Patent Publication Number: US-9884354-B2

Title: Water dispenser with a cleaning mechanism

Description:
FIELD OF THE INVENTION 
     The subject matter relates generally to water dispensers, and more specifically to mineral water dispensers having a cleaning mechanism. 
     BACKGROUND OF THE INVENTION 
     Water dispensers are used in both businesses and for residential use to provide available water to users. The demands to ensure safety of drinking water and to pursue the quality in natural character of drinking water have been increased according to the increase of users&#39; interest with respect to drinking water. 
     Water dispensers may provide users with filtered water. Such filtered water is received at the water dispenser from a central water system and filtered via a filtering module within the water dispenser. Other water dispensers provide users with mineral water. Such mineral water is packaged in periodically replaced containers. The containers have an outlet connected to a faucet from which the water is dispensed. 
     Water dispensers having water containers or filtered water suffer from contamination of the tubes in the water dispenser. The tube provides water from the central water system or from the water container to the faucet from which the water is provided to the consumer. Such contamination significantly reduces water quality of the water dispenser. It is desired to provide a system and method for treating such contamination in water dispensers. 
     SUMMARY 
     The subject matter discloses a water dispenser apparatus, comprising a cold water tank, a hot water tank and a water outlet for dispensing water from the water dispenser apparatus, said water outlet is connected to the hot water tank and to the cold water tank. The water dispenser apparatus further comprises a suction unit for sucking water from a water tank selected from a group consisting of the cold water tank and the hot water tank, the suction unit is configured to clean tubes and tanks at the water dispenser apparatus and to transfer said water at tubes within the water dispenser apparatus. 
     In some embodiments, the suction unit comprises a suction tube connected to the cold water rank, a suction unit connected to the suction tube, configured to suck water from the cold water tank via the suction tube and a suction valve allowing water to flow from the suction tube to the hot water tank. 
     In some embodiments, the apparatus further comprises an outlet valve for controlling water dispensing from the water outlet. 
     In some embodiments, the apparatus further comprises a hot unit valve for controlling water flow from the suction unit to the hot water tank. 
     In some embodiments, the hot water is transferred from the hot water tank to tubes within the water dispenser when the hot unit valve allows water to flow from the suction unit to the hot water tank. 
     In some embodiments, the apparatus further comprises a cold unit valve for controlling water flow to a cold suction tube. 
     In some embodiments, the cleaning tubes at the water dispensing apparatus comprises cleaning a hot outlet tube and at a cold outlet tube. 
     In some embodiments, the cleaning the hot outlet tube and the cold outlet tube is performed when the cold unit valve is in a closed state, the hot unit valve is in an open state and the suction valve is in an open state. 
     In some embodiments, the cleaning the cold suction tube is performed when the cold unit valve is in an open state, the hot unit valve is in a closed state and the suction valve is in an open state. 
     In some embodiments, a user of the water dispenser activates the suction unit. In some embodiments, a control unit activates the suction unit automatically. 
     The subject matter discloses a water dispenser apparatus, comprising:
         a water container for containing water to be dispensed to a user of the water dispenser apparatus;   a cold water tank for receiving water from the water container;   a hot water tank for receiving water from the water container,   a suction unit for pumping water from the water container towards the cold water tank and the hot water tank;   a water outlet for dispensing water from the water dispenser apparatus, said water outlet is connected to the hot water tank and to the cold water tank;   wherein the suction unit is connected to the outlet of the suction tube for sucking water from the suction tube;   the suction unit is configured to clean tubes and tanks at the water dispenser apparatus and to transfer said water at tubes within the water dispenser apparatus.       

     The subject matter discloses a hot/cold water dispenser comprising: a housing enclosing a water container containing water; a water supply system configured to selectively supply water contained in said water container to a hot water reservoir and a cold water reservoir and further configured to selectively provide hot water from said hot water reservoir and cold water from said cold water reservoir to a user of said hot/cold water dispenser, and a fluid pump fluidly coupling a fluid flow system and said water supply system and being operable to pump a quantity of hot water from said hot water reservoir to an empty water container via said fluid flow system, wherein subsequent to emptying a predetermined number of said water containers, said fluid pump is activated for a first predetermined time period to pump said quantity of hot water to said empty water container via said fluid flow system thereby said quantity of hot water cleanses said fluid flow system and said empty water container. 
     The subject matter also discloses a method for cleansing a hot/cold water dispenser comprising: providing said hot/cold water dispenser, comprising: a housing enclosing a water container, and a water supply system configured to selectively supply water contained in said mineral water container to a hot water reservoir and a cold water reservoir and further configured to selectively provide hot water from said hot water reservoir and cold water from said cold water reservoir to a user of said hot/cold water dispenser, configuring a fluid pump to pump a quantity of hot water for a first predetermined time period from said hot water reservoir to an empty water container via a fluid flow system, and cleansing said mineral water container and said fluid flow system for a second predetermined time period with said quantity of hot water. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       Exemplary non-limited embodiments of the disclosed subject matter will be described, with reference to the following description of the embodiments, in conjunction with the figures. The figures are generally not shown to scale and any sizes are only meant to be exemplary and not necessarily limiting. Corresponding or like elements are optionally designated by the same numerals or letters. 
         FIG. 1  shows a water dispensing apparatus having a cleaning system, according to some exemplary embodiments of the subject matter; 
         FIG. 2  shows a flow of water at a water dispensing apparatus during a cleaning process, according to exemplary embodiments of the disclose subject matter; 
         FIG. 3  shows a flow of water at a cold suction tube of a water dispensing apparatus during a cleaning process, according to exemplary embodiments of the disclose subject matter; 
         FIG. 4  schematically presents a hot/cold water dispenser in an arrangement for cleansing a mineral water container and an associated fluid flow system, in accordance with an embodiment of the present invention; and 
         FIG. 5  schematically presents the hot/cold dispenser in an arrangement for draining the residual hot water from the hot/cold water dispenser, in accordance with an embodiment of the present invention. 
     
    
    
     DETAILED DESCRIPTION 
     The disclosed subject matter provides for a water dispensing apparatus for residential or business use. The subject matter provides a method and system for cleaning the water dispensing apparatus. Such cleaning may be enabled by adding a tube connected to one of the cold water tank or the hot water tank of the water dispensing apparatus and using a suction unit. The suction unit sucks water from one of the water tanks disclosed above and via a plurality of valves. The valves control water flow at tubes within the water dispensing apparatus, such that when cleaning, water flows in a closed system manner at the water tanks and tubes and does not exit the water dispensing apparatus. 
       FIG. 1  shows a water dispensing apparatus having a cleaning system, according to some exemplary embodiments of the subject matter. The water dispensing apparatus  105  is disposed in a housing  110 . The housing  110  covers other parts of the water dispensing apparatus, such as tubes, cold water unit, hot water unit and the like. The water dispensing apparatus  105  comprises an outlet  158  from which water are dispensed from the water dispensing apparatus  105 . 
     The water dispensing apparatus  105  comprises a water supplying unit  115 . The water supplying unit  115  may be a mineral water container. The water supplying unit  115  may be a bag in a box (BIB) unit, in which the water are contained in a bag, such as a plastic bag, and the bag is disposed in a rigid or semi rigid box, for protection. The water supplying unit  115  may be connected to a central water system from which water is provided to the water dispensing apparatus  105 . In such case, water may be filtered or purified at the water dispensing apparatus  105 . The water supplying unit  115  is connected to a supply valve  182 . The supply valve  182  controls water supply from the water supplying unit  115  to the rest of the water dispensing apparatus  105 , towards the outlet  158 . 
     The water dispensing apparatus  105  further comprises a hot water unit  120 . The hot water unit  120  comprises a heating unit  122  for heating water contained in a hot water tank  125 . The hot water tank  125  is connected to the outlet  158  via a hot outlet tube  165  and an outlet valve  148 . 
     The water dispensing apparatus  105  further comprises a cold water unit  130 . The cold water unit  130  comprises a temperature sensor  132  for detecting temperature of water contained in a cold water tank  135 . The cold water tank  135  is connected to the outlet  158  via a cold outlet tube  155  and an outlet valve  148 . The water dispensing apparatus  105  further comprises a suction unit  140 . When cleaning tubes and tanks at the water dispensing apparatus, the suction unit  140  is connected to at least one of the cold water unit  130  or the hot water unit  120  and sucks water from at least one of them. 
     The suction unit  140  is connected to a power supply (not shown). The suction unit is connected to a control unit  177 , from which the suction unit  140  receives a command to perform suction. The control unit  177  may also determine the unit from which the suction unit  140  sucks water, for example the hot water unit or the cold water unit. 
     In some exemplary cases, the water dispensing apparatus  105  further comprises a cold suction tube  150  connecting the cold water unit  130  to the suction unit  140 . When cleaning the tubes of the water dispensing apparatus  105 , the suction unit  140  may suck water from the cold water tank  135  via the cold suction tube. The suction unit is located near a cold unit valve  142  and a hot unit valve  145 . When sucking water from the cold water tank  135 , the amount of water at the cold water tank  135  reduces while water is transferred at the cold suction tube  150 . In some exemplary cases, the cold water tank  135  contains water in the range of 1.5-2 liters. A cooling unit  137  regulates the water temperature at the cold water tank  135 . When cleaning the tubes and tanks of the water dispensing apparatus, the flow rate of water sucked from the cold water tank  135  by the suction unit  140  may be, for example, in the range of 0.001-3 liters per minute. 
     In some exemplary cases, the suction unit  140  is configured to pump water from the water supplying unit  115  to the cold water tank  135  and to the hot water tank  125 . This way, water from the water supplying unit  115  cannot flow using gravitation. The suction unit  140  may be connected to the outlet of a suction tube, such as the cold suction tube  150 . In some exemplary cases, the suction tube may also be connected to the hot water tank  125 . The suction tube may be connected on a first end to the suction unit  140  and on a second end to a water tank selected from the cold water tank  135  and the hot water tank  125 . 
     Hence, the suction unit  140  may pump water from the suction tube when performing the cleaning process of the subject matter, it is shown that a single pump, the suction unit  140 , both initiates the sanitation process and delivers water from the water supplying unit  115  to the cold water tank  135  and to the hot water tank  125 . A single pump embodiment is achieved by positioning the suction tube  150  outlet in the vicinity of the suction unit  140 . A single pump that performs both the cleaning process and the water delivery is especially necessary for compact dispensing devices, for residential use. Such compact devices may be of a height of less than 60 centimeters and configured to be located on a kitchen top. 
       FIG. 2  shows a flow of water at a water dispensing apparatus during a cleaning process, according to exemplary embodiments of the disclose subject matter. In the example shown below, water is first sucked from the cold water tank  135 . In an alternative embodiment, water can be sucked from the hot water tank  125  by connecting the cold suction tube  150  to the hot water unit  120 . In an exemplary embodiment of the disclosed subject matter, cleaning the water dispenser comprises two phases. In the first phase, water flows at the hot outlet tube  165  and at the cold outlet tube  155 . In the second phase, water flows at the cold suction tube  152 , as shown in  FIG. 3 . 
     When cleaning the hot outlet tube  165  and at the cold outlet tube  155  of the water dispensing apparatus  105 , the cold unit valve  142  is in a closed state and the hot unit valve  145  is in an open state, the outlet valve  148  is in a closed state and the supply valve  182  is in a closed state. The suction valve  160  is in an open state, allowing water to flow to the suction unit  140 . Therefore, water sucked by the suction unit  140  from the cold water tank  135  cannot enter the cold water unit  130  and only flows to the hot water unit  120 . The cold unit valve  142  and the hot unit valve  145  are connected to the control unit  177  handling the cleaning process. When cleaning, the control unit  177  transmits commands to the cold unit valve  142  to be in a closed state and to the hot unit valve  145  to be in an open state. In such case, water can flow from the cold water unit  130  to the hot water unit  120  via the suction unit  140 . When a command is received from the control unit  177 , the cold unit valve  142  is in a closed state and the hot unit valve  145  is in an open state, the suction unit  140  sucks water from the cold water unit  130  and transfers the sucked water to the hot water unit  120 . 
     When water sucked from the cold water unit  130  enters the hot water unit  120 , a portion of the water previously contained at the hot water tank  125  may be pushed from the hot water tank  125  via a pressure relief tank  180  to a pressure relief tube  162 . The pressure relief tank regulates water flows upwards from the hot water tank  125  to the pressure relief tube  162  for cleaning the tubes at the first cleaning phase. Water then flows from the pressure relief tube  162  to the hot outlet tube  165  flows to the cold outlet tube  155  via the outlet valve  148  and from the cold outlet tube  155  to the cold suction tube  150 . From the cold suction tube  150 , water flows back to the hot water unit  120  via hot inlet tube  168 . Then, water flows from the hot inlet tube  168  via the hot water tank  125  to the pressure relief tube  162 . This way, water flow from the hot water tank  125  at the tubes of the cold unit and the hot unit and clean the tubes at the water dispensing apparatus  105 . 
     The pressure relief tube  162  is also connected to a drain tube  172  which leads water to a drain  170 . Water pushed from the hot water unit  120  is directed to the pressure relief tube  162  instead of the drain tube  172  by the pressure relief tank  180 . When there is excessive water at the pressure relief tank  180 , some of the water can flow to the drain  170  via the drain tube where water is gathered and later drained. The drain  170  regulates the atmospheric pressure at the tubes in the water dispensing apparatus  105 . 
     Before circulating water in the water dispensing apparatus, the condenser that cools water at the cold water tank  135  is disabled. Then, the water from the hot water tank circulates in the pumps of the water container apparatus, and water from the cold water tank  135  is circulated into the hot water tank  125 . Such circulation takes place for a period of 1-10 minutes, until the water in both the cold water tank  135  and the hot water tank  125  reaches a predefined temperature, for example 87 degrees Celsius. Then, the water is circulated in a higher speed for another period of time, for example 4 minutes. After a circulation period of about 1-10 minutes, hot water flow in the tubes of the water dispensing apparatus, and the cold water unit  130  is cleaned. The cold water tank  135 , hot water tank  125  and some of the tubes are cleaned after one circulation period. In some cases, at least a portion of the tubes of the water dispensing apparatus are also cleaned. Such tubes may be the hot inlet tube  168 , the cold outlet tube  155 , the cold suction tube  150 , pressure relief tube  162  and the hot outlet tube  165 . 
       FIG. 3  shows a method and system for cleaning a secondary cycle, according to exemplary embodiments of the disclosed subject matter. In the example disclosed above, a primary cycle is relates to the process of sucking water from one water tank and cleaning the water tank from which water is sucked. 
     In the example disclosed above, the secondary cycle refers to cleaning the cold suction tube  152 . To clean the cold suction tube  152 , the cold unit valve  142  is in an open state and the hot unit valve  145  is in a closed state and the supply valve  182  is in closed state. 
     The suction valve  160  is in an open state, allowing water to flow to the suction unit  140 . The outlet valve  148  remains closed when cleaning the cold suction tube  152 . When cleaning the cold suction tube  152 , water flows from the suction unit  140  via the cold unit valve  142  to the cold suction tube  152 . 
     Changing between cleaning the cold water tube  152  and cleaning the rest of the tubes is determined by the control unit  177 . The control unit  177  is connected to the valves and the suction unit  140 . The control unit  177  determines which of the valves are in closed state and which of the valves are in an open state. The control unit may determine the time allocated for cleaning the cold water unit  130  and the time required for cleaning the cold water tube  152 . 
     In some exemplary cases, the cold suction tube  150  added to the water dispensing apparatus  105  is connected to the hot water unit  120 , not to the cold water unit  130  as disclosed in the exemplary embodiment above. The cold suction tube  150  may be removable. In some cases, the water dispensing apparatus  105  may comprise connectors at both the hot water unit  120  and the cold water unit  130 , for enabling connection of the suction tube as an add-on and not as an integral part of the water dispensing apparatus  105 . 
     Reference is now made to  FIG. 4 , which schematically presents a hot/cold water dispenser  200  in an arrangement for cleansing a fluid flow system  206  and a fluid connector  220 . The hot/cold water dispenser  200  provides hot and/or cold water to a user by means of the water dispensing system  250 , shown schematically in  FIGS. 4 and 5  and as is known in the art. The water dispensing system  250  includes, inter alia, a hot water reservoir  214  containing hot water  215  maintained at a temperature of above 90° C. by means of a water heater  261  and a cold water reservoir  216  containing cold water  217  maintained at a temperature of about 4-15° C. by means of a water cooler  262 , as is known in the art. Selectively, mineral water  212 , contained in the mineral water container  210 , is supplied to the hot water reservoir  214  via a hot water valve  238  and a hot water conduit  237  and is supplied to the cold water reservoir  216  via a cold water valve  244  and a cold water conduit  242 . The user operates the dispenser  200  by activating hot/cold water faucets (not shown), as is known in the art, thereby selectively obtaining hot water  215  and cold water  217  from the hot/cold water dispenser  200 . 
     The hot/cold water dispenser  200  further includes, inter alia, a housing  208  enclosing the mineral water container  210 , such as a Bag-in-a-Box storage (BIB)  210  containing the mineral water  212 . 
     The fluid flow system  206  includes, inter alia, a fluid conduit  211  and a fluid connector  220 . The fluid conduit  211  fluidly couples the fluid connector  220  to a sanitation valve  213 . The BIB  210  is mechanically and fluidly coupled to the fluid connector  220  by the user of the water dispenser  200 . Typically, the user manually couples an outlet of the BIB  210  to the fluid connector  220 . The BIB  210  is in fluid communications with the fluid system  206  by means of the fluid connector  220 . 
     A fluid pump  218 , such as reversible fluid pump, is coupled between the fluid flow system  206  and the water supply system  250 , as shown in  FIG. 4 . The fluid pump  218  is operationally configured to pump a fluid in a forward pumping direction and in a reverse pumping direction. In the forward pumping direction, the fluid pump  218  pumps water in the forward flow direction from the BIB  210  to the water supply system  250  via the fluid flow system  206 . In the reverse pumping direction, the fluid pump  218  pumps water in the reverse flow direction from the water supply system  250  to the BIB  210  via the fluid flow system  206 . 
     The fluid flow system  206  is fluidly coupled to the fluid pump  218  via the sanitation valve  213  and the fluid pump  218  is fluidly coupled to the water supply system  250  via a three-way fluid junction  247 . The three-way fluid junction  247  fluidly couples the hot water reservoir  214  via the hot fluid conduit  237  and a hot flow valve  238  to the fluid pump  218 . The three-way fluid junction  247  also fluidly couples the cold water reservoir  216  to the fluid pump  218  via the cold fluid conduit  242  and a cold flow valve  244 . 
     A controller unit  226  controls the cleansing operation and is in communications with at least the fluid pump  218 , the sanitation valve  213 , the hot water valve  238  and the cold water valve  244 , as shown in  FIG. 4 , via a communications bus  256 . A display  228  is electrically coupled to the controller unit  226  and displays the operational status of the cleansing operation to a user and a control panel  252  is also electrically coupled to the controller unit  226  enabling the user to control the cleansing operation as well as supplying data and information to the controller unit  226 , as described below. 
     In accordance with another embodiment of the present invention, the hot/cold water dispenser  200  includes a water drainage system  246  which is fluidly coupled to the junction  247 , as shown in  FIG. 4 . The water drainage system  246  includes, inter alia, a drainage pump and/or drain valve  248 , a drain fluid conduit  253  and a water drain  280 . The fluid drainage system  246  provides a drainage system typically for draining residual water  270  ( FIG. 5 ) remaining in the dispenser  200  following a cleansing operation. The opening and closing of the drainage pump and/or drain valve  248  is controlled by the controller unit  226  via the communications bus  256 . 
     Following the emptying of the BIB  210 , the user inserts a replacement BIB into the housing  208 . The user inserts the replacement BIB in the housing  208  and couples the BIB  210  to the fluid connector  220 , as described above. The replacement BIB is now in an operational status for resupplying the mineral water  212  to the water supply system  250 . 
     In order to maintain the hot/cold water dispenser  200  in an hygienic status, the cleansing operation may be performed prior to replacing the empty BIB  210  with a replacement BIB unit. During the cleansing operation, hot water is pumped from the hot water reservoir  214  to the BIB  210  via the fluid flow system  206 , spraying hot water into the BIB  210 , as described below. 
     The controller unit  226  monitors and records the number of replacement BIB units inserted into the hot/cold water dispenser  200  and following the replacement of a predetermined number of BIB units, typically ten BIB units, the controller unit  226  initiates a cleansing operation of a current empty BIB unit  210  and the fluid conduit  211 . It is appreciated that the user may alter the number of replacement BIB units by inputting the required information into the controller unit  226  by means of the control panel  252 . 
     When the desired number of BIB units has been replaced, the controller unit  226  displays a notification, such as “INITIATE A CLEANSING OPERATION”, on the display  228 . Thus, the user is informed that the cleansing operation is being initiated. If the user does not wish to proceed with the cleansing operation, the user activates an appropriate control on the control panel  252  of the controller unit  226  and the cleansing operation terminates. A notification, such as “CLEANSING OPERATION USER TERMINATED”, appears on the display  228 . 
     If the user wishes to proceed with the cleansing operation, the user activates the appropriate activation control on the control panel  252  and the cleansing operation proceeds. The controller unit  226  checks the temperature of the hot water  215  contained in the hot water reservoir  214 . If the hot water  215  is at a required temperature for the cleansing operation, typically at approximately 90° C., a notification, such as “CLEANSING OPERATION INITIATED”, appears on the display  228 . 
     If the hot water temperature is less than the required temperature, the controller unit  226  forwards a heat-water instruction to the water heater  261  to commence a heating operation to heat the water in the hot water reservoir  214  to the required temperature. A notification, such as “WATER HEATING OPERATION IN PROGRESS”, appears on the display  228 . On reaching the required hot water temperature, a notification, such as “WATER HEATED TO REQUIRED TEMPERATURE”, appears on the display  228 . 
     Upon completion of heating of the water in the hot water reservoir  214 , alternatively, if the hot water in the hot water reservoir  214  is at the required temperature, the cleansing operation commences and a notification, such as “CLEANSING OPERATION COMMENCING”, appears on the display  228 . The controller unit  226  instructs the fluid pump  218  to reverse the pumping direction of the pump  218  to the reverse pumping direction. 
     Concomitantly with instructing the fluid pump  218  to reverse the pumping direction, the controller unit  226  instructs the cold water valve  244  to close and the hot water valve  238  and the sanitation valve  213  to open. On receiving confirmation that the cold water valve  244  has closed and the hot water valve  238  and the sanitation valve  213  have opened, the controller unit  226  instructs the fluid pump  218  to commence pumping a quantity of hot water from the hot water reservoir  214  to the fluid flow system  206  and the BIB  210 . The quantity of hot water pumped from the hot water tank when cleaning the fluid flow system  206  may be in a range of 5-50 ml. A notification, such as “CLEANSING OPERATION IN PROGRESS”, appears on the display  228 . 
     The fluid pump  218  commences pumping the quantity of hot water from the hot water reservoir  214  to the BIB  210  via the fluid flow system  206 , as indicated by a flow arrow  260 . The quantity of hot water  231  reaches the fluid connector  220  and is sprayed into the BIB  210  as indicated by spray arrows  263 . Thus, the flow conduit  211  is cleansed with hot water. The pumping operation continues for a first predetermined time period, typically for a period of three seconds. 
     At the termination of the first predetermined time period, the controller unit  226  instructs the fluid pump  218  to cease pumping. The quantity of hot water is retained in the fluid conduit  211 , the fluid connector  220  and the BIB  210  for a predetermined cleansing time period, typically for a time period of three minutes, typically at a temperature of approximately 90° C. In alternative embodiments, prior to the user replacing the BIB  210 , the residual hot water  270  is drained from the dispenser  200 , as described below. 
     At the termination of the cleansing time period, a notification, such as “CLEANSING OPERATION COMPLETED”, appears on the display  228 . 
     Reference is now made to  FIG. 5 , which schematically presents the hot/cold dispenser  200  in an arrangement for draining the residual hot water  270  from the hot/cold water dispenser  200 , in accordance with an embodiment of the present invention. Subsequent to completion of the cleansing operation of the BIB unit  210  and the flow fluid system  206 , the controller unit  226  forwards an instruction to the pump  218  to change the pumping direction from the reverse direction to the forward direction. 
     In accordance with another embodiment of the present invention, concomitantly with forwarding the change pump-direction instruction, the controller unit  226  instructs the hot water valve  238  to close and instructs the drainage pump and/or drain valve  248  to open. The cold water valve  244  remains closed and the sanitation valve  213  remains open. Thus, a fluid flow pathway is established from the BIB  210  to the water drainage system  246  via the fluid conduit  211  and the fluid connector  220 , as indicated by the flow arrows  273 ,  274 . 
     On receiving confirmation that the hot water valve  238  is closed and that the drainage pump and/or drain valve  248  is opened, the controller unit  226  instructs the fluid pump  218  to commence pumping for a predetermined period of 1-10 seconds and the residual water  270  is pumped from the BIB  210 , the fluid connector  220  and the fluid conduit  211  to the water drainage system  246  as indicated by a fluid flow arrows  273 ,  274 . 
     Thus, the residual hot water  270  is drained from the BIB  210  and the fluid flow system  206  to a water drain  280  via the drainage flow system  246 , or back to the hot water reservoir  214 . 
     Subsequent to draining the residual hot water  270  from the dispenser  200 , the user is able to replace the empty BIB unit with a replacement full BIB  210  and reuse the hot/cold water dispenser  200  following the cleansing operation. 
     It is appreciated that the user has an option to operate the hot/cold water dispenser  200  in an energy-saving mode. In the energy-saving mode, the temperature of the hot water  215  is typically maintained at a temperature of approximately 60° C. Alternatively, the user may not wish to heat the water in the hot water reservoir  214  and the water therein is typically at room temperature. 
     Additionally or alternatively, as described above, the user has an option not perform the cleansing operation. 
     However, in order to maintain the hygiene of the dispenser  200 , subsequent to the replacement of typically 10 BIB units, the controller unit  226  checks the temperature of the hot water  215  each time the user replaces a BIB unit. If a cleansing operation is not initiated after the replacement of, typically, 10 BIB units, the controller unit  226  continues to check the temperature of the hot water  215  each time a BIB unit is replaced. When the user selects to operate the dispenser  200  on an energy saving mode or to disable the heating unit, the controller unit  226  provides the user with a message recommending performing the sanitation process disclosed above. The controller unit  226  may sample the temperature of the hot water tank every predefined number of BIB units, to suggest the user to perform the sanitation process in case the temperature of the hot water tank is back to normal, for example above 85 degrees. 
     While the disclosure has been described with reference to exemplary embodiments, it will be understood by those skilled in the art that various changes may be made and equivalents may be substituted for elements thereof without departing from the scope of the invention. In addition, many modifications may be made to adapt a particular situation or material to the teachings without departing from the essential scope thereof. Therefore, it is intended that the disclosed subject matter not be limited to the particular embodiment disclosed as the best mode contemplated for carrying out this invention, but only by the claims that follow.