating, and wherein the airflow apparatus is adjustable to vary the magnitude of the airflow to substantially equalize the airflow and the standby convection flow of gases to create a substantially stagnant state within the conduit when the burner is not operating.

Abstract: The invention includes an apparatus and method of determining the type of igniter for a burner at each stage of a boiler. The apparatus includes a controller operable to detect whether a first type of igniter or a second type of igniter is installed in the burner based on whether the first type of igniter or the second type of igniter transmits a response to the controller after receiving an activation signal from the controller.

Abstract: The invention includes a controller for a boiler and a method of detecting a short-cycling condition of the boiler. The controller includes a user interface module, a short-cycling detection module, and an adjustment module. The method includes the acts of detecting when the boiler is in a short-cycling condition and introducing delays at various operational points throughout a heating process.

Abstract: The invention includes a gas valve control circuit for a gas-fired appliance and a method of activating the gas valve in the gas-fired appliance. The control circuit includes a controller, a first control circuit, a second control circuit, a first relay and a second relay. The first relay is operable to close when a switch in the first control circuit is activated. The second relay is operable to close when a switch in the second control circuit is activated. A third relay can be closed in response to activation of the second control circuit. The gas valve operates when the first and second relay are closed. The method includes the acts of closing a plurality of relays based on activation of a plurality of control circuits.

Abstract: A water-resistant porcelain enamel coating and method of making the same is provided. The porcelain enamel coating is prepared using a borosilicate glass frit, and mill additions of silica and a zirconia compound. The mixture is applied to a metal substrate and fired, resulting in a water-resistant coating that resists cracking and crazing. The coating is particularly useful in water heaters. In one embodiment, the coating comprises a fine zirconia compound having a median particle size of less than 10 microns.

Abstract: An apparatus for heating a medium includes a combustion chamber; a burner within the combustion chamber and operable to create products of combustion for heating the medium to be heated; a conduit for the exhaust of the products of combustion; and an airflow apparatus capable of creating airflow in the absence of any opposition to the airflow, the airflow having a pressure, the airflow apparatus communicating with the conduit and operable such that the pressure of the airflow resists standby convection flow of gases out of the conduit when the burner is not operating, and wherein the airflow apparatus is adjustable to vary the magnitude of the airflow to substantially equalize the airflow and the standby convection flow of gases to create a substantially stagnant state within the conduit when the burner is not operating.

Abstract: A corrosion-resistant, copper-finned heat exchanger for a water heater is provided. The heat exchanger includes a conduit through which water runs, heat-transfer fins extending from the conduit and an anti-corrosive coating containing electroless nickel. The heat-transfer fins contain copper, and the coating is deposited directly onto at least one of the copper heat-transfer fins.

Abstract: A water heater includes a water tank adapted to contain water; a flue extending through the water tank and having a first end communicating with the water heater's combustion chamber for the flow of products of combustion through the tank; a damper communicating with the flue; and an apparatus for creating a flow of air proximate the second end of the flue to resist the flow of warm air out of the second end of the flue due to standby convection.