A connected-type hot-water supply system includes hot-water supply apparatuses connected in parallel and a control means. The control means sets one main hot-water supply apparatus and sub-hot-water supply apparatuses, and performs leveling control of cumulative loads of the hot-water supply apparatuses by setting the main hot-water supply apparatus based on sequential rotation among the hot-water supply apparatuses. The control means includes a failure sign response mode in which it is determined whether there is a failure sign respectively for components of the hot-water supply apparatuses, and when a component of a part of hot-water supply apparatuses is a failure sign component determined to have a failure sign, a main use time of a hot-water supply apparatus having the failure sign component is increased, and the main use time is a main use time of serving as the main hot-water supply apparatus in the leveling control.

A connected-type hot-water supply system includes hot-water supply apparatuses connected in parallel and a control means. The control means sets one main hot-water supply apparatus and sub-hot-water supply apparatuses, and performs leveling control of cumulative loads of the hot-water supply apparatuses by setting the main hot-water supply apparatus based on sequential rotation among the hot-water supply apparatuses. The control means includes a failure sign response mode in which it is determined whether there is a failure sign respectively for components of the hot-water supply apparatuses, and when a component of a part of hot-water supply apparatuses is a failure sign component determined to have a failure sign, a main use time of a hot-water supply apparatus having the failure sign component is increased, and the main use time is a main use time of serving as the main hot-water supply apparatus in the leveling control.

The disclosed technology relates to a solar water heating system including a tank configured to store heat transfer fluid, a solar collector in fluid communication with the tank, and a pump system in fluid communication with the tank and the solar collector. The pump system can include a first pump, a second pump, and a valve assembly. The valve assembly can direct the heat transfer fluid from an outlet of the first pump to the solar collector when the first pump is operating and can direct the heat transfer fluid from an outlet of the second pump to the solar collector when the second pump is operating. The first pump and the second pump can transfer the heat transfer fluid from the solar collector back to the tank when the first pump and the second pump are not operating.

The present disclosure provides for a recirculating flow controller that is operably coupled to a flow switch and to a recirculation pump. The recirculating flow controller determines that hot water has begun to flow by way of the connection with the flow switch. In response, the recirculating flow controller activates the recirculation pump to circulate hot water from a water heater. The recirculating flow controller can activate the recirculation pump for a predetermined duration. The flow switch can be configured to sense flow in a hot water line connected to a water heater. The flow switch can be activated by turning on any hot water faucet connected to the water heater.

A control system is provided for controlling heating and/or cooling with a conditioning load such as fan coils and chilled beams. Based on user input and ambient conditions, the control system determines a desired temperature for the liquid entering the load and combines fresh supply liquid (e.g., from a chiller or boiler) with a portion of the liquid that has passed through the load, to achieve the target load input temperature for the liquid. A recirculation pump may be used to return a portion of the liquid exiting the load for mixing with the fresh supply liquid and a control valve may be used to adjust the ratio of fresh supply liquid and recirculated liquid to achieve the targeted temperature. The control systems can be compatible with a variety of liquid supply systems such as two- and four-pipe systems.

A method and system for providing an interactive learning heating schedule for a water boiler system, the method including the steps: (a) receiving an estimate of an amount of available hot water in a water boiler of the water boiler system; (b) receiving usage data for the water boiler system, the usage data including at least one expected usage pattern extrapolated from the usage data; and (c) generating a heating schedule for the water boiler, based on at least one expected usage pattern and the estimated amount of available hot water.

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.

A hybrid water heater incudes a storage tank, a first temperature sensor, a tankless heater fluidly coupled to the storage tank, and a controller configured to determine a target output temperature range for the tankless heater based on a temperature setpoint, measure a temperature of hot water stored in an upper portion of the storage tank using the first temperature sensor, determine whether the measured temperature of the hot water is less than a first minimum temperature setpoint, generate an adjusted target output temperature range for the tankless heater based on a determination that the measured temperature is less than the first minimum temperature by increasing a value of both the lower threshold and the upper threshold, and control the tankless heater to produce the heated water according to the adjusted target output temperature range.

A hybrid water heater incudes a storage tank, a first temperature sensor, a tankless heater fluidly coupled to the storage tank, and a controller configured to determine a target output temperature range for the tankless heater based on a temperature setpoint, measure a temperature of hot water stored in an upper portion of the storage tank using the first temperature sensor, determine whether the measured temperature of the hot water is less than a first minimum temperature setpoint, generate an adjusted target output temperature range for the tankless heater based on a determination that the measured temperature is less than the first minimum temperature by increasing a value of both the lower threshold and the upper threshold, and control the tankless heater to produce the heated water according to the adjusted target output temperature range.

A method of heating water in a water storage tank. The method includes: selecting an outlet port and an inlet port from at least three ports located in the tank at different heights along a vertical direction. The outlet port is below the inlet port. The method further includes extracting water from the outlet port, supplying the extracted water to an external heat exchanger configured for heating the extracted water, and delivering heated water from the heat exchanger to the selected inlet port.