A safety system and method to prevent water within a top portion of a tank of an electric water heater to drop below a safe temperature during a load shedding period, other than a full emergency grid failure, by a power provider whereby to prevent the propagation of harmful bacteria in a top portion the tank. A control device monitors the water temperature in the top portion of the tank by the use of a temperature sensor. If the control device detects a temperature of the water in the top portion of the tank inferior to 140 degrees F., it will by-pass the instructions of the power provider and connect power to one or more of the resistive heating elements of the tank until a predetermined temperature above 140 degrees F. is attained before switching off the resistive heating elements.

A water heating system can include a first tank-based water heater having a first inlet line and a first outlet line, where the first inlet line provides unheated water to the first tank, and where the first outlet line draws heated water from the first tank. The system can also include a first tankless water heater having a second outlet line, where the second outlet line of the first tankless water heater provides the heated water to a first heated water demand. The system can also include a first valve that controls an amount of the unheated water flowing through the first inlet line to the first tank-based water heater. The system can further include a controller operatively coupled to the first valve, where the controller controls a position of the first valve based on the first heated water demand and a first capacity of the first tankless water heater.

A water heating tank is provided comprising a reservoir with a cold water inlet into the reservoir and a hot water outlet from the reservoir. The water heating tank further comprises a heater enclosure located within the reservoir. The heater enclosure encloses at least part of a heater. The heater enclosure has an inlet, a vent and an outlet. The water heating tank further comprises a duct connected to the outlet of the heater enclosure. The duct has an exit located in an upper portion of the reservoir.

A water heating system including a tank at least one of an electric heating element and/or a heat pump assembly for heating the water in the tank and a controller operatively coupled to the at least one of an electric resistance heating element and/or a heat pump assembly configured to control operation of the water heating system is disclosed. The controller is configured to gather information comprising at least one of user preferences for the system, specifications for energy related systems of a home in which the water heating system is installed, specifications for how the water heating system is physically configured within the home, environmental parameters for a location in which the water heating system is installed, and is configured to process this information to control the water heater system to operate according to the information.

An improved boiler apparatus having multiple resistive heating elements are provided with fixed resistances that can be rewired to allow dual voltage capability and at the same time, reduced watt density. For 120 V operation, the large diameter 9 ohm coil is used alone to provide the lowest possible watt density. For 240 V operation, all three heating coils are wired in series, creating a low watt density but high wattage heater.

A smart electric heating device comprises a storage unit, a first heating unit, a second heating unit, a control unit and a first temperature sensing unit. With the first temperature sensing unit to obtain an ambient temperature, the control unit compares the ambient temperature with a maximum increased temperature and a set temperature for controlling the first heating unit and the second heating unit to actuate. In this way, each user can use hot water of sufficient temperature better.

A water heating system can include a water heater having a tank, an inlet line, and an outlet line, where the inlet line provides unheated water to the tank, and where the outlet line draws heated water from the tank. The water heating system can also include multiple sensing devices, where each sensing device of the plurality of sensing devices measures a parameter associated with the tank. The water heating system can further include a controller communicably coupled to the plurality of sensing devices, where the controller determines an amount of heated water in the tank based on measurements made by the plurality of sensing devices.

An electric water heating apparatus includes a first electric water heater having a first tank adapted to hold a quantity of water and a first electric heating structure disposed within the first tank. The electric water heating apparatus further includes a second electric water heater having a second tank adapted to hold a quantity of water; and a second electric heating structure disposed within the second tank. The electric water heating apparatus further includes a control unit that is in electrical communication with the first electric heating structure and second electric heating structure, the control unit configured to prevent both the first electric heating structure and the second electric heating structure from being simultaneously operable.

A washer fluid heating device includes a container that contains a washer fluid, a lid portion attached to a first end of the container to face an accommodation space for the washer fluid, heating means that has a proximal end portion attached to the lid portion and extends toward the accommodation space, and an outflow pipe having an outlet disposed in the accommodation space to allow the washer fluid in the accommodation space to flow out, and the outlet of the outflow pipe is provided such that a space formed between a horizontal plane passing through the outlet and an inner wall surface at a second end on an opposite side to the first end of the container corresponds to 10% or more of a volume of the accommodation space.

The metal tank portion of an electric water heater is protected against corrosion utilizing a corrosion protection system that detects a voltage potential between the sheath portion of a tank water-immersed electric heating element and the tank. In one embodiment of the corrosion protection system the sensed sheath/tank potential is utilized to enable a user of the water heater to accurately gauge the necessity of replacing a sacrificial anode extending into the tank. In another corrosion protection system, the sensed sheath/tank potential is utilized to provide impressed current cathodic protection of the tank and also to prevent dry firing of the electric water heater.