Dishwasher appliance and a freeze prevention operation

Abstract

A method of operating a dishwasher appliance may include determining a freeze prevention condition indicating an initiation of a freeze prevention operation. The method may include directing the fluid circulation assembly, the drain pump, and the sump temperature sensor according to a sump correlation procedure. The method may include comparing sump temperature data to a first sump threshold value. The method may include comparing the sump temperature data to a second sump threshold value. The method may include halting the freeze prevention operation based on comparing the temperature reading to the second sump threshold value.

Description

FIELD OF THE DISCLOSURE

[0001] The present subject matter relates generally to a dishwasher appliance, and more particularly to methods of operating a dishwasher appliance.BACKGROUND OF THE DISCLOSURE

[0002] Dishwasher appliances generally include a tub that defines a wash chamber. Rack assemblies can be mounted within the wash chamber of the tub for receipt of articles for washing. Wash fluid (e.g., various combinations of water and detergent along with optional additives) may be introduced into the tub where it collects in a sump space at the bottom of the wash chamber. During wash and rinse cycles, a pump may be used to circulate wash fluid to spray assemblies within the wash chamber that can apply or direct wash fluid towards articles disposed within the rack assemblies in order to clean such articles. During a drain cycle, a pump may periodically discharge soiled wash fluid that collects in the sump space and the process may be repeated.

[0003] Many commercial and residential buildings are equipped with dishwasher appliances. Such buildings are often located in climates which can experience very cold temperatures at certain times of the year. These cold temperatures bring the potential for the pipes to freeze, thus resulting in pipe damage creating water damage within the commercial or residential building.

[0004] Accordingly, systems and methods that obviate one or more of the above-mentioned drawbacks would be beneficial.BRIEF DESCRIPTION OF THE DISCLOSURE

[0005] Aspects and advantages of the invention will be set forth in part in the following description, or may be obvious from the description, or may be learned through practice of the invention.

[0006] In one exemplary aspect of the present disclosure, a dishwasher appliance is provided. The dishwasher appliance may include a cabinet that may include a wash tub and a sump positioned below the wash tub. The dishwasher appliance may include a fluid circulation assembly for controlling a flow of water into the wash tub. The dishwasher appliance may include a drain pump for draining water from the sump. The dishwasher appliance may include a sump temperature sensor for obtaining a temperature of a wash fluid within the sump. The dishwasher appliance may include a controller that may be operable for: determining a freeze prevention condition indicating an initiation of a freeze prevention operation, directing the fluid circulation assembly, the drain pump, and the sump temperature sensor according to a sump correlation procedure in response to determining the freeze prevention condition, comparing sump temperature data to a first sump threshold value in response directing the fluid circulation assembly, the drain pump, and the sump temperature sensor according to the sump correlation procedure, the first sump threshold value being based on a freezing temperature of water and a sump tolerance value, comparing the sump temperature data to a second sump threshold value based on comparing the sump temperature data to first sump threshold value, the second sump threshold value being based on a start threshold variable and the sump tolerance value, and halting the freeze prevention operation based on comparing the temperature reading to the second sump threshold value.

[0007] In one exemplary aspect of the present disclosure, a method of operating a dishwasher appliance is provided. The dishwasher appliance may include a cabinet. The cabinet may include a wash tub and a sump positioned below the wash tub. The dishwasher appliance may include a fluid circulation assembly for controlling a flow of water into the wash tub. The dishwasher appliance may include a drain pump for draining water from the sump. The dishwasher appliance may include a sump temperature sensor for obtaining a temperature of a wash fluid within the sump. The method may include determining a freeze prevention condition indicating an initiation of a freeze prevention operation. The method may include directing the fluid circulation assembly, the drain pump, and the sump temperature sensor according to a sump correlation procedure in response to determining the freeze prevention condition. The method may include comparing sump temperature data to a first sump threshold value in response directing the fluid circulation assembly, the drain pump, and the sump temperature sensor according to the sump correlation procedure. The first sump threshold value may be based on a freezing temperature of water and a sump tolerance value. The method may include comparing the sump temperature data to a second sump threshold value based on comparing the sump temperature data to first sump threshold value. The second sump threshold value may be based on a start threshold variable and the sump tolerance value. The method may include halting the freeze prevention operation based on comparing the temperature reading to the second sump threshold value.

[0008] 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

[0009] 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.

[0010] FIG. 1 provides a perspective view of a dishwasher appliance according to one or more exemplary embodiments of the present subject matter.

[0011] FIG. 2 provides a cross-sectional side view of the exemplary dishwasher appliance of FIG. 1 according to one or more exemplary embodiments of the present subject matter.

[0012] FIG. 3 provides a schematic diagram of an algorithm for preventing freezing within a dishwasher appliance according to one or more exemplary embodiments of the present subject matter.

[0013] FIG. 4 provides a flow chart illustrating a method of operating a dishwasher appliance according to one or more exemplary embodiments of the present subject matter.

[0014] Repeat use of reference characters in the present specification and drawings is intended to represent the same or analogous features or elements of the present invention.DETAILED DESCRIPTION

[0015] 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 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.

[0016] As used herein, the terms “first,”“second,” and “third” may be used interchangeably to distinguish one component from another and are not intended to signify location or importance of the individual components. The terms “includes” and “including” are intended to be inclusive in a manner similar to the term “comprising.” Similarly, the term “or” is generally intended to be inclusive (i.e., “A or B” is intended to mean “A or B or both”). In addition, here and throughout the specification and claims, range limitations may be combined or interchanged. Such ranges are identified and include all the sub-ranges contained therein unless context or language indicates otherwise. For example, all ranges disclosed herein are inclusive of the endpoints, and the endpoints are independently combinable with each other. The singular forms “a,”“an,” and “the” include plural references unless the context clearly dictates otherwise.

[0017] Approximating language, as used herein throughout the specification and claims, may be applied to modify any quantitative representation that could permissibly vary without resulting in a change in the basic function to which it is related. Accordingly, a value modified by a term or terms, such as “generally,”“about,”“approximately,” and “substantially,” are not to be limited to the precise value specified. In at least some instances, the approximating language may correspond to the precision of an instrument for measuring the value, or the precision of the methods or machines for constructing or manufacturing the components or systems. For example, the approximating language may refer to being within a 10 percent margin (i.e., including values within ten percent greater or less than the stated value). In this regard, for example, when used in the context of an angle or direction, such terms include within ten degrees greater or less than the stated angle or direction (e.g., “generally vertical” includes forming an angle of up to ten degrees in any direction, such as, clockwise or counterclockwise, with the vertical direction V).

[0018] The word “exemplary” is used herein to mean “serving as an example, instance, or illustration.” In addition, reference to “an embodiment” or “one embodiment” does not necessarily refer to the same embodiment, although it may. Any implementation described herein as “exemplary” or “an embodiment” is not necessarily to be construed as preferred or advantageous over other implementations.

[0019] Except as explicitly indicated otherwise, recitation of a singular processing element (e.g., “a controller,”“a processor,”“a microprocessor,” etc.) is understood to include more than one processing element. In other words, “a processing element” is generally understood as “one or more processing element.” Furthermore, barring a specific statement to the contrary, any steps or functions recited as being performed by “the processing element” or “said processing element” are generally understood to be capable of being performed by “any one of the one or more processing elements.” Thus, a first step or function performed by “the processing element” may be performed by “any one of the one or more processing elements,” and a second step or function performed by “the processing element” may be performed by “any one of the one or more processing elements and not necessarily by the same one of the one or more processing elements by which the first step or function is performed.” Moreover, it is understood that recitation of “the processing element” or “said processing element” performing a plurality of steps or functions does not require that at least one discrete processing element be capable of performing each one of the plurality of steps or functions.

[0020] Aspects of the present subject matter provide a dishwasher appliance that utilizes a weather-based algorithm to prevent water freezing in a water supply conduit thereof. The algorithm advantageously utilizes external temperature data received from an external temperature module to determine an accurate correlation between the external temperature data and sump temperature data (e.g., a water temperature at a sump of the dishwasher appliance). If the external temperature data (e.g., an external temperature value) is below a sump threshold variable (e.g., a threshold air temperature value) a sump correlation procedure can be performed to facilitate in the correlation of the sump temperature data to external temperature data. After the sump correlation procedure, if the sump temperature data is below a first sump temperature value, the dishwasher appliance can update the start temperature variable. When the external temperature data is below a second simp temperature value, the dishwasher appliance can fill and drain the water to prevent freezing in the water line and water valve.

[0021] FIGS. 1 and 2 depict an exemplary domestic dishwashing appliance or dishwasher appliance 100 that may be configured in accordance with aspects of the present disclosure. For the particular embodiment of FIGS. 1 and 2, the dishwasher appliance 100 includes a cabinet 102 having a tub 104 therein that defines a wash chamber 106. As shown, tub 104 extends between a top 107 and a bottom 108 along a vertical direction V, between a pair of side walls 110 along a lateral direction L, and between a front side 111 and a rear side 112 along a transverse direction T. Each of the vertical direction V, lateral direction L, and transverse direction T are mutually orthogonal to one another.

[0022] The tub 104 includes a front opening 114 and a door 116 hinged at its bottom for movement between a normally closed vertical position (shown in FIG. 2), wherein the wash chamber 106 is sealed shut for washing operation, and a horizontal open position for loading and unloading of articles from the dishwasher appliance 100. According to exemplary embodiments, dishwasher appliance 100 further includes a door closure mechanism or assembly 118 that is used to lock and unlock door 116 for accessing and sealing wash chamber 106.

[0023] As illustrated in FIG. 2, tub side walls 110 may accommodate a plurality of rack assemblies. More specifically, guide rails 120 may be mounted to side walls 110 for supporting a lower rack assembly 122, a middle rack assembly 124, and an upper rack assembly 126. As illustrated, upper rack assembly 126 is positioned at a top portion of wash chamber 106 above middle rack assembly 124, which is positioned above lower rack assembly 122 along the vertical direction V. Each rack assembly 122, 124, 126 is adapted for movement between an extended loading position (not shown) in which the rack is substantially positioned outside the wash chamber 106, and a retracted position (shown in FIGS. 1 and 2) in which the rack is located inside the wash chamber 106. This is facilitated, for example, by rollers 128 mounted onto rack assemblies 122, 124, 126, respectively. Although a guide rails 120 and rollers 128 are illustrated herein as facilitating movement of the respective rack assemblies 122, 124, 126, it should be appreciated that any suitable sliding mechanism or member may be used according to alternative embodiments.

[0024] Some or all of the rack assemblies 122, 124, 126 are fabricated into lattice structures including a plurality of wires or elongated members 130 (for clarity of illustration, not all elongated members making up rack assemblies 122, 124, 126 are shown in FIG. 2). In this regard, rack assemblies 122, 124, 126 are generally configured for supporting articles within wash chamber 106 while allowing a flow of wash fluid to reach and impinge on those articles (e.g., during a cleaning or rinsing cycle). According to another exemplary embodiment, a silverware basket (not shown) may be removably attached to a rack assembly (e.g., lower rack assembly 122) for placement of silverware, utensils, and the like, that are otherwise too small to be accommodated by rack 122.

[0025] Dishwasher appliance 100 further includes a plurality of spray assemblies for urging a flow of water or wash fluid onto the articles placed within wash chamber 106. More specifically, as illustrated in FIG. 2, dishwasher appliance 100 includes a lower spray arm assembly 134 disposed in a lower region 136 of wash chamber 106 and above a sump 138 so as to rotate in relatively close proximity to lower rack assembly 122. Similarly, a mid-level spray arm assembly 140 is located in an upper region of wash chamber 106 and may be located below and in close proximity to middle rack assembly 124. In this regard, mid-level spray arm assembly 140 may generally be configured for urging a flow of wash fluid up through middle rack assembly 124 and upper rack assembly 126. Additionally, an upper spray assembly 142 may be located above upper rack assembly 126 along the vertical direction V. In this manner, upper spray assembly 142 may be configured for urging or cascading a flow of wash fluid downward over rack assemblies 122, 124, and 126. As further illustrated in FIG. 2, upper rack assembly 126 may further define an integral spray manifold 144, which is generally configured for urging a flow of wash fluid substantially upward along the vertical direction V through upper rack assembly 126.

[0026] The sump 138 may include a sump temperature sensor 139 for obtaining a temperature of wash fluid within the sump 138. As used herein, “temperature sensor” or the equivalent is intended to refer to any suitable type of temperature measuring system or device positioned at any suitable location for measuring the desired temperature. Thus, for example, sump temperature sensor 139 may each be any suitable type of temperature sensor, such as a thermistor, a thermocouple, a resistance temperature detector, a semiconductor-based integrated circuit temperature sensor, etc. The sump temperature sensor 139 may be operably coupled to a controller, such as the controller 162 described in more detail below, and may output a signal, such as a voltage, to the controller that is proportional to or indicative of the temperature being measured.

[0027] The various spray assemblies and manifolds described herein may be part of a fluid distribution system or fluid circulation assembly 150 for circulating water and wash fluid in the tub 104. In certain embodiments, fluid circulation assembly 150 includes a circulation pump 152 for circulating wash liquid in tub 104. Circulation pump 152 may be located within sump 138 or within a machinery compartment located below sump 138 of tub 104.

[0028] The circulation pump 152 may be in fluid communication with an external water supply 153 (e.g., a municipal water source, a water heater appliance, or the like), and sump 138. A water inlet valve 154 may be operably coupled to a water supply conduit 155. In particular, the water inlet valve 154 may be positioned between the water supply 153 and the circulation pump 152 (e.g., to selectively allow water to flow from the water supply 153 to circulation pump 152). The water inlet valve 154 may be operably coupled to the controller 162 (e.g., described in more detail below) such that the controller 162 may selectively control the water inlet valve 154 to open to allow the flow of water into the dishwasher appliance 100 and may be selectively controlled to close and thereby cease the flow of water into the dishwasher appliance 100. In this manner, the controller 162 may regulate the operation of water control valve 149 to regulate the amount of water within the tub 104.

[0029] The fluid circulation assembly 150 also includes a pump assembly 156 for circulating water or wash fluid (e.g., detergent, water, or rinse aid) in the tub 104. For example, pump assembly 156 may include a pump motor 157 that drives pump assembly 156 to circulate or discharge wash fluid. Pump assembly 156 may be located within sump 138 or within a machinery compartment located below sump 138 of tub 104, as generally recognized in the art. Fluid circulation assembly 150 may include one or more fluid conduits or circulation piping for directing water or wash fluid from pump assembly 156 to the various spray assemblies and manifolds. For example, as illustrated in FIG. 2, a primary supply conduit 159 may extend from pump assembly 156, along rear 112 of tub 104 along the vertical direction V to supply wash fluid throughout wash chamber 106.

[0030] As illustrated, primary supply conduit 159 is used to supply wash fluid to one or more spray assemblies (e.g., to mid-level spray arm assembly 140 and upper spray assembly 142). However, it should be appreciated that according to alternative embodiments, any other suitable plumbing configuration may be used to supply wash fluid throughout the various spray manifolds and assemblies described herein. For example, according to another exemplary embodiment, primary supply conduit 159 could be used to provide wash fluid to mid-level spray arm assembly 140 and a dedicated secondary supply conduit (not shown) could be utilized to provide wash fluid to upper spray assembly 142. Other plumbing configurations may be used for providing wash fluid to the various spray devices and manifolds at any location within dishwasher appliance 100.

[0031] Each spray arm assembly 134, 140, 142, integral spray manifold 144, or other spray device may include an arrangement of discharge ports or orifices for directing wash fluid received from pump assembly 156 onto dishes or other articles located in wash chamber 106. The arrangement of the discharge ports, also referred to as jets, apertures, or orifices, may provide a rotational force by virtue of wash fluid flowing through the discharge ports. Alternatively, spray arm assemblies 134, 140, 142 may be motor-driven, or may operate using any other suitable drive mechanism. Spray manifolds and assemblies may also be stationary. The resultant movement of the spray arm assemblies 134, 140, 142 and the spray from fixed manifolds provides coverage of dishes and other dishwasher contents with a washing spray. Other configurations of spray assemblies may be used as well. For example, dishwasher appliance 100 may have additional spray assemblies for cleaning silverware, for scouring casserole dishes, for spraying pots and pans, for cleaning bottles, etc. One skilled in the art will appreciate that the embodiments discussed herein are used for the purpose of explanation only and are not limitations of the present subject matter.

[0032] In operation, pump assembly 156 draws wash fluid in from sump 138 and pumps it to a diverter assembly 158 (e.g., which may be positioned within sump 138 of dishwasher appliance 100). Diverter assembly 158 may include a diverter disk (not shown) disposed within a diverter chamber 160 for selectively distributing the wash fluid to the spray arm assemblies 134, 140, 142 or other spray manifolds or devices. For example, the diverter disk may have a plurality of apertures that are configured to align with one or more outlet ports (not shown) at the top of diverter chamber 160. In this manner, the diverter disk may be selectively rotated to provide wash fluid to the desired spray device.

[0033] According to an exemplary embodiment, diverter assembly 158 is configured for selectively distributing the flow of wash fluid from pump assembly 156 to various fluid supply conduits, only some of which are illustrated in FIG. 2 for clarity. More specifically, diverter assembly 158 may include four outlet ports (not shown) for supplying wash fluid to a first conduit for rotating lower spray arm assembly 134 in the clockwise direction, a second conduit for rotating lower spray arm assembly 134 in the counter-clockwise direction, a third conduit for spraying an auxiliary rack such as the silverware rack, and a fourth conduit for supply mid-level or upper spray assemblies 140, 142 (e.g., such as primary supply conduit 159).

[0034] The dishwasher appliance 100 may further include a drain pump 161 positioned downstream of the sump 138. The drain pump 161 may be operably coupled to the controller 162 (e.g., described in more detail below) such that the controller 162 may selectively direct operation of the drain pump 161. In this regard, the drain pump 161 may facilitate drainage of soiled wash fluid by urging or pumping the wash fluid to a drain line disposed external to the dishwasher appliance 100.

[0035] The dishwasher appliance 100 is further equipped with a controller 162 to regulate operation of the dishwasher appliance 100. The controller 162 may include one or more memory devices and one or more microprocessors, such as general or special purpose microprocessors operable to execute programming instructions or micro-control code associated with operation of the dishwasher appliance 100. The memory may represent random access memory such as DRAM, or read only memory such as ROM or FLASH. In one embodiment, the processor executes programming instructions stored in memory. The memory may be a separate component from the processor or may be included onboard within the processor. Alternatively, controller 162 may be constructed without using a microprocessor (e.g., using a combination of discrete analog or digital logic circuitry, such as switches, amplifiers, integrators, comparators, flip-flops, AND / OR gates, or the like) to perform control functionality instead of relying upon software.

[0036] The controller 162 may be positioned in a variety of locations throughout dishwasher appliance 100. In the illustrated embodiment, the controller 162 may be located within a control panel area 163 of door 116, as shown in FIGS. 1 and 2. In such an embodiment, input / output (“I / O”) signals may be routed between the control system and various operational components of dishwasher appliance 100 along wiring harnesses that may be routed through the bottom of door 116. Typically, the controller 162 may be in operative communication with a user interface panel 164 through which a user may select various operational features and modes and monitor progress of the dishwasher appliance 100. In one embodiment, the user interface 164 may represent a general purpose I / O (“GPIO”) device or functional block. In certain embodiments, the user interface 164 includes input components 166, such as one or more of a variety of electrical, mechanical or electro-mechanical input devices including capacitive touch screens / buttons, rotary dials, push buttons, and touch pads. The user interface 164 may further include one or more display components 168, such as a digital display device or one or more indicator light assemblies designed to provide operational feedback to a user. The user interface 164 may be in communication with the controller 162 via one or more signal lines or shared communication busses.

[0037] It should be appreciated that the invention is not limited to any particular style, model, or configuration of dishwasher appliance 100. The exemplary embodiment depicted in FIGS. 1 and 2 is for illustrative purposes only. For example, different locations may be provided for user interface 164, different configurations may be provided for rack assemblies 122, 124, 126, different spray arm assemblies 134, 140, 142 and spray manifold configurations may be used, and other differences may be applied while remaining within the scope of the present subject matter. Moreover, aspects of the present subject matter may be applied to other appliances as well, such as refrigerators, ovens, microwaves, etc.

[0038] Referring still to FIG. 1, a schematic diagram of an external communication system 190 will be described according to an exemplary embodiment of the present subject matter. In general, external communication system 190 is configured for permitting interaction, data transfer, and other communications between dishwasher appliance 100 and one or more external devices. For example, this communication may be used to provide and receive operating parameters, user instructions or notifications, performance characteristics, user preferences, or any other suitable information for improved performance of dishwasher appliance 100. In addition, it should be appreciated that external communication system 190 may be used to transfer data or other information to improve performance of one or more external devices or appliances or improve user interaction with such devices.

[0039] For example, external communication system 190 permits controller 162 of dishwasher appliance 100 to communicate with a separate device external to dishwasher appliance 100, referred to generally herein as an external device 192. As described in more detail below, these communications may be facilitated using a wired or wireless connection, such as via a network 194. In general, external device 192 may be any suitable device separate from dishwasher appliance 100 that is configured to provide or receive communications, information, data, or commands from a user. In this regard, external device 192 may be, for example, a personal phone, a smartphone, a tablet, a laptop or personal computer, a wearable device, a smart home system, or another mobile or remote device.

[0040] In addition, a remote server 196 may be in communication with dishwasher appliance 100 or external device 192 through network 194. In this regard, for example, remote server 196 may be a cloud-based server 196, and is thus located at a distant location, such as in a separate state, country, etc. According to an exemplary embodiment, external device 192 may communicate with a remote server 196 over network 194, such as the Internet, to transmit / receive data or information, provide user inputs, receive user notifications or instructions, interact with or control dishwasher appliance 100, etc. In addition, external device 192 and remote server 196 may communicate with dishwasher appliance 100 to communicate similar information.

[0041] In general, communication between dishwasher appliance 100, external device 192, remote server 196, or other user devices or appliances may be carried using any type of wired or wireless connection and using any suitable type of communication network, non-limiting examples of which are provided below. For example, external device 192 may be in direct or indirect communication with dishwasher appliance 100 through any suitable wired or wireless communication connections or interfaces, such as network 194. For example, network 194 may include one or more of a local area network (LAN), a wide area network (WAN), a personal area network (PAN), the Internet, a cellular network, any other suitable short- or long-range wireless networks, etc. In addition, communications may be transmitted using any suitable communications devices or protocols, such as via Wi-Fi®, Bluetooth®, Zigbee®, wireless radio, laser, infrared, Ethernet type devices and interfaces, etc. In addition, such communication may use a variety of communication protocols (e.g., TCP / IP, HTTP, SMTP, FTP), encodings or formats (e.g., HTML, XML), or protection schemes (e.g., VPN, secure HTTP, SSL).

[0042] External communication system 190 is described herein according to an exemplary embodiment of the present subject matter. However, it should be appreciated that the exemplary functions and configurations of external communication system 190 provided herein are used only as examples to facilitate description of aspects of the present subject matter. System configurations may vary, other communication devices may be used to communicate directly or indirectly with one or more associated appliances, other communication protocols and steps may be implemented, etc. These variations and modifications are contemplated as within the scope of the present subject matter.

[0043] Moreover, an external temperature module 198 may be in operable communication with the dishwasher appliance 100, for instance, via the external communication system 190. The external temperature module 198 may be configured for obtaining external temperature data (e.g., temperature data or information corresponding to a temperature of water within the water supply conduit 155). The external temperature sensor 189 may be positioned in any suitable external position to the dishwasher appliance 100 to obtain external temperature data. In some embodiments, the external temperature data includes air temperature measurements or conditions of the environment surrounding the dishwasher appliance, such as the air temperature outside of the residential or commercial building that the dishwasher appliance 100 is housed within. In this regard, the external temperature data may be an outside temperature that the external temperature module 198 is capable of obtaining.

[0044] In some other embodiments (e.g., as shown in FIG. 1), the external temperature module 198 includes or is provided as an external temperature source (e.g., a weather database or site for providing information or data of current or historical weather conditions) hosted on the remote server 196. For example, the remote server may store information or data corresponding to current or historical weather condition and transmit the information or data to the controller 162 of the dishwasher appliance 100. In some other embodiments, the external temperature module may include or be provided as an external temperature sensor configured for obtaining an outside temperature. As described above, “temperature sensor” or the equivalent is intended to refer to any suitable type of temperature measuring system or device positioned at any suitable location for measuring the desired temperature. Thus, for example, external temperature sensor of the external temperature module may each be any suitable type of temperature sensor, such as a thermistor, a thermocouple, a resistance temperature detector, a semiconductor-based integrated circuit temperature sensors, etc. The external temperature sensor may be operably coupled to the controller 162 and may output a signal, such as a voltage, to the controller 162 that is proportional to or indicative of the temperature being measured.

[0045] Now that the construction of dishwasher appliance 100 and the controller 162 according to exemplary embodiments has been presented, exemplary methods of operating a dishwasher appliance will be described. In exemplary embodiments, the various method steps as disclosed herein may be performed by controller 162, or a separate dedicated controller. Furthermore, some or all of the various method steps may be performed remotely, e.g., in a distributed computing environment such as the cloud, fog, or edge, wherein the controller 162 communicates with one or more remote computing devices of the distributed computing environment, such as processing, may be performed in the cloud and the output of such process may be transmitted to and received by the dishwasher appliance 100, such as by the controller 162 thereof via the network 194.

[0046] Exemplary methods for operating a dishwasher appliance, such as a dishwasher appliance as described above, are provided. In this regard, for example, a controller of the dishwasher appliance, e.g., controller 162, may be configured for implementing some or all steps of one or more of the following exemplary methods. However, it should be appreciated that the exemplary methods are discussed herein only to describe exemplary aspects of the present subject matter, and are not intended to be limiting.

[0047] Referring now to FIG. 3, a flow diagram of a method 200 for a dishwasher appliance is provided. In general, the method 200 is provided to prevent freezing of water or wash fluid at the dishwasher appliance. As will be appreciated in more detail below, the method 200 advantageously correlates external temperature data to sump temperature data to determine when water or wash fluid at the dishwasher appliance is most at risk for freezing. Notably, by correlating the external temperature condition to the sump temperature condition, the method 200 increases freeze prevention capabilities of the dishwasher appliance and minimizes a run time of the freeze prevention operation (e.g., when compared to existing methods that do not correlate the external temperature condition to the sump temperature condition).

[0048] At 202, external temperature data (e.g., data or information corresponding to the outside temperature) is obtained, for instance, via an external temperature module (e.g., described in more detail above). The external temperature data may be transmitted from the external temperature module and received at the controller of the dishwasher appliance. The external temperature data may include or correspond to the external temperature conditions (e.g., measurements or values) that are indicative of the current air temperature outside of the commercial or residential building that the dishwasher appliance is located within (e.g., an outside temperature).

[0049] At 204, the method 200 includes deciding if the external temperature data (e.g., an external temperature measurement or value of the external temperature data) is less than or equal to a start threshold variable 205 (e.g., a threshold air temperature value). For instance, the start threshold variable 205 may include data or information (e.g., stored within a memory of the controller) that corresponds to the threshold air temperature value. In particular, the data or information may correspond to a threshold air temperature value that, when reached, indicates water at the dishwasher appliance (e.g., water within the water supply conduit) may be approaching a freezing condition. In this regard, deciding if the external temperature data is less than or equal to the start threshold variable 205 includes comparing the external temperature data to the threshold air temperature value of the start threshold variable 205. At start-up of the dishwasher appliance, such as prior to an initiation of a first freeze prevention operation (e.g., at 206) or after a prior freeze prevention operation, the start threshold variable 205 may include data or information that corresponds to a predetermined start temperature value (PSTV). The PSTV may be a threshold air temperature value, such as thirty degrees Fahrenheit (30° F.), thirty-two degrees Fahrenheit (32° F.), thirty-three degrees Fahrenheit (33° F.), or any other suitable air temperature value that, when reached, indicates that water at the dishwasher appliance may be approaching a freezing condition. As will be appreciated in more detail below, the data or information of the start threshold variable 205 that corresponds to the threshold air temperature value may be updated and changed during the execution of method 200.

[0050] If, at 204, it is decided that the external temperature data is not less than or equal to the start threshold variable 205 (e.g., the external temperature data is greater than the PSTV) the method 200 may repeat 204, until external temperature data that is less than or equal to the start threshold variable 205 is received. If, at 204, it is decided that the external temperature data is less than or equal to the start threshold variable 205 the method 200 may initiate a freeze prevention operation and may proceed to 206.

[0051] At 206, the method 200 includes performing a sump correlation procedure (e.g., a first sump correlation procedure) upon, or in response to, deciding the external temperature data is less than or equal to the start threshold variable 205. At 206, the sump correlation procedure may be performed to determine a correlation between the external temperature data and a sump temperature data (e.g., a temperature of water collected within the sump of the dishwasher appliance). In some embodiments, performing the sump correlation procedure includes directing one or more components of the dishwasher appliance according to a fill process. For example, directing one or more components of the dishwasher appliance according the fill process may include directing a fluid circulation assembly according to the fill process. Directing the fluid circulation assembly according to the fill process may include directing a circulation pump and a water inlet value to flow a fill of water into the wash tub. In some embodiments, directing the circulation pump and the water inlet valve includes opening the water inlet valve to selectively allow water to flow from a water source to the circulation pump (e.g., through a water supply line) and directing the circulation pump to pump or urge the flow of water into the dishwasher appliance. The fluid circulation assembly may be directed according to the fill process for a predetermined interval (e.g., a predetermined time interval, a predetermined water volume interval, or the like) to move (e.g., flow) water through the water supply conduit or the wash tub.

[0052] In addition, in some embodiments, the sump correlation procedure includes directing one or more components of the dishwasher appliance according to a drain process, for instance, upon the completion of the fill process. Directing one or more components of the dishwasher appliance according to the drain process may include directing a drain pump of the dishwasher appliance according to a drain process upon the completion of the fill process. For instance, upon completion of the fill process, the drain pump may be directed to facilitate drainage of water or wash fluid within the dishwasher appliance by urging or pumping the water or wash fluid to a drain line in fluid communication with the dishwasher appliance.

[0053] Further, the sump correlation procedure may include obtaining, with a sump temperature sensor disposed at the sump, a temperature value of water within the sump (e.g., a sump temperature data). As should be appreciated, during the sump correlation procedure (e.g., prior to, during, or after, the drain process) water may be collected within the sump of the dishwasher appliance. The temperature of the water collected within the sump may be indicative of the temperature of water at the dishwasher appliance. For example, the temperature of the water collected in the sump may be indicative of the temperature of water within the water supply conduit.

[0054] Notably, performing the sump correlation procedure in response to 204 advantageously prevents or mitigates freezing within the water supply conduit as water is flowed or moved through the water supply conduit prior to water within the water supply conduit reaching a freezing temperature.

[0055] Upon completion of the sump correlation procedure at 206, the method 200 may proceed to 208. At 208, the method 200 includes deciding if the sump temperature data is less than or equal to a first sump threshold value (FSTV). The FSTV may be based on a freezing temperature of water and a first sump tolerance value. For example, the FSTV may be determined by the formulaFSTV=freezing⁢ temeprature⁢ of⁢ water+sump⁢ tolerance⁢ valuewherein the “freezing temperature of water” is data or information that corresponds to a freezing temperature of water, such as thirty-two degrees Fahrenheit (32° F.) and the “first sump tolerance value” is data or information that corresponds to a temperature tolerance or offset that may be added to the freeze value, such as one degree Fahrenheit, two degrees Fahrenheit, or the like that may provide a suitable temperature offset to the freezing temperature of water. Notably, by adding the first sump tolerance value to the freezing temperature of water, the FSTV may be a temperature threshold that, when reached, indicates the temperature of water within the sump is approaching or susceptible to a freezing condition.In some embodiments, deciding if the sump temperature data is less than or equal to the FSTV includes comparing the sump temperature data (e.g., obtained at 206) to the FSTV. For instance, the controller may compare the temperature of water within the sump to the FSTV to determine if the temperature of water within the sump is approaching the freezing condition or otherwise susceptible to freezing. If it is decided, at 208, that the sump temperature data is not less than or equal to the FSTV (e.g., the sump temperature data is greater than the FSTV), the method 200 may proceed to 214 (e.g., described in more detail below).

[0057] If it is decided, at 208, that the sump temperature data is less than or equal to the FSTV, the method 200 may proceed to 210. At 210, the method 200 includes updating the start threshold variable 205. Updating the start threshold variable 205 may include changing the PSTV (e.g., described above) of the start threshold variable to an updated start temperature value (USTV). For example, at initial start-up or at the first performance of method 200, the start threshold variable 205 may include data or information that corresponds to a PSTV (e.g., described above). Thus, at 210, the method 200 may include updating the PSTV to the USTV. The USTV may be based on the PSTV, a freezing temperature of water, and the sump temperature data (e.g., obtained at 206). For example the USTV may be determined by the formula:USTV=PSTV+32⁢°⁢ F.-Sump⁢ Temperature⁢ Reading

[0058] In response to updating the start threshold variable 205, at 210, the method 200 may proceed to 212. At 212, the method 200 includes performing a sump correlation procedure. In some embodiments, the sump correlation procedure performed at 212 is the same as the sump correlation procedure performed at 206. For example, the sump correlation performed at 212 may include directing the fluid circulation procedure according to a fill process, directing the drain pump according to a drain process upon completion of the fill process, and obtaining a sump temperature data.

[0059] In response to obtaining the sump temperature data at 212, the method 200 may proceed to 214. At 214, the method 200 may decide if the sump temperature data is greater than a second sump threshold temperature (SSTV). The SSTV may be based on the start threshold variable 205 and a second sump tolerance value (e.g., described above). For example, the SSTV may be determined using the formulaSSTV=start⁢ threshold⁢ variable+tolerance⁢ valuewherein the “start threshold variable” is the start threshold variable 205, and the “second sump tolerance value” is data or information that corresponds to a temperature tolerance or offset that may be added to the start variable, such as one degree Fahrenheit, two degrees Fahrenheit, or the like that may provide a suitable temperature offset to the start threshold variable.If the sump temperature data is less than or equal to the start threshold variable and the tolerance value, the method 200 may repeat 212 until the sump temperature data is greater than the start threshold variable and the tolerance value. If the sump temperature data is greater than the start threshold variable and the tolerance value the method 200 may proceed to 216. At 216, the freeze prevention algorithm may be halted. In response to halting the freeze prevention algorithm, the method 200 may repeat to 204 wherein it is decided if the external temperature data is less than or equal to the start threshold variable.

[0061] Notably, by using external temperature data from the external temperature module, the method 200 advantageously minimizes the run time of the method 200 as the sump correlation procedures, and more particularly, the fill and drain process, are only performed when water within the water supply conduit is at risk of freezing. In this regard, unexpected noises from the dishwasher appliance (e.g., that may typically be caused by the performance of the fill or drain process) may be minimized.

[0062] Referring now to FIG. 4, a method 300 of operating a dishwasher appliance is provided. At 310, the method 300 includes determining a freeze prevention condition indicating an initiation of a freeze prevention operation. Determining the freeze prevention condition includes receiving (e.g., continuously or at a predetermined interval) external temperature data from an external temperature module in wireless communication with the controller. As mentioned above, the external temperature module may include any suitable device or source that may be operable for obtaining external temperature data (e.g., temperature measurements corresponding to a current outside temperature, such as a current air temperature of an environment surrounding the dishwasher appliance). For example, the external temperature module may be one of an external temperature sensor in or a weather database hosted on a remote server in operative communication with the controller.

[0063] Determining the freeze prevention condition may further include comparing the external temperature data received from the external temperature module (e.g., the temperature measurements corresponding to the current outside air temperature received from the external temperature module) to a predetermined start temperature value (PSTV) of the start threshold variable. The PSTV may be “predetermined” in that is it preloaded or prestored within a memory of the controller at the start of method 300, such as prior to 310. The PSTV may be any suitable temperature value that may indicate water at the dishwasher appliance is at or approaching a freezing condition. For example, at initial start-up of the dishwasher appliance, the PSTV may be thirty-two degrees Fahrenheit (32° F.). In some other embodiments, the PSTV may correspond to an updated start temperature variable (USTV) of a prior or a previous freeze prevention operation, such as determined at 330 described below. In other words, after the completion of a freeze prevention operation, the PSTV may be updated or changed based on an USTV that may be generated during the prior freeze prevention operation.

[0064] In some embodiments, determining the freeze prevention operation includes determining the external temperature data (e.g., external temperature measurements corresponding to a current outside temperature), is less than or equal to the start threshold variable based on comparing the external temperature data to the predetermined start temperature value of the start threshold variable. If it is determined that the external temperature data is less than or equal to the start threshold variable the method 300 may proceed to 320. If it is determined that the external temperature data is greater than the start threshold variable the method 300 may repeat 310 until the external temperature data received is less than or equal to the start threshold.

[0065] At 320, the method 300 includes directing a fluid circulation assembly, a drain pump, and a sump temperature sensor of the dishwasher appliance according to a sump correlation procedure in response to determining the freeze prevention condition. 320 may be utilized to help prevent or mitigate freezing of water at the dishwasher appliance. Directing the fluid circulation assembly may include directing a water control valve and a circulation pump of the fluid circulation assembly according to a fill process (e.g., as described above). The fill process may be utilized to flow a fill of water (e.g., a predetermined amount of water, such as a predetermined volume of water or a predetermined amount of time) into the wash tub of the dishwasher appliance. Directing the fluid circulation assembly may include directing the drain pump according a drain process (e.g., as described above) upon completing the fill process. The drain process may be utilized to drain or urge the fill of water from the wash tub and the sump of the dishwasher appliance. Directing the sump temperature sensor according to the sump correlation procedure may include obtaining a sump temperature data (e.g., temperature measurements corresponding to a water temperature at the sump) via the sump temperature sensor. The sump temperature data may be obtain via the sump temperature sensor when water is present within the sump, such as before, during, or after (e.g., immediately after) the drain process.

[0066] At 330, the method 300 includes comparing the sump temperature data (e.g., obtained at 320) to a FSTV in response directing the fluid circulation assembly, the drain pump, and the sump temperature sensor according to the sump correlation procedure. In some embodiments, the FSTV is based on a freezing temperature of water (e.g., thirty-two degrees Fahrenheit [32° F.]) and a first sump tolerance value (e.g., a tolerance temperature value or offset). In some embodiments, comparing the sump temperature data to the FSTV includes determining the sump temperature data (e.g., obtained at 320) is less than or equal to the FSTV. In such embodiments, comparing the sump temperature data, and more particularly, the temperature measurements corresponding to a temperature of water at the sump to the FSTV further includes updating the start threshold variable in response to determining the sump temperature data is less than or equal to the FSTV. Updating the start threshold variable may include changing the predetermined start temperature value of the start threshold variable to an USTV. In some embodiments, the USTV is based on the predetermined start temperature value, a freezing temperature value of water (e.g., thirty-two degrees Fahrenheit [32° F.]), and the sump temperature data (e.g., obtained at 320).

[0067] In such embodiments, comparing the sump temperature data to the FSTV includes directing the fluid circulation assembly, the drain pump, and the sump temperature sensor according to a subsequent sump correlation procedure in response to updating the start threshold variable. The subsequent sump correlation procedure may be substantially similar to the sump correlation procedure performed at 320. For example, the subsequent sump correlation procedure may include directing the fluid circulation assembly according to a fill process, directing the drain pump according to a drain process, and obtaining a subsequent sump temperature data via the sump temperature sensor. In some embodiments, comparing the sump temperature data to the FSTV includes determining the sump temperature data is greater than the FSTV. In such embodiments, the method 300 may proceed directly to 340.

[0068] At 340, the method 300 may include comparing the sump temperature data to a second sump threshold value (SSTV) based on comparing the sump temperature data to FSTV. The SSTV may be based on the start threshold variable and the sump tolerance value. In some embodiments, comparing the sump temperature data to the SSTV may be in response to directing the fluid circulation assembly, the drain pump, and the sump temperature sensor according to the subsequent sump correlation procedure. For example, after the completion of the subsequent sump correlation procedure (e.g., at 330), the method may compare the sump temperature data (e.g., obtained at 330) to the SSTV. In such embodiments, the SSTV is based on the start threshold variable (e.g., that includes data or information corresponding to the USTV) and the sump tolerance value.

[0069] In some embodiments, comparing the sump temperature data to the SSTV includes determining the sump temperature data is less than or equal to the SSTV. If it is determined that the sump temperature threshold is less than or equal to the SSTV, the method 300 may include redirecting the fluid circulation assembly, the drain pump, and the sump temperature sensor according to the subsequent sump correlation procedure (e.g., described above).

[0070] At 350, the method 300 may include halting the freeze prevention operation based on comparing the temperature reading to the SSTV. Halting the freeze prevention operation may include one or more components of the dishwasher appliance (e.g., the fluid circulation assembly, the drain pump, or the like) to temporarily suspend operation. After halting the freeze prevention operation the USTV of the start threshold variable may be changed to the predetermined temperature value. In this regard, at the next (e.g., a subsequent) initiation of a freeze prevention operation, the freeze prevention operation may advantageously utilize data or information, such as the USTV, that is correlated to the sump temperature data and the external temperature data. In some embodiments, comparing the sump temperature data to the FSTV includes determining the sump temperature data is greater than a second sump threshold value. If, at 340, it is determined that the sump temperature data is greater than the second sump threshold value, the method 300 may proceed to 350.

[0071] 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.

Claims

1. A dishwasher appliance comprising:a cabinet comprising a wash tub and a sump positioned below the wash tub;a fluid circulation assembly for controlling a flow of water into the wash tub;a drain pump for draining water from the sump;a sump temperature sensor for obtaining a temperature of a wash fluid within the sump; anda controller being operable for:determining a freeze prevention condition indicating an initiation of a freeze prevention operation,directing the fluid circulation assembly, the drain pump, and the sump temperature sensor according to a sump correlation procedure in response to determining the freeze prevention condition,comparing sump temperature data to a first sump threshold value in response directing the fluid circulation assembly, the drain pump, and the sump temperature sensor according to the sump correlation procedure, the first sump threshold value being based on a freezing temperature of water and a sump tolerance value,comparing the sump temperature data to a second sump threshold value based on comparing the sump temperature data to first sump threshold value, the second sump threshold value being based on a start threshold variable and the sump tolerance value, andhalting the freeze prevention operation based on comparing the temperature reading to the second sump threshold value.

2. The dishwasher appliance of claim 1, wherein determining the freeze prevention condition comprisesreceiving external temperature data from an external temperature module in wireless communication with the controller,comparing the external temperature data to a predetermined start temperature value of the start threshold variable, anddetermining the external temperature data is less than or equal to the start threshold variable based on comparing the external temperature data to the predetermined start temperature value of the start threshold variable.

3. The dishwasher appliance of claim 2, wherein the external temperature module comprises an external temperature sensor in wireless communication with the controller.

4. The dishwasher appliance of claim 2, wherein the external temperature module is hosted on a remote server in operative communication with the controller.

5. The dishwasher appliance of claim 1, wherein directing the fluid circulation assembly, the drain pump, and the sump temperature sensor according to a sump correlation procedure in response to initiating the freeze prevention operation comprisesdirecting a water control valve and a circulation pump of the fluid circulation assembly according to a fill process,directing the drain pump according to a drain process upon completing the fill process, andobtaining sump temperature data via the sump temperature sensor.

6. The dishwasher appliance of claim 1, wherein comparing the sump temperature data to the first sump threshold value comprisesdetermining the sump temperature data is less than or equal to the first sump threshold value,updating a start threshold variable based on a predetermined start temperature value of the start threshold variable, a freezing temperature value of water, and the sump temperature data in response to determining the sump temperature data is less than or equal to the first sump threshold value, anddirecting the fluid circulation assembly, the drain pump, and the sump temperature sensor according to a subsequent sump correlation procedure in response to updating the start threshold variable,wherein comparing the sump temperature data to the second sump threshold value is in response to directing the fluid circulation assembly, the drain pump, and the sump temperature sensor according to the subsequent sump correlation procedure.

7. The dishwasher appliance of claim 6, wherein updating the start threshold variable comprises changing a predetermined start temperature value of the start threshold variable to an updated start temperature value, andwherein the updated start temperature value being based on the predetermined start temperature value, a freezing temperature value of water, and the sump temperature data.

8. The dishwasher appliance of claim 6, wherein comparing the sump temperature data to the first sump threshold value comprisesdetermining the sump temperature data is less than or equal to the second sump threshold value, andredirecting the fluid circulation assembly, the drain pump, and the sump temperature sensor according to the subsequent sump correlation procedure in response to determining the sump temperature data is less than or equal to the second sump threshold value.

9. The dishwasher appliance of claim 6, wherein comparing the sump temperature data to the first sump threshold value comprisesdetermining the sump temperature data is greater than a second sump threshold value, the second sump threshold value based on the start threshold variable and the sump tolerance value,wherein halting the freeze prevention operation is in response to determining the sump temperature data is greater than a second sump threshold value.

10. The dishwasher appliance of claim 1, wherein comparing the sump temperature data to the first sump threshold value comprisesdetermining the sump temperature data is greater than the first sump threshold value,wherein comparing the sump temperature data to the second sump threshold value in response determining the sump temperature data is greater than the first sump threshold value.

11. A method of operating a dishwasher appliance, the dishwasher appliance comprising a cabinet comprising a wash tub and a sump positioned below the wash tub, a fluid circulation assembly for controlling a flow of water into the wash tub, a drain pump for draining water from the sump, and a sump temperature sensor for obtaining a temperature of a wash fluid within the sump, the method comprising:determining a freeze prevention condition indicating an initiation of a freeze prevention operation;directing the fluid circulation assembly, the drain pump, and the sump temperature sensor according to a sump correlation procedure in response to determining the freeze prevention condition;comparing sump temperature data to a first sump threshold value in response directing the fluid circulation assembly, the drain pump, and the sump temperature sensor according to the sump correlation procedure, the first sump threshold value being based on a freezing temperature of water and a sump tolerance value;comparing the sump temperature data to a second sump threshold value based on comparing the sump temperature data to first sump threshold value, the second sump threshold value being based on a start threshold variable and the sump tolerance value; andhalting the freeze prevention operation based on comparing the temperature reading to the second sump threshold value.

12. The method of claim 11, wherein determining the freeze prevention condition comprisesreceiving external temperature data from an external temperature module in wireless communication with the controller,comparing the external temperature data to a predetermined start temperature value of the start threshold variable, anddetermining the external temperature data is less than or equal to the start threshold variable based on comparing the external temperature data to the predetermined start temperature value of the start threshold variable.

13. The method of claim 12, wherein the external temperature module comprises an external temperature sensor in wireless communication with the dishwasher appliance.

14. The method of claim 12, wherein the external temperature module is hosted on a remote server in operative communication with the dishwasher appliance.

15. The method of claim 11, wherein directing the fluid circulation assembly, the drain pump, and the sump temperature sensor according to a sump correlation procedure in response to initiating the freeze prevention operation comprisesdirecting a water control valve and a circulation pump of the fluid circulation assembly according to a fill process,directing the drain pump according to a drain process upon completing the fill process, andobtaining sump temperature data via the sump temperature sensor.

16. The method of claim 11, wherein comparing the sump temperature data to the first sump threshold value comprisesdetermining the sump temperature data is less than or equal to the first sump threshold value,updating a start threshold variable based on a predetermined start temperature value of the start threshold variable, a freezing temperature value of water, and the sump temperature data in response to determining the sump temperature data is less than or equal to the first sump threshold value, anddirecting the fluid circulation assembly, the drain pump, and the sump temperature sensor according to a subsequent sump correlation procedure in response to updating the start threshold variable,wherein comparing the sump temperature data to the second sump threshold value is in response to directing the fluid circulation assembly, the drain pump, and the sump temperature sensor according to the subsequent sump correlation procedure.

17. The method of claim 16, wherein updating the start threshold variable comprises changing a predetermined start temperature value of the start threshold variable to an updated start temperature value, andwherein the updated start temperature value being based on the predetermined start temperature value, a freezing temperature value of water, and the sump temperature data.

18. The method of claim 16, wherein comparing the sump temperature data to the first sump threshold value comprisesdetermining the sump temperature data is less than or equal to the second sump threshold value, andredirecting the fluid circulation assembly, the drain pump, and the sump temperature sensor according to the subsequent sump correlation procedure in response to determining the sump temperature data is less than or equal to the second sump threshold value.

19. The method of claim 16, wherein comparing the sump temperature data to the first sump threshold value comprisesdetermining the sump temperature data is greater than a second sump threshold value, the second sump threshold value based on the start threshold variable and the sump tolerance value,wherein halting the freeze prevention operation is in response to determining the sump temperature data is greater than a second sump threshold value.

20. The method of claim 11, wherein comparing the sump temperature data to the first sump threshold value comprisesdetermining the sump temperature data is greater than the first sump threshold value,wherein comparing the sump temperature data to the second sump threshold value in response determining the sump temperature data is greater than the first sump threshold value.

Images