A system and method for controlling power to a water heater. The method comprises providing the water heater in a locked state, wherein at least one heating element of the water heater is inoperable when the water heater is in the locked state, coupling a digital key module to a communications port of the water heater, and receiving a digital key from the digital key module through the communications port. The method comprises coupling an electrical grid controller to the water heater through the communications port and placing the water heater in an unlocked state, wherein the at least one heating element of the water heater is operable when the water heater is in the unlocked state.

A water heater may include a water tank, a burner, a pilot for igniting the burner, an ignitor for igniting the pilot, a thermoelectric device in thermal communication with a flame of the pilot, a controller for controlling an ignition sequence of the pilot using the ignitor, and a rechargeable power storage device for supplying power to the ignitor and the controller. The rechargeable power storage device may be rechargeable using the energy produced by the thermoelectric device. The controller is configured to selectively ran only the pilot for at least pan of a heating cycle to increase the recharge lime of the rechargeable power storage device while still healing the water in the water heater.

A water heater system includes a controller configured to integrate control of both recovery and recirculation operations of a recovery pump and a recirculation pump. As such, a separate device, installation location, and power source (e.g., available outlet) is not needed with the controller. Because a single controller is configured to control both recovery and recirculation operations, additional control functions are available. The controller may be in communication with an internal controller of the water heater and configured to receive an error notification upon abnormal operation of the water heater. The controller can stop recovery and recirculation operations in response to an error notification, unlike with traditional water heating systems which may otherwise continue to function. The recovery and recirculation operations are based on a setpoint temperature of the water heater such that changes made to the setpoint temperature will automatically adjust in the recovery and recirculation operations.

The water heater may be configured to execute a normal operation in which a heating means is continuously operated in an ON state in a case where a required heat quantity is greater than or equal to a minimum heat quantity. The water heater may be configured to execute an intermittent operation in which the heating means is alternately and repeatedly operated in the ON state and an OFF state repeatedly in a case where the required heat quantity is less than the minimum heat quantity. The water heater may be configured to change a distribution ratio of a flow control mechanism in the normal operation and in the intermittent operation. An operating speed of the flow control mechanism in the intermittent operation may be faster than an operating speed of the flow control mechanism in the normal operation.

A heat pump apparatus includes: a refrigerant circuit which circulates refrigerant; a heat medium circuit which makes a heat medium flow; a heat exchanger which cause heat exchange to be performed between the refrigerant and the heat medium; and an indoor unit which houses at least the heat exchanger. The heat exchanger has a double-wall structure. The indoor unit includes a container which houses the heat exchanger. In the container, a first opening port is formed to communicate with an outdoor space without communicating with an indoor space.

Disclosed systems and methods relate to a water heater sensor for detecting a corrosion of an anode rod. According to embodiments, a system can include the anode rod in contact with water in a water heater, where the anode rod includes a corrodible sheath having a cavity. The system can include two electrical wires, where first ends of the two electrical wires, disposed within the cavity, are configured to come in contact with the water when the corrodible sheath of the anode rod corrodes to a certain point. The system can include a controller coupled to second ends of the two electrical wires, where the controller can detect whether the water is in contact with the first ends of the two electrical wires. The system can include an indicator to provide an indication when the water is in contact with the first ends of the two electrical wires.

Disclosed herein is a water heating system including a water heater having a tank, and a first temperature sensor disposed toward a top end of the tank to measure a first temperature and a second temperature sensor disposed toward a bottom end of the tank to measure a second temperature. The water heating system can further include a controller communicably coupled to the first temperature sensor and the second temperature sensor, where the controller determines an amount of heated water in the tank based on one or more algorithms and measurements made by the first and second temperature sensors.

Disclosed embodiments include apparatuses, systems, and methods for circulating and managing temperature of a liquid in a vessel. An illustrative embodiment includes an apparatus having a control section with a pump to receive liquid and expel the liquid via a pump outlet, a temperature interface to modulate a supply of energy, and a control interface to direct operation of the pump and the temperature control interface. An immersible section is configured to be at least partially immersed in the liquid and includes at least one temperature control surface to heat the liquid in response to the energy received from the temperature interface, a pump inlet to draw the liquid into the pump, and a filtration housing covering the at least one temperature control surface and the pump inlet to prevent particles over a predetermined size from passing into the pump inlet and coming into contact with the at least one temperature control surface.

A water preconditioner system comprising a user interface for manually or automatically receiving inputs from a user, a mixing assembly including a plurality of control valves coupled to hot and cold water supply lines, and a controller in communication with the plurality of control valves and the user interface for controlling the operation of the system. The controller is configured to operate in a plurality of modes to precondition the water to one of a desired preset water dispensing temperature or a target temperature different from the desired preset water dispensing temperature.

In an aspect, an HVAC system includes an inducer motor to provide combustion airflow, and a pressure sensor to measure an output airflow pressure of the inducer motor. The HVAC system may initiate the inducer motor, and receive a pulse width modulation (PWM) signal from the inducer motor, wherein the PWM signal indicates a PWM signal of the inducer motor corresponding to a predetermined airflow pressure of the inducer motor and measured by the pressure sensor. The HVAC system may compare the PWM signal to a baseline value, and control the inducer motor based on the comparing of the PWM signal to the baseline value. The HVAC system may also generate a status notification of the combustion airflow of the HVAC system in response to the comparing the PWM signal to the baseline value.