Patent Publication Number: US-2018051911-A1

Title: Water heater appliance

Description:
FIELD OF THE INVENTION 
     The present subject matter relates generally to water heater appliances, and more particularly, to mixing valve and plumbing configurations for water heater appliances. 
     BACKGROUND OF THE INVENTION 
     Certain water heater appliances include a tank therein. Heating elements, such as gas burners, electric resistance elements, or sealed systems, heat water within the tank during operation of such water heater appliances. In particular, the heating elements generally heat water within the tank to a predetermined temperature. The predetermined temperature is generally selected such that heated water within the tank is suitable for showering, washing hands, etc. 
     During operation, relatively cool water flows into the tank, and the heating elements operate to heat such water to the predetermined temperature. Thus, the volume of heated water available at the predetermined temperature is generally limited to the volume of the tank. Accordingly, water heater appliances are sold in various sizes to permit consumers to select a proper tank volume and provide sufficient heated water. However, large water heater appliances with large tanks occupy large amount of space within a residence or business. In certain buildings, space is limited and/or expensive. Thus, utilizing large water heater appliances can be impractical and/or prohibitively expensive despite needing large volumes of heated water. 
     To provide relatively large volumes of heated water from relatively small tanks, certain water heater appliances utilize a mixing valve. The mixing valve permits water within the water heater&#39;s tank to be stored at relatively high temperatures. The mixing valve mixes such high temperature water with relatively cool water in order to bring the temperature of such water down to suitable and/or more usable temperatures. Thus, such water heater appliance can provide relatively large volumes of heated water without requiring large tanks. 
     Many conventional water heater appliances have hot and cold water conduits that extend from a side of the water heater appliance to connect to a mixing valve. Fluidly coupling conventional mixing valves with such side mounted water conduits often requires rerouting the plumbing and/or reorienting the mixing valve. Such plumbing adjustments require additional parts and labor, thus increasing maintenance and repair times and costs. Furthermore, additional space adjacent the water heater appliance may be required to accommodate the additional plumbing. 
     Accordingly, a water heater appliance having a mixing valve that includes features for simplifying installation into the water heater appliance would be useful. More specifically, a water heater appliance having a mixing valve that includes water inlet conduits that align with existing water heater conduits would be particularly beneficial. 
     BRIEF DESCRIPTION OF THE INVENTION 
     The present subject matter provides a water heater appliance defining a vertical direction and a horizontal direction. The water heater appliance includes a side that extends along the vertical direction between a top and a bottom of the water heater appliance. The water heater appliance includes a heated water conduit and a cold water conduit extending from the side substantially along the horizontal direction. A mixing valve has a heated water inlet that shares a common axis with the heated water conduit. A bypass conduit extends substantially along the vertical direction between the cold water conduit and a cold water inlet to the mixing valve. In this manner, the mixing valve may be quickly and easily interchangeable within the water heater appliance without requiring the rerouting or manipulation of the existing plumbing. Additional aspects and advantages of the invention will be set forth in part in the following description, or may be apparent from the description, or may be learned through practice of the invention. 
     In a first exemplary embodiment, a water heater appliance defining an axial direction and a radial direction is provided. The water heater appliance includes a casing and a tank disposed within the casing. The tank defines an interior volume and includes a side that extends along the axial direction between a top of the tank and a bottom of the tank. A cold water conduit extends from the side of the tank substantially along the radial direction, the cold water conduit being configured for directing water into the interior volume of the tank. A heated water conduit extends from the side of the tank substantially along the radial direction, the heated water conduit being configured for directing water out of the interior volume of the tank. A bypass conduit extends from the cold water conduit. A mixing valve includes a heated water inlet fluidly coupled to the heated water conduit and a cold water inlet fluidly coupled to the bypass conduit, the mixing valve being configured for selectively mixing water from the heated water conduit and water from the bypass conduit to provide mixed water to a mixed water conduit, the heated water inlet sharing a common axis with the heated water conduit. 
     In a second exemplary embodiment, a mixing valve for a water heater appliance is provided. The water heater appliance defines a vertical direction and a horizontal direction and includes a cold water conduit and a heated water conduit extending along the horizontal direction. The mixing valve includes a valve body defining a heated water inlet, a cold water inlet, and a mixed water outlet, the heated water inlet extending along the horizontal direction and sharing a common axis with the heated water conduit, and the cold water inlet extending perpendicular to the heated water inlet. 
     In a third exemplary embodiment, a water heater appliance defining a vertical direction and a horizontal direction is provided. The water heater appliance includes a tank including a side that extends along the vertical direction between a top of the tank and a bottom of the tank. A cold water conduit extends from the side of the tank along a first axis, a heated water conduit extends from the side of the tank along a second axis, and a bypass conduit extends from the cold water conduit. A mixing valve includes a heated water inlet, a cold water inlet, and a mixed water outlet, the heated water inlet extending along the second axis. 
     These and other features, aspects and advantages of the present invention will become better understood with reference to the following description and appended claims. The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments of the invention and, together with the description, serve to explain the principles of the invention. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       A full and enabling disclosure of the present invention, including the best mode thereof, directed to one of ordinary skill in the art, is set forth in the specification, which makes reference to the appended figures. 
         FIG. 1  provides a perspective view of a water heater appliance according to an exemplary embodiment of the present subject matter. 
         FIG. 2  provides a schematic view of certain components of the exemplary water heater appliance of  FIG. 1  and an electronic mixing valve according to an exemplary embodiment of the present subject matter. 
     
    
    
     DETAILED DESCRIPTION 
     Reference now will be made in detail to embodiments of the invention, one or more examples of which are illustrated in the drawings. Each example is provided by way of explanation of the invention, not limitation of the invention. In fact, it will be apparent to those skilled in the art that various modifications and variations can be made in the present invention without departing from the scope or spirit of the invention. For instance, features illustrated or described as part of one embodiment can be used with another embodiment to yield a still further embodiment. Thus, it is intended that the present invention covers such modifications and variations as come within the scope of the appended claims and their equivalents. 
       FIG. 1  provides a perspective view of a water heater appliance  100  according to an exemplary embodiment of the present subject matter.  FIG. 2  provides a schematic view of certain components of water heater appliance  100  including an exemplary mixing valve  102 , as will be described in detail below. As may be seen in  FIGS. 1 and 2 , water heater appliance  100  includes a casing  104  and a tank  106  mounted within casing  104 . 
     As may be seen in  FIG. 1 , water heater appliance  100  generally defines an axial direction A and a radial direction R. According to the illustrated exemplary embodiment, when water heater appliance is installed, the axial direction A corresponds to a vertical direction V and the radial direction R corresponds to a horizontal direction H. Thus, water heater appliance  100  is generally vertically oriented. Water heater appliance  100  can be leveled, e.g., such that casing  104  is plumb in the vertical direction V, in order to facilitate proper operation of water heater appliance  100 . 
     Casing  104  extends between a top portion  108  and a bottom portion  110  along a vertical direction V. A drain pan  112  is positioned at bottom portion  110  of water heater appliance  100  such that water heater appliance  100  sits on drain pan  112 . Drain pan  112  sits beneath water heater appliance  100  along the vertical direction V, e.g., to collect water that leaks from water heater appliance  100  or water that condenses on an evaporator  138  (discussed below) of water heater appliance  100 . It should be understood that water heater appliance  100  is provided by way of example only and that the present subject matter may be used with any suitable water heater appliance. 
     Turning now to  FIG. 2 , tank  106  includes a side wall  114  that extends along the axial direction A between a top portion  116  and a bottom portion  118  of tank  106 . According to the illustrated embodiment, tank  106  is cylindrically shaped. However, it should be appreciated that tank  106  could be any suitable shape, such as rectangular, elliptical, etc. Tank  106  generally defines an interior volume  120  for heating water therein. Water heater appliance  100  also includes a cold water conduit  122  and a heated water conduit  124  that are both in fluid communication with tank  120  within casing  104 . As an example, cold water from a water source, e.g., a municipal water supply or a well, enters water heater appliance  100  through cold water conduit  122 . From cold water conduit  122 , such cold water enters interior volume  120  of tank  106  wherein the water is heated to generate heated water. Such heated water exits water heater appliance  100  at heated water conduit  124  and, e.g., is supplied to a bath, shower, sink, or any other suitable feature. 
     As may be seen in  FIG. 2 , cold water conduit  122  is mounted to tank  106  at or adjacent bottom portion  118  of tank  106 . In addition, heated water conduit  124  is mounted to tank  106  at or adjacent top portion  116  of tank  106 . Thus, cold water conduit  122  and heated water conduit  124  are spaced apart from each other on tank  106 , e.g., along the vertical direction V. Cold water conduit  122  and heated water conduit  124  extend from side wall  114  of tank  106 . For this reason, water heater appliance  100  may be referred to as a “side-mounted” water heater. It should be appreciated, however, that aspects of the present subject matter may apply to any suitable water heater appliance. 
     Water heater appliance  100  includes an upper heating element  126 , a lower heating element  128  and a sealed system  130  for heating water within interior volume  120  of tank  106 . Thus, water heater appliance  100  is commonly referred to as a “heat pump water heater appliance.” Upper and lower heating elements  126  and  128  can be any suitable heating elements. For example, upper heating element  126  and/or lower heating element  128  may be an electric resistance element, a microwave element, an induction element, or any other suitable heating element or combination thereof. Lower heating element  126  may also be a gas burner. 
     Sealed system  130  includes a compressor  132 , a condenser  134 , a throttling device  136  and an evaporator  138 . Condenser  134  is thermally coupled or assembled in a heat exchange relationship with tank  106  in order to heat water within interior volume  120  of tank  106  during operation of sealed system  130 . In particular, condenser  134  may be a conduit coiled around and mounted to tank  106 . During operation of sealed system  130 , refrigerant exits evaporator  138  as a fluid in the form of a superheated vapor and/or high quality vapor mixture. Upon exiting evaporator  138 , the refrigerant enters compressor  132  wherein the pressure and temperature of the refrigerant are increased such that the refrigerant becomes a superheated vapor. The superheated vapor from compressor  132  enters condenser  134  wherein it transfers energy to the water within tank  106  and condenses into a saturated liquid and/or high quality liquid vapor mixture. This high quality/saturated liquid vapor mixture exits condenser  134  and travels through throttling device  136  that is configured for regulating a flow rate of refrigerant therethrough. Upon exiting throttling device  136 , the pressure and temperature of the refrigerant drop at which time the refrigerant enters evaporator  138  and the cycle repeats itself. In certain exemplary embodiments, throttling device  136  may be an electronic expansion valve (EEV). 
     A fan or air handler  140  may assist with heat transfer between air about water heater appliance  100 , e.g., within casing  104 , and refrigerant within evaporator  138 . Air handler  140  may be positioned within casing  104  on or adjacent evaporator  138 . Thus, when activated, air handler  140  may direct a flow of air towards or across evaporator  138 , and the flow of air from air handler  140  may assist with heating refrigerant within evaporator  138 . Air handler  140  may be any suitable type of air handler, such as an axial or centrifugal fan. 
     Water heater appliance  100  also includes a tank temperature sensor  150 . Tank temperature sensor  150  is configured for measuring a temperature of water within interior volume  120  of tank  106 . Tank temperature sensor  150  can be positioned at any suitable location within or on water heater appliance  100 . For example, tank temperature sensor  150  may be positioned within interior volume  120  of tank  106  or may be mounted to tank  106  outside of interior volume  120  of tank  106 . When mounted to tank  106  outside of interior volume  120  of tank  106 , tank temperature sensor  150  can be configured for indirectly measuring the temperature of water within interior volume  120  of tank  106 . For example, tank temperature sensor  150  can measure the temperature of tank  106  and correlate the temperature of tank  106  to the temperature of water within interior volume  120  of tank  106 . Tank temperature sensor  150  may also be positioned at or adjacent top portion  116  of tank  106 , e.g., at or adjacent an inlet of heated water conduit  124 . 
     Tank temperature sensor  150  can be any suitable temperature sensor. For example, tank temperature sensor  150  may be a thermocouple or a thermistor. As may be seen in  FIG. 2 , tank temperature sensor  150  may be the only temperature sensor positioned at or on tank  106  that is configured for measuring the temperature of water within interior volume  120  of tank  106  in certain exemplary embodiments. In alternative exemplary embodiments, additional temperature sensors may be positioned at or on tank  106  to assist tank temperature sensor  150  with measuring the temperature of water within interior volume  120  of tank  106 , e.g., at other locations within interior volume  120  of tank  106 . 
     Water heater appliance  100  also includes an ambient temperature sensor  152 , an evaporator inlet temperature sensor  154 , and an evaporator outlet temperature sensor  156 . Ambient temperature sensor  152  is configured for measuring a temperature of air about water heater appliance  100 . Ambient temperature sensor  152  can be positioned at any suitable location within or on water heater appliance  100 . For example, ambient temperature sensor  152  may be mounted to casing  104 , e.g., at or adjacent top portion  108  of water heater appliance  100 . Ambient temperature sensor  152  can be any suitable temperature sensor. For example, ambient temperature sensor  152  may be a thermocouple or a thermistor. 
     Evaporator inlet temperature sensor  154  is configured for measuring a temperature of refrigerant at or adjacent inlet of evaporator  138 . Thus, evaporator inlet temperature sensor  154  may be positioned at or adjacent inlet of evaporator  138 , as shown in  FIG. 2 . For example, evaporator inlet temperature sensor  154  may be mounted to tubing that directs refrigerant into evaporator  138 , e.g., at or adjacent inlet of evaporator  138 . When mounted to tubing, evaporator inlet temperature sensor  154  can be configured for indirectly measuring the temperature of refrigerant at inlet of evaporator  138 . For example, evaporator inlet temperature sensor  154  can measure the temperature of the tubing and correlate the temperature of the tubing to the temperature of refrigerant at inlet of evaporator  138 . Evaporator inlet temperature sensor  154  can be any suitable temperature sensor. For example, evaporator inlet temperature sensor  154  may be a thermocouple or a thermistor. 
     Evaporator outlet temperature sensor  156  is configured for measuring a temperature of refrigerant at or adjacent outlet of evaporator  138 . Thus, evaporator outlet temperature sensor  156  may be positioned at or adjacent outlet of evaporator  138 , as shown in  FIG. 2 . For example, evaporator outlet temperature sensor  156  may be mounted to tubing that directs refrigerant out of evaporator  138 , e.g., at or adjacent outlet of evaporator  138 . When mounted to tubing, evaporator outlet temperature sensor  156  can be configured for indirectly measuring the temperature of refrigerant at outlet of evaporator  138 . For example, evaporator outlet temperature sensor  156  can measure the temperature of the tubing and correlate the temperature of the tubing to the temperature of refrigerant at outlet of evaporator  138 . Evaporator outlet temperature sensor  156  can be any suitable temperature sensor. For example, evaporator outlet temperature sensor  156  may be a thermocouple or a thermistor. 
     Water heater appliance  100  further includes a controller  160  that is configured for regulating operation of water heater appliance  100 . Controller  160  is in, e.g., operative, communication with upper heating element  126 , lower heating element  128 , compressor  132 , tank temperature sensor  150 , ambient temperature sensor  152 , evaporator inlet temperature sensor  154 , evaporator outlet temperature sensor  156 , and air handler  140 . Thus, controller  160  may selectively activate upper and lower heating elements  126  and  128  and/or compressor  132  in order to heat water within interior volume  120  of tank  106 , e.g., in response to signals from tank temperature sensor  150 , ambient temperature sensor  152 , evaporator inlet temperature sensor  154 , and/or evaporator outlet temperature sensor  156 . 
     Controller  160  includes memory and one or more processing devices such as microprocessors, CPUs or the like, such as general or special purpose microprocessors operable to execute programming instructions or micro-control code associated with operation of water heater appliance  100 . The memory can represent random access memory such as DRAM, or read only memory such as ROM or FLASH. The processor executes programming instructions stored in the memory. The memory can be a separate component from the processor or can be included onboard within the processor. Alternatively, controller  160  may be constructed without using a microprocessor, e.g., using a combination of discrete analog and/or digital logic circuitry (such as switches, amplifiers, integrators, comparators, flip-flops, AND gates, and the like) to perform control functionality instead of relying upon software. 
     Controller  160  may operate upper heating element  126 , lower heating element  128  and/or compressor  132  in order to heat water within interior volume  120  of tank  106 . As an example, a user may select or establish a set temperature, t s , for water within interior volume  120  of tank  106 , or the set temperature t s  for water within interior volume  120  of tank  106  may be a default value. Based upon the set temperature t s  for water within interior volume  120  of tank  106 , controller  160  may selectively activate upper heating element  126 , lower heating element  128 , and/or compressor  132  in order to heat water within interior volume  120  of tank  106  to the set temperature t s  for water within interior volume  120  of tank  106 . The set temperature t s  for water within interior volume  120  of tank  106  may be any suitable temperature. For example, the set temperature t s  for water within interior volume  120  of tank  106  may be between about one hundred degrees Fahrenheit and about one hundred and eighty-degrees Fahrenheit. As used herein with regards to temperature approximations, the term “about” means within ten degrees of the stated temperature. 
     Referring still to  FIG. 2 , water heater appliance  100  also includes a mixing valve  102  for selectively mixing water from cold water conduit  122  and water from heated water conduit  124  to provide mixed water at the desired temperature. Mixing valve generally includes a valve body  170 , a heated water inlet  172 , a cold water inlet  174 , and a mixed water conduit  176 . Mixing valve  102  is in fluid communication with heated water conduit  124  via heated water inlet  172 . In addition, a bypass conduit  178  places cold water inlet  174  in fluid communication with cold water conduit  122 . Accordingly, heated water from interior volume  120  of tank  106  may flow into a mixing chamber of valve body  170  via heated water conduit  124 , and cold water from cold water conduit  122  may flow into the mixing chamber of valve body  170  via bypass conduit  178 . As discussed in greater detail below, mixing valve  102  is configured for selectively directing water from cold water conduit  122  and heated water conduit  124  into mixed water conduit  176  in order to regulate a temperature of water within mixed water conduit  176 . 
     As an example, mixing valve  102  can selectively adjust between a first position and a second position. In the first position, mixing valve  102  can permit a first flow rate of relatively cool water from cold water conduit  122  and a first flow rate of relatively hot water from heated water conduit  124  into mixed water conduit  176 . In such a manner, based on the ratio of hot and cold water, the mixed water within mixed water conduit  176  can have a first particular temperature when mixing valve  102  is in the first position. Similarly, in the second position, mixing valve  102  can permit a second flow rate of relatively cool water from cold water conduit  122  and a second flow rate of relatively hot water from heated water conduit  124  into mixed water conduit  176 . The first and second flow rates of the relatively cool water and relatively hot water are different such that water within mixed water conduit  176  can have a second particular temperature when mixing valve  102  is in the second position. In such a manner, mixing valve  102  can regulate the temperature of water within mixed water conduit  176  and adjust the temperature of water within mixed water conduit  176  between the first and second particular temperatures. 
     It should be understood that, in certain exemplary embodiments, mixing valve  102  is adjustable between more positions than the first and second positions. In particular, mixing valve  102  may be adjustable between any suitable number of positions in alternative exemplary embodiments. For example, mixing valve  102  may be infinitely adjustable in order to permit fine-tuning of the temperature of water within mixed water conduit  176 . 
     Valve body  170  may be formed such that heated water inlet  172 , cold water inlet  174 , and mixed water conduit  176  of valve body  170  are integrally formed with one another. Thus, e.g., valve body  170  may be cast from a suitable metal, such as steel, aluminum, bronze, etc. Valve body  170  may also be formed of any other suitable rigid and/or ductile material, such as a plastic, a composite, etc., that is suitable for shipping and installing water heater appliance  100  without fracturing valve body  170 . 
     Water heater appliance  100  also includes a position sensor  182 . Position sensor  182  is configured for determining a position of mixing valve  102 . Position sensor  182  can monitor the position of mixing valve  102  in order to assist with regulating the temperature of water within mixed water conduit  176 . For example, position sensor  182  can determine when mixing valve  102  is in the first position or the second position in order to ensure that mixing valve  102  is properly or suitably positioned depending upon the temperature of water within mixed water conduit  176  desired or selected. Thus, position sensor  182  can provide feedback regarding the status or position of mixing valve  102 . 
     Position sensor  182  may be any suitable type of sensor. For example, position sensor  182  may be a physical sensor, such as an optical sensor, Hall-effect sensor, etc. In alternative exemplary embodiments, water heater appliance  100  need not include position sensor  182 , and controller  160  may determine or measure a motor position of mixing valve  102  based on a previously commanded position of mixing valve  102 . Thus, controller  160  may determine that the current position of mixing valve  102  corresponds to a latest position that controller  160  commanded for mixing valve  102  in a previous iteration. 
     Controller  160  can also operate mixing valve  102  to regulate the temperature of water within mixed water conduit  176 . For example, controller  160  can adjust the position of mixing valve  102  in order to regulate the temperature of water within mixed water conduit  176 . As an example, a user can select or establish a set-point temperature of mixing valve  102 , or the set-point temperature of mixing valve  102  may be a default value. Based upon the set-point temperature of mixing valve  102 , controller  160  can adjust the position of mixing valve  102  in order to change or tweak a ratio of relatively cool water flowing into mixed water conduit  176  from cold water conduit  122  and relatively hot water flowing into mixed water conduit  176  from heated water conduit  124 . In such a manner, controller  160  can regulate the temperature of water within mixed water conduit  176 . 
     The set-point temperature of mixing valve  102  can be any suitable temperature. For example, the set-point temperature of mixing valve  102  may be between about one hundred degrees Fahrenheit and about one hundred and twenty degrees Fahrenheit. In particular, the set-point temperature of mixing valve  102  may be selected such that the set-point temperature of mixing valve  102  is less than the set-point temperature for water within interior volume  120  of tank  106 . In such a manner, mixing valve  102  can utilize water from cold water conduit  122  and heated water conduit  124  to regulate the temperature of water within mixed water conduit  176 . 
     Water heater appliance  100  may also include one or more temperature sensors for measuring the temperature of water at various locations within water heater appliance  100 . For example, temperature sensors may be placed in tank  106 , cold water conduit  122 , heated water conduit  124 , mixed water conduit  176 , bypass conduit  178 , etc. Temperature measurements from these temperature sensors can be used by controller  160  to operate water heater appliance  100 , e.g., by ensuring the water in mixed water conduit  176  matches the set-point temperature. 
     Mixing valve  102  further includes a motor  184 , such as a stepper motor. Thus, mixing valve  102  is generally referred to as an “electronic mixing valve.” Motor  184  is coupled to a plunger (not shown) within valve body  170 , and motor  184  is operable to adjust a position of the plunger within valve body  170 . As an example, the plunger may be positioned such that the plunger blocks or significantly limits fluid flow from heated water inlet  172  of valve body  170  when the plunger is in a fully open position. Thus, all or most of water flowing to mixed water conduit  176  of valve body  170  is from cold water inlet  174 , and water within mixed water conduit  176  of valve body  170  is at or about the temperature of water within cold water inlet  174  when the plunger is in the fully open position. Conversely, the plunger may be positioned such that the plunger blocks or significantly limits fluid flow from cold water inlet  174  of valve body  170  when the plunger is in a fully closed position. Thus, all or most of water flowing to mixed water conduit  176  of valve body  170  is from heated water inlet  172  and water within mixed water conduit  176  of valve body  170  is at or about the temperature of water within heated water inlet  172  when the plunger is in the fully closed position. 
     Motor  184  may adjust the plunger between the open and closed positions. In addition, motor  184  may adjust the plunger to any suitable position between the open and closed positions. In such a manner, motor  184  may adjust the temperature of water exiting mixing valve  102  at mixed water conduit  176  of valve body  170  to any suitable temperature between the temperature of water within cold water inlet  174  and the temperature of water within heated water inlet  172 . 
     Although mixing valve  102  described above is an electronic mixing valve, it should be appreciated that mixing valve  102  is only used for the purpose of explaining aspects of the present subject matter. Other types and configurations of mixing valves may be used. For example, mixing valve  102  may be a thermostatic mixing valve such that mixing valve  102  automatically adjusts a mixing ratio of mixing valve  102 . Indeed, mixing valve  102  may be any device suitable for mixing two fluid streams, i.e., for mixing liquid from heated water conduit  124  with liquid from bypass conduit  178 . 
     According to some embodiments, mixing valve  102  may also include a thermal safety sensor (not shown). The thermal safety sensor may be any suitable type of temperature sensor or switch. For example, the thermal safety sensor may be a bimetal switch, a thermal cutoff (TCO), a thermistor, a thermocouple, etc. The thermal safety sensor may be in communication with controller  160 , e.g., such that controller  160  deactivates compressor  132 , upper heating element  126  and/or lower heating element  128  when temperature measurements from the thermal safety sensor exceed a temperature limit. As another example, thermal safety sensor may be directly wired to compressor  132 , upper heating element  126 , and/or lower heating element  128 , e.g., such that the thermal safety sensor interrupts power supply to compressor  132 , upper heating element  126  and/or lower heating element  128  when temperature measurements from the thermal safety sensor exceed the temperature limit. The temperature limit may be any suitable temperature. For example, the temperature limit may be one-hundred and forty degrees Fahrenheit, one-hundred and fifty degrees Fahrenheit, one-hundred and sixty degrees Fahrenheit, etc. As another example, the temperature limit may be selected such that the temperature limit is greater than the set temperature of mixing valve  102  and less than the set temperature t s  for water within interior volume  120  of tank  106 . The thermal safety sensor may positioned downstream of mixing valve  102  on mixed water conduit  176  or at any other suitable location within water heater appliance  100 . Moreover, thermal safety sensor may be positioned on a thermal mass to assist with avoiding nuisance tripping of the thermal safety sensor, e.g., when temperature measurements from thermal safety sensor  230  momentarily or briefly exceed the temperature limit. 
     According to the illustrated exemplary embodiment, heated water conduit  124  shares a common axis  190 , such as a common central axis, with heated water inlet  172  of mixing valve  102 . More specifically, heated water conduit  124  extends from tank  106  substantially along the radial direction R and defines common axis  190 . As used herein, when used to specify a directional orientation, “substantially” is intended to refer to within ten degrees of the stated direction. Similarly, when mixing valve  102  is mounted to heated water conduit  124 , e.g., by screwing or gluing heated water inlet  172  to heated water conduit  124 , heated water inlet  172  extends along common axis  190 . In this manner, heated water conduit  124  and heated water inlet  172  of valve body  170  may be positioned coaxially with each other, and may both extend horizontally within casing  104  of water heater appliance  100 . In addition, according to an exemplary embodiment, mixed water conduit  176  may also be coaxial with heated water conduit  124  and heated water inlet  172  such that it extends along common axis  190  in the horizontal direction H. 
     In addition, cold water inlet  174  of valve body  170  may be oriented such that cold water inlet  174  extends orthogonally to heated water inlet  172  and mixed water conduit  176  of valve body  170 . In this manner, heated water conduit  124 , cold water conduit  122 , bypass conduit  178 , and heated water inlet  172  extend along or are disposed within a plane defined by the axial direction A and common axis  190  of heated water conduit  124 . Such an arrangement of heated water inlet  172 , cold water inlet  174 , and mixed water conduit  176  of valve body  170  may assist with preserving valuable volume within casing  104  of water heater appliance  100 . In particular, such arrangement of heated water inlet  172 , cold water inlet  174 , and mixed water conduit  176  of valve body  170  may assist with limiting an area occupied by mixing valve  102 , e.g., in a plane that is perpendicular to the vertical direction V, while allowing easy access to mixing valve  102  within casing  104 . 
     According to the exemplary embodiment, mixing valve  102  may be positioned or disposed within casing  104  of water heater appliance  100 , e.g., adjacent top portion  116  of tank  106 , such that mixing valve  102  is integrated within water heater appliance  100 . Similarly, bypass conduit  178  may extend perpendicular to cold water conduit  122  along the vertical direction within casing  104 . However, it should be appreciated that according to alternative embodiments, mixing valve  102 , bypass conduit  178 , and other components of water heater appliance  100  may be positioned outside casing  104 , or at any other suitable location. 
     This written description uses examples to disclose the invention, including the best mode, and also to enable any person skilled in the art to practice the invention, including making and using any devices or systems and performing any incorporated methods. The patentable scope of the invention is defined by the claims, and may include other examples that occur to those skilled in the art. Such other examples are intended to be within the scope of the claims if they include structural elements that do not differ from the literal language of the claims, or if they include equivalent structural elements with insubstantial differences from the literal languages of the claims.