# Patent

## Title
Tankless water heater assembly

## Abstract

A tankless water heating assembly that heats water on a continuous basis as it passes from a conventional water source and through a heating system. It basically includes a housing assembly, a plumbing assembly, a heating system, and an electrical system. The tankless water heater assembly heats water in a real time basis, as is being used, resulting in an efficient method of hot water utilization. The heating system comprises heating elements that are submerged within water as the water passes continuously through the heating units to prevent heating unit burnout, and the electrical system has means to properly measure water temperature as it is flowing within the heating system.

## Background
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to water heating systems, and more particularly, to tankless water heating assemblies.
2. Description of the Related Art
The most commonly used water heaters utilize a rather large storage tank for water with intrinsic inefficiency due to the fact that the water maintain within such storage tank is effectively reheated even when the water is not being utilize on a regular basis.
To the contrary, an existing alternative to such storage tank water heater is a continuous flow or “tankless” water heater, wherein water is almost instantaneously heated as it passes through the continuous flow system. Prior art teaches tankless water heater assemblies for the purpose of only heating water, which is currently being used.
However, such prior art continuous flow water heaters are recognized as being unreliable because they often require replacement of heating units. To a large extent, this is caused by the inability to keep the plurality of individual heating elements submerged within water as the water passes continuously through the heating units to prevent heating unit burnout. In addition, such prior art continuous flow water heaters are also recognized as being unreliable because of a lack of structural integrity of the plumbing assembly as it is fitted onto the housing assembly. Furthermore, such prior art continuous flow water heaters are also recognized as being unreliable because they often improperly measure the temperature of the water as it is flowing within the heating system.
Applicant believes that the only reference corresponds to Applicant's own U.S. Pat. No. 5,408,578, issued on Apr. 18, 1995 for a tankless water heater assembly. However, it differs from the present invention, because in that patent Applicant taught a tankless water heater assembly, specifically adapted to heat water on a continuous basis as it passes from a conventional water source, into a heat transferring chamber, or chambers, containing immersible high power electrical heating elements.
Other patents describing the closest subject matter provide for a number of more or less complicated features that fail to solve the problem in an efficient and economical way. None of these patents suggest the novel features of the present invention.
SUMMARY OF THE INVENTION
The instant invention is specifically adapted to heat water on a continuous basis as it passes from a conventional water source and through a heating system.
More specifically, the instant invention is a tankless water heater assembly designed to heat a continuous supply of water, comprising a housing assembly. A plumbing assembly comprises at least a cold-water inlet and a hot-water outlet. A heating system comprises at least first and second heating units that house first and second heating elements respectively. The first and second heating units each have a top end and a bottom end. The first and second heating units are connected to each other by at least one bypass and at least one pipe. The bypass is positioned at or below the top ends, and the pipe is positioned below the bypass. In this configuration, air entering from the cold-water inlet or the hot-water outlet, is expelled via the bypass. Thus, keeping the first and second heating elements continuously submerged within water. The instant invention also comprises an electrical system.
The electrical system comprises a thermistor assembly having a heat sensing thermistor located at the pipe, in between the first and second heating units. The thermistor assembly has sending means to send a signal to regulate an amount of power delivered to the first and second heating elements under diverse water flow conditions. The housing assembly comprises a rear panel, first and second lateral panels, and a base panel. The cold-water inlet has a first threaded fitting and the hot-water outlet has a second threaded fitting. The cold-water inlet and the hot-water outlet are fitted onto the housing assembly. The cold-water inlet has first and second plates that are mounted onto each side of the first lateral panel, and the hot-water outlet has third and fourth plates that are mounted onto each side of the second lateral panel. The plumbing assembly further comprises a flow switch assembly, and the electrical system comprises a thermostat assembly. The thermostat assembly comprises thermal connection means. The thermal connection means provides heat transfer functionality.
It is therefore one of the main objects of the present invention to provide a tankless water heater assembly that is compact.
It is another object of the present invention to provide a tankless water heater assembly that heats water in a real time basis, as is being used, resulting in an efficient method of hot water utilization.
It is another object of the present invention to provide a tankless water heater assembly having heating elements submerged within water as the water passes continuously through the heating units to prevent heating unit burnout.
It is another object of the present invention to provide a tankless water heater assembly that comprises better structural integrity of the plumbing assembly as it is fitted onto the housing assembly.
It is another object of the present invention to provide a tankless water heater assembly that properly measures the temperature of the water as it is flowing within the heating system.
It is another object of the present invention to provide a tankless water heater assembly that provides satisfactory continuous flow requirements for domestic and commercial use.
It still is another object of this invention to provide such a device that is inexpensive to manufacture and maintain while retaining its effectiveness.
Further objects of the invention will be brought out in the following part of the specification, wherein detailed description is for the purpose of fully disclosing the invention without placing limitations thereon.



BRIEF DESCRIPTION OF THE DRAWINGS
With the above and other related objects in view, the invention consists in the details of construction and combination of parts as will be more fully understood from the following description, when read in conjunction with the accompanying drawings in which:
FIG. 1 represents an isometric view of the present invention partially housed within its housing assembly.
FIG. 2 is a front elevational view of the present invention, which has been partially cross-sectioned to illustrate the water level and path of water flow through various components.
FIG. 3 is a top plan view of the present invention, which has been partially cross-sectioned to illustrate the path of water flow through various components.
FIG. 4 is a cross-section view taken along line 4-4 from FIG. 1, showing the thermistor.



DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring now to the drawings, the present invention is generally referred to with numeral 10. It can be observed that it basically includes housing assembly 20, plumbing assembly 40, heating system 120, and electrical system 170.
As seen in FIG. 1, present invention 10 is directed to a continuous flow water heater and includes an outer casing or housing assembly 20 that surrounds components shown and to be described in greater detail hereinafter. Housing assembly 20 comprises rear panel 22, lateral panels 24 and 26, and base 28. Although not illustrated, it is noted that housing 20 may include an outer door or cover, which may be opened or removed to facilitate minimal access to the components and to effect at least minimal repairs. However, it should be emphasized that the structure and integrity of the components of the present invention minimizes the necessity for entering into the “guts” of the subject invention to accomplish major repairs.
As illustrated in FIGS. 1 and 2, plumbing assembly 40 comprises threaded fitting 42, defining a cold-water inlet that is connected to a conventional source of water such as the city or municipal water supply. Threaded fitting 42 includes filtering element 44 in order to eliminate any debris from entering into instant invention 10 as best possible. Plates 46 and 52 are mounted onto pipe 50, and on each side of lateral panel 24, to provide better structural integrity for plumbing assembly 40 as it is fitted onto housing assembly 20. It is noted that pipe 50 extends from heating unit 124 and terminates at threaded fitting 42.
Similarly, plumbing assembly 40 also comprises threaded fitting 98, defining a hot-water outlet that is connected to additional plumbing for a domestic or commercial structure. Threaded fitting 98 includes filtering element 96 in order to eliminate any debris from exiting instant invention 10 as best possible. Plates 94 and 100 are mounted onto pipe 90, and on each side of lateral panel 26, to provide better structural integrity for plumbing assembly 40 as it is fitted onto housing assembly 20. It is noted that pipe 90 extends from heating unit 130 and terminates at threaded fitting 98.
Furthermore, as defined above, plumbing assembly 40 defines an improved and more reliable method of water pipe connection, whereby threaded fittings 42 and 98, for both the cold-water inlet and the hot-water outlet respectively, are fully integrated onto housing assembly 20, providing better structural integrity without requiring fittings as separate attachments to the housing assembly 20 that require soldering in a production process. Plumbing assembly 40 reduces water leaks, resulting in a dramatic improvement in quality and reliability.
Pipe 50 partially contains flow switch assembly 60. Interior to pipe 50, flow switch assembly 60 comprises flow switch 62 comprising magnet 64 mounted onto spring 66. Flow switch 62 moves in a direction indicated by the numerous directional arrows, defined as water flow WF, indicating a positive path of water flow as it enters through the cold-water inlet, and exits through the hot-water outlet. Flow switch assembly 60 also comprises housing 68 that is mounted onto pipe 50. Housing 68 comprises contacts 70 and 72. Cables 74 extend from contacts 70 and 72 to block 236.
Electrical system 170 comprises conduit 172 having electrical wiring 174 that originate from an electrical power source. Electrical wiring 174 connects to terminal block 180, and electrical wiring 182 connects from terminal block 180 to control electronic board 186 having control knob 188. Electrical wiring 190 also extends from control electronic board 186 to thermistor assembly 200. Thermistor assembly 200 comprises lead 202 that inserts into cover 204. Cables 184 also extend from terminal block 180 to thermostat block 224 of thermostat assembly 220. Cable 226 extends from thermostat block 224 to block 234 of element terminal 230, and cable 228 extends from thermostat block 224 to block 236 of element terminal 232. Cable 238 connects block 234 to block 236.
Although not illustrated, electrical system 170 further comprises a power supply voltage of approximately 6 volts DC regulated; a chip supply voltage of approximately 4.4 volts DC, which results in better regulation; and a main oscillator output level of approximately 800 millivolts at a frequency of 46.5 hertz (21.5 msec). Furthermore, inputs of all operational amplifiers that are not used within the chip are grounded, resulting in a better signal to noise ratio and a more precise control of the temperature of the water. Values of gate resistors of SCR's are also optimized to establish SCR conduction at a “zero crossing” point. In addition, control electronic board 186 has cooperative dimensions to allow easier access to the high voltage terminals, and power rating of a voltage-lowering resistor is approximately 7 W.
Thermostat assembly 220 comprises thermostat 240. Thermostat 240 is a single protective thermostat. In the preferred embodiment, plate 222, is a central metal plate that thermally connects heating units 124 and 130. The thermal connection provides a heat transfer functionality required by thermostat 240, defining thermal connection means. This feature results in fewer false “safety disconnects”, and a more reliable operation of instant invention 10.
As best seen in FIGS. 2 and 3, heating system 120 comprises heating units 124 and 130 that are connected to each other by pipe 128 and bypass 136. Heating unit 124 houses heating element 126 and heating unit 130 houses heating element 132. In the preferred embodiment, pipe 128 is approximately 0.20 inches in diameter. Pipe 128 provides for equal water-pressure within heating units 124 and 130 and keeps them submerged below water level WL, even when the water source has been closed to instant invention 10. This feature provides protection for heating elements 126 and 132 from overheating, since water is always present within heating units 124 and 130, thus improving the reliability and safety of instant invention 10 and extending the life of heating elements 126 and 132.
As best seen in FIG. 4, thermistor assembly 200 also comprises thermistor 206 that protrudes from lead 202 and more specifically cover 204. Thermistor 206 is a heat sensing thermistor, located at pipe 128 between the heating units 124 and 130 to provide for a better and faster control of the water temperature. Thermistor 206 is inserted into a small opening of pipe 128, and sends a signal, via electrical wiring 190, to control electronic board 186 that regulates the amount of power delivered to the heating elements 126 and 132 under diverse water flow conditions, defining sending means.
In operation, instant invention 10 comprises sufficient water to reach water level WL, as seen in FIG. 2. Water flow WF, indicating a positive path of water flow, enters through the cold-water inlet and travels through pipe 50 and primarily through heating unit 124, through pipe 128, through heating unit 130, and exits through the hot-water outlet. However, a small amount of water flow WF also travels through bypass 136. When this occurs, any and all trapped air at the uppermost ends of heating units 124 and 130 is expelled via bypass 136. In addition, water originating from the cold-water inlet may also comprise air that becomes trapped air at the uppermost ends of heating units 124 and 130, and it too is expelled via bypass 136. Bypass 136 allows heating elements 126 and 132 to always be submerged within the water as water flow WF travels continuously through heating units 124 and 130 of heating system 120 to prevent heating unit burnout.
It is emphasized that a siphoning effect is caused when water from the cold-water inlet or the hot-water outlet is turned off, or when a pipe breaks, defining back flow WF′, seen in FIGS. 2 and 3. In the present invention, water flow WF′ only travels through bypass 136, and not through heating units 124 and 130, to keep heating elements 126 and 132 submerged within the water. Without bypass 136 of the instant invention, back flow WF′ would cause water to be sucked out of heating units 124 and 130 by vacuum pressure. Such back flow WF′ would expose heating elements 126 and 132, since they would not be submerged within water, and would cause heating units 124 and 130 to burnout if the tankless water heater assembly 10 is dry started if there is an air bubble coming into it due to a rupture in the cold-water inlet or an interruption of water flow WF.
The foregoing description conveys the best understanding of the objectives and advantages of the present invention. Different embodiments may be made of the inventive concept of this invention. It is to be understood that all matter disclosed herein is to be interpreted merely as illustrative, and not in a limiting sense.

## Claims

1. A tankless water heater assembly designed to heat a continuous supply of water, comprising:
A) a housing assembly;
B) a plumbing assembly comprising at least a cold-water inlet and a hot-water outlet;
C) a heating system comprising at least first and second heating units that house first and second heating elements respectively, said at least first and second heating units each having a top end and a bottom end, said first and second heating units are connected to each other by at least one bypass and at least one pipe, said at least one bypass positioned at or below said top ends and said at least one pipe positioned below said at least one bypass, said at least one bypass, said at least a cold-water inlet and said hot water outlet are all on a same axis; and
D) an electrical system.

2. The tankless water heater assembly designed to heat a continuous supply of water set forth in claim 1, further characterized in that air entering from said cold-water inlet or said hot-water outlet is expelled via said at least one bypass, thus keeping said first and second heating elements continuously submerged within water.

3. The tankless water heater assembly designed to heat a continuous supply of water set forth in claim 1, further characterized in that said electrical system comprises a thermistor assembly having a thermistor.

4. The tankless water heater assembly designed to heat a continuous supply of water set forth in claim 3, further characterized in that said thermistor is a heat sensing thermistor, located at said at least one pipe in between said at least first and second heating units.

5. The tankless water heater assembly designed to heat a continuous supply of water set forth in claim 4, further characterized in that said thermistor assembly has sending means to send a signal to regulate an amount of power delivered to said first and second heating elements under diverse water flow conditions.

6. The tankless water heater assembly designed to heat a continuous supply of water set forth in claim 1, further characterized in that said housing assembly comprises a rear panel, first and second lateral panels, and a base panel.

7. The tankless water heater assembly designed to heat a continuous supply of water set forth in claim 6, further characterized in that said cold-water inlet has a first threaded fitting and said hot-water outlet has a second threaded fitting, said cold-water inlet and said hot-water outlet are fitted onto said housing assembly.

8. The tankless water heater assembly designed to heat a continuous supply of water set forth in claim 7, further characterized in that said cold-water inlet has first and second plates that are mounted onto each side of said first lateral panel and said hot-water outlet has third and fourth plates that are mounted onto each side of said second lateral panel.

9. The tankless water heater assembly designed to heat a continuous supply of water set forth in claim 1, further characterized in that said plumbing assembly further comprises a flow switch assembly.

10. The tankless water heater assembly designed to heat a continuous supply of water set forth in claim 1, further characterized in that said electrical system comprises a thermostat assembly.

11. The tankless water heater assembly designed to heat a continuous supply of water set forth in claim 10, further characterized in that said thermostat assembly comprises thermal connection means, said thermal connection means provides heat transfer functionality.

12. A tankless water heater assembly designed to heat a continuous supply of water, comprising:
A) a housing assembly;
B) a plumbing assembly comprising at least a cold-water inlet and a hot-water outlet;
C) a heating system comprising at least first and second heating units that house first and second heating elements respectively, said at least first and second heating units each having a top end and a bottom end, said first and second heating units are connected to each other by at least one bypass and at least one pipe, said at least one bypass positioned at or below said top ends and said at least one pipe positioned below said at least one bypass, air entering from said cold-water inlet or said hot-water outlet is expelled via said at least one bypass, thus keeping said first and second heating elements continuously submerged within water, said at least one bypass, said at least a cold-water inlet and said hot water outlet are all on a same axis; and
D) an electrical system.

13. The tankless water heater assembly designed to heat a continuous supply of water set forth in claim 12, further characterized in that said electrical system comprises a thermistor assembly having a heat sensing thermistor located at said at least one pipe in between said at least first and second heating units.

14. The tankless water heater assembly designed to heat a continuous supply of water set forth in claim 13, further characterized in that said thermistor assembly has sending means to send a signal to regulate an amount of power delivered to said first and second heating elements under diverse water flow conditions.

15. The tankless water heater assembly designed to heat a continuous supply of water set forth in claim 12, further characterized in that said housing assembly comprises a rear panel, first and second lateral panels, and a base panel.

16. The tankless water heater assembly designed to heat a continuous supply of water set forth in claim 15, further characterized in that said cold-water inlet has a first threaded fitting and said hot-water outlet has a second threaded fitting, said cold-water inlet and said hot-water outlet are fitted onto said housing assembly.

17. The tankless water heater assembly designed to heat a continuous supply of water set forth in claim 16, further characterized in that said cold-water inlet has first and second plates that are mounted onto each side of said first lateral panel and said hot-water outlet has third and fourth plates that are mounted onto each side of said second lateral panel.

18. The tankless water heater assembly designed to heat a continuous supply of water set forth in claim 12, further characterized in that said plumbing assembly further comprises a flow switch assembly.

19. The tankless water heater assembly designed to heat a continuous supply of water set forth in claim 12, further characterized in that said electrical system comprises a thermostat assembly.

20. The tankless water heater assembly designed to heat a continuous supply of water set forth in claim 19, further characterized in that said thermostat assembly comprises thermal connection means, said thermal connection means provides heat transfer functionality.