# US 7,744,008 B2 · System and method for reducing energy consumption by controlling a water heater and HVAC system via a thermostat and thermostat for use therewith > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 7,744,008 B2 - Document ID: US7744008B2 - Status: Granted - Kind: B2 - Application number: 11/031,255 - Filed: 2005-01-06 - Published: 2005-07-14 - Granted: 2010-06-29 - Earliest claimed: 2004-01-08 - Assignees: Robertshaw Controls Company - Inventors: John Gilman Chapman, Jr.; Nicholas Ashworth; Robert Burt; Timothy E. Wallaert - Web page: https://patentgrep.com/patent/US7744008B2 ## CPC - G05D 23/1904: {variable in time} - F24H 9/2007: {for water heaters} - F24H 15/104: Inspection; Diagnosis; Trial operation - F24H 15/156: Reducing the quantity of energy consumed; Increasing efficiency - F24H 15/172: Scheduling based on user demand, e.g. determining starting point of heating - F24H 15/174: Supplying heated water with desired temperature or desired range of temperature - F24H 15/269: Time, e.g. hour or date - F24H 15/281: Input from user - F24H 15/395: Information to users, e.g. alarms - F24H 15/45: remotely accessible - G05D: SYSTEMS FOR CONTROLLING OR REGULATING NON-ELECTRIC VARIABLES - F24H: FLUID HEATERS, e.g. WATER OR AIR HEATERS, HAVING HEAT-GENERATING MEANS, e.g. HEAT PUMPS, IN GENERAL (steam generation F22) ## Abstract The system of the present invention provides energy saving control for a water heater via an intelligent thermostat. This intelligent thermostat provides programmatic control over the HVAC system as is conventional, and provides coordinated control over the water heater temperature set point. This control over the water heater is accomplished via a communications network between the intelligent thermostat and the water heater. In one embodiment the communications are wireless, although wired and network bus communications may also be utilized. Enhanced and coordinated control is also provided so that different operational temperature cycles can be provided to coordinate with the intelligent thermostat's programmatic control of the HVAC system. Separate programmatic control of the water heater is also provided whereby different operational temperature modes may be commanded, e.g. Wake, Sleep, and Demand modes of operation. ## Claims ### Claim 1 A system for reducing energy consumption, comprising: a hot water heater having a storage tank, a heating element and an electronic controller operable to regulate a temperature of water within the storage tank; and an intelligent thermostat remotely located from the hot water heater for controlling a dwelling's heating, ventilating and air conditioning (HVAC) system, the intelligent thermostat operably coupled to the electronic controller of the hot water heater for communications therewith to control a temperature set point thereof; wherein the intelligent thermostat is configured to provide a user selectable HVAC vacation mode setting for the HVAC system, and wherein the intelligent thermostat transmits a hot water heater vacation mode control signal to the electronic controller of the hot water heater when the user selectable HVAC vacation mode has been selected to initiate a hot water heater vacation mode within the electronic controller. ### Claim 2 (depends on 1) The system of claim 1, wherein the intelligent thermostat transmits a cancel hot water heater vacation mode control signal to the electronic controller of the hot water heater when the user selectable HVAC vacation mode has been deselected to cancel the hot water heater vacation mode. ### Claim 3 (depends on 1) The system of claim 1, wherein the intelligent thermostat is operably coupled to the electronic controller of the hot water heater for communications via a wired communications channel. ### Claim 4 (depends on 1) The system of claim 1, wherein the intelligent thermostat is operably coupled to the electronic controller of the hot water heater for communications via a wireless communications channel. ### Claim 5 A system for reducing energy consumption, comprising: a hot water heater having a storage tank, a heating element and an electronic controller operable to regulate a temperature of water within the storage tank; an intelligent thermostat remotely located from the hot water heater for controlling a dwelling's heating, ventilating and air conditioning (HVAC) system, the intelligent thermostat operably coupled to the electronic controller of the hot water heater for communications therewith to control a temperature set point thereof; and wherein the intelligent thermostat includes a user display screen, and wherein the intelligent thermostat is configured to display a hot water heater set mode menu on the user display screen, the hot water heater set mode menu including a user selectable programming setting and a user selectable hot water heater vacation mode setting. ### Claim 6 (depends on 5) The system of claim 5, wherein the intelligent thermostat transmits a hot water heater vacation mode control signal to the electronic controller of the hot water heater when the user selectable hot water heater vacation mode has been selected from the hot water heater set mode menu to initiate a hot water heater vacation mode within the electronic controller. ### Claim 7 (depends on 5) The system of claim 5, wherein the intelligent thermostat displays a hot water heater programming menu when the user selectable programming setting is selected by a user to allow a user to program different operating modes for the hot water heater. ### Claim 8 (depends on 7) The system of claim 7, wherein the operating modes provided by the intelligent thermostat comprise a wake mode, a sleep mode, and a demand mode. ### Claim 9 (depends on 8) The system of claim 8, wherein the intelligent thermostat provides programmability of at least one of temperature set point, time of day, tolerance band, and temperature differential for each of the operating modes. ### Claim 10 (depends on 8) The system of claim 8, wherein the intelligent thermostat is configured to transmit a control signal to the electronic controller to adjust hot water heater control parameters therein for each of the operating modes. ### Claim 11 A thermostat for controlling a dwelling's heating, ventilating and air conditioning (HVAC) system, the dwelling having installed therein a hot water heater having an electronic controller operable to control a temperature of water held therein, the thermostat comprising: a user interface display; and a means for communicating with the electronic controller of the hot water heater; wherein the thermostat is configured to transmit temperature control information to the electronic controller of the hot water heater to override a temperature setpoint thereof; and wherein the thermostat is configured to transmit a hot water heater vacation mode control signal to the electronic controller of the hot water heater to initiate a hot water heater vacation mode within the electronic controller. ### Claim 12 (depends on 11) The thermostat of claim 11, wherein the thermostat is configured to display a set mode screen having a user selectable hot water heater vacation mode entry, and wherein the thermostat transmits the hot water heater vacation mode control signal to the electronic controller of the hot water heater when the user selectable hot water heater vacation mode has been selected. ### Claim 13 (depends on 11) The thermostat of claim 11, wherein the thermostat is configured to display a hot water heater programming menu to allow a user to program different operating modes for the hot water heater. ### Claim 14 (depends on 13) The thermostat of claim 13, wherein the operating modes provided by the thermostat comprise a wake mode, a sleep mode, and a demand mode. ### Claim 15 (depends on 14) The thermostat of claim 14, wherein the thermostat provides programmability of at least one of temperature set point, time of day, tolerance band, and temperature differential for each of the operating modes. ### Claim 16 (depends on 14) The thermostat of claim 14, wherein the thermostat is configured to transmit a control signal to the electronic controller to adjust hot water heater control parameters therein for each of the operating modes. ### Claim 17 A thermostat for controlling a dwelling's heating, ventilating and air conditioning (HVAC) system, the dwelling having installed therein a hot water heater having an electronic controller operable to control a temperature of water held therein, the thermostat comprising: a user interface display; and a means for communicating with the electronic controller of the hot water heater; and wherein the thermostat is configured to transmit temperature control information to the electronic controller of the hot water heater to override a temperature setpoint thereof; wherein the thermostat is configured to transmit a hot water heater vacation mode control signal to the electronic controller of the hot water heater; wherein the thermostat is configured to provide a user selectable HVAC vacation mode setting for the HVAC system; and wherein the thermostat transmits the hot water heater vacation mode control signal to the electronic controller of the hot water heater when the user selectable HVAC vacation mode has been selected. ### Claim 18 A method of reducing energy consumption of a hot water heater, comprising the steps of: receiving by a thermostat a user input selecting a vacation mode of operation for a dwelling's heating, ventilating and air conditioning (HVAC) system; transmitting by the thermostat a hot water heater vacation mode control signal to an electronic controller of a hot water heater to initiate a hot water heater vacation mode of operation controlled by the electronic controller of the hot water heater.