Abstract: A controller for a tankless water heater is programmed to perform a descaling procedure that includes: closing a bypass valve to prevent fluid from bypassing a heat exchanger of the tankless water heater; activating a pump to cause a descaling solution to circulate through the tankless water heater; monitoring a flow rate of the descaling solution; and deactivating the pump responsive to one of: i) an amount of time that the pump is active exceeding a time limit, ii) the flow rate exceeding a first threshold, or iii) a change in the flow rate exceeding a second threshold.

Abstract: A vent attachment facilitates attaching a coaxial air intake and exhaust vent of a tankless water heater to a Category I vent, such as B-vent. The vent attachment comprises a first end with a coaxial connector comprising a central exhaust pathway and a circumferential air intake pathway. The vent attachment also comprises a second end with a tubular exhaust vent connector in fluid communication with the central exhaust pathway. The vent attachment further comprises a frame that encloses the central exhaust pathway and comprises a mesh configured to provide fluid communication through the frame with the air intake pathway. Additionally, operation of the tankless water heater is modified to ensure that the exhaust generated is suitable for venting through a Category I vent. The tankless water heater maintains a high fuel consumption rate such that the temperature of hot water produced increases throughout each of a plurality of burner stages.

Abstract: 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.

Abstract: 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).

Abstract: A hot water circulation system comprises a water heater having a cold-water inlet and a hot water outlet. A water pump circulates water through the water heater to produce hot water. The hot water is circulated to a thermal bypass valve, which is configured to close when hot water contacts a heat activated seal. A bypass circuit is coupled between the hot water outlet and the cold water inlet of the water heater. The bypass circuit prevents hot water from circulating from the hot water outlet to the cold-water inlet when the thermal bypass valve is open and promotes circulating hot water from the hot water outlet to the cold water inlet when the thermal bypass valve is closed. Upon a temperature sensor sensing hot water entering the cold-water inlet, the water heater turns of the water pump.

Abstract: A water heater system includes a water heater rack system with a plurality of vertically stacked tankless water heaters and a water heater storage tank and provides the ability to install a water heater in environments where horizontally oriented heater rack systems would not fit. The tankless water heaters comprise a bifurcated vent arrangement with separate intake and exhaust vents. Accordingly, vent pipes of diameters of two (2) inches or less may be used in comparison to coaxial vent arrangements which may have diameters of three inches or more. The smaller vent pipe diameter allows a plurality of water heaters to be stacked, one above the other, such that the water heater rack system has a maximum height of 76 inches or less. This vertical orientation may allow tankless water heaters to be installed in an environment where a horizontally configured plurality of tankless water heaters would not fit.

Abstract: Various implementations include a water heater system. The system includes a variable speed pump. The variable speed pump has having an inlet and an outlet. The system includes a heat exchanger, having an inlet and an outlet. The heat exchanger outlet is fluidically connected to the variable speed pump inlet. The system includes an output temperature sensor disposed downstream of the heat exchanger outlet. The system includes a controller configured to receive a first temperature reading from the output temperature sensor. The controller is configured to control operation of the variable speed pump to adjust an output flow rate in response to the first temperature reading. The controller is further configured to receive a second temperature reading from a recovery temperature sensor on a storage tank. The controller is configured to turn off the variable speed pump upon a determination that the second temperature reading has reached a maximum temperature.

Abstract: Various implementations include a hot water heating system having a spine and two or more water heating units. The spine includes a top surface defining one or more top openings, two or more coupling areas, and cold water, hot water, and fuel manifolds. One or more top openings provide access to a cold water manifold inlet, a hot water manifold outlet, and a fuel manifold inlet. At least one of the coupling areas is located above another coupling area when the spine is oriented with the top surface facing upwardly. The water heating units are coupled to coupling areas such that a cold water inlet of the unit is fluidically coupled to the cold water manifold outlet, a hot water outlet of the unit is fluidically coupled to the hot water manifold inlet, and a fuel inlet of the unit is fluidically coupled to the fuel manifold outlet.

Abstract: 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.

Abstract: A hybrid tank and tankless hot water system with an inlet bypass and an outlet bypass are configurable between a hybrid heater configuration and an on-demand configuration. In the hybrid heater configuration, the inlet bypass supplies cold water to a cold water inlet of a storage tank and the outlet bypass supplies hot water from an outlet manifold to a recirculation inlet of the storage tank. In an on-demand configuration, the inlet bypass supplies cold water to a cold water manifold for directly providing cold water to hot water heaters and the outlet bypass supplies hot water from the outlet manifold directly to a system hot water outlet. In the bypass configuration, a storage tank and/or recirculation pump are fluidically isolated from one or more hot water heaters to facilitate their maintenance, repair, replacement while still supplying hot water on demand from the hot water heaters.

Abstract: To facilitate a wall-mounted installation of multi-unit water heaters in a location with limited clear wall space, spacer brackets may be installed on the wall to extend a mounting surface away from a plane of the wall. A mounting bracket may be attached to the mounting surface of the spacer brackets. To reduce installation time and costs, a plurality of water heaters may be affixed to a frame prior to installation. A hot water, cold water, and fuel supply manifolds may be coupled to each hot water outlet, cold water inlet, and fuel supply inlet, respectively, of the plurality of water heaters. The mounting bracket comprises a mounting shelf configured to receive the frame, thereby securing the multi-unit water heater system to the wall. The multi-unit water heating system, the spacer brackets, and the mounting bracket may be provided as a kit.

Abstract: A hot water circulation system comprises a water heater having a cold-water inlet and a hot water outlet. A water pump circulates water through the water heater to produce hot water. The hot water is circulated to a thermal bypass valve, which is configured to close when hot water contacts a heat activated seal. A bypass circuit is coupled between the hot water outlet and the cold water inlet of the water heater. The bypass circuit prevents hot water from circulating from the hot water outlet to the cold-water inlet when the thermal bypass valve is open and promotes circulating hot water from the hot water outlet to the cold water inlet when the thermal bypass valve is closed. Upon a temperature sensor sensing hot water entering the cold-water inlet, the water heater turns of the water pump.

Abstract: A vent attachment facilitates attaching a coaxial air intake and exhaust vent of a tankless water heater to a Category I vent, such as B-vent. The vent attachment comprises a first end with a coaxial connector comprising a central exhaust pathway and a circumferential air intake pathway. The vent attachment also comprises a second end with a tubular exhaust vent connector in fluid communication with the central exhaust pathway. The vent attachment further comprises a frame that encloses the central exhaust pathway and comprises a mesh configured to provide fluid communication through the frame with the air intake pathway. Additionally, operation of the tankless water heater is modified to ensure that the exhaust generated is suitable for venting through a Category I vent. The tankless water heater maintains a high fuel consumption rate such that the temperature of hot water produced increases throughout each of a plurality of burner stages.

Abstract: An offset mounting bracket that comprises a primary member and a stabilization member can be used to mount multiple heat engines to a water storage tank. An offset mounting bracket can include a primary member, having a top surface, a bottom surface, an inner surface, and an outer surface. The offset mounting bracket can also have a stabilization member, having a top surface and a bottom surface, a supporting surface that is opposed and connected to the primary member outer surface. The offset mounting bracket can also have a connecting member. The connecting member can be configured to fasten to the top of a water storage tank. There, the offset mounting bracket, can provide a surface to mount a heat engine that otherwise would not fit onto the water storage tank structure.

Abstract: 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.

Abstract: A hot water supply system decouples an intelligent hot water storage system from a water heating engine system. The water heating engine system includes a plurality of instantaneous water heaters that provide for redundant operation for improved reliability. The intelligent hot water storage system includes a storage tank that encloses a volume for storage of water. The intelligent hot water storage system includes a recirculation loop driven by an integrated pump and operated by an integrated controller. By positioning the tank recirculation outlet and inlet farther apart from each other, additional usable volume of hot water is provided by the intelligent hot water storage system. Isolation valves positioned on the input and output of a recirculation pump in the recirculation loop facilitate repair or replacement of the recirculation pump. The hot water system provides for increased capacity while providing redundant heating engines in a smaller floor space than conventional systems.

Abstract: A hot water supply system decouples an intelligent hot water storage system from a water heating engine system. The water heating engine system includes a plurality of instantaneous water heaters that provide for redundant operation for improved reliability. The intelligent hot water storage system includes a storage tank that encloses a volume for storage of water. The intelligent hot water storage system includes a recirculation loop driven by an integrated pump and operated by an integrated controller. By positioning the tank recirculation outlet and inlet farther apart from each other, additional usable volume of hot water is provided by the intelligent hot water storage system. Isolation valves positioned on the input and output of a recirculation pump in the recirculation loop facilitate repair or replacement of the recirculation pump. The hot water system provides for increased capacity while providing redundant heating engines in a smaller floor space than conventional systems.