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 building management system (BMS) gateway comprises a BMS router and a water heater hub configured to be communicatively coupled to a plurality of water heaters. The BMS router facilitates communication of status and control data between a BMS and the water heaters connected to the water heater hub. Connecting multiple water heaters to a single BMS gateway provides simplified installation and networking requirements. For installations with more water heaters than are able to be coupled to the water heater hub, additional BMS gateways may be installed. Local controls for water heaters managed by the BMS are typically disabled or overwritten by the BMS to prevent changes to settings. A local BMS user interface (UI) is configured to connect with the BMS gateway(s) and facilitate secure access, display, and/or adjustment of water heater status and control data for the plurality of water heaters connected to the BMS gateway(s).

A building management system (BMS) gateway comprises a BMS router and a water heater hub configured to be communicatively coupled to a plurality of water heaters. The BMS router facilitates communication of status and control data between a BMS and the water heaters connected to the water heater hub. Connecting multiple water heaters to a single BMS gateway provides simplified installation and networking requirements. For installations with more water heaters than are able to be coupled to the water heater hub, additional BMS gateways may be installed. Local controls for water heaters managed by the BMS are typically disabled or overwritten by the BMS to prevent changes to settings. A local BMS user interface (UI) is configured to connect with the BMS gateway(s) and facilitate secure access, display, and/or adjustment of water heater status and control data for the plurality of water heaters connected to the BMS gateway(s).

A system that accommodates such high number of input/output (I/O) terminals of a single big complex application, by splitting the application into smaller, logical fixed applications so that each application can be deployed in one small controller that small and medium buildings can afford. This system also has a feature of an easy and intuitive way of installing, configuring and commissioning these multiple controllers for a single application by abstracting the complexity of entire application/program logic.

A system that accommodates such high number of input/output (I/O) terminals of a single big complex application, by splitting the application into smaller, logical fixed applications so that each application can be deployed in one small controller that small and medium buildings can afford. This system also has a feature of an easy and intuitive way of installing, configuring and commissioning these multiple controllers for a single application by abstracting the complexity of entire application/program logic.

A temperature sensor securing system and method is described for securing two or more temperature sensors against an outer surface of a side wall of a tank of an electric water heater. The temperature sensors are secured spaced apart on an elongated support such as a circuit board which is held in position against the tank outer surface by support means. An expandable liquid foam causes the temperature sensors to be biased against the outer surface of the tank side wall to sense the temperature of the side wall at the location of the sensors and to generate actual temperature signals to a controller which is programmed to communicate with a subscriber and/or energy provider to control the water temperature inside the tank.

A low leakage current fluid heater and systems and methods thereof. The fluid heater has a configuration whereby a heating element is isolated from a fluid channel so as to leak into fluid passing through the channel an allowed amount of leakage current. Fluid passing through the fluid heater can be heated to a desired temperature. A controller can provide control signals to driver the fluid heater to the desired temperature and maintain the temperature at the desired temperature.

An aspect of some embodiments of the current invention relates to an integrated system for heat distribution among a plurality of users. In some embodiments, the system includes a separate automatic control of heat distribution to each user and/or separate billing to each user. For example, a system may supply hot fluid to a plurality of apartments in a building and/or in multiple buildings. Optionally, each apartment has separate remote controlled valves controlling flow of heated fluid to the apartment and/or a sensor sensing how much heat enters and leaves the apartment in the hot fluid. In some embodiments, a processor controls the valve and/or receives data from sensors. The processor optionally controls devices that generate and/or store and/or dissipate heat. Optionally the processor predicts energy availability, costs and needs controls valves and/or devices to provide for predicted and/or unexpected needs while reduce cost of the energy.

A temperature sensor securing system and method is described for securing two or more temperature sensors against an outer surface of a side wall of a tank of an electric water heater. The temperature sensors are secured spaced apart on an elongated support such as a circuit board which is held in position against the tank outer surface by support means. An expandable liquid foam causes the temperature sensors to be biased against the outer surface of the tank side wall to sense the temperature of the side wall at the location of the sensors and to generate actual temperature signals to a controller which is programmed to communicate with a subscriber and/or energy provider to control the water temperature inside the tank.

A temperature sensor securing system and method is described for securing two or more temperature sensors against an outer surface of a side wall of a tank of an electric water heater. The temperature sensors are secured spaced apart on an elongated support such as a circuit board which is held in position against the tank outer surface by support means. An expandable liquid foam causes the temperature sensors to be biased against the outer surface of the tank side wall to sense the temperature of the side wall at the location of the sensors and to generate actual temperature signals to a controller which is programmed to communicate with a subscriber and/or energy provider to control the water temperature inside the tank.