A powered anode current drive device is configured to automatically determine an anode drive current that offsets galvanic corrosion in a vessel. A method alerts a user on a change of an output of a powered anode current drive device. The method includes receiving an anode drive level output of the powered anode current drive device, determining electrical characteristics of the anode drive level output, analyzing the determined electrical characteristics for anomalous behavior, and generating an alert of the anomalous behavior.

Systems and methods for monitoring anodic protection are disclosed. The system can include a sacrificial anode having an anode body, at least one cavity within the anode body, a conductor disposed within the at least one cavity, and electronic circuitry in communication with the conductor. The sacrificial anode can be electrically connected to a component or structure that is subject to galvanic corrosion. The cavity can be positioned such that as the anode degrades to a certain point, the conductor will contact water. In response, an alert can be provided to inform a user that the sacrificial anode needs replacement. The alert can be provided by activating a light, siren, or other device. The alert can also be sent to a mobile device or website.

Disclosed herein are corrosion prevention devices comprising a sacrificial anode and a mass sensor. Also disclosed herein are corrosion prevention devices comprising a controller in communication with the mass sensor and sacrificial anode. The controller can be configured to receive mass data to detect when the mass of the sacrificial anode has fallen below a predetermined threshold. Upon determining that the mass has fallen below the predetermined threshold, the controller can designate that the sacrificial anode is depleted. In response, the controller can output instructions for performing one or more corrective actions to protect the desired structure from corrosion.

A water heating apparatus includes: a water container configured to heat water via a convection process by receiving the water through an inlet and passing water through an outlet; and one positive temperature coefficient (PTC) heating element or a plurality of PTC heating elements arranged within the water container and configured to be immersed during the convection process. The plurality of PTC heating elements have a gap between each PTC heating element. Further, the water heating apparatus includes at least one ultrasonic transducer attached to the water container and configured to project ultrasound onto and around the PTC heating element or the plurality PTC heating elements within the water container and to descale the PTC heating element or the plurality of PTC heating elements.

A water heater can include a heat source and a heat exchanger that transfers heat to the water. A header attached to the heat exchanger provides an inlet and an outlet for water to flow into and out of the heat exchanger. The header can also include an anode assembly that releasably attaches to the header. The anode assembly can be located at a bottom of the header so that an anode in the anode assembly remains in contact with the water when water is flowing through the heat exchanger.

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.

Provided are a heat exchange method of tap water using a heat exchanger, and the heat exchanger. The content of residual chlorine in the tap water is about 2 ppm or more, the heat exchanger comprises a plurality of heat plates, which comprise ferritic stainless steel, and copper brazing configured to couple the heat plates, and the ferritic stainless steel contains less than about 0.5 wt % of nickel, about 0.1 wt % to about 2 wt % of copper, and about 0.03 wt % or less of carbon.

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.

A water heater tank anode support and or locator device for an anode provided in a water heater tank, the support device having an anode engaging portion to engage said anode, and a tank engaging formation for operatively engaging a base of the tank.

An electric water heater tank adapted for connection to a controller, the tank including one or more electrical heating elements temperature sensing means mounted on the exterior of the tank wall and adapted to obtain a measurement of the temperature of the water in the tank, the temperature sensing means and each heating element being connected to an externally accessible connection means. The tank can include one or more heating element control means each connected to a corresponding one of the heating elements. The element control means can be connected to the externally accessible connection means.