GB2427259A

GB2427259A - A water-saving device

Info

Publication number: GB2427259A
Application number: GB0520317A
Authority: GB
Inventors: Derick Sinclair
Original assignee: Individual
Current assignee: Individual
Priority date: 2005-06-14
Filing date: 2005-10-06
Publication date: 2006-12-20
Also published as: GB0512051D0; GB0520317D0

Abstract

A water-saving device (2), for use in a water supply system, to prevent the waste of clean water which is either too hot or too cold for the user's particular need. The device (2) comprises a body defining a chamber having an inlet (3), which is connectable to the water supply system, and a first (4) and second water outlet (5). The first outlet (4) being connectable in fluid communication with a discharge means to enable water to discharge from the water supply system. The second outlet (5) being connectable to the water supply system to enable re-circulation of water. The device (2) also comprises a thermally actuated diverter valve (6) operable dependant on the temperature of water entering the chamber via the inlet to control whether water exits the chamber via the first outlet (4) or the second outlet (5). The device (2) further comprises an inlet valve (9), for controlling the flow of water through the inlet (3), having a valve actuating member (8) connected to or connectable with a manual control member (7) of the discharge means (1) to enable opening and closing of the inlet valve (9). The water-saving device may be used in a shower or a tap (1).

Description

WATER-SAVING APPARATUS

Field of the Invention

The present invention relates to water-saving devices and more specifically to a device for diverting and re-circulating water that would otherwise be wasted.

Background of the Invention

The conservation of clean water is of increasing concern. This concern is most clearly felt in areas of the World such as Africa, the Middle East and Australia, where the environmental can he harsh. However, even in countries with a plentiful supply of water, domestic water must be stored in reservoirs and it must be treated to be fit for human consumption.

In areas where water is in plentiful supply, the levels of wasted water are high. On an individual level waste may not be huge, but the accumulated wasted water from all the users represents a large amount of clean water that is simply fed down the drain.

One particular source of waste occurs every morning when it takes time for the hot water to come through the water pipes to the hot tap. As a result the first user at each tap usually turns on the tap until the water runs hot. In this way, in any one city on any one morning, millions of litres of clean water can be wasted.

Various solutions to the above problem have be put forward. However, all of the offered solutions have disadvantages, which have prevented their wide-scale adoption.

Canadian Patent No 2252350 describes a water supply system wherein water that is either too hot or too cold is prevented from exiting the system via an open tap. The system prevents the wastage of water discussed above by diverting water of the wrong temperature back around the system until the water reaching the chosen tap is the correct temperature.

One of the main problems with the above system is that it requires a complete re-plumbing of the water supply system, including the pipes and taps. This may not be a huge issue with new build properties, but it can be prohibitive in older properties, where the total water savings by the individual property do not warrant the plumbing costs. Furthermore, the nature of the valve system used in Canadian Patent No 2252350 is such that new bathroom furniture (e.g. taps, shower-heads, etc.) must be fitted also. This further increases the costs involved as well as limiting the level of aesthetic choice available to the owners of the property.

Another solution is offered by the "demand system", this system uses the same principal as is used for central heating, it has the hot water being constantly pumped around the water pipes, so when a faucet is opened the passing hot water is there ready for use, this system requires quite an alteration to the plumbing, also needs a supply of electricity for the pump and switches and a water pump that is expensive to buy and run, it also needs the returned and cooled water to be constantly re-heated which is a very uneconomical operation, and is therefore both expensive to install and run, and uses large amounts of valuable energy to constantly re-heat the circulating water. The actual system is extremely expensive and the cost is not recoverable from saved water bills, so is in very little use, and rarely seen on the market, US Patent No 4554688 is an example of this form of water supply system.

US Patent No 5165456 describes a more basic solution to the abovementioned problem with the previously wasted water being diverted to a portable water tank. Whilst such invention provides a solution to the above problem without the disadvantages of the Canadian patent, the invention is impractical and intrusive. The constant need for the user to lift and move the water storage tank would inevitably lead to the system being abandoned.

In view of the above solutions to the water waste problem identified above, and the disadvantages thereof, there is a need for water saving system that has minimised hurdles to adoption, so that the average consumer will not be discouraged from adopting a water saving system.

Summary of the Invention

The present invention provides a water-saving device, for use in a water supply system, the device comprising: a body defining a chamber having an inlet, which is connectable to the water supply system, and a first and second water outlet; the first outlet being connectabte in fluid communication with a discharge means to enable water to discharge from the water supply system; the second outlet being connectable to the water supply system to enable re-circulation of water; a thermally actuated diverter valve operable dependant on the temperature of water entering the chamber via the inlet to control whether water exits the chamber via the first outlet or the second outlet; and an inlet valve, for controlling the flow of water through the inlet, having a valve actuating member connected to or connectable with a manual control member of the discharge means to enable opening and closing of the inlet valve.

Preferably the thermally actuated diverter valve may be arranged to direct water to the second outlet until such time as the water entering the chamber is within a desired temperature range.

Preferably the thermally actuated diverter valve may comprises a thermal wax expansion unit, which expands upon heating to displace the valve from a first position, wherein water is directed via the second outlet to the water supply system, and a second position, wherein water is directed via the first outlet to discharge from the water supply system via the discharge means.

Preferably the inlet valve actuating member may comprise a rod or spindle or shaft which extends into the chamber through the first outlet, and is operationally connectable with or mountable on the discharge means such that the discharge means can be used to operate the inlet valve.

It would be advantageous if the valve actuating member comprises a thin, flexible length of a non-corrosive material.

Preferably the second outlet may be connected to a water storage tank which is arranged to collect the re-circulated water, said tank being further arranged to enable the water held in the water storage tank to be re- introduced into the water supply system. Further preferably the water storage tank is pressurised to improve the rate at which the water is reintroduced into the water supply system.

In preferred possibility the water storage tank may comprise a toilet cistern.

It is appreciated that it may be advantageous for the water saving device to be housed within the water storage tank. One benefit of this arrangement would be the space saving achieved.

Alternatively the second outlet could preferably be connected via a recirculation conduit to a junction with the water supply system that is upstream of the chamber inlet, said junction comprising a one-way valve that only permits water to pass from the second outlet to the water supply.

Further preferably the re-circulation conduit could have a capacity that is at least equal to the capacity of the pipe-work that connects the chamber to the source of the water of desired temperature, whereby the necessary amount of re-circulated water can be stored as the water of desired temperature moves towards the chamber.

Furthermore the re-circulation conduit could comprise a spiral of pipework, which enables an increased capacity to store the re-circulated water.

In a first preferred embodiment of the present invention the water- saving device of the present invention forms part of a shower unit. The shower further comprises: a mixing valve, which is in fluid communication with the first outlet of the device, located down-stream of the device; a hot water supply conduit, which comprises the water-saving device, the conduit having a first end, which is connectable with a source of hot water and a second end, which connected to the mixing valve; a cold water supply conduit having a first end, which is connectable with a cold water supply, and a second end, which is in fluid communication with the mixing valve; a shower-head located in fluid communication with the mixing valve; and wherein the water storage tank is connected to the supply conduit via a one-way valve so that the water stored in the tank can re-enter the cold water supply conduit.

Preferably the shower further comprising a pressure reducing valve located on the supply conduit at a position up-stream of the one-way valve.

The pressure reducing valve serves to create a pressure gradient that prevents the flow of hot water back into the cold water system, which must be avoided for general health and safety reasons.

Preferably the cold water supply conduit may be substantially housed within the water storage tank. This arrangement would once again provide a more space-efficient assembly.

In a second preferred embodiment of the present invention the watersaving device of the present invention forms part of a tap. The tap comprising a tap handle and wherein the control member is operationally connected to the tap handle whereby the tap controls the flow of water through the inlet valve of the device.

Brief Description of the Preferred Embodiments

In the drawings, which illustrate exemplary embodiments of the invention: Figure 1 is a cut-away view of the water-saving device of the present invention connected to a tap assembly; Figure 2 is a more detailed view of the thermally actuated diverter valve that is preferably used in the water-saving device of the present invention; Figure 3 is another detailed view of the diverter valve shown in Figure 2, wherein the valve has been actuated by the correct temperature of the water entering the device; Figure 4 is a cross-sectional view of the piston element of the diverter valve shown in Figures 2 and 3; Figure 5 is an example of a water supply system comprising the water- saving device of the present invention; Figure 6 shows a preferred embodiment of the water re-circulating portion of the device of the present invention; and Figure 7 is a cut-away view of an alternative application of the water- saving device of the present invention.

Detailed Description of the Drawings

The nature of the water-saving device of the present invention is such that it can be introduced in to an exisfing water supply system without the need for major re-plumbing. With this in mind, attention is now drawn to Fig. 1 of the drawings which shows the general water-saving device of the present invention 2 in association with a standard tap body 1.

The water-saving device 2 comprises a body which defines a chamber with one inlet 3 and two outlets 4 & 5. In use, the inlet 3 is connected to the existing pipe-work of the water supply system, this can be either the cold or hot water supply. It will be appreciated by the skilled man that any means of providing a water-tight connection between the inlet 3 and the supply system could be reasonably applied, including a welded joint or a screw-fitting.

The first outlet 4 of the water-saving device is arranged so that, in use, it can be connected in fluid communication with the standard tap body 1.

Once again, it is understood that the skilled man will be aware of suitable water-tight connection mechanisms for this purpose.

Preferably, the arrangement of the inlet 3 and the first outlet 4 is such that the water-saving device of the present invention can simply be used to replace a section of pipe-work in the area of the water supply system local to the tap 1.

The second outlet 5 of the water-saving device is adapted to direct water away from the tap 1 back towards the water supply system. In this way no water is unnecessarily lost from the water supply system. Details regarding the preferred destinations of the diverted water can be found in the description related to Figs. 5 - 7.

The water-saving device 2 of the present invention also comprises a thermally actuated diverter valve 6, which is located within the chamber between the inlet 3 and the two outlets 4 & 5. The role of the diverted valve 6 is to control which of the two outlets 4 or 5 the water, which enters the device 2 via the inlet 3, uses to exit the device 2.

Preferably, in order to prevent water unnecessarily being wasted from the water supply system, the diverted valve has a default setting wherein the water entering the device 2 is diverted to the second outlet 5.

It will be appreciated by the skilled man that the sensitivity of the thermally actuated diverted valve can be set to be actuated, i.e. switched from a first position, where the water exits the device via the second outlet, and a seond position, where the water exits the device via the first outlet.

It is appreciated that various types of thermally actuated diverter valve can be suitably used in the present invention. However, a preferred form of diverted valve is described, with reference to Figures 2 - 4, hereinafter.

In order that the water-saving device of the present invention can be installed into an existing water supply system without the need for completely replacing the original taps, the present invention provides a mechanism to communicate the on/off control of the tap handle to the inlet 3 of the water- saving device 2.

In order to prevent a situation where water is constantly entering the water-saving device 2, an inlet valve 9 is provided to control the flow of water through the inlet 3. The inlet valve 9 is attached to a control, or actuating, member 8. The other end of the control member 8 is connected to the handle 7 of the tap 1, whereby the tap handle 7 can be used to essentially open and closed the inlet valve 3, i.e. turn the water supply on and off.

Whilst the tap handle 7 is not necessarily considered to constitute part of the invention its description is necessary in order to clarify how the present invention works.

In the preferred embodiment of the present invention that is shown in Fig. 1, the control member extends from the inlet valve 3, through the chamber and up through the first outlet into the tap 1, where it connects with the tap handle 7. It will be appreciated by the skilled man that alternative styles of tap handle will require an alternative design of control member to the straight rod shown in Fig. 1. In styles of tap where the tap handle is not located on the same axis as the inlet valve 3, a more flexible control member can be suitably used.

The attachment of the control member 8 to the tap handle 7 could be by way of a simple screw-fitting. However, it is appreciated that alternative fixing methods are also possible.

It will also be appreciated that the dimensions of the control member will be such that the control member does not restrict the flow of water through the device 2 and the tap 1. Preferably the control member will be constructed from a non-corrosive material.

Figures 2 and 3 show the thermally actuated diverter vIve 6 that is preferably used in the present invention. Figure 2 shows the diverter valve in the first position, i.e. when the water is being directed out of the device via the second outlet. Figure 3 shows the diverter valve in the second position, i.e. when the water is being directed out of the device via the first outlet.

As mentioned above, the diverter valve 6 is located between the inlet 3 and the two outlets 4 & 5 within the chamber of the water-saving device 2.

The diverter valve 6 comprises a piston 10 with inlet ports (not visible in Figs. 2 & 3) and outlet ports 11. The ports direct the movement of water through the piston 10.

On the internal walls of the device 2 are located a pair of seals 12. In the present embodiment the seals 12 are circular in shape and provide a water-tight seal with the piston 10. It is understood that the seals can be attached to the walls of the device 2 by any suitable means. The nature of the arrangement between the seals 12 and the piston 10 is such that the only way water can get from the inlet to one of the outlets 4 & 5 is by flowing through the piston ports 11. This arrangement can be more clearly seen from Figure 4.

The first and second seals 12 are preferably located above and below the second outlet 5 in such a way as to completely isolate the second outlet 5 from the first outlet 4.

The arrangement of the first and second seals 12 is such that the chamber of the device is split into three separate sub-chambers. The first subchamber comprising the inlet 3 and thus being where water enters the device 2. The second sub-chamber is in constant fluid communication with the second outlet 5 and is accessible from the first sub-chamber only via the piston ports 11. The third sub-chamber is in constant fluid communication with the first outlet 4 and is accessible from the first sub-chamber only via the piston ports 11.

By the above described arrangement the diverter valve can control which one of the outlets 4 & 5 is in fluid communication with the inlet 3.

In the preferred embodiment the piston 10 is slideably mounted on the control member 8, which extends through the device 2 from the inlet 3 to the first outlet 4. It will be appreciated that the nature of the mounting of the piston on the control member 8 should be water-tight to prevent the valve "short- circuiting".

The diverter valve further comprises a temperature sensitive mechanism, which is connected to the piston in such a way as to drive the movement of the piston from a first position to a second position. In a preferred embodiment of the present invention the temperature sensitive mechanism comprises a thermal wax expansion unit 15, which will expand with a tremendous force when it reaches a predetermined temperature. The thermal wax expansion unit 15 is in turn connected to an abutment 14, which contacts the piston 10.

In a preferred embodiment the thermal wax expansion unit 15 comprises a plunger unit consisting of a sealed tube that is filled with a wax substance which, when heated at a determined temperature, will expand rapidly and push an encapsulated rod outwards. This rod is attached to the base of the piston 10, by a pivoted and forked arm to ensure that trust is at the centres of the piston valve, so that when heated it pushes the piston 10 upwards and moves the piston ports 11 from one sub- chamber to another.

As mentioned above, the piston 10 has a default position (shown in Figure 2) wherein the water entering the device via the inlet 3 is diverted to the second outlet 5. In the preferred embodiment the piston is biased towards the default position by the presence of a resilient biasing means 13, which could be a spring made from a non-corrosive material.

The preferred embodiment of the present invention, which is arranged to prevent water that is not hot from discharging via the hot water tap and thus being wasted, can be seen to work as follows.

Upon working of the tap handle 7 the control member 8 causes the inlet valve 9 to open and allow water to enter into the first sub-chamber of the device 2. This water, which is likely to be too cold for use if the hot water tap has not been used for some time, will thus flow through the piston 10 and through the second outlet back to the water supply system; in this way no water is wasted.

After a relatively short period of time the temperature of the water entering the device via the inlet should have increased to a more suitable temperature. Whilst it is understood that a suitable temperature is usually 40 C for showers and 50 C for kitchen outlets, the present invention is not necessarily limited to specific temperatures. This increase in the temperature within the first sub-chamber of the device will cause the thermal wax expansion unit 15 to expand, thus causing the piston 10 to move from its first position to the its second position. Once the piston 10 is in the second position the water entering the device 2 is directed via the piston 10, through the first outlet 3 and out of the tap 1.

When the tap handle 7 is worked to close the inlet valve 9, water ceases to enter the device and the thermal wax expansion unit 15 is allowed to cool and contract. As the thermal wax expansion unit 15 contracts the piston 10 is forced back to its default position by the resilient biasing means 13.

It will be appreciated that, whilst the above discussed embodiment is arranged to prevent water that is too cold from exiting a hot water tap, the same device could be adapted to prevent water that is too hot from exiting a cold water tap without too difficulty. It is understood that by swapping the connections of the first and second outlets 4 & 5, and adjusting the sensitivity of the thermal wax expansion unit 15, the above discussed device could be used to re-circulate water that is too warm to exit a cold tap. Of course, alternative adaptations of the device 2 shown in Figs. 2 & 3 could also be carried out to produce the same effect.

Whilst the specific destination of the water which is diverted through the second outlet 5 back to the water supply system is not necessarily essential to the present invention, there are a several preferred alternatives.

The skilled man will appreciate that, in arrangements where water that is too warm is being re-circulated, it is perfectly acceptable to simply direct the water to the hot water supply pipe via a suitable one-way junction.

However, whilst the diversion of fresh (warm) cold water to the hot water system is generally acceptable, the diversion of (cool) hot water to the cold water system is prohibited in most countries for the health and safety reasons. As a result there is a need for a more sophisticated mechanism of water diversion.

Figure 5 shows a first preferred embodiment of a diversion destination for the (cool) hot water. The simplified system shon in Fig. 5 comprises the tap 1 and water-saving device 2 discussed above. In addition the system comprises a hot water supply 16, which could be a boiler. Fresh cold water enters the system via input point A. In the exemplary system the hot water supply tank 16 provides water for both a tap I and a shower 19. When water is diverted through the second outlet of device 2 because it is too cool to exit the hot tap 1, the diverted water is directed to a ho'ding tank 17. Preferably the holding tank is pressurised to allow for the possibility of over-filling of the system.

The holding tank 17, which is also supplied with cold water from the cold water supply point A, provides water to destinations where the water will not be drunk such as the cistern 18 of a toilet or a shower 1 9.

It will be appreciated that in situations where the shower 19 is an electric-type the only supply of water may come frorii the holdinq tank 17, with such water being heated by the shower as required.

Figure 6 shows a second preferred embodiment of a diversion destination for the (cool) hot water. This embodiment works by providing the water, diverted via the second outlet 5, with a re-circulation pathway 20 that eventually allows the water to be gradually re-introduced into the hot water supply at a point up stream of the device 2. This embodiment makes possible the provision of a completely self-contained water-saving device, which does not require additional re-plumbing of the general water supply system.

It is understood that the re-circulation pathway could comprise a storage tank similar to that described above. However, rather that connecting the tank to the water supply system as described above, the tank could have a junction that facilitates the gradual return of water to the hot water supply.

In the preferred embodiment shown in Fig. 6 the re-circulation pathway comprises a spiral of pipe-work so as to provide a suitable length of pipe- work within a limited space (e.g. under a sink). At the junction point 21, where the pipe-work rejoins the water supply system up stream of the water-saving device 2, there is preferably provided a one-way valve that only permits the movement of water from the pathway 20 to the hot water supply pipe.

Preferably the total capacity of the re-circulation pathway will be enough to receive the volume of water which it takes for the water reaching the water-saving device 2 to turn hot. It will be appreciated that the capacity of the re-circulation pathway 20 might ideally be equal to, or greater than, the capacity of the pipe-work that connects the device 2 with the hot water supply, e.g. boiler.

Alternatively, or in addition, the re-circulation pathway 20 might be pressurised to enable the volume of the water diverted to the pathway 20 to be accommodated.

In operation, the re-circulation pathway 20 will receive the (cool) hot water that enters the water-saving device 2 until such time that the water is of adequate temperature to activate the diverter valve and leave the water supply system via the hot tap. During the period while (cool) hot water is being pushed through the re-circulation pathway 20 the hot water is travelling from the hot water source. The water that flows through the re-circulation pathway eventually re-joins the hot water supply system at junction point 21. The one-way valve at junction point 21 prevents the flow of water into the re- circulation pathway 20 and ensures that the water circulates in one direction only. However, as the water flows towards the water-saving device 2 past the junction point 21 the (cool) hot water is gradually drawn back into the hot water supply by way of the venturi effect.

Although it is appreciated that the re-mixing of (cool) hot water with the hot water will result in a slight cooling of the hot water entering the water- saving device 2, this temperature loss can be negated by a slight increase in the temperature output of the hot water source, e.g. boiler.

It is appreciated that a pumping mechanism might enhance the re- mixing of the re-circulated water with the hot water supply. It is also appreciated that a pressurised re-circulation pathway 20 would enhance the re-mixing of the diverted (cool) hot water with the hot water from the hot water source.

If the re-circulation pathway 20 has a level of pressurisation, a pumping mechanism, or a combination of the two, the diverted water will be reintroduced with the hot water supply even after the hot tap has been turned off. Thus allowing the re-circulation pathway to at least partially empty of water in preparation for the next time the water is diverted via the re- circulation pathway 20.

Preferably, the thermally actuated diverter valve 6, and more preferabiy the wax thermal expansion unit 15, will be arranged so that the time it takes the diverter valve 6 to cool and return to its first position (i.e. where water is diverted exits the device 2 via the second outlet 5) is adequate time for the majority of water stored in the re-circulation pathway to be re-introduced back into the hot water supply system. In this way the re-circulation pathway is never allowed to over-fill. As a result, in situations where the hot tap is turned on before enough of the re-circulated water has re-entered the hot water supply, water can still exit the system via the tap 1.

Figure 7 shows an alternative preferred embodiment of the water- saving device of the present invention, this time used in a shower set-up 30 rather than a tap. The core water-saving device 2 remains the same to that described previously, although the equivalent components thereof are now referred to as 2A, 3A, 4A, 5A, GA, 7A, 8A and 9A respectively.

The water-saving device 2A is housed within a water storage tank 32 of the shower unit 30, which has a standard shower head 31.

The shower 30 is mounted on or in - as is the case in the illustrated embodiment - a wall 36 and is connected to both a hot and a cold water supply. The hot water supply, which is passed through the water-saving device 2A, is mixed with the water from the cold water supply at a standard mixing valve 33, which allows the user to control the temperature of the water leaving the showerhead 31.

The water-saving device 2A of the present embodiment works in essentially the same manner to the other embodiments described above, with the showerhandle 7A being workable to use the control member 8A to open the inlet valve 9A. It will be appreciated that it may be advantageous to adapt the shower handle 7A and control member 8A to open and close the mixing valve 33 thus effectively turning the shower 30 on and off.

Preferably the mixing valve 33 is a tempering valve, such valves are

well-known in the technical field of plumbing.

Once the inlet valve 9A is open the hot water can enter the water- saving device and the water can be directed to the first outlet 4A or the second outlet 5A dependant on the temperature of the water.

Water that is too cool is diverted out of the device 2A via the second outlet 5A into the water storage tank 3 where it collects.

The cold water supply conduit 34 passes through the water storage tank 32 to reach the mixing valve 33. The cold water supply conduit 34 also comprises a one-way valve 35 which is arranged to allow the flow of water from the water storage tank 32 into the water supply conduit 34. In this way the water in the storage tank 32 does not over fill the tank. In fact, as the tank fills the water therein is put under more pressure to pass through the one-way valve 35 and enter the supply conduit 34. It is appreciated that the water storage tank 32 may be pressurised to improve the flow of water into the supply conduit 34.

The skilled man will appreciate that the second outlet 5A could also have a non-return valve to prevent water passing back through the outlet 5A when the water in the storage tank 32 reaches a certain level. In order to negate the likelihood of a return flow of water back into the second outlet 5A the water-saving device 2A is preferably located towards the top of the water storage tank 32.

Preferably, the water supply conduit is connected to the cold water supply via a one-way valve, such as a pressure reducing valve, so that the cold water in the shower system, which has been mixed with the water from the hot water system, cannot re-enter the drinking water system.

Preferably, the shower tank 32 has a bleed-off tap 37, which can be used to empty the shower 30 if it has not been used for sometime. The bleedoff tap 37 allows the water to collected and re-used, for example to water the garden.

The shower may also have a standard thermal safety valve, which can be arranged to re-circulate water that is too hot back to the water storage tank 32.

Claims

1. A water-saving device, for use in a water supply system, the device comprising: a body defining a chamber having an inlet, which is connectable to the water supply system, and a first and second water outlet; the first outlet being connectable in fluid communication with a discharge means to enable water to discharge from the water supply system; the second outlet being connectable to the water supply system to enable re-circulation of water; a thermally actuated diverter valve operable dependant on the temperature of water entering the chamber via the inlet to control whether water exits the chamber via the first outlet or the second outlet; and an inlet valve, for controlling the flow of water through the inlet, having a valve actuating member connected to or connectable with a manual control member of the discharge means to enable opening and closing of the inlet valve.

2. The device of claim 1, wherein the thermally actuated diverter valve is arranged to direct water to the second outlet until such time as the water entering the chamber is within a desired temperature range.

3. The device of claim 1 or 2, wherein the thermally actuated diverter valve comprises a thermal wax expansion unit, which expands upon heating to displace the valve from a first position, wherein water is directed via the second outlet to the water supply system, and a second position, wherein water is directed via the first outlet to discharge from the water supply system via the discharge means.

4. The device of claim 1, 2 or 3, wherein the inlet valve actuating member comprises a rod or spindle or shaft which extends into the chamber through the first outlet, and is operationally connectable with or mountable on the discharge means such that the discharge means can be used to operate the inlet valve.

5. The device of any of claims 1 to 4, wherein the valve actuating member comprises a thin, flexible length of a non-corrosive material.

6. The device of any of claims I to 5, wherein the second outlet is connected to a water storage tank which is arranged to collect the recirculated water, said tank being further arranged to enable the water held in the water storage tank to be re-introduced into the water supply system.

7. The device of claim 6, wherein the water storage tank is pressurised.

8. The device of claim 6 or 7, wherein the water storage tank is a toilet cistern.

9. The device of claim 6 or 7, wherein the water saving device is housed within the water storage tank.

10. The device of any of claims I to 5, wherein the second outlet is connected via a re-circulation conduit to a junction with the water supply system that is up-stream of the chamber inlet, said junction comprising a one- way valve that only permits water to pass from the second outlet to the water supply.

11. The device of claim 10, wherein the re-circulation conduit has an capacity that is at least equal to the capacity of the pipe-work that connects the chamber to the source of the water of desired temperature, whereby the necessary amount of re-circulated water can be stored as the water of desired temperature moves towards the chamber.

12. The device of claim 10 or 11, wherein the re-circulation conduit comprises a spiral of pipe-work, which enables an increased capacity to store the re-circulated water.

13. A water-saving device, for use in a water supply system, substantially as described, with reference to the drawings, hereinbefore.

14. A shower unit comprising the water saving device of claim 9, wherein the shower further comprises: a mixing valve, which is in fluid communication with the first outlet of the device, located down-stream of the device; a hot water supply conduit, which comprises the water-saving device, the conduit having a first end, which is connectable with a source of hot water and a second end, which connected to the mixing valve; a cold water supply conduit having a first end, which is connectable with a cold water supply, and a second end, which is in fluid communication with the mixing valve; a shower-head located in fluid communication with the mixing valve; and wherein the water storage tank is connected to the supply conduit via a one-way valve so that the water stored in the tank can re-enter the cold water supply conduit.

15. The shower of claim 14, further comprising a pressure reducing valve located on the supply conduit at a position up-stream of the one-way valve.

16. The shower of claim 14 or 15, wherein the cold water supply conduit is substantially housed within the water storage tank.

17. A shower unit substantially as described, with reference to the drawings, hereinbefore.

17. A tap comprising the device of any of claims 1 to 12, said tap comprising a tap handle and wherein the control member is operationally connected to the tap handle whereby the tap controls the flow of water through the inlet valve of the device.

18. A tap substantially as described, with reference to the drawings, hereinbefore.