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Title:
METHOD OF DETERMINING A LEAK IN A WATER HEATING SYSTEM AND WATER HEATING SYSTEM
Document Type and Number:
WIPO Patent Application WO/2022/168051
Kind Code:
A1
Abstract:
The present disclosure provides a computer-implemented method of determining a leak in a water heating system (100), the water heating system comprising a control module (110) configured to control operation of the water heating system, at least one water heating modules (140, 150) configured to heat water to be circulated around a sealed heating circuit, a first valve (280-1) configured to control water flow returning from the heating circuit to the water heating system and a second valve (280-2) configured to control water flow from the water heating system to the heating circuit, the method being performed by the control module and comprising: receiving first sensor data from a first pressure sensor (270-1) 10 disposed upstream of the first valve; receiving second sensor data from a second pressure sensor (270-2) disposed downstream of the first valve; upon determining that the first sensor data and/or the second sensor data indicates a water pressure below a reference water pressure, closing the first valve and the second valve to isolate the heating circuit and the first pressure sensor from the water heating system and the second pressure sensor; monitoring the first sensor data indicating a water pressure in the heating circuit and the second sensor data indicating a water pressure in the water heating system; and upon determining that the second sensor data indicates a fall in water pressure, determining a leak in the water heating system.

Inventors:
KONOWALCZYK PETER (GB)
Application Number:
PCT/IB2022/051083
Publication Date:
August 11, 2022
Filing Date:
February 07, 2022
Export Citation:
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Assignee:
OCTOPUS ENERGY GROUP LTD (GB)
International Classes:
F24D19/10; F24H15/12; F24H15/242; F24H15/31
Foreign References:
EP3654009A22020-05-20
US20180245801A12018-08-30
DE102017100416A12018-07-12
DE3905054C11990-04-19
Attorney, Agent or Firm:
KAZI, Ilya (GB)
Download PDF:
Claims:
CLAIMS

1. A computer-implemented method of determining a leak in a water heating system (100), the water heating system comprising a control module (110) configured to control operation of the water heating system, at least one water heating modules (140, 150) configured to heat water to be circulated around a sealed heating circuit, a first valve (280-1) configured to control water flow returning from the heating circuit to the water heating system and a second valve (280-2) configured to control water flow from the water heating system to the heating circuit, the method being performed by the control module and comprising: receiving first sensor data from a first pressure sensor (270-1) disposed upstream of the first valve; receiving second sensor data from a second pressure sensor (270-2) disposed downstream of the first valve; upon determining that the first sensor data and/or the second sensor data indicates a water pressure below a reference water pressure, closing the first valve and the second valve to isolate the heating circuit and the first pressure sensor from the water heating system and the second pressure sensor; monitoring the first sensor data indicating a water pressure in the heating circuit and the second sensor data indicating a water pressure in the water heating system; and upon determining that the second sensor data indicates a fall in water pressure, determining a leak in the water heating system.

2. The method of claim 1, further comprising, upon determining that the first sensor data indicates a fall in water pressure, determining a leak in the heating circuit.

3. The method of claim 1 or 2, further comprising, upon determining that the water pressure indicated by the first sensor data and the water pressure indicated by the second sensor data remain substantially constant, releasing the first valve and a third valve (230) to allow mains water into the heating circuit to increase the water pressure to at least the reference water pressure.

4. The method of claim 3, further comprising, upon the water pressure in the heating circuit reaching at least the reference water pressure, closing the third valve to isolate mains water from the heating circuit and releasing the other one of the first or second valve.

5. The method of any preceding claim, further comprising generating a warning upon determining a leak in the heating circuit and/or the water heating system.

6. The method of any preceding claim, wherein monitoring the first sensor data and the second sensor data comprises comparing the first sensor data received at a first time step, Tl, with the first sensor data received at a second time step, T2, after a predetermined time interval, and determining whether the first sensor data received at the second time step, T2, indicates a lower water pressure than the first sensor data received at the first time step, Tl.

7. The method of any preceding claim, wherein monitoring the first sensor data and the second sensor data comprises comparing the second sensor data received at a third time step, T3, with the second sensor data received at a fourth time step, T4, after a predetermined time interval, and determining whether the second sensor data received at the fourth time step, T4, indicates a lower water pressure than the second sensor data received at the third time step, T3.

8. The method of claim 6 or 7, further comprising generating a warning when a difference between a water pressure indicated by the first sensor data received at the first time step, Tl, and a water pressure indicated by the first sensor data received at the second time step, T2, exceeds a pressure drop threshold, and/or when a difference between a water pressure indicated by the second sensor data received at the third time step, T3, and a water pressure indicated by the second sensor data received at the fourth time step, T4, exceeds a pressure drop threshold.

9. The method of claim 5 or 8, wherein the warning comprises a light signal, an audio signal, a verbal, text or multimedia notification, or a combination thereof.

10. The method of any preceding claim, wherein the reference water pressure corresponds to a deviation from an operating water pressure for the heating circuit.

11. The method of any preceding claim, wherein the reference water pressure corresponds to a minimum operating pressure for the heating circuit.

12. The method of any preceding claim, further comprising adjusting the reference water pressure based on operating conditions of the water heating system, wherein the operating conditions comprise indoor ambient air temperature, outdoor air temperature, atmospheric pressure, or a combination thereof.

13. A computer-readable medium comprising machine-readable code, which, when executed by a processor, causes the processor to perform the method of any preceding claim.

14. A water heating system (100) comprising: at least one water heating modules (140, 150) configured to heat water to be circulated around a sealed heating circuit; a first valve (280-1) configured to control water flow returning from the heating circuit to the water heating system; a second valve (280-2) configured to control water flow from the water heating system to the heating circuit; a first pressure sensor (270-1) configured to measure a water pressure in the heating circuit disposed upstream of the first valve; a second pressure sensor (270-2) configured to measure a water pressure in the heating circuit disposed downstream of the first valve; and a control module configured to control operation of the water heating system, the control module comprising: at least one processor; and a non-transitory computer-readable medium having stored thereon software instructions that, when executed by the at least one processor, cause the control module to: receive first sensor data from the first pressure sensor (270-1); receive second sensor data from the second pressure sensor (270-2); upon determining that the first sensor data and/or the second sensor data indicates a water pressure below a reference water pressure, closing the first valve (280-1) and the second valve (280-2) to isolate the heating circuit and the first pressure sensor from the water heating system and the second pressure sensor; monitoring the first sensor data indicating a water pressure in the heating circuit and the second sensor data indicating a water pressure in the water heating system; and upon determining that the second sensor data indicates a fall in water pressure, determining a leak in the water heating system.

15. The water heating system of claim 14, wherein the software instructions further cause the control module to, upon determining that the first sensor data indicates a fall in water pressure, determining a leak in the heating circuit.

16. The water heating system of claim 14 or 15, further comprising a third valve (230) configured to control a flow of mains water into the heating circuit, wherein the software instructions further cause the control module to, upon determining that the water pressure indicated by the first sensor data and the water pressure indicated by the second sensor data remain substantially constant, releasing the first valve and the third valve to allow mains water into the heating circuit to increase the water pressure to at least the reference water pressure.

17. The water heating system of any of claims 14 to 16, wherein the one or more water heating modules comprise a heat pump (140) configured to transfer heat from the surroundings to a thermal energy storage (150), the thermal energy storage comprises at least one heat exchanger (154) for transferring stored thermal energy to water to be circulated around the sealed heating circuit.

18. The water heating system of any of claims 14 to 17, further comprising the heating circuit, wherein the heating circuit comprises one or more radiating heating modules configured to heat an indoor area.

21

Description:
METHOD OF DETERMINING A LEAK IN A WATER HEATING SYSTEM AND WATER HEATING SYSTEM

The present disclosure relates generally to water heating systems in both domestic and industrial applications. In particular, the present disclosure relates to methods and systems for determining a fault in a water heating system to prevent a backflow from a sealed heating circuit.

BACKGROUND

Indoor heating can be provided through a sealed central heating system, which comprises a water heater that supplies heated water to a plurality of radiating heaters fluidly connected by a plurality of pipes in a closed heating circuit. Such a sealed central heating system generally comprises, amongst other things, a pump for urging water around the heating circuit, a pressure gauge for measuring the water pressure within the heating circuit, and a filling circuit between the cold water main and a return pipe (through which water is returned from the radiating heaters to the water heater) for filling the heating circuit with cold mains water so as to increase the pressure within the heating circuit.

A sealed central heating system should operate at a predetermined range of operating pressure, and when the water pressure within the heating circuit falls below the predetermined range of operating pressure, the filling circuit is used so as to repressurise the heating circuit to the desired operating pressure. Since the central heating circuit is pressurised, to protect incoming mains water from being contaminated by a backflow from the central heating system, the filling circuit is commonly provided with an isolation valve downstream for stopping water from the heating circuit from entering the filling circuit as well as a flow control valve upstream for releasing mains water into the filling circuit.

There can be different reasons for the pressure in the heating circuit to fall, for example air being trapped in the closed heating circuit, a leak in one or more valves in the radiating heaters, a fault in one or more pipes in the heating circuit, or a fault or leak in the water heating system that heats the water of the heating circuit. If the fault or leak is in the water heating system and the heating circuit is repressurised without the fault or leak being remedied, the drop in pressure in the water heating system as a result of the fault or leak may lead to water from the heating circuit back-feeding into the water heating system, potentially causing a contamination of the mains water supply directed to other water outlets such as taps and shower.

Conventionally, to identify the cause for pressure loss, a skilled engineer would first inspect for leaks on valves and pipes around the heating circuit, and if a leak cannot be found, a test on the water heating system is performed by pressuring the system to the predetermined operating pressure then engaging the isolation valve to the heating circuit to determine whether the water heating system maintains the operating pressure. During testing of the water heating system, the water heating system is prevented from operation. If the water heating system fail to maintain the operating pressure for a sufficient length of time (e.g. a day), then the fault is deemed to lie within the water heating system.

Such manual inspections and tests are time consuming and prone to error. For example, a leak in a valve or pipe of the heating circuit may be missed during manual inspections, and the engineer is required to balance between disrupting the normal operation of the water heating system and allowing a long enough time to determine whether the water heating system is able to maintain the operating pressure, so the engineer may be required to attend the water heating system over a long period of time or a fault in the water heating system may be missed.

It is therefore desirable to provide improved methods and systems for determining a leakage in a water heating system to prevent a backflow from a sealed heating circuit.

SUMMARY

An aspect of the present technology provides a computer-implemented method of determining a leak in a water heating system, the water heating system comprising a control module configured to control operation of the water heating system, at least one water heating modules configured to heat water to be circulated around a sealed heating circuit, a first valve configured to control water flow returning from the heating circuit to the water heating system and a second valve configured to control water flow from the water heating system to the heating circuit, the method being performed by the control module and comprising: receiving first sensor data from a first pressure sensor disposed upstream of the first valve; receiving second sensor data from a second pressure sensor disposed downstream of the first valve; upon determining that the first sensor data and/or the second sensor data indicates a water pressure below a reference water pressure, closing the first valve and the second valve to isolate the heating circuit and the first pressure sensor from the water heating system and the second pressure sensor; monitoring the first sensor data indicating a water pressure in the heating circuit and the second sensor data indicating a water pressure in the water heating system; and upon determining that the second sensor data indicates a fall in water pressure, determining a leak in the water heating system.

According to embodiments of the present technology, it is possible to determine whether there is a leak or a fault in the water heating system when the water pressure in the heating circuit falls below the reference water pressure (or a minimum water pressure). In doing so, it is possible to give an early warning when a leak occurs to prevent more serious issues caused by a delay in detection. Moreover, if there is a leak or fault in the water heating system and the heating circuit is repressurised without the leak or fault being repaired, it can lead to a backflow from the heating circuit into the mains water feeding loop, contaminating water supply with bacteria harmful to health. Through embodiments of the present technology, it is possible to prevent backflow by determining whether there is a leak or fault in the water heating system before the heating circuit is repressurised.

A further aspect of the present technology provides a computer-readable medium comprising machine-readable code which, when executed by a processor, causes the processor to perform the methods described above.

A yet further aspect of the present technology provides a water heating system comprising: at least one water heating modules configured to heat water to be circulated around a sealed heating circuit; a first valve configured to control water flow returning from the heating circuit to the water heating system; a second valve configured to control water flow from the water heating system to the heating circuit; a first pressure sensor configured to measure a water pressure in the heating circuit disposed upstream of the first valve; a second pressure sensor configured to measure a water pressure in the heating circuit disposed downstream of the first valve; and a control module configured to control operation of the water heating system, the control module comprising: at least one processor; and a non-transitory computer-readable medium having stored thereon software instructions that. when executed by the at least one processor, cause the control module to: receive first sensor data from the first pressure sensor; receive second sensor data from the second pressure sensor; upon determining that the first sensor data and/or the second sensor data indicates a water pressure below a reference water pressure, closing the first valve and the second valve to isolate the heating circuit and the first pressure sensorfrom the water heating system and the second pressure sensor; monitoring the first sensor data indicating a water pressure in the heating circuit and the second sensor data indicating a water pressure in the water heating system; and upon determining that the second sensor data indicates a fall in water pressure, determining a leak in the water heating system.

Implementations of the present technology each have at least one of the above- mentioned objects and/or aspects, but do not necessarily have all of them. It should be understood that some aspects of the present technology that have resulted from attempting to attain the above-mentioned object may not satisfy this object and/or may satisfy other objects not specifically recited herein.

Additional and/or alternative features, aspects and advantages of implementations of the present technology will become apparent from the following description, the accompanying drawings and the appended claims.

BRIEF DESCRIPTION OF THE DRAWINGS

Embodiments of the present disclosure will now be described with reference to the accompanying drawings, in which:

Fig. 1 is a schematic system overview of a water supply branch of an exemplary water heating system;

Fig. 2 is a schematic system overview of a central heating branch of the exemplary water heating system of Fig. 1; and

Fig. 3 is a flow diagram illustrating an exemplary method of determining a leak according to an embodiment.

DETAILED DESCRIPTION In view of the foregoing, the present disclosure provides various approaches for determining a leak in a water heating system.

Water Heating System

In embodiments of the present techniques, a centralized water provision/heating system provides cold and heated water to a plurality of water outlets, including taps, showers, etc. and heated water to be circulated around a sealed heating circuit to provide central heating in a building in a domestic or industrial/commercial setting. An exemplary water provision system according to an embodiment is shown in Fig. 1.

In the present embodiment, the water heating system 100 comprises a control module 110. The control module 110 is communicatively coupled to, and configured to control, various elements of the water heating system, including a flow control 130 for example in the form of one or more valves arranged to control the flow of water into, out of and around the system, a (ground source or air source) heat pump 140 configured to extract heat from the surroundings and deposit the extracted heat in a thermal energy storage 150 to be used to heat water, and one or more electric heating elements 160 configured to directly heat cold water to a desired temperature by controlling (by the control module 110) the amount of energy supplied to the electric heating elements 160. Heated water, whether heated by the thermal energy storage 150 or heated by the electric heating elements 160, is then directed to one or more water outlets as and when needed. In the embodiments, the heat pump 140 extracts heat from the surroundings into a thermal energy storage medium within the thermal energy storage 150. The thermal energy storage medium may optionally also be heated by other sources such as the electric heating elements 160 if desired. The heat pump 140 continues to deposit extracted heat to the thermal energy storage medium until it reaches a desired operation temperature, then cold water e.g. from the mains can be heated by the thermal energy storage medium in a heat exchanger 152 to the desired temperature. The heated water may then be output for distribution around a water distribution network that comprises e.g. various hot/cold water taps, shower(s), etc.

In the present embodiment, the control module 110 comprises one or more processors 120 configured to execute instructions for controlling operations of the water heating system. In particular, the control module 110 is configured to receive sensor data from a plurality of sensors 170-1, 170-2, 170-3, ..., 170-n. The plurality of sensors 170-1, 170-2, 170-3, ..., 170-n may for example include one or more air temperature sensors disposed indoor and/or outdoor, one or more water temperature sensors, one or more water pressure sensors, one or more timers, and may include other sensors not directly linked to the water provision system 100 such as one or more motion sensors, a GPS signal receiver, calendar, weather forecasting app on e.g. a smartphone carried by an occupant and in communication with the control module via a communication channel. The one or more processors 120 of the control module 110 is configured, in the present embodiment, to use the received input to perform a variety of control functions, for example controlling the flow of water through the flow control 130 to the thermal energy storage 150 or to the electric heating elements 160 to be heated.

In the present embodiment, a pressure sensor 170-1 is disposed at a position in the water heating system 100 to measure the water pressure of heated water output by the water heating system 100, and sensor data indicating the measured water pressure is received by the control module 110 which processes the sensor data and controls operation of the water heating system based on the results. A flow control e.g. valve 180-1 is disposed at a position in the water heating system 100 to control the flow of heated water output by the water heating system 100 to the water distribution network. The control module 110 is configured to control the operation of the valve 180-1 based on the received sensor data from the pressure sensor 170-1.

Embodiments of the present technology make use of a heat pump and a thermal energy storage (or heat reservoir) as a source of heat for heating cold water. While a heat pump is generally more energy efficient for heating water compared to an electrical resistance heater, a heat pump requires time to start up as it performs various checks and cycles before reaching a normal operation state, and time to transfer sufficient amount of thermal energy into a thermal energy storage medium before reaching the desired operation temperature. On the other hand, an electrical resistance heater is generally able to provide heat more immediately. Thus, a heat pump can take longer to heat the same amount of water to the same temperature compared to an electrical resistance heater. Moreover, in some embodiments, the heat pump 140 may for example use a phase change material (PCM), which changes from a solid to a liquid upon heating, as a thermal energy storage medium. Additional time may therefore be required to for the heat pump to first transferred a sufficient amount of heat to turn the PCM from solid to liquid, if it has been allowed to solidify, before it can further raise the temperature of the liquified thermal storage medium. Although this approach of heating water is slower, it consumes less energy to heat water compared to electric heating elements, so overall, energy is conserved and the cost for providing heated water is reduced.

Phase Change Materials

In the present embodiments, a phase change material may be used as a thermal storage medium for the heat pump. One suitable class of phase change materials are paraffin waxes which have a solid-liquid phase change at temperatures of interest for domestic hot water supplies and for use in combination with heat pumps. Of particular interest are paraffin waxes that melt at temperatures in the range 40 to 60 degrees Celsius (°C), and within this range waxes can be found that melt at different temperatures to suit specific applications. Typical latent heat capacity is between about 180kJ/kg and 230kJ/kg and a specific heat capacity of perhaps 2.27Jg 1 K 1 in the liquid phase, and 2.1Jg 1 K 1 in the solid phase. It can be seen that very considerable amounts of energy can be stored taking using the latent heat of fusion. More energy can also be stored by heating the phase change liquid above its melting point. For example, when electricity costs are relatively low during off-peak periods, the heat pump may be operated to "charge" the thermal energy storage to a higher-than-normal temperature to "overheat" the thermal energy storage.

A suitable choice of wax may be one with a melting point at around 48°C, such as n- tricosane C23, or paraffin C20-C33, which requires the heat pump to operate at a temperature of around 51°C, and is capable of heating water to a satisfactory temperature of around 45°C for general domestic hot water, sufficient for e.g. kitchen taps, shower/bathroom taps. Cold water may be added to a flow to reduce water temperature if desired. Consideration is given to the temperature performance of the heat pump. Generally, the maximum difference between the input and output temperature of the fluid heated by the heat pump is preferably kept in the range of 5°C to 7°C, although it can be as high as 10°C.

While paraffin waxes are a preferred material for use as the thermal energy storage medium, other suitable materials may also be used. For example, salt hydrates are also suitable for latent heat energy storage systems such as the present ones. Salt hydrates in this context are mixtures of inorganic salts and water, with the phase change involving the loss of all or much of their water. At the phase transition, the hydrate crystals are divided into anhydrous (or less aqueous) salt and water. Advantages of salt hydrates are that they have much higher thermal conductivities than paraffin waxes (between 2 to 5 times higher), and a much smaller volume change with phase transition. A suitable salt hydrate for the current application is NazSzOs-SFhO, which has a melting point around 48°C to 49°C, and latent heat of 200-220 kJ/kg.

Fig. 2 shows a central heating branch of the water heating system 100 of Fig. 1. Like elements are indicated by like reference numerals. As can be seen in Fig. 2, the heating branch (heating circuit) is a sealed or closed loop comprising elements of a central heating system 190 which, for example, includes one or more radiating heating elements/modules disposed in multiple locations around the building.

Water circulating around the heating circuit is heated by heat exchanger 252 in the thermal energy storage 150, which is arranged to store thermal energy (heat) extracted from the surroundings by the heat pump 140 (optionally also received from the electric heating elements 160). Heated water is output from the water heating system 100 via a valve 280-2 (second valve) which controls the flow of the output heated water. The heated water circulates the heating circuit and dissipated by the central heating system 290 via one or more radiating heating elements. Cooled water returns from the central heating system 290 around the heating circuit to the water heating system via a valve 280-1 (first valve) which controls the flow of the returned water. The pressure of the heating circuit is measured by a first pressure sensor 270-1 and a second pressure sensor 270-2, and sensor data from the first and second pressure sensors 270-1, 270-2 is received by the control module 110, which monitors the water pressure of the heating circuit.

As can be seen in Fig. 2, the first pressure sensor 270-1 is positioned upstream of the first valve 280-1 and downstream of the second valve 280-2, while the second pressure sensor 270-2 is positioned downstream of the first valve 280-1. With this arrangement, the first and second pressure sensors 270-1, 270-2 and the first and second valves 280-1, 280-2 are positioned such that, when the first and second valves are in a closed position, the heating circuit (or central heating 290) is fluidly isolated from the water heating system, and the first pressure sensor 270-1 is in a position to measure the isolated water pressure in the heating circuit while the second pressure sensor 270-2 is in a position to measure the isolated water pressure in the water heating system.

For the central heating system to perform optimally, the water pressure within the heating circuit is preferably maintained at a level that is within an optimal operating range. If the pressure in the heating circuit falls below the operating range, the heating circuit may first be fluidly isolated by closing the first valve 280-1, and then mains water is released into the return flow by operating a third valve 230 to an open position so as to increase the water pressure in the heating circuit to a level within the optimal range.

However, there may be different causes that lead to the heating circuit losing pressure. For example, there may be a buildup of air within the heating circuit, a leak somewhere in the heating circuit, such as a valve of one of the radiating heating modules, a damaged pipe or joint, or a leak or fault somewhere in the water heating system. In cases where the loss of pressure is not a result of a fault ora leak, e.g. an air pocket in the heating circuit, then topping up the heating circuit with mains water to remove the air pocket would resolve the issue. However, in cases where the loss of pressure is caused by a fault or a leak, simply restoring the operating pressure in the heating circuit by introducing mains water into the heating circuit will not resolve the issue and may worsen the problem, such as causing further leakage and/or risking heating circuit water back-feeding to water supply (backflow).

It is therefore desirable to determine if there is a leak or fault, and whether the leak or fault is in the heating circuit or the water heating system, before repressurizing the heating circuit. The water heating system 100 according to embodiments of the present disclosure enables such a determination to be made through the use of the first and second pressure sensors 270-1, 270-2 and the first and second valves 280-1, 280-2, as illustrated in Fig. 3 by way of an example.

Active leak detection and backflow prevention

Fig. 3 shows a method of detecting water leakages in a water heating system such as the water heating system 100, according to an embodiment. The method is performed by a control unit or control module, such as the control module 110, that is configured to control operations of various elements of the water heating system. In particular, the method may be a computer-implemented method that comprises software instructions which, when executed by one or more processors, such as the one or more processors 120, performs the various steps of the method.

The method begins at S301 when the control module receives sensor data from the first pressure sensor 270-1 (first sensor data) and sensor data from the second pressure sensor 270-2 (second sensor data), indicating a water pressure in the heating circuit.

The control module compares the received first sensor data and second sensor data with a predetermined reference water pressure at S302, and upon determining that the water pressure in the heating circuit is at or above the reference water pressure (NO branch), the method returns to S301 and the control module continues to receive sensor data from the first and second pressure sensors and monitors the water pressure of the heating circuit. If, at S302, the control module determines from the first and/or second sensor data that the water pressure in the heating circuit is below the reference water pressure (YES branch), the control module outputs control signals at S303 to operate the first valve 280-1 and the second valve 280-1 to a closed position in order to fluidly isolate the heating circuit from the water heating system.

Herein, the predetermined reference water pressure may be any suitable water pressure that represents a lower threshold or minimum water pressure at which the heating circuit branch of the water heating system can operate. For example, an optimal operating water pressure, e.g. 1.5 bar, may be set by a human operator during the initial installation of the water heating system or subsequent maintenance of the water heating system and heating circuit. In some embodiments, the reference water pressure may be set at the optimal operating water pressure. However, it may be desirable to take into account of a range of normal operating conditions such as outdoor air temperature, indoor air temperature, atmospheric pressure, etc. when setting the reference water pressure. Thus, in some embodiments, a normal operating pressure range may instead be adopted to account for a normal expected deviation from the optimal operating water pressure, and the reference water pressure may be set at the lower end of the operating pressure range or at the minimum of the operating pressure range. In some embodiments, it may be desirable for the control module to adjust the reference water pressure based on operating conditions of the water heating system, or to provide recommendation or suggestion to a human operator to adjust the reference water pressure based on operating conditions of the water heating system.

After operating the first and second valves 280-1, 280-2 to the closed position at S303, the control module at S304 continues to receive first sensor data from the first pressure sensor 270-1 to monitor the water pressure in the heating circuit (first water pressure) to determine, at S305, whether the first water pressure continues to fall. If the first water pressure continues to fall, this can be used as an indication that the isolated heating circuit is losing water despite water within the heating circuit is not being circulated. Thus, upon determining at S305 that the first water pressure continues to fall (YES branch), the control module determines at S306 that there is a leak (or fault) in the heating circuit.

The control module further receives second sensor data from the second pressure sensor 270-2 to monitor the water pressure in the water heating system (second water pressure) at S307, and at S308, determines whether the second water pressure continues to fall. This can be performed simultaneously with, alternately, before, or after S304. If the second water pressure continues to fall, this can be used as an indication that there may be a leak or a fault in the water heating system. Thus, upon determining at S308 that the second water pressure continues to fall (YES branch), the control module determines at S309 that there is a fault or a leak in the water heating system.

The control module may simultaneously or in turn determine whether the first water pressure or the second water pressure continues to fall (S305, S308), and only when both the first water pressure and the second water pressure are determined to remain substantially constant for a sufficient length of time after operating the first and second valves 280-1, 280- 2 to the closed position (NO branch), the control module repressurises the heating circuit at S310 by releasing the second valve 280-2, to allow water to flow from the water heating system to the heating circuit, while maintaining the first valve 280-1 in the closed position to prevent water from returning from the heating circuit to the water heating system, and operating the third valve 230 to introduce mains water into the return route to increase the water pressure in the heating circuit until it reaches a desired pressure, e.g. at or above the reference water pressure, the optimal operating pressure, etc. When the heating circuit has been repressurised to the desired pressure, the control module at S311 closes the third valve 230 to stop the flow of mains water and releases the first valve 280-1 to allow normal operation of the heating circuit to resume.

According to the present embodiment, it is possible to determine whether there is a leak or a fault in the water heating system and/or the heating circuit when the water pressure in the heating circuit falls below the reference water pressure (or a minimum water pressure). Only when it is determined that there is no leak in either the water heating system or the heating circuit would the heating circuit be repressurised. In doing so, it is possible to give an early warning when a leak occurs to prevent a more serious leak caused by late detection and/or pressurising a faulty circuit. Moreover, if there is a leak or fault in the water heating system and the heating circuit is repressurised without the leak or fault being repaired, it can lead to a backflow from the heating circuit into the mains water feeding loop, contaminating water supply with bacteria harmful to health. Through the present embodiment, it is possible to prevent backflow by only repressurising the heating circuit after it is determined that there is no leak in the water heating system.

In some embodiments, to determine whether the first (second) water pressure continues to fall, the control module may compare first (second) sensor data received at a first time step, Tl, with first (second) sensor data received subsequently at a second time step, T2, after a predetermined time interval from Tl, and determine whether the first (second) sensor data received at T2 indicates a lower water pressure than the first (second) sensor data received at Tl. Tl and T2 may be any suitable and desirable time steps, for example Tl may be the time at which the first (second) water pressure is detected to fall below the reference water pressure, and T2 may be a time after a predetermined interval from Tl, e.g. after 10 minutes, 30 minutes, 1 hour, 1 day, etc. Present embodiments are not limited to taking only two measurements of water pressure, three, four or more measurements may be taken, and the control module may be configured to only determine that there is a leakage in the water heating system after two, three, four or more consecutive water pressure measurements indicate a continuous fall in water pressure. In some embodiments, the control module may be configured to only determine that there is a leakage in the heating circuit (the water heating system) when the first (second) water pressure falls below a lower water pressure threshold, or when the difference between two water pressure measurements (sensor data) is above a difference threshold.

In some embodiments, the control module may be configured to determine a rate at which the water pressure falls or decreases based on the sensor data received at T2 and T1 (and any other subsequently received sensor data). For example, the water pressure decrease rate may be determined by dividing the difference in water pressure by the corresponding time interval. In an embodiment, the thus determined water pressure decrease rate can be used to determine an extent or severity of the water leakage by comparing the determined rate with one or more rate thresholds. For example, a lower rate indicates a less severe water leakage while a higher rate indicates a more severe water leakage.

In some embodiments, upon determining at S306 that there is a leakage in the heating circuit, and/or upon determining at S309 that there is a leakage in the water heating system, the control module may generate a warning signal to notify a human operator of the water leakage. For example, the warning signal may comprise different form and colour light signal, an audio signal such as a discrete or continuous alarm, a verbal, text or multimedia warning, or a combination thereof.

In an embodiment, the control module may be configured to only generate a warning signal when a difference between the water pressure as indicated by sensor data received at T2 and the water pressure as indicated by sensor data received at T1 exceeds a pressure drop threshold. In doing so, a human operator is only notified if and when the water leakage is deemed problematic.

In an embodiment, the control module may be configured to generate different forms of warning, such as a traffic light system, different speed of flashing light signal, different verbal warning, etc., based on the severity of the water leakage. For example, the control module may select a form of warning based on the extent of the water leakage determined by the rate at which the water pressure of the water heating system is falling. In doing so, a human operator can quickly and easily judge the severity of the leakage and take appropriate action.

In some embodiments, upon determining at S306 that there is a leakage in the heating circuit, and/or upon determining at S309 that there is a leakage in the water heating system, the control module may provide on a display an option for a human operator to switch off the water heating system. The display may be an integrated display on the control module or an external display (e.g. a smartphone, a tablet, a computer, etc.) in communication, wirelessly or with a wired connection, with the control module. Alternatively or in addition, the control module may be configured to automatically switch off the water heating system. For example, the control module may be configured to automatically switch off the water heating system if it is determined that the water leakage is severe, and/or if a human operator has not responded to a recommendation to switch off within a predetermined time, wherein the predetermined time may be dependent on the severity or extent of the leakage.

In alternative embodiments, the first and second pressure sensors 270-1, 270-2 may be disposed at other positions within the water heating system and heating circuit to measure water pressure in different parts of the water heating system and heating circuit, and more than two pressure sensors may be provided to measure water pressure at multiple locations throughout the water heating system and/or the heating circuit, as desired.

As will be appreciated by one skilled in the art, the present techniques may be embodied as a system, method or computer program product. Accordingly, the present techniques may take the form of an entirely hardware embodiment, an entirely software embodiment including the use of artificial intelligence and machine learning, or an embodiment combining software and hardware.

Furthermore, the present techniques may take the form of a computer program product embodied in a computer readable medium having computer readable program code embodied thereon. The computer readable medium may be a computer readable signal medium or a computer readable storage medium. A computer readable medium may be, for example, but is not limited to, an electronic, magnetic, optical, electromagnetic, infrared, or semiconductor system, apparatus, or device, or any suitable combination of the foregoing. Computer program code for carrying out operations of the present techniques may be written in any combination of one or more programming languages, including object-oriented programming languages and conventional procedural programming languages.

For example, program code for carrying out operations of the present techniques may comprise source, object or executable code in a conventional programming language (interpreted or compiled) such as C, or assembly code, code for setting up or controlling an ASIC (Application Specific Integrated Circuit) or FPGA (Field Programmable Gate Array), or code for a hardware description language such as VerilogTM or VHDL (Very high-speed integrated circuit Hardware Description Language).

The program code may execute entirely on the user's computer, partly on the user's computer and partly on a remote computer or entirely on the remote computer or server. In the latter scenario, the remote computer may be connected to the user's computer through any type of network. Code components may be embodied as procedures, methods or the like, and may comprise sub-components which may take the form of instructions or sequences of instructions at any of the levels of abstraction, from the direct machine instructions of a native instruction set to high-level compiled or interpreted language constructs.

It will also be clear to one of skill in the art that all or part of a logical method according to the preferred embodiments of the present techniques may suitably be embodied in a logic apparatus comprising logic elements to perform the steps of the method, and that such logic elements may comprise components such as logic gates in, for example a programmable logic array or application-specific integrated circuit. Such a logic arrangement may further be embodied in enabling elements for temporarily or permanently establishing logic structures in such an array or circuit using, for example, a virtual hardware descriptor language, which may be stored and transmitted using fixed or transmittable carrier media.

The examples and conditional language recited herein are intended to aid the reader in understanding the principles of the present technology and not to limit its scope to such specifically recited examples and conditions. It will be appreciated that those skilled in the art may devise various arrangements which, although not explicitly described or shown herein, nonetheless embody the principles of the present technology and are included within its scope as defined by the appended claims.

Furthermore, as an aid to understanding, the above description may describe relatively simplified implementations of the present technology. As persons skilled in the art would understand, various implementations of the present technology may be of a greater complexity.

In some cases, what are believed to be helpful examples of modifications to the present technology may also be set forth. This is done merely as an aid to understanding, and, again, not to limit the scope or set forth the bounds of the present technology. These modifications are not an exhaustive list, and a person skilled in the art may make other modifications while nonetheless remaining within the scope of the present technology. Further, where no examples of modifications have been set forth, it should not be interpreted that no modifications are possible and/or that what is described is the sole manner of implementing that element of the present technology.

Moreover, all statements herein reciting principles, aspects, and implementations of the technology, as well as specific examples thereof, are intended to encompass both structural and functional equivalents thereof, whether they are currently known or developed in the future. Thus, for example, it will be appreciated by those skilled in the art that any block diagrams herein represent conceptual views of illustrative circuitry embodying the principles of the present technology. Similarly, it will be appreciated that any flowcharts, flow diagrams, state transition diagrams, pseudo-code, and the like represent various processes which may be substantially represented in computer-readable media and so executed by a computer or processor, whether or not such computer or processor is explicitly shown.

The functions of the various elements shown in the figures, including any functional block labeled as a "processor", may be provided through the use of dedicated hardware as well as hardware capable of executing software in association with appropriate software. When provided by a processor, the functions may be provided by a single dedicated processor, by a single shared processor, or by a plurality of individual processors, some of which may be shared. Moreover, explicit use of the term "processor" or "controller" should not be construed to refer exclusively to hardware capable of executing software, and may implicitly include, without limitation, digital signal processor (DSP) hardware, network processor, application specific integrated circuit (ASIC), field programmable gate array (FPGA), read-only memory (ROM) for storing software, random access memory (RAM), and non-volatile storage. Other hardware, conventional and/or custom, may also be included. Software modules, or simply modules which are implied to be software, may be represented herein as any combination of flowchart elements or other elements indicating performance of process steps and/or textual description. Such modules may be executed by hardware that is expressly or implicitly shown.

It will be clear to one skilled in the art that many improvements and modifications can be made to the foregoing exemplary embodiments without departing from the scope of the present techniques.