# US 2019/0170398 A1 · Tank-Based and Tankless Water Heater Systems > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2019/0170398 A1 - Document ID: US20190170398A1 - Status: Published application - Kind: A1 - Application number: 15/830,552 - Filed: 2017-12-04 - Published: 2019-06-06 - Earliest claimed: 2017-12-04 - Assignees: Rheem Manufacturing Company - Applicants: Rheem Manufacturing Company - Inventors: Raheel A. Chaudhry; David I. Vega; Michael C. Mitchell - Web page: https://patentgrep.com/patent/US20190170398A1 ## CPC - F24H 9/2007: {for water heaters} - F24D 19/1051: {for domestic hot water} - F24H 1/22: Water heaters other than continuous-flow or water-storage heaters, e.g. water heaters for central heating - F24H 9/13: for water heaters - F24H 9/2028: {Continuous-flow heaters} - F24H 15/238: Flow rate - F24H 15/31: of valves having only one inlet port and one outlet port, e.g. flow rate regulating valves - F24H 15/37: of electric heaters - F24H 15/443: using a central controller connected to several sub-controllers - G05B 15/02: electric - G05D 23/19: characterised by the use of electric means {(G05D23/1393 takes precedence)} - G05D 23/1919: {characterised by the type of controller} - F24H 1/202: {with resistances} - F24H 15/108: Resuming operation, e.g. after power outages - F24H 15/12: Preventing or detecting fluid leakage - F24H 15/156: Reducing the quantity of energy consumed; Increasing efficiency - F24H 15/20: characterised by control inputs - F24H 15/215: before heating - F24H 15/225: at different heights of the tank - F24H 15/235: Temperature of exhaust gases - F24H 15/242: Pressure - F24H 15/395: Information to users, e.g. alarms - F24H 15/421: using pre-stored data - F24H 15/45: remotely accessible - F24H 15/486: using timers - F24H: FLUID HEATERS, e.g. WATER OR AIR HEATERS, HAVING HEAT-GENERATING MEANS, e.g. HEAT PUMPS, IN GENERAL (steam generation F22) - F24D: DOMESTIC- OR SPACE-HEATING SYSTEMS, e.g. CENTRAL HEATING SYSTEMS; DOMESTIC HOT-WATER SUPPLY SYSTEMS; ELEMENTS OR COMPONENTS THEREFOR (using steam or condensate extracted or exhausted from steam engine plants for heating purposes F01K17/02) - G05B: CONTROL OR REGULATING SYSTEMS IN GENERAL; FUNCTIONAL ELEMENTS OF SUCH SYSTEMS; MONITORING OR TESTING ARRANGEMENTS FOR SUCH SYSTEMS OR ELEMENTS (systems for controlling or regulating non-electric variables G05D; systems for regulating electric or magnetic variables G05F; control devices or systems insofar as characterised by mechanical features only G05G) - G05D: SYSTEMS FOR CONTROLLING OR REGULATING NON-ELECTRIC VARIABLES ## Abstract 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. ## Claims ### Claim 1 A water heating system, comprising: a first tank-based water heater comprising a first tank, a first heating system, a first inlet line, and a first outlet line, wherein the first inlet line provides unheated water to the first tank, and wherein the first outlet line draws heated water from the first tank; a first tankless water heater comprising a second heating system, a second inlet line, and a second outlet line, wherein the second outlet line of the first tankless water heater provides the heated water to a first heated water demand; a first valve that controls an amount of the unheated water flowing through the first inlet line to the first tank-based water heater; and a controller operatively coupled to the first valve, wherein the controller controls a position of the first valve to regulate the amount of unheated water flowing to the first tank-based water heater, wherein the position of the first valve is based on the first heated water demand and a first capacity of the first tankless water heater. ### Claim 2 (depends on 1) The system of claim 1, wherein the controller is part of the first tank-based water heater, wherein the controller is communicably coupled to a first local controller of the first tankless water heater, wherein the first local controller communicates the first heated water demand and the first capacity of the first tankless water heater to the controller. ### Claim 3 (depends on 1) The system of claim 1, wherein the first outlet line of the first tank-based water heater is coupled to the second inlet line of the first tankless water heater. ### Claim 4 (depends on 1) The system of claim 1, wherein the first outlet line of the first tank-based water heater is coupled to the first heated water demand, and wherein the second outlet line of the first tankless water heater is further coupled to the first heated water demand. ### Claim 5 (depends on 1) The system of claim 1, further comprising: a second tankless water heater comprising a third heating system, a third inlet line, and a third outlet line, wherein the third outlet line of the second tankless water heater provides the heated water to a second heated water demand. ### Claim 6 (depends on 5) The system of claim 5, wherein the first outlet line of the first tank-based water heater is coupled to the third inlet line of the second tankless water heater. ### Claim 7 (depends on 5) The system of claim 5, wherein the first outlet line of the first tank-based water heater is further coupled to the second heated water demand, and wherein the third outlet line of the second tankless water heater is further coupled to the second heated water demand. ### Claim 8 (depends on 5) The system of claim 5, wherein the controller acts a master controller that is communicably coupled to a first local controller of the first tankless water heater and a second local controller of the second tankless water heater. ### Claim 9 (depends on 8) The system of claim 8, wherein the master controller activates the first tank-based water heater when the master controller determines that the first heated water demand exceeds the first capacity of the first tankless water heater. ### Claim 10 (depends on 9) The system of claim 9, wherein the first local controller acts as the master controller prior to when the first tank-based water heater is activated. ### Claim 11 (depends on 8) The system of claim 8, wherein the master controller activates the first tank-based water heater for a first period of time, and wherein the master controller activates a second tank-based water heater for a second period of time when the first period of time has expired. ### Claim 12 (depends on 1) The system of claim 1, further comprising: a second tank-based water heater comprising a third heating system, a third inlet line, and a third outlet line; a second flow meter that measures the unheated water flowing through the third inlet line to the second tank-based water heater; and a second valve that controls an additional amount of the unheated water flowing through the third inlet line to the second tank-based water heater, where the second valve is adjusted by the controller based on the first heated water demand, the position of the first valve, the first capacity of the first tankless water heater, and historical usage data for the first tankless water heater. ### Claim 13 (depends on 1) The system of claim 1, further comprising: a first flow meter coupled to the controller, wherein the first flow meter measures the unheated water flowing through the first inlet line to the first tank-based water heater. ### Claim 14 A controller, comprising: a control engine that is configured to: receive a request from a heated water demand; evaluate the request from the heated water demand relative to a first capacity of heated water of a first tankless water heater; determine that the first capacity is insufficient to satisfy the request; activate a first tank-based water heater to supply an additional heated water quantity to supplement the first capacity of the heated water provided by the first tankless water heater, wherein the control engine activates the first tank-based water heater, in part, by adjusting a first valve to control a first flow of unheated water into the first tank-based water heater. ### Claim 15 (depends on 14) The controller of claim 14, wherein the control engine is further configured to: activate a second tank-based water heater to supply more additional heated water quantity to supplement the first capacity of the heated water provided by the first tankless water heater and the additional heated water quantity provided by the first tank-based water heater, wherein the control engine activates the second tank-based water heater, in part, by adjusting a second valve to control a second flow of unheated water into the second tank-based water heater. ### Claim 16 (depends on 14) The controller of claim 14, further comprising: memory that stores a plurality of instructions; and a hardware processor coupled to the control engine, wherein the hardware processor executes the plurality of instructions to perform functions of the control engine. ### Claim 17 A non-transitory computer-readable medium comprising instructions that, when executed by a hardware processor, perform a method for providing heated water to a heated water demand, the method comprising: receiving a request for heated water from the heated water demand; evaluating a plurality of water heaters in a water heater system; and adjusting an operation of at least one water heater of the plurality of water heaters to satisfy the heated water demand, wherein adjusting the operation comprises adjusting a flow valve for water flowing to a tank-based water heater of the plurality of water heaters. ### Claim 18 (depends on 17) The non-transitory computer-readable medium of claim 17, further comprising: designating a first local controller of a water heater in the water heating system as a master controller that controls a remainder of local controllers of a plurality of local controllers in the water heater system. ### Claim 19 (depends on 18) The non-transitory computer-readable medium of claim 18, wherein a second local controller is designated as the master controller based on adjusting the operation of the at least one water heater based on historical usage data for the plurality of water heaters. ### Claim 20 (depends on 19) The non-transitory computer-readable medium of claim 19, wherein the second local controller is among the remainder of local controllers, wherein the second local controller is part of a supplemental water heater that is activated when adjusting the operation.