Abstract: A storage-type water heater including a tank for supporting water to be heated, a first heating element, a first relay connected to the first heating element, a second heating element, a second relay connected to the second heating element, and a controller for selectively operating the first relay and the second relay. The controller includes instructions for selecting a mode from at least, a no-sequencing mode, wherein the first relay and the second relay are operated concurrently, and a sequencing mode, wherein the first relay and the second relay are operated sequentially. The controller also operates the first relay to supply power to the first heating element, and operates the second relay to supply power to the second heating element, based on the selected mode.

Abstract: A storage-type water heater including a tank for supporting water to be heated, a first heating element, a first relay connected to the first heating element, a second heating element, a second relay connected to the second heating element, and a controller for selectively operating the first relay and the second relay. The controller includes instructions for selecting a mode from at least, a no-sequencing mode, wherein the first relay and the second relay are operated concurrently, and a sequencing mode, wherein the first relay and the second relay are operated sequentially. The controller also operates the first relay to supply power to the first heating element, and operates the second relay to supply power to the second heating element, based on the selected mode.

Abstract: A storage-type water heater includes a tank for supporting water to be heated, a first heating bank including a first heating surface disposed within the tank, a first contactor connected to the first heating bank, a second heating bank including a second heating surface disposed within the tank, a second contactor connected to the second heating bank, and a controller for selectively operating the first contactor and the second contactor.

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: A storage-type water heater includes a tank for supporting water to be heated, a first heating bank including a first heating surface disposed within the tank, a first contactor connected to the first heating bank, a second heating bank including a second heating surface disposed within the tank, a second contactor connected to the second heating bank, and a controller for selectively operating the first contactor and the second contactor.

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: 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: 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.