Abstract:
A system ( 10 ) for automatically filling a bathtub ( 14 ), is operatively arranged to supply heated water to the bathtub and to drain water from the bathtub through a drain outlet ( 12 ) after use, the system comprising a conduit ( 14   b ) through which water from the drain outlet is recirculated back to the bathtub in use. The bathtub outlet comprises a passageway having an upstream end connectable in fluid communication with the bathtub, a downstream end connectable to a drain ( 60 ) and a servo-actuated valve ( 34 ) disposed to control water flow through the passageway, the passageway comprising a branch ( 80 ) in fluid communication with it at a region between the upstream end and the servo-actuated valve. The branch may be used to fill the bathtub and/or for the water recirculation. Alternatively the bathtub overflow outlet ( 30 ) comprises an inlet ( 18 ) connectable to an external supply ( 50 ) of filling water and directing this filling water into the bathtub in use. The overflow outlet may further comprise an inlet connectable to the recirculation conduit ( 14   b ) and directing water from the recirculation conduit into the bathtub in use. The drain outlet may also be used to recirculate water back into the bathtub via an inlet branch ( 81 , FIGS.  7   a   , 9 ).

Description:
FIELD OF THE INVENTION 
       [0001]    This invention concerns control systems and apparatus for automatically filling bathtubs. 
       BACKGROUND OF THE INVENTION 
       [0002]    Bathtubs are usually filled by manually inserting a plug in the drain or plughole (this includes closing “pop-up” waste valves) and turning the hot and cold taps on. To fill a bathtub in this traditional way takes time and often the result is a bathtub not filled to the desired level and temperature. Adjusting water level and temperature to the final stage involves the undivided attention of the user and errors and inattention often necessitate releasing some water into the drain. A person taking a bath daily is wasting many hours a year filling and adjusting the water temperature and level. Another aspect of the problem of manual or semi-automatic filling of bathtubs is that water and energy are wasted. There are devices of varying complexity on the market that have attempted to provide a solution to this problem but these often spoil the appearance of the bath. Some of these devices time the periods for which the hot and cold supplies are on without compensating for water pressure and temperature fluctuation. Closing the plug is often left to the person filling the bathtub and sometimes this is simply forgotten, pouring into the drain a bath full of water or more and hence the energy needed to heat it, not to mention that this wastage may have used up most of the available hot water, precluding successful bath filling immediately afterwards. Another serious problem is overfilling of bathtubs when the overflow is insufficient to take the excess water into the drain. When this happens flooding can cause extensive damage and very high insurance claims. Manual filling can present the danger of scalding, too. 
         [0003]    DE10031665 shows apparatus for automatically filling a bathtub, including mechanically interlinked automatically controlled inlet valves on both the hot and cold water supply pipes. The apparatus allows blending of the filling water to achieve a desired temperature. The filling level is controlled by a pressure sensor in the base of the bathtub or by a turbine flow meter which measures the total water inflow. The bath outlet is provided with a servo-operated poppet valve. The disclosed system is therefore capable of automatically closing the outlet valve and filling the tub to a desired level with water at a predetermined elevated temperature. When bathing has finished, the tub can be emptied again through the servo-operated outlet valve. However the system as disclosed is incapable of maintaining the water in the tub at the desired temperature for extended periods. Also, the monitoring sensor needs to be mounted in an aperture cut into the tub, spoiling the appearance of the tub and providing a further potential leak path. Also, this location does not compensate for localised cooling of the water from heat losses through the bath, resulting in the bath being filled with warmer or colder water than anticipated. 
         [0004]    GB2174219 discloses a bath having an automated hot and cold water inlet mixer valve and an automated outlet for waste water. A control system senses the level and temperature of the water in the bath during filling and regulates the mixer valve to achieve a user-specified depth and temperature at a point when the mixer valve is closed. The user can also adjust the water temperature during bathing by activating the control system to add hot or cold water. When the level of water in the bath becomes excessive, the control system opens the waste valve until the surplus water has been drained off. The bath is also provided with a water recirculation pipe connected to an intake in the side of the bath and having an outlet end connected to a pump and conventional Jacuzzi jets. The recirculation pipe is provided with a through flow water heater which can be used to maintain the water at a pre-set temperature once the bath has been filled. For installation, this system therefore requires several further apertures or other penetrations through the side of the bath than are conventionally needed, with attendant disadvantages as above. 
         [0005]    JP2002-206802 concerns a bath filling control system in which filling and recirculation of bath water takes place in some embodiments through a recirculation adapter which forms a part of a drain fitting for the bath. The fitting is relatively complex in construction and the recirculation passages provided are of restricted cross-section due to space constraints. 
         [0006]    GB2424367 relates to an automated bath in which water from the bath may be filtered, heated and recirculated back into the bath via a three-way mixer. 
       SUMMARY OF THE INVENTION 
       [0007]    The present invention addresses these problems by providing a system for automatically filling a bathtub, the system being operatively arranged to supply heated water to the bathtub and to drain water from the bathtub through a drain outlet after use, the system comprising a recirculation conduit through which water from the drain outlet is recirculated back to the bathtub in use, characterised in that the recirculation conduit is connected to a filling inlet that is combined with an overflow outlet for the bathtub or formed as a spout mounted on an adjacent wall or ceiling area. This helps to maintain an even temperature throughout the water in the bathtub, without requiring additional apertures or penetrations through the side of the bathtub. 
         [0008]    An external water supply for filling the bath may be connected to the filling inlet or to an inlet combined with the drain outlet. The usual taps and tap hole(s) can then be eliminated, giving the bath a clean and uncluttered appearance. 
         [0009]    The system may be operatively arranged to fill the bathtub to a predetermined depth. Thereafter, to maintain the water at a predetermined temperature, the system may be arranged to automatically add heated water to the bath from the external filling supply. A quantity of water may also be released through the drainage outlet to a drain so as either to maintain the depth of water at the predetermined depth, or to maintain the depth of water below a maximum depth. 
         [0010]    Alternatively, after filling the bathtub to the predetermined depth, to maintain the predetermined water temperature in the bath, the system may be arranged to automatically add heated water to the bath through the recirculation conduit. For this purpose, the recirculation conduit may be provided with a water heater. 
         [0011]    The system may comprise a main inlet and an auxiliary inlet, to one, the other or both of which the heated water may be selectively supplied. For example, the main inlet may be combined with one or more of a separate filling inlet, a combined filling inlet/drain outlet and a combined filling inlet/overflow outlet, and the auxiliary inlet may be connected to a shower head, body jets or the like. 
         [0012]    The control system may be programmable to fill the bath at a predetermined time. It may be programmable for this or any other purpose either by local control, such as a directly connected keypad or the like. Additionally or alternatively, the control system may be remotely programmable, for example from a “wireless” handset using an infrared, ultrasonic or radio link. Remote programming may also be via a LAN, home automation network, the internet, the public telephone system, broadband cable or the like. 
         [0013]    The invention also provides a bathtub overflow fitting comprising an inlet connectable to an external supply of filling water and directing this filling water into the bathtub in use, the overflow fitting further comprising an inlet connected to a recirculation conduit and directing water from the recirculation conduit into the bathtub in use. 
         [0014]    In a further aspect, the invention provides a bathtub fitting comprising a passageway having an upstream end connectable in fluid communication with a drain aperture of a bathtub, a downstream end connectable to a drain and a valve disposed to control water flow through the passageway; characterised in that the fitting comprises first and second branches in fluid communication with the passageway at a region between the upstream end and the valve, for recirculation of water from the bathtub back into the bathtub. 
         [0015]    At least one of the branches may be used as a filling inlet for the bathtub. The passageway may comprise an overflow connection downstream of the valve. A sensor or sensors may be provided, for sensing pressure and/or temperature of the water upstream of the valve. The valve may be servo-actuated, and may comprise a manual override. In one embodiment, the valve comprises an upwardly extending baffle which divides the passageway into two parts, respectively in fluid communication with the first and second branches. 
         [0016]    The invention in its various aspects is applicable not only to bathtubs for installation in domestic bathrooms, but to similar sanitary appliances such as sinks and washbasins, spa baths, hydrotherapy pools, whirlpool baths (“Jauzzi”® baths), foot baths and the like. The term “bathtub” as used in this specification should be construed accordingly. 
         [0017]    Further preferred features and advantages of the invention will be apparent from the following description of illustrative embodiments, made with reference to the drawings. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0018]      FIG. 1  is a diagram of a bathtub filling control system embodying the invention; 
           [0019]      FIGS. 2   a ,  2   b  and  2   c  show modifications of the system of  FIG. 1 ; 
           [0020]      FIG. 3  is a cross-sectional view of a drain outlet assembly for use in the control system of  FIGS. 1 and 2   a - c;    
           [0021]      FIGS. 4 and 5  are cross-sectional views taken on line A—A in  FIG. 3 , showing a poppet valve in open and closed positions respectively; 
           [0022]      FIG. 6  is a cross-sectional view taken on line B-B in  FIG. 4 ; 
           [0023]      FIG. 7   a  is a diagrammatic representation of a bathtub filling control system embodying the further aspect of the invention, in which the inlet to and the outlet from the circulation pump are both from the drain assembly; 
           [0024]      FIG. 7   b  is similar to  FIG. 7   a , but with the conventional overflow eliminated, and 
           [0025]      FIGS. 8 and 9  show modifications to the drain outlet assembly and poppet valve, for use with the systems of  FIGS. 7   a  and  7   b ,  FIG. 9  being a section on line C-C in  FIG. 8 . 
       
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENTS 
       [0026]    This invention relates to a system  10  and apparatus for facilitating the control, preferably including remote control, of a bathtub, advantageously for enhanced comfort and optimal use of energy and water. In a preferred embodiment, the system  10  at a command closes the drain  12  of a bathtub  14  and fills it with water to a user-defined depth and temperature. In the embodiment illustrated in  FIG. 1 , a circulation pump  16  moves the water from the drainage outlet of the bathtub (upstream of a motorised poppet valve  34  which selectively closes off a drainage outlet pipe  60 ) back into the bath through an inlet  18  during filling, at intervals or continuously, so ensuring temperature losses from the water in the bathtub are compensated for by the temperature of the filling water. This water is evenly mixed with water already in the bathtub to give a more uniform temperature. The inlet  18  may be combined with an overflow  30  connected to the drain outlet  12  in the usual way. When the bathtub  14  is filled and left to stand, the system  10  could either maintain the temperature and level of the water by releasing water into the drain  12  and then filling with more water, or circulating water via an optional heater/cooler  20  from the drain  12  and back into the bathtub  14  through the inlet  18 . The system  10  can be controlled with a simple hand-held remote controller, a wall or similarly-mounted console  40  with a keypad  42  and an LCD or similar numeric display  44 , and/or via the Internet, telephone network, a LAN, a home automation system or any other suitable way as desired, for example using the RS232/RS484 and/or TCP/IP interfaces  46 ,  48  illustrated. 
         [0027]    Hot and cold external water supply pipes  50  are connected to a motorised blending valve  54  via non-return valves  52 . Water blended to a desired temperature is supplied from the valve  54  to a volume (flow rate) or simple on/off motorised control valve  56 . The outlet from the flow control valve  56  is connected to the inlet of a manually operated or motorised diverter valve  58 . This may be of the known kind having a main and an auxiliary outlet, the inlet being connected to the main outlet in the default no-flow condition, and the inlet remaining connected to whichever of the main and auxiliary outlets is set in the flow condition. The main outlet  26  of the diverter valve  58  is connected to the bath filling inlet  18 . One or more auxiliary water inlets  22  are connected to the auxiliary outlet of the diverter valve  58  and are provided for connection to a shower head, body jets or for many other uses. 
         [0028]    An electronic control unit  62  has control outputs  64 ,  66 ,  68 ,  70 ,  72  respectively connected to the blending valve  54 , the flow control valve  56 , an actuator  32  for the motorised poppet valve  34 , the heater  20  and the circulation pump  16 . The control unit has inputs  74 ,  76 ,  78  respectively from a temperature sensor  73  mounted in or on the conduit connecting the valves  56 ,  58 , and from a combined pressure and temperature sensor  42  in the drain  12  upstream of the poppet valve  34 . There is also an input  75  signalling the position of the actuator  32 , and hence whether or not the poppet valve  34  is closed. The control unit may be programmable from the console  40  or interfaces  46 ,  48  to fill the bath to a specified depth and temperature, either immediately or at a specified future time. The temperature and water depth may also be adjusted from the console  40  or interfaces  46 ,  48  after the initial bath filling cycle is completed. The control unit  62  may be programmed to maintain the water depth at the specified depth and temperature, either by circulating water through the heater  20 , or by from time to time opening the poppet valve  34  to release water into the drainage outlet  60  and topping up the bath  14  with hot water from the blending valve  52 . The heater  20  is therefore optional. Both the heater  20  and the circulation pump can be deactivated and the poppet valve  34  can be opened to drain the bath  14 , using the control panel  40  or interfaces  46 ,  48 . 
         [0029]    The bathtub filling from the external water supply if desired could be done from the “waste” or drain  12 , creating more unusual feel and reducing the noise associated with filling to almost silent filling. This filling arrangement is shown in  FIG. 2   a , in which instead of being connected to the bath inlet/overflow  18 / 30 , the main outlet  26  from the diverter valve  58  is connected to the bath drain outlet  12 , upstream of the poppet valve  34 . With this arrangement, the overflow  30 /inlet  18  is nevertheless still used as the inlet for returning the water recirculated to the bathtub, so as to maintain an even water temperature within the bathtub  14 . This system and apparatus with minor variations fits most bathtubs without any modifications to the bathtubs or spoiling of their appearance. No extra apertures need be cut through the bathtub to accommodate the system connections and components. 
         [0030]      FIGS. 2   b  and  2   c  show further variants in which the output from the circulation pump  16  is connected to the conduit interconnecting the flow control and diverter valves  56 ,  58 , or to the conduit interconnecting the blending and flow control valves  54 ,  56 . In  FIGS. 2   a - 2   c , the control unit  62 , interfaces  40 ,  46 ,  48  and their electrical connections are omitted for clarity, but will be similar to those shown in  FIG. 1 . 
         [0031]    As shown, the system may comprise four main apparatus components controllable by a variety of suitable controllers/interfaces including but not limited to TCP/IP (Ethernet), RS232/RS484 or a basic LCD interface with push buttons. The main components are as follows 
       I. Drain Assembly 
       [0032]    The drain assembly  12  comprises the device  32  for motorised actuation of the poppet valve  34 , the assembly having a circulation/monitoring chamber  38  containing an outlet  80  for feeding of the circulation pump  16  and a connection  82  for accommodating a combined temperature and pressure sensor  42 . Alternatively, these sensors may be separate. A connection  84  for the overflow outlet  30  is present below the point of operation of the poppet valve  34  allowing unobstructed flow of water to discharge into the drainage pipe  60 . The drain assembly is shown in more detail in  FIGS. 3 to 6 , and comprises the following parts: 
       ITEM NO. DESCRIPTION 
       [0000]    
       
           1  domed drain outlet cover 
           2  outlet cover support arms 
           14  bath tub 
           3  tubular valve housing 
           4  Bowden cable connecting to linear actuator  32   
           5  slider 
           6  Bowden cable connecting to poppet valve manual override, e.g. a knob mounted in front of the overflow outlet  30  in known manner 
           7  guide tube 
           8  arm 
           9  actuating lever 
           34  poppet valve 
           11  sealing ring 
           12   a  sensor wires and pressure sensor balancing tube 
           42  combined pressure and temperature sensor 
           80  circulation outlet 
           15 ,  16   a  gaskets 
           17  externally threaded sleeve 
       
     
         [0050]    The poppet valve  34  closes against a seat  38   a  formed in the bottom of the circulation/monitoring chamber  38  and seals against this seat by means of sealing ring  11 . The poppet valve  34  is guided for linear sliding movement in the tubular valve housing  3  by four depending legs  34   a  which are a close sliding fit in the drainage outlet pipe  60 . The guide tube  7  is arranged parallel to the overflow inlet connection  84  and accommodates the slider  5 . The actuating lever  9  is bent as seen most clearly in  FIG. 6  and has a first end engaged beneath the poppet valve  34 , between the legs  34   a . A second end of the lever  9  is journalled in a bore formed in a boss  3   a  attached to the overflow connection  84 . The second end of the lever  9  is sealed in the bore by O rings  9   a . The arm  8  is fixed to extend transversely of the second end of the lever  9 , upwardly into the guide tube  7  through a slot  7   a . The upper end of the arm  8  engages in a recess  5   a  in the slider  5 . Linear movement of the slider  5  in the guide tube  7  under the action of the Bowden cables  4  or  6  therefore causes the arm  8  to pivot the second end of the lever  9  in the bore in the boss  3   a , and hence causes the first end of the lever to move up and down, opening or closing the poppet valve  34  against the seat  38   a . The circulation outlet  80  and sensor connection  82  are in fluid communication with the circulation/monitoring chamber  38  above the seat  38   a ; whereas the drainage outlet pipe  60  and overflow connection  84  are below the seat  38   a.    
         [0051]    Where the bath is to be filled from the external water supply via the drain assembly  12  as in  FIG. 2   a , the motorised blending valve  54  having inlets connected to hot and cold external water supplies  50  via non-return valves  54 , together with the flow control valve  56  and diverter valve  58 , have their main outlet  26  connected to the circulation/monitoring chamber  38  or to the circulation outlet  80 , or to the circulation conduit  14   b  connected to that outlet. 
         [0052]    The circulation/monitoring chamber  38  has an internally threaded upper rim  38   b  for reception of the externally threaded sleeve  17 . The usual drainage aperture is formed at the lowest point of the bath  14  and the rim of this aperture is clamped between the gaskets  15 ,  16   a  sandwiched between an upper flange  17   a  on the sleeve  17  and the upper rim  38   b  of the circulation/monitoring chamber  38 . The drain outlet cover  1  is supported on the sleeve  17  by the arms  2 . The rim of the cover  1  is spaced above the flange  17   a  to define an annular gap allowing fluid communication between the interior of the bath  14  and the circulation/monitoring chamber  38 . The entire drain assembly, apart from the cover  1 , flange  17   a  and gasket  16 , is thus sealingly suspended beneath the usual drainage aperture in the bath  14 . The cover  1  is readily removable for cleaning purposes. The poppet valve  34  is provided with a stem  35  which can be grasped for removal of the valve  34  from the body  30  through the chamber  38 , for cleaning purposes. 
         [0053]    A further bathtub filling, emptying and water recirculation system and associated control circuitry is shown in  FIG. 7   a . Here the inlet to and outlet from the circulation pump  16  are both from the drain assembly  12 . The required modification to the drain assembly and poppet valve are described in further detail below, with reference to  FIGS. 8 and 9 . The required control circuitry, including the controllers and interfaces that may be used, may be substantially identical to that described and shown with reference to  FIG. 1 . For brevity such description is not repeated here. 
         [0054]    A still further system shown in  FIG. 7   b  is similar to that of  FIG. 7   a  except that the overflow  30  is eliminated. Instead either electronic (e.g. pressure sensor) water level monitoring is used alone, or a “hidden” overflow is used, of the kind described in U.S. Pat. No. 5,121,509, or similar. In  FIG. 7   b , the control unit  62 , interfaces  40 ,  46 ,  48  and their electrical connections are omitted for simplicity, but will be similar to those shown in  FIGS. 1 and 7   a.    
         [0055]      FIG. 8  shows a modified form of the drain assembly  12  for use with the systems shown in  FIGS. 7   a  and  7   b , in which the circulation/monitoring chamber  38  is not only provided with the circulation outlet  80  connected to the pump inlet, through which water is removed from the bathtub  14  via the drain assembly  12 , but also an inlet  81  that may be connected to the pump outlet for returning the circulated water back into the bathtub via the circulation/monitoring chamber  38 . As shown in  FIG. 9 , with this arrangement, two of the cover support arms  2  shown in  FIG. 4  are replaced by a depending double transverse baffle  2   a . The poppet valve stem  34  is replaced by an upwardly extending transverse baffle  35  an upper end of which engages snugly between the two lowermost parts of the double transverse baffle  2   a . This still allows vertical sliding movement of the poppet valve relative to the drain assembly body and cover. The interengaging baffles divide the circulation/monitoring chamber into two parts: one in fluid communication with the circulation outlet  80  and the other in fluid communication with the inlet  81 . The inlet and outlet flows to and from the bathtub via the drain assembly  12  are represented by the arrows I,  0  respectively. As these flows take place through opposite sides of the annulus defined between the base of the bathtub  14  and the cover  1 , substantial mixing of the bath water will take place, despite the fact that water flows are all to or from the drain assembly  12 . This is so even if some water is permitted to “leak” around the edges of the baffles  2   a ,  35 . The guide tube and slider are also shown in  FIG. 9 , appearing in transverse section, to the right of the poppet valve. 
       II. Inlet/Overflow 
       [0056]    As one option, the overflow device provides a recirculation inlet into the bathtub, used in some instances for filling the bathtub as well as for water recirculation. The device may incorporate filler inlet  18 , bathtub overflow  30  and a lever or knob for manual actuation of the poppet valve  34 . This is a remote manual waste actuator, e.g. a control knob at the overflow inlet, connected to the poppet valve  34  via the Bowden cable  6 . The two inlets  50  connected to hot and cold external water supplies via the non return valves  52  are optionally connected to the filler inlet  18  as shown in  FIG. 1 . The device  54  for motorised blending of water and the device  56  for flow control (if not connected to the drain assembly  12  as described above) optionally fills the bathtub from these inlets while the circulation pump  16  taking water from the circulation/monitoring chamber  38  via the circulation conduit  14   b  is also connected to the filler inlet  18  (if not connected to a combined recirculation and drainage fitting as described above, particularly with reference to  FIGS. 8 and 9 ). The circulation pump output and the blending valve output may be connected to the filler inlet  18  via one outlet of the manual or motorised diverter valve  58 . The other outlet of the diverter valve may be connected to an auxiliary water inlet  22  for the bathtub, such as a shower head, body jet nozzles or the like. The circulation circuit is in place to move water around the bathtub from the circulation/monitoring chamber  38  to the filler inlet  18  and/or the auxiliary inlet(s)  22 , (and/or a drainage fitting inlet branch  81 , if present) while filling is in progress, facilitating an accurate temperature reading for the bathtub water from the temperature sensor  42 . Circulation at a time interval predetermined by the controller  62  ensures accurate monitoring of temperature by the controller. When bathtub water is left for some time, temperature can be adjusted by discharging some water via the motorised poppet valve  34  and adding some more water at suitable temperature. When the bathtub is filled and left for some time the controller  62  with the means of circulation through the device for heating or cooling  20  can maintain the predefined temperature without discharging water. 
         [0057]    The combined filler inlet  18 /overflow  30  assembly may be as described in U.S. Pat. No. 6,823,539. Alternatively a separate spout mounted to a convenient adjacent surface such as a wall or ceiling may be used to fill the bathtub and/or return recirculated water to the bathtub. 
       III. Filling Control Valves 
       [0058]    These are provided by the device for motorised blending of water and flow control, as mentioned above. This comprises a valve assembly having thermostatic  54  and volume  56  valves with motors and the temperature sensor  73 . Hot and cold water incoming via the check valves  52  is blended to the correct predetermined temperature by the motorised thermostatic valve  54 . The motorised volume control valve  56  controls the water flow from completely closed status to fully open. The main function of this valve is as an ON/OFF valve in relation to the bathtub filing. The volume control function is used in conjunction with the circulation pump and/or when a hand shower is connected to the auxiliary filling inlet  22 . 
       IV. System Control Unit 
       [0059]    The control unit  62  for the devices as mentioned above, may have a basic interface  40  having a keypad and LCD or other visual display as described above, and/or other data interfaces such as  40 ,  46  described above. The user chooses a bathtub filling depth and temperature setting via preset buttons or as user defined values via a numeric keypad. The flow rate for the auxiliary output is set and the user confirms the choice by selecting ON. 
         [0060]    For bathtub filling, initialisation starts by establishing that the bathtub is empty. The actuator  32  of the poppet valve  34  is energised and when the poppet valve is closed filling commences. The volume control valve  56  fully opens and blending of water starts at the user predefined temperature monitored by temperature sensor  42  until sufficient quantity of water is discharged into the bathtub (preset, but programmable) for the circulation pump  16  to start working. With the circulation pump in operation the temperature reading from temperature sensor  42  is compared with the user predefined temperature and temperature sensor  73  limits the temperature at the blending valve  54  not to exceed the predefined maximum temperature to prevent scalding. The pressure sensor  42 , which utilises technology that compensates for ambient pressure variations, facilitates the water level monitoring and when the desired level is achieved the volume control valve  56  is turned off. Temperature sensor  42  and the pressure sensor  42  can be combined or housed in the same housing for ease of servicing. Bathtub filling can be interrupted at any time by selecting OFF (manual shutdown override). 
         [0061]    For use of the auxiliary inlet  22  (e.g. hand shower), the volume control valve  56  opens and blending of water starts at the user predefined volume and temperature, monitored by temperature sensor  73 . 
         [0062]    The basic LCD interface  40  is intended to be located within reach of the bather. An additional remote basic LCD interface without the auxiliary (hand shower) functions could be located on a nearby wall. The interface  40  may be configured as a waterproofed battery operated remote handset, the communication channel  41  with the control unit  62  being provided via an infrared, radio or ultrasonic link. The link  41  is preferably bidirectional as shown, so that system status information is available at the interface  40 , but in simplified form the link may be unidirectional, for supplying commands to the control unit  62  only. 
         [0063]    Communication to the controller via TCP/IP protocol allows remote operation and full control from a mobile device or Internet/Intranet with a customisable user interface. Communication to the controller via RS232/RS484 protocol allows integration with home automation systems. Other connectivity options are possible. 
         [0064]    By using circulation and temperature monitoring at the circulation/monitoring chamber  38  at the bottom of the bathtub via temperature sensor  42 , accurate bathtub water temperature measurement and control is achieved. This method for monitoring the water temperature compensates for the heat loss to ambient before filling, during filling and during bathing. 
         [0065]    The bath filling inlet  18  need not be combined with the overflow outlet  30 , but could instead be in the form of a spout mounted e.g. on an adjacent wall or ceiling area.