TEMPERATURE EVALUATIONS USING WATER TEMPERATURE AND HUMIDITY SENSOR IN A WASHING MACHINE

Abstract

A laundry appliance includes a tub, a drum rotatably mounted within the tub and defining a chamber configured for receiving a load of clothes, a water temperature sensor in the tub, and a humidity sensor having an air temperature sensor in an exhaust in fluid communication with the chamber. A controller is configured to take a series of readings from the water temperature sensor and the air temperature sensor, to determine a difference or average of the temperature changes in those sensors, and to compare the rate of temperature change over time. Where the controller determines that the rate of change between the water temperature sensor and the air temperature sensor is inconsistent, the controller provides a notification to the user that one or both of the temperature sensors is in error and requires servicing.

Claims

1. A laundry appliance comprising: a cabinet; a tub within the cabinet; a drum rotatably mounted within the tub and defining a chamber; an exhaust in fluid communication with the chamber; a first temperature sensor; a second temperature sensor; a controller operably coupled to the first temperature sensor and the second temperature sensor, the controller being configured to: execute a wash cycle; receive a first temperature from the first temperature sensor; receive a first temperature from the second temperature sensor; receive a second temperature from the first temperature sensor; receive a second temperature from the second temperature sensor; determine the temperature change of the first temperature sensor and the second temperature sensor based at least in part on the first temperature and the second temperature of the first temperature sensor and the second temperature sensor; compare the temperature change of the first temperature sensor to the temperature change of the second temperature sensor; determine if either of the first temperature sensor or the second temperature sensor are malfunctioning based on the comparison.

2. The laundry appliance of claim 1, wherein the controller is further configured to provide a notification to the user if it is determined that either of the first temperature sensor or the second temperature sensor are malfunctioning.

3. The laundry appliance of claim 1, wherein the first temperature sensor is disposed in the tub.

4. The laundry appliance of claim 3, wherein the first temperature sensor measures a water temperature.

5. The laundry appliance of claim 1, wherein the second temperature sensor is disposed in the exhaust.

6. The laundry appliance of claim 5, wherein the second temperature sensor measures an air temperature.

7. The laundry appliance of claim 6, wherein the second temperature sensor is part of a humidity sensor.

8. The laundry appliance of claim 1, wherein the temperature change of the first temperature sensor and the second temperature sensor is an average change of temperature of the first temperature sensor and the second temperature sensor based on a plurality of temperature readings of the first temperature sensor and the second temperature sensor.

9. The laundry appliance of claim 8, wherein comparing the temperature change of the first temperature sensor and the second temperature sensor further includes comparing the average change of temperature of the first temperature sensor and the second temperature sensor.

10. The laundry appliance of claim 1, wherein determining if either of the first temperature sensor or the second temperature sensor are malfunctioning further includes determining whether the temperature change of the first temperature sensor is consistent with the temperature change of the second temperature sensor.

11. The laundry appliance of claim 10, wherein the temperature change of the first temperature sensor is consistent with the temperature change of the second temperature sensor if the temperature change of the first temperature sensor and the second temperature sensor both increase, decrease, or remain the same.

12. The laundry appliance of claim 10, wherein the temperature change of the first temperature sensor is not consistent with the temperature change of the second temperature sensor if the temperature change of one of the first temperature sensor or the second temperature sensor has a temperature change and the other does not.

13. The laundry appliance of claim 1, wherein the wash cycle continues if it is determined that the first temperature sensor and the second temperature sensor are not malfunctioning.

14. The laundry appliance of claim 13, wherein the controller is further configured to repeat the steps of receiving the first temperature and the second temperature from the first temperature sensor and the second temperature sensor, determining the temperature change of the first temperature sensor and the second temperature sensor, comparing the temperature change of the first temperature sensor and the second temperature sensor, and determining if either of the first temperature sensor or the second temperature sensor is malfunctioning throughout the wash cycle.

15. A method for monitoring for temperature sensor malfunctions in a laundry appliance having a cabinet, a tub within the cabinet, a drum rotatably mounted within the tub and defining a chamber, an exhaust in fluid communication with the chamber, a first temperature sensor in the tub for measuring water temperature, and a second temperature sensor in a humidity sensor disposed in the exhaust for measuring air temperature, the method comprising: executing a wash cycle; receiving a first temperature from the first temperature sensor; receiving a first temperature from the second temperature sensor; receiving a second temperature from the first temperature sensor; receiving a second temperature from the second temperature sensor; determining the temperature change of the first temperature sensor and the second temperature sensor based at least in part on the first temperature and the second temperature of the first temperature sensor and the second temperature sensor; comparing the temperature change of the first temperature sensor to the temperature change of the second temperature sensor; determining if either of the first temperature sensor or the second temperature sensor are malfunctioning based on the comparison.

16. The method of claim 15, wherein the method further comprises providing a notification to the user if it is determined that either of the first temperature sensor or the second temperature sensor are malfunctioning.

17. The method of claim 15, wherein the temperature change of the first temperature sensor and the second temperature sensor is an average change of temperature of the first temperature sensor and the second temperature sensor based on a plurality of temperature readings of the first temperature sensor and the second temperature sensor.

18. The method of claim 17, wherein comparing the temperature change of the first temperature sensor and the second temperature sensor further includes comparing the average change of temperature of the first temperature sensor and the second temperature sensor.

19. The method of claim 15, wherein determining if either of the first temperature sensor or the second temperature sensor are malfunctioning further includes determining the temperature change of the first temperature sensor is consistent with the temperature change of the second temperature sensor.

20. The method of claim 19, wherein the temperature change of the first temperature sensor is not consistent with the temperature change of the second temperature sensor if the temperature change of one of the first temperature sensor or the second temperature sensor has a temperature change, and the other does not.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0010] 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.

[0011] FIG. 1 provides a perspective view of an exemplary washing machine appliance according to an exemplary embodiment of the present subject matter.

[0012] FIG. 2 provides a side cross-sectional view of the exemplary washing machine appliance of FIG. 1.

[0013] FIG. 3 provides a perspective view of a fan and humidity sensor within a washing machine appliance according to an exemplary embodiment of the present subject matter.

[0014] FIG. 4 provides a graph of temperature over time for a functioning air temperature sensor and a functioning water temperature sensor according to an exemplary embodiment of the present subject matter.

[0015] FIG. 5 provides a flow diagram illustrating a portion of an exemplary process for monitoring for temperature sensor malfunctions according to an exemplary embodiment of the present subject matter.

[0016] 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

[0017] 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.

[0018] 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”). Approximating language, as used herein throughout the specification and claims, is 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 “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. For example, the approximating language may refer to being within a 10 percent margin.

[0019] Referring now to the figures, an exemplary laundry appliance that may be used to implement aspects of the present subject matter will be described. Specifically, FIG. 1 is a perspective view of an exemplary horizontal axis washing machine appliance 100 and FIG. 2 is a side cross-sectional view of washing machine appliance 100. As illustrated, washing machine appliance 100 generally defines a vertical direction V, a lateral direction L, and a transverse direction T, each of which is mutually perpendicular, such that an orthogonal coordinate system is generally defined. Washing machine appliance 100 includes a cabinet 102 that extends between a top 104 and a bottom 106 along the vertical direction V, between a left side 108 and a right side 110 along the lateral direction, and between a front 112 and a rear 114 along the transverse direction T (FIG. 2).

[0020] Referring to FIG. 2, a drum 120 is rotatably mounted within cabinet 102 such that it is rotatable about an axis of rotation A. A motor 122, e.g., such as a pancake motor, is in mechanical communication with drum 120 to selectively rotate drum 120 (e.g., during an agitation or a rinse cycle of washing machine appliance 100). Drum 120 is received within a wash tub 124 and defines a wash chamber 126 that is configured for receipt of articles for washing. The wash tub 124 holds wash and rinse fluids for agitation in drum 120 within wash tub 124. As used herein, “wash fluid” may refer to water, detergent, fabric softener, bleach, or any other suitable wash additive or combination thereof. Indeed, for simplicity of discussion, these terms may all be used interchangeably herein without limiting the present subject matter to any particular “wash fluid.”

[0021] Drum 120 may define one or more agitator features that extend into wash chamber 126 to assist in agitation and cleaning articles disposed within wash chamber 126 during operation of washing machine appliance 100. For example, as illustrated in FIG. 2, a plurality of ribs 128 extends from basket 120 into wash chamber 126. In this manner, for example, ribs 128 may lift articles disposed in drum 120 during rotation of drum 120.

[0022] Referring generally to FIGS. 1 and 2, cabinet 102 also includes a front panel 130 which defines an opening 132 that permits user access to drum 120 of wash tub 124. More specifically, washing machine appliance 100 includes a door 134 that is positioned over opening 132 and is rotatably mounted to front panel 130. In this manner, door 134 permits selective access to opening 132 by being movable between an open position (not shown) facilitating access to a wash tub 124 and a closed position (FIG. 1) prohibiting access to wash tub 124.

[0023] A window 136 in door 134 permits viewing of drum 120 when door 134 is in the closed position, e.g., during operation of washing machine appliance 100. Door 134 also includes a handle (not shown) that, e.g., a user may pull when opening and closing door 134. Further, although door 134 is illustrated as mounted to front panel 130, it should be appreciated that door 134 may be mounted to another side of cabinet 102 or any other suitable support according to alternative embodiments. Washing machine appliance 100 may further include a latch assembly 138 (see FIG. 1) that is mounted to cabinet 102 and/or door 134 for selectively locking door 134 in the closed position and/or confirming that the door is in the closed position. Latch assembly 138 may be desirable, for example, to ensure only secured access to wash chamber 126 or to otherwise ensure and verify that door 134 is closed during certain operating cycles or events.

[0024] Referring again to FIG. 2, drum 120 also defines a plurality of perforations 140 in order to facilitate fluid communication between an interior of drum 120 and wash tub 124. A sump 142 is defined by wash tub 124 at a bottom of wash tub 124 along the vertical direction V. Thus, sump 142 is configured for receipt of and generally collects wash fluid during operation of washing machine appliance 100. For example, during operation of washing machine appliance 100, wash fluid may be urged by gravity from drum 120 to sump 142 through plurality of perforations 140.

[0025] A drain pump assembly 144 is located beneath wash tub 124 and is in fluid communication with sump 142 for periodically discharging soiled wash fluid from washing machine appliance 100. Drain pump assembly 144 may generally include a drain pump 146 which is in fluid communication with sump 142 and with an external drain 148 through a drain hose 150. During a drain cycle, drain pump 146 urges a flow of wash fluid from sump 142, through drain hose 150, and to external drain 148. More specifically, drain pump 146 includes a motor (not shown) which is energized during a drain cycle such that drain pump 146 draws wash fluid from sump 142 and urges it through drain hose 150 to external drain 148.

[0026] A spout 152 is configured for directing a flow of fluid into wash tub 124. For example, spout 152 may be in fluid communication with a water supply 154 (FIG. 2) in order to direct fluid (e.g., clean water or wash fluid) into wash tub 124. Spout 152 may also be in fluid communication with the sump 142. For example, pump assembly 144 may direct wash fluid disposed in sump 142 to spout 152 in order to circulate wash fluid in wash tub 124.

[0027] As illustrated in FIG. 2, a detergent drawer 156 is slidably mounted within front panel 130. Detergent drawer 156 receives a wash additive (e.g., detergent, fabric softener, bleach, or any other suitable liquid or powder) and directs the fluid additive to wash tub 124 during operation of washing machine appliance 100. According to the illustrated embodiment, detergent drawer 156 may also be fluidly coupled to spout 152 to facilitate the complete and accurate dispensing of wash additive. It should be appreciated that according to alternative embodiments, these wash additives could be dispensed automatically via a bulk dispensing unit (not shown). Other systems and methods for providing wash additives are possible and within the scope of the present subject matter.

[0028] In addition, a water supply valve 158 may provide a flow of water from a water supply source (such as a municipal water supply 154) into detergent dispenser 156 and into wash tub 124. In this manner, water supply valve 158 may generally be operable to supply water into detergent dispenser 156 to generate a wash fluid, e.g., for use in a wash cycle, or a flow of fresh water, e.g., for a rinse cycle. It should be appreciated that water supply valve 158 may be positioned at any other suitable location within cabinet 102. In addition, although water supply valve 158 is described herein as regulating the flow of “wash fluid,” it should be appreciated that this term includes, water, detergent, other additives, or some mixture thereof.

[0029] Referring again to FIG. 1, control panel 160 including a plurality of input selectors 162 is coupled to front panel 130. Control panel 160 and input selectors 162 collectively form a user interface input for operator selection of machine cycles and features. For example, in one embodiment, a display 164 indicates selected features, a countdown timer, and/or other items of interest to machine users. Operation of washing machine appliance 100 is controlled by a controller or processing device 166 that is operatively coupled to control panel 160 for user manipulation to select washing machine cycles and features. In response to user manipulation of control panel 160, controller 166 operates the various components of washing machine appliance 100 to execute selected machine cycles and features.

[0030] Controller 166 may include a memory and microprocessor, such as a general or special purpose microprocessor operable to execute programming instructions or micro-control code associated with a cleaning cycle. 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 166 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. Control panel 160 and other components of washing machine appliance 100 may be in communication with controller 166 via one or more signal lines or shared communication busses.

[0031] During operation of washing machine appliance 100, laundry items are loaded into drum 120 through opening 132, and washing operation is initiated through operator manipulation of input selectors 162. Wash tub 124 is filled with water, detergent, and/or other fluid additives, e.g., via spout 152 and/or detergent drawer 156. One or more valves (e.g., water supply valve 158) can be controlled by washing machine appliance 100 to provide for filling drum 120 to the appropriate level for the amount of articles being washed and/or rinsed. By way of example for a wash mode, once drum 120 is properly filled with fluid, the contents of drum 120 can be agitated (e.g., with ribs 128) for washing of laundry items in drum 120.

[0032] After the agitation phase of the wash cycle is completed, wash tub 124 can be drained. Laundry articles can then be rinsed by again adding fluid to wash tub 124, depending on the particulars of the cleaning cycle selected by a user. Ribs 128 may again provide agitation within drum 120. One or more spin cycles may also be used. In particular, a spin cycle may be applied after the wash cycle and/or after the rinse cycle in order to wring wash fluid from the articles being washed. During a final spin cycle, drum 120 is rotated at relatively high speeds and drain assembly 144 may discharge wash fluid from sump 142. After articles disposed in drum 120 are cleaned, washed, and/or rinsed, the user can remove the articles from drum 120, e.g., by opening door 134 and reaching into drum 120 through opening 132.

[0033] Notably, controller 166 of washing machine appliance 100 (or any other suitable dedicated controller) may be communicatively coupled to control panel 160 and input selectors 162, and other components of washing machine appliance 100, such as fan 204, humidity sensor 202, first temperature sensor 216, and second temperature sensor 218 as described below. As explained in more detail below, controller 166 may be programmed or configured for automating elements of the washing machine appliance 100 at particular times as part of particular cycles, e.g., such as initiating an automated drying cycle upon completion of a self-cleaning cycle with little or no user intervention.

[0034] 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 with washing machine appliance 100. For example, this communication may be used to provide and receive operating parameters, cycle settings, performance characteristics, user preferences, user notifications, or any other suitable information for improved performance of washing machine appliance 100.

[0035] External communication system 190 permits controller 166 of washing machine appliance 100 to communicate with external devices either directly or through a network 192. For example, a consumer may use a consumer device 194 to communicate directly with washing machine appliance 100. For example, consumer devices 194 may be in direct or indirect communication with washing machine appliance 100, e.g., directly through a local area network (LAN), Wi-Fi, Bluetooth, Zigbee, etc. or indirectly through network 192. In general, consumer device 194 may be any suitable device for providing and/or receiving communications or commands from a user. In this regard, consumer device 194 may include, for example, a personal phone, a tablet, a laptop computer, or another mobile device.

[0036] In addition, a remote server 196 may be in communication with washing machine appliance 100 and/or consumer device 194 through network 192. 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. In general, communication between the remote server 196 and the client devices may be carried via a network interface using any type of wireless connection, using a variety of communication protocols (e.g. TCP/IP, HTTP, SMTP, FTP), encodings or formats (e.g. HTML, XML), and/or protection schemes (e.g. VPN, secure HTTP, SSL).

[0037] In general, network 192 can be any type of communication network. For example, network 192 can include one or more of a wireless network, a wired network, a personal area network, a local area network, a wide area network, the internet, a cellular network, etc. According to an exemplary embodiment, consumer device 194 may communicate with a remote server 196 over network 192, such as the internet, to provide user inputs, transfer operating parameters or performance characteristics, receive user notifications or instructions, etc. In addition, consumer device 194 and remote server 196 may communicate with washing machine appliance 100 to communicate similar information.

[0038] 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 laundry 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.

[0039] Referring again to the embodiment of FIG. 1, door 134 may further include air intake openings 206. Air intake openings 206 may be one or more openings in door 134 that permit air to pass between the outside and the inside of wash tub 124. To enable this function, air intake openings 206 may be located on both the interior and exterior surfaces of door 134. In some embodiments, air intake openings 206 may constitute numerous small, individual openings. In alternative embodiments, air intake openings 206 may constitute only a single opening. The surface area of the air intake openings 206 (or the combined surface area in the case of multiple air intake openings 206) may be varied to control, in part, the flow of air between the exterior and interior of the tub. In some embodiments, it may be desirable to include a screen or other filter (not pictured) over the air intake openings to discourage the passage of lint or other solids from entering the wash tub 124. Although air intake openings 206 are located in door 134 in the embodiment of FIG. 1, it will be recognized that air intake openings 206 may be located elsewhere on washing machine appliance 100 in alternative embodiments. Indeed, air intake openings 206 may be located anywhere that would allow passage of air between the inside and the outside of wash tub 124, such as on a surface of cabinet 130.

[0040] As shown in FIG. 1, washing machine appliance 100 may further include a damper 208. In the embodiment of FIG. 1, damper 208 may include a first end 210 and a second end 212. A damper opening 214 may be located at the second end 212 of damper 208. Damper 208 may be movable between an open and closed position, wherein the open position is characterized by alignment of damper opening 214 with air intake openings 206 and the closed position is characterized by alignment of the first end 210 of damper 208 with air intake openings 206. When in the closed position, damper 208 blocks the passage of air between the inside and the outside of wash tub 124. Conversely, in the open position, damper 208 permits such air flow. Although a particular embodiment of damper 208 is provided in FIG. 1, it will be recognized that other embodiments for selectively permitting air flow into the wash tub 124 through air intake openings 206 fall within the scope of the present disclosure. For example, in some embodiments, damper 208 may lack a damper opening 214 altogether. In such an embodiment, the open position of damper 208 is characterized by no portion of damper 208 being position in alignment with air intake openings 206. In still other embodiments, damper opening 214 may consist of a plurality of openings corresponding to the plurality air intake openings 206. In such embodiment, opening or closing of damper 208 need not involve movement from a first end 210 to a second end 212 (or vice versa), but rather shifting of the alignment of the plurality of damper openings 214 with the plurality of air intake openings 206. In still other embodiments, damper 208 may consist of a series of planar elements aligned with the air intake openings 206 that individually rotate about a vertical axis, the rotation resulting in covering and uncovering the air intake openings 206. Those of ordinary skill will recognize that other embodiments of a moving damper that selectively allow air flow through the air intake openings 206 are intended to fall within the scope of the present disclosure.

[0041] Referring now to FIG. 3, washing machine appliance 100 further includes an exhaust 200. Exhaust 200 couples tub 124 to the exterior of cabinet 102, proving a path to exhaust air from tub 124 and chamber 126. Exhaust 200 further includes a fan 204, a conduit 205, and humidity sensor 202. Fan 204 may be positioned on the rear 114 of cabinet 102. Fan 204 may be attached to conduit 205. Conduit 205 may be further attached to wash tub 124. Fan 204 operates by drawing air out of wash tub 124, through conduit 205, and exhausting the air from washing machine appliance 100. Washing machine appliance may further include a humidity sensor 202 for measuring the humidity of the air being exhausted from wash tub 124. As shown in FIG. 3, fan 204 is situated along the rear 114 of cabinet 102 and humidity sensor 202 is situated in close proximity to fan 204. However, in alternative embodiments, fan 204 and humidity sensor 202 may be located in alternative locations, so long as fan 204 serves to draw air from wash tub 124 and exhaust it from washing machine appliance 100, and humidity sensor 202 is positioned to read the humidity level of this exhausted air.

[0042] Washing machine appliance 100 may further include a first temperature sensor 216 (FIG. 2). First temperature sensor 216 may, in some embodiments, be situated at least partially within tub 124. Preferably, in these embodiments, first temperature sensor may be situated near a bottom of tub 124 to aid in measuring the temperature of water within tub 124 even when the water volume is low. In alternative embodiments, first temperature sensor 216 may be located at a water inlet to tub 124. Alternative locations are possible and are intended to fall within the scope of the present disclosure, though its location should be downstream of the point where hot and cold water are mixed. First temperature sensor 216, in one embodiment, measures water temperature. The temperature reading of first temperature sensor 216 may be used, for example, to control the flow of hot water, cold water, or both to alter the temperature of water used in a given cycle.

[0043] Washing machine appliance 100 may further include a second temperature sensor 218 (FIG. 3). In some embodiments, temperature sensor 218 may be situated within exhaust 200 and may measure the temperature of air exhausted from tub 124. Second temperature sensor 218 may be an element of humidity sensor 202, in some embodiments, or may be a separate and independent from humidity sensor 202 in alternative embodiments. Where humidity sensor 202 measures relative humidity (i.e., a measurement of water vapor in the air relative to the temperature), it is common for the humidity sensor 202 to include a temperature sensor which may be used as second temperature sensor 218. In alternative embodiments, second temperature sensor 218 may also measure water temperature and may be situated with tub 124 or at such other location downstream of the introduction of hot and cold water.

[0044] Referring now to FIG. 4, the initiation of a wash cycle may begin a process of taking readings from first temperature sensor 216 and second temperature sensor 218. FIG. 4 provides a graph of such temperature readings over time in an embodiment including first temperature sensor 216 measuring the temperature of water within tub 124 (lower graph line) and second temperature sensor 218 measuring air temperature within exhaust 200 (upper graph line) of washing machine appliance 200. As shown, although the temperature of the exhaust air is substantially higher than the temperature of the water measured, the temperatures trends are consistent with one another insofar as a rise in the water temperature is reflected in a rise in air temperature at the exhaust. As a result, by measuring the temperature of both and comparing the results, it can be determined whether one of the first temperature sensor 216 and second temperature sensor 218 has malfunctioned (i.e., one registers a temperature change over time and the other does not).

[0045] While described in the context of a specific embodiment of horizontal axis washing machine appliance 100, using the teachings disclosed herein it will be understood that horizontal axis washing machine appliance 100 is provided by way of example only. Other washing machine appliances having different configurations, different appearances, and/or different features may also be utilized with the present subject matter as well, e.g., a combination washer/dryer appliance.

[0046] Now that the construction of washing machine appliance 100 and the configuration of controller 166 according to exemplary embodiments have been presented, an exemplary method 300 of operating a washing machine appliance will be described. Referring now to FIG. 5, method 300 includes, at step 310, commencing a washing cycle. During the course of the wash cycle, controller 166 receives a series of temperature readings from the first temperature sensor 216 and the second temperature sensor 218. In particular, method 300 requires at least receiving a first temperature from the first temperature sensor 216 (step 320), a first temperature from the second temperature sensor 218 (step 330), a second temperature from the first temperature sensor 216 (step 340), and a second temperature from the second temperature sensor 218 (step 350).

[0047] This temperature data is used by controller 166 to determine a temperature change associated with the first temperature sensor 216 and a temperature change associated with the second temperature sensor 218 at step 360. This temperature change is based at least in part on the first temperature and the second temperature of the first temperature sensor 216 and the second temperature sensor 218 at steps 320 through 350. It will be understood that the temperature change is not limited to these data points, however. For example, in certain embodiments, controller 166 may receive a plurality of temperature readings over time from first temperature sensor 216 and second temperature sensor 218. In this scenario, the temperature change determined by controller 166 may be an average change of temperature associated with first temperature sensor 216 and second temperature sensor 218 over a fixed period of time, for example. In alternative embodiments, the temperature change may reflect the absolute differences between the first temperature reading and the most recent temperature reading in each of the first temperature sensor 216 and the second temperature sensor 218. Other techniques for determining the change of temperatures will be apparent to those skilled in the art and are intended to fall within the scope of the present subject matter.

[0048] At step 370 of method 300, the temperature change associated with the first temperature sensor 216 is compared to the temperature change associated with the second temperature sensor 218 and controller 166 determines if either of the first temperature sensor or the second temperature sensor are malfunctioning. In comparing the temperature change associated with the first temperature sensor 216 with the temperature change associated with the second temperature sensor 218, it will be understood that the temperature changes are based on measurements using like techniques. For example, in embodiments where a plurality of temperature readings from first temperature sensor 216 and temperature sensor 218 are received and averaged, the controller 166 will compare the average temperature change associated with first temperature sensor 216 to the average temperature change associated with second temperature sensor 218. Alternatively, where an absolute difference is determined at step 360, the comparison will be between those absolute differences in temperature change.

[0049] In determining if either of the first temperature sensor 216 or second temperature sensor 218 are malfunctioning, controller 166 determines whether the temperature change of the first temperature sensor is consistent with the temperature change of the second temperature sensor. As used herein, consistency of the temperature changes is not intended to require precise equality between the temperature changes associated with first temperature sensor 216 and second temperature sensor 218. Rather, consistency is intended to be measured by the temperature trend of the temperature change.

[0050] For example, in a hot wash cycle, it would be expected for the water temperature and air temperatures to rise during the course of the wash cycle. If both the first temperature sensor 216 and the second temperature sensor 218 are working properly, both will reflect this rise in temperature. However, the air temperature will be a function of the water temperature and will necessarily lag behind. Thus, even in a perfectly operating laundry appliance, the second temperature sensor 218 may not reflect a temperature rise over exactly the same time frame that the first temperature sensor 216 registers a rise in temperature. Nor will the temperature rises be identical due to a variety of factors, including at least heat absorption by articles of laundry and other portions of the appliance and due to the imprecision of the temperature sensors themselves. Thus, the term consistency, as used herein, may be attained if the first temperature sensor 216 and the second temperature sensor 218 both register an increase in temperature over an extended period of time (e.g., 180 seconds). Consistency would likewise be achieved if both sensors registered a decrease or both registered a maintaining of temperature over time. By contrast, the temperature changes associated with first temperature sensor 216 and second temperature sensor 218 would be inconsistent if the temperature change of one of the first temperature sensor 216 or the second temperature sensor 218 has a temperature change over the extended period of time and the other does not.

[0051] If it is determined at step 370 that the temperature changes of first temperature sensor 216 and second temperature sensor 218 are consistent, the wash cycle simply continues, as shown at step 380. However, if it is determined at step 370 that the temperature changes of first temperature sensor 216 and second temperature sensor 218 are inconsistent, this is an indication that one or both of first temperature sensor 216 and second temperature sensor 218 are malfunction. Continued use of the washing machine appliance 100 may therefore lead to less effective washing cycles and a poor perception of the appliance itself. Accordingly, in the case of inconsistent temperature changes, a notification may be provided to the user that first temperature sensor 216 or second temperature sensor 218 are faulty, or that service is otherwise required. This notification may take the form of a light or other signal on control panel 160 or display 164 in certain embodiments. In alternative embodiments, the notification may take the form of an indication sent to consumer device 164. In still other embodiments, the fault may be relayed to a remote server 196, which may result in a message being delivered to the user. Alternatively, combinations of the above forms of notification may be employed. Regardless of the form of notification, the wash cycle may continue, as the fault does not present a safety issue.

[0052] It will be understood that method 300 may further include repeated checks of the temperature sensors during a given wash cycle. That is the controller 166 may be configured to repeat the steps of receiving the first temperature and the second temperature from the first temperature sensor and the second temperature sensor, determining the temperature change of the first temperature sensor and the second temperature sensor, comparing the temperature change of the first temperature sensor and the second temperature sensor, and determining if either of the first temperature sensor or the second temperature sensor is malfunctioning throughout the wash cycle. Thus, method 300 may be understood to be an iterative process.

[0053] FIG. 5 depicts steps performed in a particular order for purposes of illustration and discussion. Those of ordinary skill in the art, using the disclosures provided herein, will understand that the steps of any of the methods discussed herein can be adapted, rearranged, expanded, omitted, or modified in various ways without deviating from the scope of the present disclosure. Moreover, although aspects of method 300 are explained using washing machine appliance 100 as an example, it should be appreciated that these methods may be applied to the operation of any suitable washing machine appliance.

[0054] 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.