Supply interruptions hot water, especially in the summer, happen with enviable constancy. To solve this problem, many are forced to equip an autonomous source of hot water in their apartment. Quite often, our choice stops at a flowing electric water heater. Of course, you need to decide which instantaneous water heater is better and how to choose the right model.
The instantaneous pressure water heater under the sink is invisible and usefulThese units are different small size, low electricity consumption, and in terms of efficiency it is no worse than storage-type modifications. In such devices, the liquid is instantly heated and you can not be afraid that, when taking a shower from the horn, you will find yourself under a cold stream of water, because the hot one has ended in the storage tank.
How does an instantaneous water heater work?
A flowing water heater is a plastic or metal casing, inside of which a tubular electric heating element (TEH) is located. The principle of operation of an instantaneous water heater is not complicated: the cold water entering the inlet of the apparatus, in contact with the heating element, acquires the desired temperature at the outlet. Energy is consumed only during the operation of the device. The best instantaneous water heaters have the following advantages:
- low weight and overall dimensions;
- the possibility of placing in any convenient place;
- unlimited amount of heated liquid;
- electricity consumption in interval mode;
- small price.
The internal structure of an instantaneous water heater - an example of modern technology It must be understood that the more often the water heater works similar design, the greater will be the cost of paying bills. Basically, it depends on the number of people living in the apartment, the location of the water intake points, and so on. The best low-power flow heaters used in the country are very economical.
Which is better: electric or gas water heater?
Flowing water heaters, depending on the energy source used, are divided into electric and gas. The principle of operation is essentially the same, so you need to choose a source of energy. Asked if it's better geyser or electric water heater, there is no single answer: each unit has its own advantages and disadvantages.
Price gas fuel below, but gas water heaters require equipment exhaust ventilation with a chimney and compliance with a number of fire safety requirements.
The geyser requires a special permit from the relevant authorities, which means that do-it-yourself installation is prohibited, and a certified specialist is needed.
In addition, the geyser requires constant Maintenance, and for the operation of the unit, it is necessary to have a constant working pressure in the gas line. They have large overall dimensions, have restrictions on the installation site and burn oxygen.
A small size instantaneous water heater will harmoniously fit into any interior Instantaneous water heaters, which are powered by electric current, are much safer to use. Their installation is not difficult and can be done by hand. It should be borne in mind that powerful models have an increased load on the electrical wiring, so a safe connection should be provided. These units are compact in size and can be installed anywhere.
What is the difference between pressure and non-pressure models
Non-pressure models are distinguished by the fact that the internal pressure in the system is close to atmospheric. Pressure modifications are always under pressure from the fluid of the water main. Non-pressure water heaters do not have high power, as a result they heat water weakly and are used mainly as auxiliary devices for hot water supply, they work great in summer cottages.
The water heater can be built right into the faucet The package of non-pressure models, designed to service one water intake point, includes a shower hose, watering can or faucet. Units of this type do not exert an increased load on the electrical network to which they are connected, so in most cases it is not necessary to replace the wiring with a more powerful one. This is again convenient for giving. Non-pressure models are always installed after a tap or faucet that blocks water access.
Instantaneous water heater option with tap Pressure water heaters are mounted directly into the distribution of the water supply network and can serve several water intake points at the same time. Most often they are installed under the sink, hung on the wall or placed behind the door. kitchen furniture. These units can maintain a constant temperature regime heated water and automatically turn on when the tap is opened.
Connecting water heaters
Water heaters are connected to engineering communications supply of water and electricity. At the same time, there are differences in the wiring of pressure and non-pressure models, but grounding must be done in any case. Non-pressure water heaters are much easier to connect to a water source.
The water heater under the sink takes up very little space Pressure units are connected to two water supply lines, through which hot and cold water is supplied. In almost any case, it will be correct to equip the power supply with a separate line, since overloading the existing wiring is unacceptable, and all safety requirements must be observed. Electrical installation water heaters operated in rooms with high humidity must be carried out especially carefully.
Connecting a non-pressure model to a water source
The installation of an instantaneous water heater always starts with hydraulic installation, because it is necessary to press out air locks and fill its body with water. Connecting a non-pressure model to a source cold water is not difficult and can be done by hand. The device is mounted through a gasket that has dielectric properties and is included in the device package.
Heated shower head - another instantaneous water heater option A mixer or shut-off valve must be present at the heater inlet. This is necessary so that in the container in which the liquid is heated to the desired temperature, pressure is not created for which it is not designed.
If a shut-off valve is connected at the outlet of the water heating device, a container rupture may occur, since the automation that controls the workflow does not monitor the pressure of the liquid at the place of its heating, but controls its presence or absence only at the system inlet.
The supply of hot water coming from the water heater is carried out through a long hose with a shower arm or gander. It is not possible to replace the mixer or spiral hose supplied with the unit, as they are specially designed for the required heating and economical consumption water. During operation, it is necessary to exclude the ingress of water splashes on the unit and the provision of external mechanical impact on it.
Connecting a pressurized water heater to the water supply
Pressure execution of a water heater provides connection to a water supply system in a section of pipeline system. A tee is used, installed to the nearest pipe branch. In order to be able to turn off the unit with a centralized supply of hot water, liquid shut-off valves are installed on the inlet pipes.
Connecting a pressurized instantaneous water heater to a faucet In addition, their presence helps to remove the device for repair or replacement without blocking the center line. Before the tee it is better to install a filter for cleaning tap water, since its quality in the vast majority of cases can lead to a reduction in the life of the device.
Electrical installation
The electrical installation of the instantaneous water heater is carried out after it is fixed in the selected place and the device body is filled with water. Low-power models can be plugged directly into an outlet. If the apartment has electric stove, the cable that feeds it is activated.
Wiring diagram for connecting instantaneous water heater For some powerful units, three-phase network equipment with a nominal voltage of three hundred and eighty volts is required. In all cases, it is imperative to provide for the implementation of high-quality grounding. In addition, it is necessary to have a device protective shutdown, which interrupts the operation of the unit in the event of a danger of electric shock to a person. Detailed instructions about connecting RCD you will find in the article
Control options for water heaters
The efficiency of their functioning largely depends on the quality of control of water heaters. There are the following implementations of this function:
- Devices using hydraulic type automation. In this case, a special sensor is located at the system inlet, which controls the appearance of the flow of sheath fluid and turns on the heating element. The disadvantage of this design is that it connects only one level of heating power. In some models, it can be changed manually by push-button switching.
- Using an electronic microprocessor. It controls the operation of the heater using monitoring sensors and allows you to maintain the same temperature regime of the heated liquid.
Hydraulic control makes it possible to obtain an increase in the temperature of the serviced liquid only by a certain amount. Which one depends on the power of the tubular electric heating element. It is believed that the temperature of the water at the entrance varies from twenty to twenty-five degrees.
It turns out that in the summer hydraulic control allows you to provide hot water, but in winter the unit may not be able to cope with heating too cold water.
Electronic control allows you to maintain the desired temperature of the heated liquid, regardless of the time of year. Such units are much more expensive and have more power, as a result, they require a separate connection line and mandatory installation protective shutdown devices.
Determining the required capacity of an instantaneous water heater
The power of an instantaneous water heater is its most important operational parameter. It determines the amount of hot water heated by the unit for a certain period of time. A low-power unit is able to heat about five liters of water within a minute, enough for cooking dinner or taking a shower.
The capacity of an instantaneous water heater required to meet the demand for hot water can be simply determined by dividing this parameter by half. The result obtained will show quite accurately how many liters of liquid, the temperature of which will increase by approximately thirty degrees, will be consumed in a minute interval. For example, a unit with a capacity of eighteen kilowatts will provide an output of nine liters of hot water per minute.
By determining the daily consumption of hot water depending on the number of people living in the apartment, you can easily calculate required power instantaneous water heater. It increases by about one and a half times if a bath is taken instead of a shower, and there are many water intake points.
Depending on the design and purpose, the power of the water heater will be different. In practice, in the case of using a non-pressure water heater with a tap, a power of 3.5 kW is sufficient. If you need to heat water only for the shower, choose a device with a power of 5 kW. In the case of the possible use of a shower and a tap at the same time, it is better to purchase a water heater with a power of 7 kW.
Assessment of possible water consumption
The possible water consumption is estimated depending on the size of the family living in the apartment, the presence or absence of a bathroom, and so on. What will be the average water consumption for an average family of three? Let's try to figure it out.
Taking a shower, an adult man spends about fifteen liters of hot water, a woman, on average, ten liters more. Adding here morning hygiene procedures, washing dishes and hands, we get that a family of three will spend about a hundred liters of water. At the same time, thirty liters will be enough for one person.
Real offer on store shelves
On the modern market There is a huge variety of modifications of instantaneous water heaters, both pressure and non-pressure. Actual offers of pressure models can be compared with the help of the following table.
| Table of characteristics of instantaneous water heaters | ||||||
| Name of the water heater | Number of points | Powerful, watt | Dimensions, mm | Productivity, l/min | control type | We stand, % |
| Electrolux Smartfix 2.0TX | 1 | 6500 | 270x135x100 | 3,7 | hydraulic | 100 |
| Thermex System 800 | 1 to 3 | 8000 | 270x95x170 | 6 | hydraulic | 160 |
| Electrolux NPX 8 Flow Active | 1 to 3 | 8800 | 226x88x370 | 4,2 | electr | 490 |
| AEG RMC 75 | 1 to 3 | 7500 | 200x106x360 | 1 to 3 | electr | 510 |
| Evan W1-9.45 | 1 | 9450 | 260x190x705 | 3,8 | mechanical | 530 |
| Stiebel Eltron DHM3 | 1 to 3 | 3000 | 190x82x143 | 3,7 | hydraulic | 660 |
When choosing a specific device for a house or apartment, it is necessary to take into account the totality of all operating parameters. The most important part of an instantaneous water heater is the tubular electric heating element. For long-term trouble-free operation of the unit, it is necessary high-quality protection this part from direct contact with the heated liquid. Other structural elements in contact with water must be made of brass, copper or stainless steel.
The body of the instantaneous water heater is exposed to high temperatures, aggressive chemical components in the composition of the liquid flowing through it, therefore it is made from chemically and mechanically durable material. Materials such as copper and polypropylene have proven themselves well, the cases made from them are distinguished by a long service life.
It is convenient to install such a kit instead of a regular crane. An important factor is the convenience of using the unit for all family members. It is very important to ensure the safety of operation, you need to choose a device with an overheating protection function, complete it with a filter for water purification. It will be useful to have an indication of inclusion, a scoreboard on which the temperature of the heated liquid is displayed.
Calculation of the power of instantaneous water heater
When choosing an instantaneous water heater, its power plays a decisive role. The power of an instantaneous water heater can be determined based on the purpose of use (for example, showering, washing hands, etc.).
To do this, use the table below. First determine the required hot water flow (l/min) for the largest hot water point. Even if you will use the instantaneous water heater for several points, then select its power according to the water intake point with the largest required power.
|
Required temperature, ºС |
Required flow, l/min |
Required water volume of storage water heater, l |
|
|
hand washing |
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|
Kitchen sink |
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Knowing the flow rate at the largest point of water consumption, the power is calculated by the formula:
P=G*∆t/14.3
P– water heater power, kW;
G– flow or flow, l/min;
∆t– required temperature increase, ºС, ∆t = T-t in ;
T- required temperature at the water heater outlet, ºС,
t in– temperature of cold water, ºС (+5 ºС in winter, +15 ºС in summer).
If you plan to use several points at the same time, then the power of the instantaneous water heater should be increased by another one and a half times.
Important! It is possible to get a comfortable full-fledged stream of hot water using an instantaneous water heater only if its power is from 8 kW and above. In houses of old buildings with 16-ampere plugs, a water heater with a power of more than 3.5 kW simply cannot be installed. And in houses with electric stoves and new houses where there are 40- or 32-ampere meters, it is permissible to install “flow-throughs” with a power of up to 6 kW.
On a note. There is also a more simplified calculation. In order to estimate the required power of the water heater, you can use a simpler calculation: divide the power value (kW) in half. As a result, a fairly accurate value of water flow (l / min) will be obtained when it is heated by about 25-30 ºС. For example, for taking a shower, a 16 kilowatt device will provide a water flow of 8 liters per minute.
Single phase or three phase
There are instantaneous water heaters for both single-phase (up to 12 kilowatts) and three-phase networks (from 12 to 36 kilowatts).
With a centralized installation, if you have the opportunity to install a three-phase water heater, install it, as it is more powerful. The more powerful the water heater, the more comfortable and economical it is.
When installing instantaneous water heaters at each water intake point separately, install predominantly single-phase ones, having previously calculated their power, as described above.
Pressure and non-pressure
According to the method of installation in the water supply network, instantaneous water heaters are divided into pressure and non-pressure.
System (pressure) instantaneous water heaters (from 4.5 kW and above). They only provide inlet and outlet for water. They are cut into hot and cold water pipes, i.e. hot water is "bred" to the whole apartment. This is very convenient, because during the period when hot water is turned off, you can not only take a shower, but also use hot water from any tap in the apartment. Such a water heater turns on and off automatically, reacting to the flow of water.
The pressure water heater in the image below cuts into the water supply system and can power all water intake points.
Non-pressure instantaneous water heaters (from 3.5 to 8 kW) are equipped with their own shower or kitchen nozzle (it is included in the device kit) and work only on one water intake point. Such devices cannot be used with other fittings than the one that was sold complete with this water heater. Such water heaters are convenient, say, in the country.
The image below shows a pressureless water heater. Distinctive feature non-pressure water heaters is the presence of a tap at the entrance to it and never at the exit.
It is recommended to use small instantaneous water heaters equipped with shower heads with a power of 3 to 6 kW only in summer. In winter, there are often complaints that the water heater worked fine in summer, and now, during a heating network failure, it refuses to heat water. Reason: in summer, the temperature of “cold” water “incoming” from the tap was + 15 ° C. His small instantaneous water heater with a capacity of 3.5 kW (with ∆t - 25°, giving 3 l / min) in the summer easily "heated up" it by another 25°. That is, 15° + 25° = 40°C is quite a suitable temperature for washing. And in winter, the water in the tap is colder, about 5 degrees. So: 5 ° + 25 ° = 30 ° С - under such water, of course, you will freeze. And the device itself has nothing to do with it, it works as usual, nothing has broken in it. Small instantaneous water heaters were developed for the warm countries of Asia and Africa. And there are no such differences between winter and summer temperatures, and the temperature of the water in the tap is always about + 15 °. It just needs to be warmed up a bit.
A few words about the efficiency of instantaneous water heaters
In a household with a need for hot water of 150 l / day,.
Considering the low cost of an instantaneous water heater, its compact size and the fact that it is almost always equipped with kitchen faucet or a shower head, it is reasonable to buy such a water heater for each water intake point separately, because. this leads to energy savings in heating water in pipes if the water intake points are significantly removed from the water heater.
Since the water in an instantaneous water heater is heated only during consumption, energy is not spent on maintaining the temperature of a certain amount of water, as in storage water heaters, and this reduces operating costs.
In addition, instantaneous water heaters minimize water consumption due to the fact that the user does not have to wait long for water to reach the required temperature.
Instantaneous water heaters are very durable. Their service life is more than 20 years, while the accumulative 8-10 years with proper maintenance.
Price and brand
After you have selected several alternative models for yourself according to the characteristics described above, you will only have to call our office if you need to ask all your questions, clarify what is currently available and choose the water heater that suits you best for the price and by manufacturer's brand.
The highest quality instantaneous water heaters are Aeg and Stiebel Eltron, so these are the companies
If there is electricity in a house, apartment or cottage, it is not at all difficult to provide a family with hot water. The market offers an exceptionally wide selection heating appliances for heating tap water.
The most popular are storage boilers, but flow models have their fans. To figure out how to choose a flowing electric water heater, you should study the features of the operation of this device.
The design of an instantaneous water heater is very simple. This is a flask for water, in which a powerful electric heating element made of copper is installed. Additionally, there is a control unit, with its help you can configure the functioning of the device as needed.
The water flow enters the flask, where it is almost instantly heated to the desired temperature and supplied to the distribution points. More powerful models allow you to heat the flow up to 60 degrees, and less powerful ones - up to about 40 degrees.
The photo clearly shows the device of a household electric instantaneous water heater, in which the role of the heating element is performed by a high-power heating element.
The spread of characteristics of instantaneous water heaters in terms of power is quite wide, it varies between 3-27 kW. Devices with a power of up to 8 kW can be safely connected even to an ordinary single-phase 220 V socket, although electricians still recommend that a separate line be drawn from the meter for this powerful device.
High-power heaters can only be connected to a three-phase 380 kW electrical network, which is usually equipped with houses with electric stoves.
If you need to connect a powerful heater, and confidence in your reliability electrical network No, you should consult an experienced electrician. Sometimes the network can be modified, but this is not always possible.
Advantages and disadvantages of "protochnik"
Among the advantages of flow heaters, several points should be noted:
- Usually these are compact devices, it is easier to find a suitable place for them.
- A separate tank is not required to obtain a stable flow of hot water.
- Electricity is consumed only during the operation of the device.
- The device is not difficult to install and operate.
- Installation does not require a chimney.
- The operation of the device does not depend on the characteristics of the supply and exhaust ventilation.
But when choosing an instantaneous water heater, you should also remember about its shortcomings. To begin with, “protochniki” consume quite a bit during operation. a large number of electricity, which is inevitably reflected in utility bills.
In addition, the quality of heating will depend on how many hot water consumption points the heater serves at the same time. If there are many such points, and the power of the device is not enough, there will be too little water, or it will not warm up fast enough.
Instantaneous water heaters are compact in size, which greatly facilitates their installation. When installing, it is important to comply with the requirements for power supply characteristics.
High power consumption requires appropriate operating conditions. Installation of a device with a power of more than 8 kW is possible only to a modern three-phase electrical network.
Unfortunately, old houses are not always equipped in this way. In such conditions, installation of flow heaters with a power of up to 6 kW is allowed. You can clarify the features of your electrical network in the housing office or with a local electrician.
The condition of the wiring in the house also matters. Of course, it must be correct. It is recommended to use high-quality copper wire for such powerful devices as flow heaters.
The cross section of the cable must correspond to the power of the device. On this issue, you can also consult with a good electrician.
Low-power devices have a significant drawback: they are convenient for operation only in the warm season, when the temperature of the water coming from the water supply is at least 15 degrees. A low-power device can raise the temperature of the water by another 25 degrees, i.e. up to a very comfortable 40 degrees.
If for some reason the water supplied to the heater does not have time to warm up to right level, the quality of heating will be unsatisfactory.
There are instantaneous water heaters that are installed directly on the sink. In this case, there is no need to bring separate hot water pipes to the sink.
Attempts to connect a device designed for a three-phase network to a conventional 220 V power supply can be fatal for an instantaneous water heater, and for electricians, and even for people. Do not take risks and arrange an electrical accident in the house. A network with the necessary characteristics can be connected to a private household, a summer house or a cottage.
To do this, contact the local power supply company and obtain a special permit - specifications to connect the electrical installation.
You can get acquainted with the features of connecting and operating an Electrolux electric instantaneous water heater with a power of 3.5 kW in the following video:
What you need to know about the types of flow heaters
Although manufacturers offer big choice flow type water heaters, according to the type of installation and features of operation, they can be divided into two large groups: pressure and non-pressure.
Pressure models are mounted in the water supply riser, they are designed to simultaneously provide hot water to several points of consumption.
Pressure-type instantaneous water heaters are connected directly to the water supply system of a house or apartment. They can serve several points of hot water consumption at once.
The device is equipped with an inlet for cold water and an outlet for hot water, from which water is supplied through pipes to the places of consumption.
Thus, if with the help of a flow heater it is supposed to provide hot water to the entire apartment or the whole house, it makes sense to opt for a pressure water heater.
Non-pressure instantaneous water heaters are usually characterized by low power, moderate price and high popularity. The device is equipped with special attachments, such as a shower head
Non-pressure devices are used in cases where only one specific point of consumption needs hot water. Usually this is a shower or bath, a sink in the kitchen, etc.
The device is installed in close proximity to the point of hot water consumption, cold water enters through the inlet pipe, and hot water is supplied through a special nozzle, for example, through a shower head. Heaters of this type are a popular choice for summer cottages.
Device selection: what to look for
Before you go to the store, you should decide on a number of indicators that characterize the operation of the water heater:
- The number of consumption points to which heated water will be supplied.
- The total volume of water that will be consumed per unit of time when switched on simultaneously at all points of consumption.
- The power of the device, which will provide sufficient heating temperature.
In addition, a number of questions should be clarified already in the store:
- The level of complexity of the installation of the device, which can be carried out independently or with the help of a specialist.
- The cost of installing a heater (sometimes you can get a discount or even free installation services).
- Availability and cost of spare parts that may be needed in the event of a product breakdown.
- Duration of the warranty period.
- The procedure for warranty service.
The last point is very important, because sometimes it is quite difficult to get a warranty repair service from a little-known manufacturer, despite the fact that the warranty is provided. The warranty repair center may be located in a neighboring city, region, or even in another country.
The maximum amount of hot water that the device can produce per unit of time depends on the heater power. Low-power appliances can supply two to six liters of water per minute. The actual heating when using such a device usually takes only 20 seconds.
Usually this amount of water is enough to quickly take a shower and wash the dishes. If the needs of the residents of the house exceed these figures, a more powerful water heater will be needed.
Using this diagram, it is not difficult to determine what level of hot water a family needs for comfortable living in home
To find out your family's need for hot water, you can make simple practical calculations using a bucket of known capacity, for example 8, 10 or 12 liters. Water is let in with the usual pressure and the time during which the bucket is filled is noted.
Dividing the number of liters by the number of seconds obtained and multiplying the result by 60 determines the need for hot water for this particular point of consumption. You can immediately divide liters into minutes so that you do not have to additionally multiply by 60, but if the number of minutes is not an integer, you should correctly convert additional seconds to tenths / hundredths of a minute. For example:
1 min. 30 sec. = 1.5 min.
45 sec. = 0.75 min.
2 minutes. 15 sec. = 2.25 min. etc.
The same practical measurements and simple calculations should be carried out for each hot water consumption point, and then summarize the result.
Information about the performance of an instantaneous water heater is contained in the product data sheet, and this indicator is also usually indicated in the product description on the websites of manufacturers, online stores, in brochures, etc.
To determine the power of an instantaneous water heater, you can use a completely scientific formula that uses data on the need for a point of consumption / house / apartment in hot water. Calculate the power of the device according to the following formula:
P \u003d Q × (t 1 - t 2) × 0.073, where:
P— power of instantaneous water heater, W;
Q- the required flow of hot water, l / min .;
t1- the required temperature of hot water supplied to the point of consumption, 0 С;
t2 is the temperature of the water entering the heating device, 0 С;
0,073 - correction factor.
Here is an approximate calculation of the power of an instantaneous water heater for a conditional situation when the hot water consumption level is 15 l / min, the outlet water temperature should be 400C, and the inlet working temperature water is on average 100C.
In this case, the power of the instantaneous water heater should be P = 15 × (40-10) × 0.073 = 32.85 kW. This is enough high power, the acquisition of such a device will be expensive.
Before choosing a suitable instantaneous water heater, you should evaluate the upcoming costs not only for its purchase and installation, but also for further operation.
The higher the power of the device, the more electricity is consumed during its operation, but the higher the water temperature that can be obtained using such a device. It all depends on the needs and specific conditions.
For example, if in the country house hot water is needed only for washing dishes or for taking a shower, a model with a power of up to 8 kW is sufficient. Such a device is quite enough to solve these small household tasks.
If you need to provide hot water to a large house, especially throughout the year, and not just in the summer, you will have to consider devices with a capacity of 18 kW or more.
It is also worth evaluating the location of hot water consumption points. Usually, if the shower stall and the kitchen are nearby, it is possible to use one low power device for these two points.
True, hot water will be supplied to only one consumer: either in the shower or in the kitchen.
The diagram clearly demonstrates the features of installing an instantaneous water heater. It is worth deciding on the location of the device and the order of its connection even before purchase
If funds allow, you can increase the comfort in the house with the help of two small-capacity water heaters. One is placed in the kitchen, and the other is in the bathroom or in the shower.
They do not take up much space, so having two devices will not create big problems. For a shower, it makes sense to buy a water heater equipped with a block remote control. However, the device can be placed directly in the shower.
Such devices are usually designed to work in conditions high humidity, so he is not afraid of splashes.
Some models of instantaneous water heaters are equipped with a remote control unit. Such devices are very convenient to use in the shower.
What is the price?
It should be noted that in Russia the most popular flow heaters are Termex, Electrolux, etc. Traditionally high quality different models of the well-known company Bosch.
Among Electrolux devices, the Smartfix 5.5 T, Smartfix 6.5 T, Smartfix 2.0 6.5 T models with a power of 5.5-6.5 kW are very popular. The cost of such devices ranges from 50-70 dollars.
Popular instantaneous water heaters from Termex include the Stream 350, Stream 500, Stream 700 models, their power is 3.5 kW, 5.0 kW and 7.0 kW, respectively. The price varies approximately within the limits of 80-100 dollars.
If you need to pick up a high-power device, it makes sense to consider the line of instantaneous water heaters from VAILLANT. The cost of devices with a power of 12-27 kW ranges from 210 to 230 dollars.
In general, buyers tend to choose low-power models of “protos” that are simpler and more convenient to operate. Where a large amount of hot water is required, the choice is usually made in favor of storage water heater, which in the process of operation is a little cheaper.
This explains the low popularity of instantaneous water heaters with high power.
To reduce energy consumption and minimize the flow of water by providing sufficient water pressure, very small holes are made in the shower heads of free-flow “flows”. Over time, these holes become clogged due to lime scale and poor water quality.
After this contamination is usually not difficult to remove with a stiff brush or a metal sponge.
The holes in the shower head of an instantaneous water heater are specially made small to reduce water consumption. Special filters help protect the device from pollution
When a specific heater model is selected, it is recommended to carefully study the manufacturer's instructions before purchase. This will help to understand the installation features of the device, as well as to evaluate the features of its operation, i.e. how convenient it will be to use the device after installation.
Small water heaters that are purchased for summer cottages are recommended to be removed and taken to a warm apartment at the end of the season.
In the spring, it is not difficult to connect the heater again, but it can be quite difficult to provide sufficiently good storage conditions in an unheated cottage.
The summer season is associated with a trip to the country house, the repair of city water arteries, and the lack of hot water supply. A flowing electric water heater, a compact device, will solve the problem. The advantage of the device is the instant heating of running water in a tap or shower. No space-consuming storage tank required. Due to the heating elements built into the jacket, the passing water, washing them, heats up.
The principle of operation of instantaneous water heaters
In principle, hot water distribution is not needed. Heated water can be supplied through the cold water line, but then it cannot be diluted.
There are two fundamental various schemes heating - flowing pressure and non-pressure. AT this case the scheme is considered non-pressure, since the water inlet for heating after the valve, and its free flow to the shower, passes under atmospheric pressure. In this scheme, a temperature controller is used, the flow rate at the inlet is determined by the user manually. The circuit includes a valve to turn off the power when there is no water in the pipe. This prevents water overheating and accidents. A flowing electric water heater can operate at a power of 2-8 kW and does not require separate wiring. 
The pressure flow system is more complicated. In order to receive required parameters flow and temperature, two control systems are involved - pressure and temperature. Pressure systems are complex, use additional options and their cost is much higher. But they are designed to connect several sampling points, and turn on automatically when a flow appears in the pipe. The system requires a separate wire, designed for the power of the device.
So that when heated, water does not create deposits on the heating elements, it is subjected to magnetic treatment with a compact activator built into the system. An electric flow-through water heater is an alternative to a boiler. The equipment has one task, but different principle actions. In the boiler, water is heated constantly, with a power of 1-2 kW, for flow heating it is necessary to give a volley with a power of 3-30 kW, depending on the selected equipment. On the other hand, excess water in the tank cools down, energy is wasted.
A flowing electric water heater takes power only when using a tap or shower.
Flow heater device
Numerous models of flow heaters use similar heating methods. Brands are distinguished by design and materials used in the layout of products. The installation of an electric flow-through shower is carried out from models of pressure and non-pressure rows. The low power of non-pressure devices does not allow getting water warmer than 60 C. But this temperature is standard for supplying coolant to central heating lines. A non-pressure heater is able to serve only one point of analysis. However, the device is compact, easy to install on its own and can provide the need, provided that a special nozzle is used. Due to the different sections of the inlet and outlet of water, the time spent by the liquid in the heating chamber is regulated. Outflow from the narrow end creates a comfortable pressure.
Here is a drawing of a non-pressure flow heater AEG BS 35 E made in Germany. The company specializes in the production of flow heaters of various categories. A non-pressure device can operate at low power and operate a maximum of two points in turn. The pressure water heater AEG RCM 6 E can be installed on mains up to 10 bar. Bulb and heating element in copper version. Such heaters are installed in a separate cabinet, and they cannot be called economical.
Installing an instantaneous electric water heater on a faucet
At first glance, the faucet-mounted device appears to be an ordinary faucet. Only the wiring gives away the placement of the appliance. A coiled heater and a regulator that controls the process are hidden in the robust body of the tube. AT design solutions different mains supply can be used. All devices include:
- flask;
- heater;
- temperature relay with shutdown function;
- a water movement relay that gives a start command;
- water filter;
- load regulator.
Usually instantaneous electric water heaters are used for summer cottages. Wash dishes and hands warm water possible from a low-power device. The lower the power of the device and the simpler the execution, the cheaper it is. For seasonal use, you can find a model costing less than three thousand rubles. In this case, you will have to manually regulate the flow of water. The higher the inlet flow, the lower the outlet temperature. It is considered optimal if the device gives the flow-temperature ratio:
- washing in the kitchen - 3-5 l / min at t 45-50 0 С;
- washbasin - 2-4 l / min at t 35-37 C;
- shower - 4-10 minutes at t 37-40 C.
Such indicators will give a device with a power of 3-6 kW. The crane model KDR-4E-3 of the Delimano brand provides heating under these conditions up to 60 degrees. Inexpensive flowing water heaters from Electrolux (Electrolux) took first place in the ranking for price and functionality. It is worth paying attention to Electrolux Smartfix 3.5 T and Garanterm GHM 350, Russian-made brands.
Choosing a flowing electric water heater for a country house
There are certain norms of water consumption for each person. Therefore, it is necessary to calculate the purchase of a water heater based on the total need for hot water. For a large building with several sanitary points, it is better to use a storage heating system. Boilers operate on a conventional network and consume energy economically.
If there is a need to install an electric instantaneous water heater in an old apartment building, the device should be selected in the power range up to 8 kW, with a separate line.
If a voltage of 380 V is supplied to the building, then you can get a powerful device. It is important to choose a safe heater that uses:
- enameled heating chamber;
- elements in a stainless casing;
- flask and heating elements copper, quartz coated.
How to choose the right instantaneous electric water heater in terms of power? Experts advise:
- in summer, a power of 3.5 kW is enough, since the water has a temperature of about 18 degrees;
- in winter, models with a power above 5 kW are effective;
- models with options that require more than 7 kW, in standard apartment not worth buying.
The range of electric instantaneous water heaters, their prices and characteristics
The demand for flow heaters is due to the need to create comfortable conditions life under any circumstances. The compact size of the devices allows you to install equipment in cramped conditions. The water heats up within a few seconds and it is possible to maintain a stable indicator.
When choosing a device, they are guided by its power, design and options. However, the main indicator is the power of the water heater.
For a choice, we present an overview of several brands.
manufactured on own production in Israel.
The quality of products is confirmed:
- working resource - 15 years;
- special design of heating element, power up to 12 kW with instantaneous action;
- network operation using an electronic sensor that controls the flow;
- the ability to install in tight spaces.
If the pressure in the system is less than permissible, the electricity is turned off, the indicator goes out. Atmor heaters can be used in apartment buildings old building. As an example, we can offer for consideration a model of an electric instantaneous water heater Atmor ENJOY 100 5000 Showers, costing about 3 thousand. Its productivity is 3 l / min, when heated up to 65 C, the connection power is 5 kW. As a pressure option for these parameters, the Atmor In-Line 5 model is offered, two thousand rubles more expensive.
Flowing water heater Termeks (Thermex) represents a closed structure with two buttons displayed on the panel. We offer products of the Stream series with a power of 3.5 - 7 kW and Sistem, a device closed in the case with a connection for 6-10 kW. The unit has chemical protection against salt formation, heating temperature adjustment.
Advantages of running water heater:
- the design is equipped with a water flow sensor, a copper heater, a temperature control sensor and an RCD;
- serves several points at the same time;
- easy installation;
- fast water heating.
The stylish Thermex System 600 White pressure model with a capacity of 5 l / min costs no more than 5 thousand rubles.
made in Great Britain has 250 service centers for its equipment in Russia. Products are represented by several series, which, in turn, are multivariate.
Common to all models are:
- work in the range of 0.25 - 6.0 bar;
- automatic shutdown of heating when reaching 57 C;
- the presence of a display on the instrument panel;
- complete with water filter and pressure regulator;
- own accessories included in delivery - spout, shower.
Vega and Gamma are considered inexpensive models. Their cost does not exceed 3 thousand. But the Polaris Smart model is considered the most affordable.
When choosing a model of an electric instantaneous water heater, we advise you to pay attention to products under the Electrolux and AEG brands. First of all, it is necessary to focus on the state of the electrical network from which the water heater is powered.
Overview of instantaneous water heater testing - video
A flow-type domestic water heater does not need a special storage tank. The principle of its operation lies in the fact that the required amount of thermal energy is reported to the flow of water for that short period while it passes through the device.
- through electrical energy, heating a heating element or an uninsulated metal spiral;
- using a gas burner;
- using a heat exchanger in which water receives thermal energy from any coolant.
The last of these options is extremely rare, one of the first two is used much more often.
In order to choose the right instantaneous water heater for an apartment, it is necessary to consistently answer a number of questions:
1. Energy source: gas or electricity? If there are chimney channels in your house and the housing office allows the installation of gas equipment, then the most preferable option would be to install a gas column.
The power of a standard gas burner is even enough to heat water for a shower in winter period. If your house is not equipped with chimneys, then you will have to install an electric water heater.
Its maximum power depends on the type of existing wiring.
For example, in old houses, in the shields of which fuses are installed, designed for a maximum current of 16 amperes, water heaters with a power of no more than 3.5 kW can be installed.
During the construction of houses in a later period, electrical networks were laid, designed for 32 and even 40 amps.
Such wiring will withstand a heater with a power of up to 8 kW. If you want to install a more powerful unit, you must coordinate with the electricity supplier to lay a separate power cable.
At the same time, it should be taken into account that instantaneous water heaters with a capacity of from 8 kW are designed for three-phase voltage.
Thus, in apartment buildings, powerful "protochnikov" are used quite rarely, this option more suitable for individual construction.
Video - types and types of electric instantaneous water heaters:
2. Type of water heater: pressure or non-pressure? For hot water supply to the entire apartment, you will have to install a pressurized water heater that cuts directly into the cold water riser.
Such equipment is capable of providing hot water to several points of water intake. If you just want to comfortably take a shower during the summer hot water shutdowns, choose a non-pressure heater.
As a rule, such devices have low power and are equipped with shower heads. However, it must be borne in mind that they are suitable for heating water in the summer.
In winter, when the temperature of the water in the pipes drops to 5 degrees, there will be little sense from a low-power free-flow "flow".
3. What capacity of water heater do I need? It will be much easier for you to determine not so much the power as the flow of water at known incoming and outgoing temperatures.
It is this parameter that the manufacturer indicates in the passport of his equipment. Open the water in the usual mode and note how long it takes, say, a bucket of water with a capacity of 10 liters.
Convert the received data into consumption per minute and feel free to go to the store. Now you can definitely choose the most suitable instantaneous water heater.
Be wary of buying dubious products or outright fakes, even if the seller promises you a significant discount.
Poor quality electrical or gas equipment will not only add to your repair hassle, but also may cause fires or explosions, the consequences of which will be much more expensive.
When buying equipment, ask the seller to show quality certificate and also ask what guarantee period provided for this equipment.
Popular electric heaters (cost and characteristics) ^
As already mentioned, the use of a powerful instantaneous water heater in an apartment is associated with great difficulties.
Therefore, in this review, we will only talk about low-power devices that occupy a leading position in terms of sales. In our country, the following brands have proven themselves well:
1. "Atmor Summer" (power - 3.5 kW, flow rate - up to 3 l / min). Inexpensive budget class heater. Able to "give out" a temperature of 40 degrees, provided that at the entrance it is not lower than 18. Approximate cost - 800-1500 rubles.
2. "Polaris Vega T 5.5" (power - 5.5 kW, flow - up to 4.4 l / min). A compact device with slightly more power.
Easily and conveniently mounted under a bathtub or washbasin, absolutely no claim to the free space of the bathroom. It is completed with a tap or a shower head (depending on the installation site).
3. "Proton" PEVN 5.0-220 (power - 5.0 kW, flow rate - 5 l / min). The approximate cost of this Russian model is 2500 rubles.
This device, like others of domestic production, is good because its creators tried to take into account the low quality of water in our water networks. As a result, it is characterized extended service life.
4. "Stiebel Eltron DHC 3" (power - 3.0 kW, flow rate - up to 3 l / min). This manufacturer can be safely attributed to the premium class, which, of course, was reflected in the cost of the model: 8000 rubles.
But for this money you get, as motorists like to say, “full stuffing”: double protection against overheating, protection against water ingress (IP24), trouble-free German automation, as well as a convenient and informative indicator system.
5. "AEG MP 8" (power - 5.0 kW, flow - up to 4.4 l / min). Another solid brand, the cost of one model fluctuates within 7500-8000 rubles.
Reliable and unpretentious device, relatively high price is fully justified by the quality and functionality.
Any water heater requires periodic replacement of the heating element. Read all about the heaters for water heaters in this article:
, learn how to choose, replace, where to buy better.
Instantaneous gas water heater ^
This type of instantaneous water heater is better known to us as a gas water heater. As already mentioned, the installation of such equipment requires coordination with gas services, and also needs a chimney. Exist two ways to ignite a gas burner:
1. Ignition with a wick. This column has a small gas wick, which is set on fire once, for example, in the morning and burns throughout the day.
It is from the wick that the gas burner ignites when the tap is opened. This ignition system is cheaper, but is characterized by inefficient use of gas.
2. Piezoelectric. A similar principle is often used in lighters for cooker. This system is battery operated, the spark is supplied automatically when the tap is opened.
Inexpensive models of gas "protochnik" are hydraulically controlled. This means that the flow of water simply turns on gas burner without changing its power.
In more expensive models, "smart" electronics are installed, which analyzes the power of the water flow, the temperature at the inlet to the device and at the outlet of it.
In accordance with the data received, the valve on the burner is controlled, so that the unit always works in the optimal mode.
An important requirement: in the room where gas water heating equipment is installed, the window must be ajar without fail.
This is done to prevent carbon monoxide poisoning.
Do-it-yourself installation of the "protochnik" ^
1. Connecting the heater to the water supply system. It is believed that the most common low-power instantaneous water heaters serve exclusively in the summer, when the hot water supply is turned off for preventive purposes.
Therefore, major changes to install such a device do not need to be done. It is most rational to connect the outlet pipe to the shower tube, and the inlet pipe through a tee to the cold water supply system.
More powerful pressurized water heaters, like boilers, connect on a return basis.
2. Electrical connection. Even if the water heater has an average power of approximately 6 kW, it is still necessary to connect it it is necessary to stretch a separate wire from the shield.
This has to be done for the reason that most meters are not designed for such a current load (approximately 27 amperes).
The cross section of the wire and the type of circuit breakers (in this case, you need to install an RCD) are selected according to special tables. Remember that the outlet into which the water heater is connected must have a ground wire.
3. Connection to the gas main.
It is forbidden to make such a connection on your own!
After gas water heater mounted and connected to the water supply system, it is necessary to invite a representative of the gas service, who will connect the equipment to the gas supply system.
A short video about the pros and cons of instantaneous water heaters:
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