Multi-mode soft water heater

Abstract

The utility model discloses a multi-mode soft water heater which comprises a water inlet pipeline, a heating assembly and a water outlet pipeline which are sequentially connected, the heating assembly comprises a heating piece and a heat exchanger, the heating piece is used for heating the heat exchanger, the multi-mode soft water heater further comprises a water return branch pipe, a water storage piece, a water softening device and a salt box assembly, a first valve is arranged on the water return branch pipe and used for controlling circulation among the water inlet pipeline, the heat exchanger, the water outlet pipeline and the water return branch pipe to be opened or closed, the water storage piece is used for storing hot water, and the water softening device is arranged on the water inlet pipeline or the water outlet pipeline and used for softening water. The salt box assembly is connected with the water softening device and used for regenerating resin in the water softening device, and through cooperation of all the elements, a structural foundation is provided for achieving the functions of heating, water softening, internal circulation, water softening device regeneration and the like.

Description

TECHNICAL FIELD

[0001] The utility model relates to water heater technical field especially relates to a multi -mode soft water water heater. BACKGROUND

[0002] As an indispensable household appliance in modern family life, the performance and function of water heater are more and more concerned by consumers. However, the traditional water heater has obvious limitation in working mode, mainly showing single working mode, and cannot integrate multiple working modes to meet the diversified needs of users.

[0003] Most of the water heaters on the market can only provide single heating mode, users cannot flexibly choose according to specific use scene and demand, and cannot make corresponding adjustment according to the demand under different purposes, thereby reducing the use experience of users. UTILITY MODEL CONTENT

[0004] In order to overcome at least one defect of the prior art, the utility model provides a multi-mode soft water water heater, which can solve the problem of single function of the prior art water heater.

[0005] The utility model employs the technical scheme that:

[0006] A multi-mode soft water water heater, comprising a water inlet pipeline, a heating assembly and a water outlet pipeline, the heating assembly comprises a heating piece and a heat exchanger, the heating piece is used for heating the heat exchanger, two ends of the water inlet pipeline are a first water inlet end and a first water outlet end respectively, the first water inlet end is communicated with an external water supply pipe, the first water outlet end is communicated with the heat exchanger, two ends of the water outlet pipeline are a second water inlet end and a second water outlet end respectively, the second water inlet end is communicated with the heat exchanger, the second water outlet end is communicated with an external water outlet assembly, so that the water flowing into the heat exchanger from the water inlet pipeline is heated and then discharged through the water outlet pipeline;

[0007] It further comprises a backwater branch pipe, a water storage piece, a soft water device and a salt tank assembly, one end of the backwater branch pipe is communicated between the first water inlet end and the first water outlet end of the water inlet pipeline, the other end is communicated between the second water inlet end and the second water outlet end of the water outlet pipeline, a first valve is arranged on the backwater branch pipe, so as to control the opening or closing of the circulation between the water inlet pipeline, the heat exchanger, the water outlet pipeline and the backwater branch pipe, the water storage piece is arranged on the water inlet pipeline or the water outlet pipeline, so as to store hot water, the soft water device is arranged on the water inlet pipeline or the water outlet pipeline, and the salt tank assembly is connected with the soft water device.

[0008] Further, the soft water device is connected with an inlet pipe and an outlet pipe, one end of the inlet pipe is connected with the soft water device, the other end is connected to the inlet pipe line, one end of the outlet pipe is connected with the soft water device, the other end is connected to the inlet pipe line, a three-way valve is arranged at the connection between the inlet pipe and the inlet pipe line, or a three-way valve is arranged at the connection between the outlet pipe and the inlet pipe line, so as to control whether the inlet pipe line flows into the soft water device.

[0009] Further, the three-way valve is an electric three-way valve.

[0010] Further, the salt tank assembly comprises a salt tank and a salt shortage detection device arranged in the salt tank for detecting the salt storage amount in the salt tank.

[0011] Further, the salt shortage detection device is a distance sensor arranged at the top of the salt tank for detecting the salt storage height in the salt tank.

[0012] Further, the salt shortage detection device is a brine concentration sensor arranged at the bottom of the salt tank for detecting the solution concentration after the salt storage in the salt tank is dissolved.

[0013] Further, the soft water device is connected with a waste water discharge pipe.

[0014] Further, a one-way valve is arranged on the return water branch pipe, so that the flow direction of the return water branch pipe is from the side of the return water branch pipe close to the outlet pipe line to the side of the return water branch pipe close to the inlet pipe line.

[0015] Further, a second valve is arranged on the pipe line between the first inlet end of the inlet pipe line and the connection between the inlet pipe line and the return water branch pipe.

[0016] Further, a water pump is arranged on the inlet pipe line or the outlet pipe line.

[0017] In summary, the multi-mode soft water water heater has the following technical effects:

[0018] The water heater can complete a simple heating mode by the inlet pipe line, the heat exchanger and the outlet pipe line.

[0019] When water is needed, the soft water device is operated to soften the water before or after entering the heat exchanger, so as to complete the soft water mode.

[0020] When the resin soft water performance is regenerated in the soft water device, the connection of the soft water device and the salt tank assembly can supply the diluted brine in the salt tank assembly into the soft water device to regenerate the resin in the soft water device, and the soft water device regeneration mode is completed;

[0021] When the water heater is closed, the first valve is opened, and the corresponding control water inlet pipeline, heat exchanger, water outlet pipeline and backwater branch pipe are opened in circulation, the residual hot water is backflowed to the water storage element through the backwater branch pipe, and a part of the hot water can be reheated by the preheating of the heat exchanger and stored in the water storage element, so that when the water heater is opened again, that is, during the fan pre-cleaning and ignition process, the hot water stored in the water storage element is preferentially supplied, thereby avoiding the unstable phenomenon that the water temperature is first heated and then cooled, that is, the internal circulation mode.

[0022] Through the above structure, the water heater has a structure basis of multiple mode switching, thereby being capable of meeting multiple requirements of normal heating, softening water, soft water device regeneration and internal circulation for reducing water temperature fluctuation. BRIEF DESCRIPTION OF DRAWINGS

[0023] Figure 1 It is a connection relationship schematic diagram of the multifunctional soft water water heater.

[0024] Among them, the sign meaning is as follows: 1, water inlet pipeline; 11, first water inlet end; 12, first water outlet end; 21, burner; 22, heat exchanger; 3, water outlet pipeline; 31, second water inlet end; 32, second water outlet end; 4, backwater branch pipe; 5, water storage element; 6, soft water device; 61, water inlet pipe; 62, water outlet pipe; 63, three-way valve; 64, waste water discharge pipe; 65, salt tank assembly; 71, first valve; 72, one-way valve; 73, second valve; 8, smoke hood; 9, combustion chamber; 10, water pump. DETAILED DESCRIPTION

[0025] In order to better understand and implement, the technical solutions in the embodiments of the present application will be clearly and completely described and discussed below in combination with the drawings of the present application. Obviously, only some examples of the present application are described here, and not all examples. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative labor belong to the protection scope of the present application.

[0026] In order to facilitate the understanding of the embodiments of the present application, the following will be further explained and described in combination with specific embodiments as examples, and each embodiment does not constitute a limitation on the embodiments of the present application.

[0027] In the description of the utility model, it is necessary to explain, the terms "upper", "lower", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer" and so on indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawing, just for the convenience of describing the utility model and simplifying the description, and not indicate or imply that the indicated device or element must have a particular orientation, be constructed and operated in a particular orientation, therefore cannot be understood as limiting the utility model.

[0028] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which the utility model belongs. The terminology used in the specification of the utility model herein is only for the purpose of describing specific embodiments and is not intended to limit the utility model.

[0029] Referring to Figure 1 The utility model discloses a kind of multi-mode soft water water heater, including water inlet pipeline 1, heating assembly and water outlet pipeline 3, heating assembly includes heating piece and heat exchanger 22, heating piece is used to heat heat exchanger 22, the two ends of water inlet pipeline 1 are first water inlet end 11 and first water outlet end 12 respectively, first water inlet end 11 is communicated with external water supply pipe, and first water outlet end 12 is communicated with heat exchanger 22, the two ends of water outlet pipeline 3 are second water inlet end 31 and second water outlet end 32 respectively, second water inlet end 31 is communicated with heat exchanger 22, and second water outlet end 32 is communicated with external water outlet assembly, so that the water that flows into heat exchanger 22 by water inlet pipeline 1 is heated, and is discharged through water outlet pipeline 3 after being heated;

[0030] It also includes backwater branch pipe 4, water storage piece 5, soft water device 6 and salt tank assembly 65, one end of backwater branch pipe 4 is communicated between first water inlet end 11 and first water outlet end 12 of water inlet pipeline 1, and the other end is communicated between second water inlet end 31 and second water outlet end 32 of water outlet pipeline 3, first valve 71 is equipped on backwater branch pipe 4, to be used to control to open or close the circulation between water inlet pipeline 1, heat exchanger 22, water outlet pipeline 3 and backwater branch pipe 4, water storage piece 5 is arranged on water inlet pipeline 1 or water outlet pipeline 3, to be used to store hot water, soft water device 6 is arranged on water inlet pipeline 1 or water outlet pipeline 3, and salt tank assembly 65 and soft water device 6 are connected.

[0031] Specifically, the two ends of the water inlet pipeline 1 are a first water inlet end 11 and a first water outlet end 12, respectively. The first water inlet end 11 is in communication with an external water supply pipe to provide raw water for the water heater. The first water outlet end 12 is connected to the heat exchanger 22 to introduce the externally introduced raw water into the heat exchanger 22. The heating assembly is composed of a heating element and the heat exchanger 22. The heating element is responsible for generating heat and transferring the heat to the heat exchanger 22. The heat exchanger 22 efficiently transfers the heat absorbed to the raw water in the heat exchanger 22 to warm it up. The two ends of the water outlet pipeline 3 are a second water inlet end 31 and a second water outlet end 32, respectively. The second water inlet end 31 is in communication with the heat exchanger 22. The second water outlet end 32 is in communication with an external water outlet assembly to discharge the water that has been heated by the water inlet pipeline 1 and flowed into the heat exchanger 22, such as a faucet in a home, for dispensing hot water.

[0032] One end of the water return branch pipe 4 is in communication between the first water inlet end 11 and the first water outlet end 12 of the water inlet pipeline 1, and the other end is in communication between the second water inlet end 31 and the second water outlet end 32 of the water outlet pipeline 3, thereby forming a circulating pipeline between the water inlet pipeline 1, the heat exchanger 22, the water outlet pipeline 3, and the water return branch pipe 4. The first valve 71 is provided on the water return branch pipe 4. When the first valve 71 is opened, the circulation between the water inlet pipeline 1, the heat exchanger 22, the water outlet pipeline 3, and the water return branch pipe 4 is correspondingly controlled. The residual hot water is returned to the water storage element 5 by the water return branch pipe 4. A part of the hot water can be preheated and reheated in the heat exchanger 22 and stored in the water storage element 5, so that when the water heater is turned on again, i.e., during the pre-cleaning and ignition process of the fan, the hot water stored in the water storage element 5 is used for priority supply, thereby avoiding the unstable phenomenon of water temperature first heating and then cooling.

[0033] The water softening device 6 is placed on the water inlet pipeline 1 or the water outlet pipeline 3 to treat the water flow passing through it, remove calcium and magnesium ions, improve water quality, prevent scale deposition, prolong equipment life, and protect household appliances from hard water damage. The salt tank assembly 65 is connected to the water softening device 6 to replenish the regenerant required in the softening process.

[0034] The heating element can be a gas heater or an electric heater. The heat exchanger 22 is one or a combination of finned heat exchangers 22, plate heat exchangers 22, coil heat exchangers 22, and heat pipe heat exchangers 22. Specifically, users can choose one or more heat exchangers 22 for combined use according to different use scenarios and needs. For example, in situations where efficient heat exchange is required and space is limited, a combination of finned heat exchangers 22 and plate heat exchangers 22 can be selected. In situations where complex working conditions and environments need to be addressed, heat pipe heat exchangers 22 can be selected.

[0035] The working modes that can be completed by the above structure specifically include:

[0036] When only the raw water heating needs to be completed, water is fed through the water inlet pipe 1, and the heating element heats the heat exchanger 22, the water inlet pipe 1 transmits water to the heat exchanger 22, and the heat exchanger 22 transmits the heat absorbed by the heating element to the water flowing through the heat exchanger 22, thereby completing the heating of the water. The heated water flows out through the water outlet pipe 3, and the heating of the raw water is completed.

[0037] When water needs to be softened, the water is fed into the water softening device 6 before or after entering the heat exchanger 22, and the water is softened in the water softening device 6.

[0038] When the resin softening performance of the water softening device 6 is regenerated, the connection of the water softening device 6 and the salt tank assembly 65 can supply the diluted brine in the salt tank assembly 65 to the water softening device 6 to regenerate the resin in the water softening device 6. The salt tank assembly 65 can be pumped to the water softening device 6 by a power device, or a Venturi valve can be used to form a negative pressure state in the water softening device 6 by the continuous flow of water in the water softening device 6, and then the salt tank assembly 65 is acted on by the air pressure to complete the regeneration of the resin in the water softening device 6.

[0039] When the water heater is turned off, the first valve 71 is opened, and the corresponding control of the opening of the circulation between the water inlet pipe 1, the heat exchanger 22, the water outlet pipe 3, and the backwater branch pipe 4 is opened. The residual hot water is returned to the water storage device 5 by the backwater branch pipe 4, or a part of the hot water is reheated in the preheating of the heat exchanger 22 and stored in the water storage device 5, so that when the water heater is turned on again, that is, during the pre-cleaning and ignition of the fan, the hot water stored in the water storage device 5 is used for priority supply, thereby avoiding the unstable phenomenon of the water temperature being hot first and then cold.

[0040] It should be noted that the water softening device 6 can choose to store waste water in a storage device, and then discharge it manually or automatically, or directly discharge it, which is not limited here.

[0041] In some embodiments, the water softening device 6 is connected with a water inlet pipe 61 and a water outlet pipe 62. One end of the water inlet pipe 61 is connected with the water softening device 6, and the other end is connected to the water inlet pipe 1. One end of the water outlet pipe 62 is connected with the water softening device 6, and the other end is connected to the water inlet pipe 1. A three-way valve 63 is arranged at the connection between the water inlet pipe 61 and the water inlet pipe 1, or a three-way valve 63 is arranged at the connection between the water outlet pipe 62 and the water inlet pipe 1, for controlling whether the water inlet pipe 1 flows into the water softening device 6.

[0042] The water inlet pipe 61 of the water softening device 6 is connected to the water softening device 6 at one end and connected to the water inlet pipe 1 of the water heater at the other end, which is used to introduce water to be softened into the water softening device 6. The water outlet pipe 62 is connected to the water softening device 6 at one end and also connected to the water inlet pipe 1 of the water heater at the other end, which is used to deliver the softened water back to the water inlet pipe 1 of the water heater for subsequent heating use.

[0043] The three-way valve 63 can be arranged at the connection between the water inlet pipe 61 and the water inlet pipe 1, or at the connection between the water outlet pipe 62 and the water inlet pipe 1. The three-way valve 63 is used to control whether the water in the water inlet pipe 1 flows into the water softening device 6. That is, the three-way valve 63 can be switched to connect the water inlet pipe 1, and correspondingly, the water bypasses the water softening device 6 and directly enters the heat exchanger 22 for heating; the three-way valve 63 can also be switched to connect the water inlet pipe 1 and the water softening device 6, and the water flows through the water softening device 6 for softening treatment before flowing into the water inlet pipe 1 for subsequent heating and use.

[0044] Further, the three-way valve 63 is an electric three-way valve 63.

[0045] Specifically, the electric three-way valve 63 can realize automatic switching of the water path, has fast response speed, and accurate control. In the internal circulation water softening water heater, the path of the water flow can be quickly adjusted according to preset conditions or user instructions, that is, the water is introduced into the water softening device 6 for treatment, or the original water path is maintained, thereby improving the intelligent level of the overall system.

[0046] In some embodiments, the salt tank assembly 65 includes a salt tank and a salt shortage detection device arranged in the salt tank for detecting the amount of salt stored in the salt tank.

[0047] Specifically, the salt tank is used to store salt for water softening treatment. These salts will be used in the process of resin regeneration in the water softening device 6 to restore the ability of the resin to exchange calcium and magnesium ions. The salt shortage detection device is installed inside the salt tank for monitoring the amount of salt remaining in the salt tank. It can timely find the salt shortage state and provide a structural basis to ensure that the water softening process can continue effectively.

[0048] In some embodiments, the salt shortage detection device is a distance sensor arranged at the top of the salt tank for detecting the height of the salt stored in the salt tank.

[0049] As an option, the salt tank assembly has a detachable salt tank inside which has soft water salt blocks, and the salt deficiency detection device is located above the salt blocks. By detecting whether the distance between the sensor and the salt blocks exceeds a threshold value, if it exceeds the preset threshold value, it means that the salt is deficient, and the user is reminded to add salt (such as a flashing light or an alarm) when the salt is deficient. At this time, if it is not yet time to regenerate the water softener 6, that is, the resin in the water softener 6 is still not saturated, the corresponding water softener 6 can not be closed, and the normal use can continue until the resin in the water softener 6 is saturated and needs to be regenerated. At this time, the water softener 6 is closed, and after the water softener 6 is regenerated, the water softener 6 is opened again for soft water operation.

[0050] In other embodiments, the salt deficiency detection device is a salt water concentration sensor, which is arranged at the bottom of the salt tank to detect the concentration of the solution after the salt in the salt tank is dissolved.

[0051] Specifically, the salt water concentration sensor is located at the bottom of the salt tank, so as to accurately measure the concentration of the dissolved salt water solution.

[0052] As an option, the salt water concentration sensor can choose to measure the salt concentration in the solution based on the principles of electrical conductivity, refractive index or optical transmission, etc. After the salt and water in the salt tank are fully mixed, the salt water concentration sensor monitors the fully mixed salt water, thereby realizing accurate monitoring of the salt water concentration. When the salt water concentration is lower than the normal level, it proves that the salt in the salt tank is insufficient, and then the customer is notified in time to add salt.

[0053] In some embodiments, the water softener 6 is connected with a waste water discharge pipe 64.

[0054] Specifically, the water softener 6 is connected with a waste water discharge pipe 64, and correspondingly, there is no need to set a waste water storage part inside the water softener 6. The waste water can be directly discharged through the waste water discharge pipe 64, thereby simplifying the internal structure of the water heater, and further facilitating the miniaturization design of the water heater, making it more suitable for the space utilization demand of modern families.

[0055] In some embodiments, the water heater further comprises a one-way valve 72 arranged on the backwater branch pipe 4, so that the flow direction of the backwater branch pipe 4 is from the side of the backwater branch pipe 4 close to the water outlet pipe 3 to the side of the backwater branch pipe 4 close to the water inlet pipe 1.

[0056] Specifically, the one-way valve 72 is arranged on the backwater branch pipe 4, which controls the flow direction of the backwater branch pipe 4. The one-way valve 72 allows water to flow from the side of the backwater branch pipe 4 close to the water outlet pipe 3 to the side of the backwater branch pipe 4 close to the water inlet pipe 1, but prevents reverse flow, thereby assisting the first valve 71 to open and ensuring the flow direction of the internal circulation.

[0057] Specifically, the check valve 72 is installed on the return branch 4, and its main function is to control the direction of water flow, ensuring that water can only flow from the end close to the outlet pipe 3 to the end close to the inlet pipe 1, and preventing any reverse flow. When the first valve 71 is opened to start the internal circulation mode, the check valve 72 can assist the first valve 71 to ensure that hot water can circulate in the direction of flowing from the outlet pipe 3 through the return branch 4 back to the inlet pipe 1, while preventing water from flowing in the opposite direction, thereby maintaining the stability and efficiency of the internal circulation system. Furthermore, after the water heater is turned off, the residual hot water can be effectively returned to the storage device 5, or a part of the hot water can be preheated and reheated in the heat exchanger 22 to be stored in the storage device 5 for the next use, so as to avoid the unstable phenomenon of the water temperature becoming cold first and then hot.

[0058] In some embodiments, a second valve 73 is provided on the pipeline between the first inlet end 11 of the inlet pipe 1 and the inlet pipe 1 and the return branch 4.

[0059] Specifically, the second valve 73 is provided on the pipeline between the first inlet end 11 of the inlet pipe 1 and the inlet pipe 1 and the return branch 4, and controls the water flow from the external water supply pipe into the water heater. The second valve 73 is used to control the water flow from the external water supply pipe into the water heater. When the second valve 73 is closed, the external water source can be cut off to prevent water from entering the water heater. This is particularly useful when maintaining, cleaning or repairing the water heater.

[0060] As an option, when the water heater is in the internal circulation mode, the second valve 73 can work in cooperation with the first valve 71 on the return branch 4. By closing the second valve 73 and opening the first valve 71, it can be ensured that the water circulation inside the water heater will not be disturbed by the external water source, thereby achieving more stable and efficient water temperature control. When hot water is not needed, closing the second valve 73 can prevent accidental water flow during the shutdown or repair of the water heater.

[0061] In some embodiments, a water pump 10 is provided on the inlet pipe 1 or the outlet pipe 3.

[0062] Specifically, the water pump 10 can be installed on the inlet pipe 1 or the outlet pipe 3 of the water heater, and the specific location is determined by the design requirements and actual installation conditions of the equipment. Its main function is to provide additional power for water flow, helping to overcome pipe resistance, raise water level or accelerate water flow speed, ensuring that water flow can smoothly and efficiently pass through the entire hot water system, including the inlet pipe 1, the heat exchanger 22, the outlet pipe 3 and the return branch 4.

[0063] More importantly, the water pump 10 makes the hot water assembly no longer completely dependent on external water supply pressure. Therefore, even in low water pressure areas or high-rise buildings, the water heater can maintain stable operation performance. This not only improves the reliability and response speed of the system, but also significantly expands the application range of the water heater, making it suitable for more diverse environments and conditions.

[0064] The technical means disclosed in the utility model scheme are not limited to the technical means disclosed in the above-mentioned embodiments, and also include technical solutions composed of any combination of the above technical features. It should be pointed out that, for ordinary skilled persons in the art, without departing from the principles of the utility model, a number of improvements and refinements can be made, and these improvements and refinements are also considered within the protection scope of the utility model.

Claims

1. A multi-mode soft water water heater, comprising an inlet pipe (1), a heating assembly, and an outlet pipe (3), wherein the heating assembly comprises a heating element and a heat exchanger (22), the heating element being used to heat the heat exchanger (22), the two ends of the inlet pipe (1) being a first inlet end (11) and a first outlet end (12), the first inlet end (11) being connected to an external water supply pipe, and the first outlet end (12) being connected to the heat exchanger (22), the two ends of the outlet pipe (3) being a second inlet end (31) and a second outlet end (32), the second inlet end (31) being connected to the heat exchanger (22), and the second outlet end (32) being connected to an external outlet assembly, so that water flowing into the heat exchanger (22) from the inlet pipe (1) absorbs heat and is then discharged through the outlet pipe (3), characterized in that: It also includes a return water branch pipe (4), a water storage device (5), a water softening device (6), and a brine tank assembly (65). One end of the return water branch pipe (4) is connected to the first inlet end (11) and the first outlet end (12) of the inlet pipe (1), and the other end is connected to the second inlet end (31) and the second outlet end (32) of the outlet pipe (3). A first valve (71) is provided on the return water branch pipe (4) to control the opening or closing of the circulation between the inlet pipe (1), the heat exchanger (22), the outlet pipe (3), and the return water branch pipe (4). The water storage device (5) is provided on the inlet pipe (1) or the outlet pipe (3) to store hot water. The water softening device (6) is provided on the inlet pipe (1) or the outlet pipe (3). The brine tank assembly (65) is connected to the water softening device (6).

2. The multi-mode soft water water heater according to claim 1, characterized in that, The water softening device (6) is connected to an inlet pipe (61) and an outlet pipe (62). One end of the inlet pipe (61) is connected to the water softening device (6), and the other end is connected to the inlet pipe (1). One end of the outlet pipe (62) is connected to the water softening device (6), and the other end is connected to the inlet pipe (1). A three-way valve (63) is provided at the connection between the inlet pipe (61) and the inlet pipe (1), or a three-way valve (63) is provided at the connection between the outlet pipe (62) and the inlet pipe (1), to control whether the water inlet pipe (1) flows into the water softening device (6).

3. A multi-mode soft water water heater according to claim 2, characterized in that, The three-way valve (63) is an electric three-way valve (63).

4. A multi-mode soft water water heater according to claim 1, characterized in that, The salt tank assembly (65) includes a salt tank and a salt shortage detection device, which is located inside the salt tank to detect the amount of salt stored in the salt tank.

5. A multi-mode soft water water heater according to claim 4, characterized in that, The salt deficiency detection device is a distance sensor, which is located at the top of the salt tank to detect the salt level inside the salt tank.

6. A multi-mode soft water water heater according to claim 4, characterized in that, The salt deficiency detection device is a salt concentration sensor, which is located at the bottom of the salt tank to detect the concentration of the solution after the salt in the tank has dissolved.

7. A multi-mode soft water water heater according to claim 1, characterized in that, The water softener (6) is connected to a wastewater discharge pipe (64).

8. A multi-mode soft water water heater according to claim 1, characterized in that, It also includes a one-way valve (72), which is installed on the return water branch pipe (4) so ​​that the flow direction of the return water branch pipe (4) is from the side of the return water branch pipe (4) close to the water outlet pipe (3) to the side of the return water branch pipe (4) close to the water inlet pipe (1).

9. A multi-mode soft water water heater according to any one of claims 1-8, characterized in that, A second valve (73) is provided on the pipeline from the first inlet end (11) of the inlet pipeline (1) to the pipeline between the inlet pipeline (1) and the return branch pipe (4).

10. A multi-mode soft water water heater according to any one of claims 1-8, characterized in that, A water pump (10) is provided on the water inlet pipe (1) or the water outlet pipe (3).

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