JP2979208B2 - Electric water heater - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electric kettle for boiling water at home and keeping the temperature warm.

[0002]

2. Description of the Related Art A conventional electric water heater will be described. In FIG. 9, a container 2 having an upper surface opening is provided in a main body 1, a lid 3 is arranged at an opening of the container 2, and a heating means 4 as a heat source for heating a liquid such as water and a container 2 are provided at an outer bottom portion.
A temperature sensor 5 for indirectly measuring the temperature of the liquid in the inside is provided. When the boiling detecting means 6 detects the boiling of the liquid from the output of the temperature sensor 5, it outputs a signal to an energization control means 7 for controlling energization of the heating means 4. Energization control means 7
After receiving the signal from the boiling detecting means 6, the heating was continued for a certain time to remove volatile impurities such as chalky.

[0003] Therefore, regardless of the sufficient removal of volatile impurities such as chalky, the water in the container 2 is boiled by heating to wastefully consume power and time, or conversely, the chalky. Although the removal of impurities such as is not sufficient, the heating boiling has ended.

[0004]

The problem of the prior art described above is that the heating and boiling time for removing impurities such as calcium dissolved in a liquid such as water in an electric water heater is performed for a predetermined time. That was the point.

An object of the present invention is to solve the above-mentioned conventional problems.
Accordingly, it is an object of the present invention to provide an electric water heater capable of efficiently and economically removing impurities such as calcium.

The above object can be achieved either automatically or manually. When the object is achieved manually, the state in which impurities are removed is automatically changed according to the change. To inform the user of the period during which the impurity removing means should be operated, or automatically display the capability of the means for removing impurities to inform the user of the replacement time of the impurity removing device. Each of them aims to provide an electric water heater capable of efficiently and economically removing impurities such as calcium.

[0007]

In order to achieve the above object, an electric water heater according to the present invention has a heating means for heating a liquid in a container, a removing means for removing impurities in the liquid, Temperature rise determining means for determining the degree of temperature rise of the liquid; water quality determining means for determining the water quality of the liquid in the container; and liquid impurity determination from the values determined by both the temperature rise determining means and the water quality determining means. The apparatus has a water purification degree judging means for judging a removal degree, and a control means for outputting an operation signal to the removal means until the value obtained by the water purification degree judgment means reaches a predetermined value.

In order to achieve the above object, an electric water heater according to the present invention comprises a heating means for heating a liquid, a removing means for removing impurities in the liquid, and a temperature rise of the liquid in the container. Temperature rise judging means, water quality judging means judging the water quality of the liquid in the container, and the presence or absence of the capability of the removing means from the values obtained by both the temperature rise judging means and the water quality judging means. A configuration comprising: a removal capability determination unit for determining; a replacement display unit for displaying replacement of the removal device of the removal unit; and a replacement display control unit for outputting a control signal from the output of the removal capability determination unit to the replacement display unit. It can be.

Further, the electric water heater according to the present invention comprises a heating means for heating the liquid in the container, an energization control means for controlling the energization of the heating means, and a temperature rise for judging the temperature rise of the liquid in the vessel. Determination means, boiling detection means for detecting the boiling state of the liquid in the container, water quality determination means for determining the water quality of the liquid in the container, and the temperature rise determination means and the water quality determination means. Water purification degree judging means for judging the degree of removal of liquid impurities from the obtained value, and control means for outputting an ON signal to the energization control means until the value obtained by the water purification degree judgment means reaches a predetermined value. It is provided.

[0010] Further, a temperature rise judging means for judging the degree of temperature rise of the liquid in the container, a water quality judging means for judging the water quality of the liquid in the container, and both the temperature rise judging means and the water quality judging means. A water purification degree judging means for judging the degree of removal of liquid impurities from the value of the means, and a display control means for outputting a signal to water quality display means for displaying water quality according to the value of the water purity judgment means. Is what you can do.

[0011]

According to the present invention, the first configuration judges the water quality of the liquid in the container and activates the removing means for removing impurities in accordance with the degree of change in the water quality. And other impurities can be removed.

[0012] Further, according to the second configuration, the ability of the removing means is accurately displayed, the replacement time of the removing device of the removing means is determined, and the user is notified, so that the usability is good.

Further, according to the third configuration, it is possible to judge the water quality of the liquid in the container and perform heating for removing impurities based on the result.

In the case of the fourth configuration, the degree of change in the water quality of the liquid in the container is displayed, so that the operation of the means for removing impurities can be terminated, and therefore the impurities can be efficiently and economically produced. Can be removed.

[0015]

【Example】

(Embodiment 1) Hereinafter, Embodiment 1 of the present invention will be described with reference to the drawings. In FIG. 1, the same components as those in the conventional example are denoted by the same reference numerals. Inside the main body 1, there is a container 2 having an upper surface opening, a lid 3 is disposed at the opening of the container 2, and a heating means 4 for heating the liquid in the container 2 and a liquid in the container 2 are provided at the outer bottom of the container 2. A temperature sensor 5 for indirectly measuring the temperature is provided, and the temperature sensor 5 is connected to the temperature rise determining means 8. An electrode 9 for measuring the conductivity of the liquid is provided at the inner bottom of the container 2 and connected to the water quality judging means 10.

A water passage is formed from a lower outlet 11 of the vessel 2 to a water passage switching means 14 through a pump 12 and a water conduit 13 serving as a circulation water passage, and this water passage is in a state of a valve 15 in the water passage switching means 14. Is switched to the external discharge port 16 or the internal discharge port 17. The liquid discharged from the internal discharge port 17 is returned to the container 2 through a removing device 18a having a built-in activated carbon constituting the removing means 18. The circulation means 19 has a motor 19a for driving the pump 12,
Driven by the circulation control means 20. When the operation knob 21 installed on the upper part of the main body 1 is operated, the operation knob 2 is operated.
The switch of the switch 22 linked to 1 is switched, and the circulation control means 20 drives the circulation means 19 by the signal.
Further, at this time, the valve 15 is switched in conjunction with the operation knob 21 to switch the water channel to the external discharge port 16, and the liquid in the container 2 is discharged to the outside.

The temperature rise judging means 8 measures the liquid temperature in the container 2 by the temperature sensor 5 and outputs it to the water purification degree judging means 23. The water quality judging means 10 uses the electrode 9 to measure the electric conductivity of the liquid in the container 2. It measures and outputs it to the water purity determination means 23. Here, the conductivity of the liquid depends on the amount of dissolved ions in the liquid. In particular, the conductivity increases as the amount of chlorine mainly composed of chlorine contained in the liquid increases, and the temperature of the liquid decreases by one.
Each time the conductivity increases, the conductivity increases by about 2 percent,
The water purification degree judging means 23 subtracts the increase value of the electric conductivity due to the temperature rise from the value measured by the water quality judging means 10, and when the descending gradient of the electric conductivity as a result of the water purification becomes gentle to a predetermined value, the circulation degree is determined. An off signal is output to the control means 20, and the circulation control means 20 outputs a control signal to the circulation means 19 according to the output signal from the water purity determination means 23.

With respect to the electric water heater configured as described above, referring to FIG. 2 which is a diagram showing a relationship between temperature rise and conductivity in one embodiment of the present invention, and FIG. 3 which is a diagram showing a relationship between water purification time and conductivity. The operation will be described. First, when the liquid is put in the container 2 and connected to a commercial power supply, the heating means 4 is energized to heat the liquid in the container 2. At the same time, the circulation means 19 is operated and the liquid is purified by the removing device 18a of the removing means 18, the temperature rise determining means 8 determines the degree of rise of the liquid temperature, and the water quality determining means 10 determines the conductivity of the liquid.

The water purity determining means 23 includes a water quality determining means 10.
3 corrects the increase in the conductivity due to the temperature rise measured by the temperature rise determination means 8 in FIG. 2 from the measured conductivity of the liquid, and decreases the conductivity gradient due to the purified water in FIG. 3 (see FIG. 3). .DELTA..lamda ./. DELTA.t). When the amount of calcium and the like contained in the liquid is reduced, the descending gradient is reduced. Therefore, t2 in FIG. 3, which is a point in time when the amount becomes less than a predetermined descending gradient, is determined to be a state in which impurities such as calcium are removed. , And outputs an off signal to the circulation control means 20.

The circulation control means 20 confirms the signal from the water purification degree judging means 23, and if the signal is a signal from which decals or the like are not sufficiently removed (ON signal), outputs a ON signal to the circulation means 19 and outputs the pump 12 Drive. Here, if the operation knob 21 is not operated, the valve 1 in the waterway switching means 14
Since the position of 5 is on the side of the internal outlet 17, the liquid in the container 2 discharged from the discharge port 11 by driving the pump 12 passes through the water guide pipe 13 and is removed from the internal discharge port 17 by the removing means 18. The impurities such as calcium are removed and returned to the container 2. The circulation control means 20 outputs an off signal to the circulation means 19 when the signal from the water purification degree judging means 23 becomes a signal (off signal) from which descaling is sufficiently removed.

When the operation knob 21 is operated, the position of the valve 15 is switched to the external discharge port 16 in conjunction with this operation, and an ON signal is output to the circulation control means 20 which is interlocked with the operation knob 21 so that the circulation is performed. The control means 20 operates the circulation means 19 to discharge the liquid in the container 2 from the external discharge port 16 to the outside.

As described above, according to the first embodiment, by providing the temperature rise judging means 8, the water quality judging means 10, the removing means 18, the circulating means 19, the circulating control means 20, and the water purification degree judging means 23, Judging the water quality of the liquid that has a difference or fluctuating depending on the season, and performs the optimum water purification according to the concentration of impurities such as chalky, so there is no waste of power consumption and extra time is required for water purification. Can be prevented.

Although the removal device 18a is described as being filled with activated carbon having adsorbing ability, the removing device 18a may be filled with another substance having adsorbing ability instead of activated carbon, or may be made of an ion-exchange resin membrane or granular material or porcelain. Naturally, it is also conceivable to fill a filter such as a fiber or a fiber.

When hard water in Europe or the like is injected into an electric water heater, the removal device 18a may be filled with an ion exchange resin for removing cations such as calcium and magnesium.

(Embodiment 2) Hereinafter, Embodiment 2 of the present invention will be described with reference to the drawings. In FIG. 4, the same components as those in the first embodiment are denoted by the same reference numerals, and description thereof is omitted.

The temperature rise judging means 8 measures the temperature of the liquid in the container 2 by the temperature sensor 5 and removes the liquid.
Output to The water quality judging means 10 measures the electric conductivity of the liquid in the container 2 with the electrode 9 and outputs the measured electric conductivity to the removing ability judging means 24. Here, the conductivity of the liquid depends on the amount of dissolved ions in the liquid, and in particular, the conductivity increases as the amount of calcium contained in the liquid increases, and the conductivity increases each time the temperature of the liquid increases by 1 degree. Since the rise is about 2%, the removal ability determining means 24 subtracts the value of the increase in conductivity due to the temperature rise from the value measured by the water quality determining means 10, and the removal ability of the removing means 18 is determined by the descending gradient of the conductivity resulting from the purification. The capability is determined, and a signal is output to the exchange display control means 25 according to the result. The exchange display control means 25 includes the removal ability determination means 2
The control signal is output to the exchange display means 26 in accordance with the signal from the control unit 4.

The operation of the electric water heater configured as described above will be described with reference to FIG. 5, which is a diagram showing the relationship between the water purification time and the electric conductivity.

The removing ability judging means 24 successively compares the decreasing gradient of the electric conductivity (denoted by Δλ / Δt in FIG. 5) due to the purified water after temperature correction in FIG. Removal means 1
8 has a removal ability, the amount of calcium in the liquid to be removed is large at the time of starting water purification, so the descending gradient is large, and the amount of calcium in the liquid decreases as the removal time passes, so the descending gradient If the removing ability of the removing means 18 is lost, on the other hand, there is almost no change in the descending gradient with the passage of the water purification time, and the state where the conductivity value is high while the gradient is kept small is maintained. From the start of the water purification, the descending gradient is compared for a predetermined time t2 in FIG. 5, and if the value does not change and the gradient remains small and the value of the conductivity is higher than the predetermined value (λ1). It is determined that the removing capability of the removing unit 18 has been lost, and an ON signal is output to the exchange display control unit 25. The exchange display control means 25 confirms the signal from the removal ability determination means 24, and if the signal is an ON signal, outputs an ON signal to the exchange display means 26 composed of a light emitting diode (hereinafter, referred to as an LED), and removes the signal. The replacement of the removing device 18a is prompted.

As described above, according to the second embodiment, the temperature rise judging means 8 for judging the degree of temperature rise of the liquid in the container, the circulation means 19 for circulating the liquid, and the liquid circulated by the circulation means 19 Removing means 18 for removing impurities of
Water quality determining means 10 for determining the water quality of the liquid in the container, and removing means 18 from the value obtained by the water quality determining means 10.
Removal determining means 24 for determining the replacement time of the removing device 18a, a replacement display device 26 for displaying replacement of the removing device 18a, and a replacement for outputting a control signal from the output of the removal capability determining means 24 to the replacement display device 26. By providing the display control means 25, the removing device 18 of the removing means 18 can be accurately provided.
In order to judge the replacement time of a and notify the user, the water purifying operation is continued even though the removing ability of the removing device 18a is lost. The problem of replacing 18a can be prevented. In the second embodiment, the replacement display device 26 uses an LED, but it goes without saying that the same effect can be obtained by using another display device. Also,
A similar effect can be obtained even when a sounding body such as a buzzer is sounded to notify the user.

(Embodiment 3) Hereinafter, Embodiment 3 of the present invention will be described with reference to the drawings. In FIG. 6, there is a container 2 having an upper surface opening in a main body 1, a lid 3 is disposed in an opening of the container 2, a heating means 4 for heating a liquid in the container 2 is provided on an outer bottom of the container 2, A temperature sensor 5 for indirectly measuring the temperature of the liquid in the container 2 is provided, and an electrode 9 for measuring the conductivity of the liquid is provided on the inner bottom of the container 2. The signal from the temperature sensor 5 is output to the boiling detecting means 6 and the temperature rise determining means 8, and the signal from the electrode 9 is output to the water quality determining means 10. The temperature rise judging means 8 indirectly measures the liquid temperature in the container 2 by the temperature sensor 5 and outputs it to the water purification degree judging means 23. The water quality judging means 10 measures the electric conductivity of the liquid in the container 2 with the electrode 9 and outputs the measured electric conductivity to the water purification degree judging means 23.
Here, the conductivity of the liquid depends on the amount of dissolved ions in the liquid. In particular, the conductivity increases as the amount of calcium contained in the liquid increases, and the calcium is volatile and is reduced by heating. Further, the conductivity increases by about 2% each time the temperature of the liquid increases by one degree.
3 is a water quality judging means for determining an increase value of the electric conductivity due to the temperature rise.
Is subtracted from the measured value, and an ON signal is output to the control means 27 at the time when the decreasing gradient of the conductivity due to the heating becomes gentle to a predetermined value. Further, the boiling detecting means 6 outputs an ON signal to the control means 27 when the liquid in the container 2 is brought into a boiling state. The control unit 27 outputs a control signal to the energization control unit 7 that controls the energization of the heating unit 4 according to input signals from the water purification degree determination unit 12 and the boiling detection unit 6.

The operation of the electric water heater configured as described above will be described with reference to FIG.

First, when the liquid is put in the container 2 and a commercial power supply is connected, the heating means 4 is energized to heat the liquid in the container 2, and the temperature sensor 5 detects the temperature of the liquid and the boiling detecting means 6
Is output to the temperature rise determining means 8. FIG. 7 is a diagram showing the relationship between the heating time and the liquid temperature. The boiling detecting means 6 calculates the temperature rise gradient (Δθ in FIG. 7) from the output of the temperature sensor 5 in FIG.
/ Δt) are successively compared, and when the liquid is brought into a boiling state, the temperature rise gradient is reduced. Therefore, the time t1 at which the temperature falls below a predetermined rise gradient is determined as the liquid boiling state, and the control is performed. An ON signal is output to the means 27. The temperature rise judging means 8 judges the degree of temperature rise of the liquid from the output of the temperature sensor 5 and outputs it to the water purification degree judging means 23. The water quality judging means 10 measures the conductivity of the liquid in the container by the electrode 9 and measures the water purity. Output to the judgment means 23. As shown in Example 1, each time the liquid temperature increases by one degree, the conductivity increases by about 2%. Therefore, the water purification degree judging means 23 corrects the increase of the electric conductivity due to the temperature rise to the electric conductivity of the liquid measured by the water quality judging means 10 based on the output of the temperature rise judging means 8, and then decreases the electric conductivity. Are sequentially compared. Then, FIG. 3 in the first embodiment can be applied to the third embodiment as well, and the conductivity due to the temperature rise is changed by removing volatile impurities such as chalky by heating. When the amount of calcium contained in the liquid decreases, the water purification degree judging means 23 determines that when the amount of the calcium decreases, the descending gradient becomes smaller than a predetermined descending gradient. And outputs an ON signal to the control means 27. Control means 2
7, when the ON signal is input from the boiling detecting means 6, the signal from the water purity determining means 23 is confirmed.

If the signal is an OFF signal, the ON signal is output to the energization control means 7 because heating is not sufficiently removed, and the heating is continued. Conversely, if the signal is an ON signal, the OFF signal is output to the energization control means 7 because the scale and the like have been removed,
The heating of the liquid is terminated.

As described above, according to the third embodiment, the temperature rise judging means 8, the control means 27, the water quality judging means 10, and the water purification degree judging means 23 are provided to judge the water quality of the liquid which differs depending on the region and the season. Since the heating after boiling is extended in accordance with the concentration of impurities such as, for example, it is possible to prevent wasteful consumption of electric power or insufficient removal of impurities and to perform optimal water purification.

(Embodiment 4) Next, Embodiment 4 of the present invention will be described with reference to the drawings. In FIG. 8, a water quality display device 28 for displaying water quality is arranged at the upper part of the main body 1, and the temperature rise judging means 8 indirectly measures the liquid temperature in the container 2 by the temperature sensor 5, Output. The water quality judging means 10 measures the electric conductivity of the liquid in the container 2 with the electrode 9 and outputs the measured electric conductivity to the water purification degree judging means 23. Here, the conductivity of the liquid depends on the amount of dissolved ions in the liquid,
In particular, the larger the amount of calcium contained in the liquid, the higher the conductivity, and this calcium is volatile and is reduced by heating. Further, since the conductivity increases by about 2% each time the temperature of the liquid rises by one degree, the water purification degree judging means 23 subtracts the increase value of the electric conductivity due to the temperature rise from the value measured by the water quality judging means 10 and heats the liquid. A signal is output to the display control means 29 according to the descending gradient of the conductivity, and the display control means 29 responds to the output signal from the water purification degree determining means 23 by
The control signal is output to the water quality display device 28.

The operation of the electric water heater configured as described above will be described. First, when the liquid is put into the container 2 and a commercial power supply is connected, the heating means 4 is energized to heat the liquid in the container 2, and the temperature sener 5 detects the temperature of the liquid and outputs it to the temperature rise determining means 8. The temperature rise judging means 8 judges the degree of temperature rise of the liquid from the output of the temperature sensor 5 and outputs it to the water purification degree judging means 23. The water quality judging means 10 measures the conductivity of the liquid in the container by the electrode 9 and measures the water purity. Judgment means 2
Output to 3. The relationship between the liquid temperature and the conductivity is such that the conductivity increases by about 2% each time the liquid temperature rises by one degree. Therefore, the water purification degree judging means 23 corrects the increase of the electric conductivity due to the temperature rise to the electric conductivity of the liquid measured by the water quality judging means 10 based on the output of the temperature rise judging means 8, and then decreases the electric conductivity. Are sequentially compared. The conductivity due to the temperature rise changes as volatile impurities such as calcium are removed by heating. When the amount of calcium contained in the liquid decreases, the water purification degree judging means 23 reduces the descending gradient. Therefore, the display control means 29 responds to the descending gradient.
Output the signal. The display control means 29 outputs a signal to the water quality display device 28 composed of an LED according to the output signal from the water purification degree judging means 23, and displays the water quality of the liquid in the container 2.

As described above, according to the fourth embodiment, the temperature rise determining means 8, the water quality determining means 10, and the water purification degree determining means 23
By providing the water quality display device 28 and the display control means 29, it is possible to display the concentration of calcium and the like contained in the liquid. It is easy to use because it can reduce the weight and the like. In the fourth embodiment, the water quality display device 28 uses an LED, but it goes without saying that the same effect can be obtained by using another display device. The same effect can be obtained by using a sounding body such as a buzzer to sound several times when the density of calcium or the like falls below a predetermined value and to notify the user.

[0038]

As described in the above embodiments, the present invention can purify water according to the dissolved state of impurities, which is different from the conventional example in which the time is fixed in advance, and wastes time and power for water purification. Thus, it is possible to realize an electric water heater that can perform accurate water purification without consuming it.

Further, it is possible to realize that an electric water heater capable of performing efficient and economical water purification by indicating that the capability of the impurity removing means has become low and notifying the user of replacement of the removing device. .

Further, by providing a water quality display device for displaying the degree of removal of liquid impurities and water quality display control means for controlling the water quality display device, the user can know the water quality and operate the impurity removal means. Therefore, it is possible to realize an electric water heater that can perform water purification efficiently and economically.

[Brief description of the drawings]

FIG. 1 is a schematic side sectional view showing a configuration of an electric water heater according to a first embodiment of the present invention.

FIG. 2 is a diagram showing a relationship between the temperature rise of the liquid and the electrical conductivity in Example 1;

FIG. 3 is a diagram showing a relationship between water purification time and conductivity in Examples 1 and 3;

FIG. 4 is a schematic side sectional view showing a configuration of an electric water heater of the second embodiment.

FIG. 5 is a diagram showing a relationship between water purification time and conductivity in Example 2;

FIG. 6 is a schematic side sectional view showing a configuration of an electric water heater of the third embodiment.

FIG. 7 is a characteristic diagram showing a relationship between a heating time and a liquid temperature in Example 3;

FIG. 8 is a side sectional view showing a configuration of an electric water heater of the fourth embodiment.

FIG. 9 is a side sectional view showing a configuration of a conventional electric water heater.

[Explanation of symbols]

 2 container 4 heating means 6 boiling detection means 7 energization control means 8 temperature rise determination means 9 electrode 10 water quality determination means 12 pump 14 water channel switching means 18 removal means 18a removal device 19 circulation means 20 circulation control means 23 water purification degree determination means 24 removal Capacity determination means 25 Exchange display control means 26 Exchange display device 27 Control means 28 Water quality display device 29 Display control means

────────────────────────────────────────────────── ─── Continued from the front page (72) Inventor Kenji Noda 1006 Kazuma Kadoma, Kadoma-shi, Osaka Matsushita Electric Industrial Co., Ltd. (56) References JP-A-5-245042 (JP, A) JP-A-5 -253064 (JP, A) JP-A-5-146358 (JP, A) JP-A-5-253066 (JP, A) JP-A-5-245043 (JP, A) JP-A-5-154050 (JP, A) ) Hikaru 4-10824 (JP, U) (58) Fields investigated (Int. Cl. ⁶ , DB name) A47J 27/21

Claims (7)

(57) [Claims] 1. A heating means for heating a liquid in a container, a removing means for removing impurities in the liquid, a temperature rise determining means for determining a degree of temperature rise of the liquid in the container, Water quality determining means for determining the water quality of the liquid; water purification degree determining means for determining the degree of removal of liquid impurities from values obtained by both the temperature rise determining means and water quality determining means; Control means for outputting an operation signal to the removing means until the value obtained reaches a predetermined value. 2. The electric water heater according to claim 1, wherein the removing means is heating means for heating the liquid in the container. 3. A heating means for heating the liquid in the container, a removing means for removing impurities in the liquid, a temperature rise judging means for judging a degree of temperature rise of the liquid in the container, Water quality judgment means for judging the water quality of the liquid; removal capacity judgment means for judging the presence or absence of the capability of the removal means from values obtained by both the temperature rise judgment means and the water quality judgment means; and the removal means An electric water heater, comprising: replacement display means for displaying replacement of the removing device; and replacement display control means for outputting a control signal to the replacement display means from the output of the removal capability determining means. 4. The electric water heater according to claim 1, wherein the removing device uses a circulating means in the circulating water channel as the removing means. 5. A heating means for heating the liquid in the container, an energization control means for controlling the energization of the heating means, a temperature rise judging means for judging a degree of temperature rise of the liquid in the container, Boiling detection means for detecting the boiling state of the liquid,
Water quality determination means for determining the water quality of the liquid in the container, water purification degree determination means for determining the degree of removal of liquid impurities from the value obtained by both the temperature rise determination means and the water quality determination means, A control unit for outputting an ON signal to the power supply control unit until the value obtained by the water purification degree determining unit reaches a predetermined value. 6. A heating means for heating the liquid in the container, a temperature rise determining means for determining the degree of temperature rise of the liquid in the container,
Water quality determining means for determining the water quality of the liquid in the container; water purity determining means for determining the degree of removal of liquid impurities from values of both the temperature rise determining means and the water quality determining means; and the water purity determining An electric water heater comprising: display control means for outputting a signal to water quality display means for displaying water quality according to the value of the means. 7. The electric device according to claim 1, wherein the water quality judging means for judging the water quality of the liquid in the container has an electrode provided in the liquid in the container to measure the conductivity of the liquid. Water heater.