Abstract: A dry-fire protection system and method. The dry-fire protection system includes a tank, a heating element, a powered electrode, a sensor, and a microcircuit. The heating element and the powered electrode are positioned in the tank, the powered electrode being positioned above the heating element. The powered electrode includes an electrode wire and a connector having an electrical connector coupled to the electrode wire, but electrically isolated from the tank, and a fastener for coupling the powered electrode to the tank. The sensor detects an electrical characteristic of a circuit formed by the tank, the powered electrode, and water in the tank. The microcircuit determines if a possible dry-fire condition exists based on a signal received from the sensor.

Abstract: Methods and systems for evaluating the condition of a water tank having a powered anode protection system. The water heater includes a storage tank to hold water, a powered anode, and a control circuit. The control circuit includes a variable voltage supply, a voltage sensor, and a current sensor. The control circuit is configured to compare a measured parameter to a threshold. In some constructions, the threshold is indicative of a condition of the storage tank at which the powered anode is no longer able to protect the storage tank from corrosion. In other constructions, the threshold is predicative of a potential failure of the storage tank caused by corrosion. In some constructions, the control circuit is configured to estimate a time remaining until the predicted failure of the storage tank.

Abstract: Methods and systems for evaluating the condition of a water tank having a powered anode protection system. The water heater includes a storage tank to hold water, a powered anode, and a control circuit. The control circuit includes a variable voltage supply, a voltage sensor, and a current sensor. The control circuit is configured to compare a measured parameter to a threshold. In some constructions, the threshold is indicative of a condition of the storage tank at which the powered anode is no longer able to protect the storage tank from corrosion. In other constructions, the threshold is predicative of a potential failure of the storage tank caused by corrosion. In some constructions, the control circuit is configured to estimate a time remaining until the predicted failure of the storage tank.

Abstract: An appliance is disclosed that includes an electrically operated load such as a gas-fired appliance having an electrically operated gas valve. A current sensing circuit is configured to sense the current provided to the load. Based upon this sensed current, it is determined whether the load is energized. Methods are also disclosed for monitoring the status of a current sensing circuit to determine the actual operating state of the load.

Abstract: A gas-fired appliance is disclosed that includes a gas valve powered by a power source. A plurality of switching units, each responsive to a condition of the appliance, are arranged in series between the gas valve and the power source. Each switching unit includes an emitter, such as an emitter of an optocoupler, that is used to monitor the opened or closed status of a switch in the switching unit. When at least one switch opens, power to the gas valve is reduced preventing the gas valve from operating. However, because this reduced power is provided to each subsequent switching unit, each optocoupler can be monitored regardless of the opened or closed status of previous switching units. As such, one or more open switches can be detected simulataneously.

Abstract: A powered anode assembly. The powered anode assembly includes an electrode wire, a shield tube, and a connector assembly. The electrode wire has a first portion and a second portion. The shield tube substantially covers the first portion of the electrode wire, leaving a small portion of the first portion open. The connector assembly includes a connector that is electrically connected to the electrode wire, and a fastener that is physically coupled to but electrically isolated from the connector.

Abstract: A dry-fire protection system and method. The dry-fire protection system includes a tank, a heating element, a powered electrode, a sensor, and a microcircuit. The heating element and the powered electrode are positioned in the tank, the powered electrode being positioned above the heating element. The powered electrode includes an electrode wire and a connector having an electrical connector coupled to the electrode wire, but electrically isolated from the tank, and a fastener for coupling the powered electrode to the tank. The sensor detects an electrical characteristic of a circuit formed by the tank, the powered electrode, and water in the tank. The microcircuit determines if a possible dry-fire condition exists based on a signal received from the sensor.

Abstract: A water heater having a powered electrode and a method of controlling the water heater. The water heater includes a tank to hold water, a heating element, an electrode, and a control circuit. The control circuit includes a variable voltage supply, a voltage sensor, and a current sensor. The control circuit is configured to controllably apply a voltage to the electrode, determine the potential of the electrode relative to the tank with the voltage sensor when the voltage does not power the electrode, determine a current applied to the tank after the voltage powers the electrode, determine a conductivity state of the water in the tank based on the electrode potential and the current, and define the voltage applied to the powered electrode based on the conductivity state. The control circuit of the water heater can also determine whether the water heater is in a dry-fire state.