Electric instantaneous water heater how to choose

Flow-through water heaters for apartments: selection tips from the master

The flow-through models of water heaters, allowing to get hot water instantly, are popular among apartment owners. Compact equipment does not require much space for placement, does not spoil the interior design of the room, which is very valuable for small objects.

At the same time, flow-through water heaters for apartments allow you to easily survive the entire period of disconnection of hot water, especially without changing the usual comfortable standard of living. Many companies are engaged in the production of this type of water heating equipment.

Devices differ in a number of technical characteristics, which should be paid attention to when choosing a model. It is important to understand that a powerful household appliance, which can provide heating of flowing water at several points of water withdrawal, will increase the load on the electrical wiring at times.

Therefore, the purchased equipment must comply with the capabilities of the power grid installed in the apartment. In addition, still take into account the frequency of use of the household appliance, the intensity of operation per unit of time, the method of connection to the water supply, the availability of space for its installation.

What is the advantage of flow-through water heaters?

When we cook about water heaters, we most often imagine a boiler with a large storage tank. a tank that contains heated water. Flow-through models do not have such tanks, it is an appliance with very modest dimensions. It can be used to heat running water rather than stored water.

And its transformation into hot water is almost instantaneous. By adjusting the water flow, you can simultaneously change the degree of its heating.

Electric flow-through water heater is a compact device that will not take up much space, but will effectively solve the problem of hot water

The principle of the flow heater is simple. Inside a small box there is a tubular electric heater (TEN) or a spiral. This heating element is washed with a small amount of water. As a result of this contact heat exchange occurs. water becomes hot.

If you increase the speed of the water, its temperature at the outlet will decrease. And at a low head, it gets hotter.

  • water is heated quickly, you will not lose time waiting;
  • The device does not need a place to install: it is compact;
  • The water is hot exactly when you need it and does not need to be heated periodically;
  • This device is much cheaper than a heater with a large storage tank.

To buy such a device is not difficult, it is much more difficult to make a choice among a large variety of devices of this type. At the creation of these models are specialized not only domestic, but also foreign manufacturers.

On the market products of companies Thermex, Electrolux, Ariston, Garanterm, Gorenje and others are widely represented.

Such heaters are available in different modifications. To avoid mistakes, you should be well-versed in water heaters and know what parameters can play a decisive role for you, and which you can just not pay attention to.

This is what one of the models of flow-through water heater of the brand Thermex looks like, which is popular among a large number of users

Rating TOP 10 best models

Atmor Platinum Tri 5

Wall-mounted model with compact size and attractive appearance. Features. power. 5 kW, capacity. 4 l / 1 min, equipped with a mechanical regulator in the form of a rotary knob and two indicators.

In addition, the unit has a digital temperature mode, protection against overheating and work without water.

  • max. the temperature of heating. 65 ° C;
  • inlet pressure. 0,3-7 atm
  • network voltage. 220 V
  • heating elements are made of copper, and their power. 5 kW
  • no water flow switch-valve;
  • type of installation. horizontal with bottom supply;
  • connection diameter. ½
  • dimensions. 295x255x210 mm;
  • weight. 2 kg
  • .


  • budget model with the highest degree of reliability and safety;
  • the small size of the case saves space;
  • model will not turn on if there is no water in the system;
  • economical electricity consumption;
  • the fastest possible heating;
  • easy to install and dismantle;
  • affordable price.


Thermex Surf 3500

electric, instantaneous, water, heater, choose

Wall-mounted instantaneous water heater is characterized by high quality workmanship, small size, simple design.

the device can be connected independently by connecting hoses ½”.

The manufacturer guarantees trouble-free operation of the unit for 2 years.

  • capacity. 3,5 kW (220 V)
  • ability to connect to a single point without pressure;
  • The presence of a power on function, 4 degrees of protection against switching on without water and overheating
  • the type of heating element. spiral, material. stainless steel, quantity. 1 pc., power. 3,5 kW;
  • material of the heat exchanger. stainless steel;
  • installation type. vertical;
  • The dimensions. 135x200x68 mm;
  • weight. 1, 3 kg
  • .


  • easy assembly, easy use;
  • fast water heating;
  • The solid body, which is not affected by rust, cracks and chips;
  • attractive design, excellent masking in any room;
  • durable heating element.


Timberk WHEL-6 OSC

The water heater has a streamlined, moisture-protected casing and modern design. Connects to only one hot water consumption point.

Copper heating element is equipped with a protective coating to increase operating life.

The model is equipped with a water filter that removes various small impurities.

  • The volume of heating. 4L/min;
  • Power. three-stage, 5, 5 kW (220 V);
  • connection to a single point without pressure;
  • the presence of the temperature limiter heating, 4 degrees of protection against overheating of water;
  • The material of the heat exchanger is copper;
  • installation type. horizontal with bottom feed, wall-mounted;
  • the sizes. 272х159х112 mm;
  • weight. 1, 9 kg;
  • warranty. 1 year;
  • .


  • instant actuation of the valve with a sensor (shutdown) when there is no water in the system;
  • comes with a shower head and faucet;
  • compact size and light weight;
  • simple installation, easy to use. modes are changed using a mechanical regulator;
  • instant water heating;
  • possibility to install in any place of the room.


Hyundai H. IWR1-3P-UIO57/S

This model heats an unlimited amount of water. The device can be installed in the bathroom or kitchen. Thanks to its elegant design and sleek lines, it looks great in any interior.

Heating element carefully cleans the water, keeping it clean and safe.

  • power. 3, 5 kW (220 V);
  • max. heating temperature. 85 ° C;
  • control type. mechanical;
  • The presence of a power indicator, protection from overheating of 4 degrees;
  • Complete with a water filter, a shower head;
  • The heat exchanger capacity. 3, 50 kW;
  • installation type. horizontal with bottom supply, wall-mounted;
  • dimensions. 258х153х95 mm;
  • weight. 1, 3 kg
  • .


  • sturdy enclosure protected against water penetration;
  • the water heater is in the disconnected mode when the water in the system is switched off;
  • the presence of the indicator allows you to determine the performance of the unit;
  • easy to assemble and disassemble;
  • TS instantaneous heaters are light and compact;
  • attractive price.


Electrolux Smartfix 2.0 5.5 TS

The model features a laconic design and fast water heating. Powerful copper heaters instantly provide a man with hot water at any time of day.

electric, instantaneous, water, heater, choose

With mechanical control, you can change the water temperature, the flow rate and the mixer.

Thanks to the presence of three power systems, it saves energy, increasing the performance of the water heater from minimum to maximum.

How to choose a flow-through water heater

Electric instantaneous electric water heaters are compact devices designed for instant hot water preparation in city apartments and cottages, where space-saving is a particular concern. In our article, we will tell you how to choose a flow-through water heater and do not make a mistake with the choice.

“Flowmeters” work on the cold water supply line, and the amount of hot water they can produce is determined by the capacity of the heating element built into the device. The more powerful the heating element, the higher the water heater performance. Choosing a flow-through water heater, remember that for its successful operation it is necessary to have a high-power electric wiring, otherwise when connecting the “flow heater” it can break down. If your home has an electric stove or a network with a three-phase power to 380 V. great! If there is neither of these, it makes sense to install a boiler, or, as a last resort, a flow-through water heater of small capacity.

The main advantage of electric instantaneous water heaters. the ability to cook an unlimited amount of hot water without unnecessary time expense, as when using storage-type water heaters. Also, there is no need to conduct regular maintenance of this type of devices, which once again proves the convenience of their use. The minus of flow-through water heaters. High connection power and quite intensive power consumption.

Another important thing to know when choosing a water heater: flow-through models differ in the type of installation. Those devices that are installed directly on the fishing line for a cold water supply (water standpipe), are called pressure water heaters. Flush-mounted devices are installed near the water drawing point (the faucet in the kitchen, bathroom faucet, etc.).п.) And most often they are recommended to install at the cottage.

Before you buy a device, consider in advance what exactly you need a flow type water heater for. It is these data that will determine the power level of your future water heater. If you plan to use the “flow heater” for washing dishes and showers, it will be fine model with a capacity of up to 8 kW. And the hot tub. another conversation. Here already requires a water heater of at least 13 kW, which requires a three-phase power supply with a voltage of 380 V. It is important to remember that in normal city apartments it is not provided: to bring such a voltage in the house or city apartment, you will need to consult a specialist about the power limit of the network.

Now you already know how to choose a flow-through water heater, thanks to our little theoretical course. Now all that is left for practice is to buy a water heater and forget about the problem of hot water supply forever.

Choosing the device: what to look for

Before you go to the store, you should decide on a number of indicators that characterize the work of the water heater:

  • The number of consumption points to which the heated water will be supplied.
  • The total volume of water that will be consumed per unit time when all points of consumption are turned on at the same time.
  • The power of the device, which will provide a sufficient heating temperature.


In addition, already in the store should clarify a number of other issues:

  • The complexity level of the device installation, which can be done independently or with the help of a specialist.
  • The cost of installing the heater (sometimes you can get a discount or even free installation services).
  • The availability and cost of spare parts that may be needed in case of product failure.
  • Duration of the warranty period.
  • Warranty service procedure.

The last point is very important, because sometimes it is quite difficult to obtain warranty repair service from a little-known manufacturer, despite the fact that the warranty is provided. The center that provides warranty repair can be located in a neighboring city, region or even in another country.

The maximum amount of hot water that the device can deliver per unit time depends on the heater capacity. Low-power devices can deliver two to six liters of water per minute. The actual heating with such a device usually takes only 20 seconds.

Usually this amount of water is enough for a quick shower and washing dishes. If your household’s needs are greater than this, you will need a larger water heater.

With this diagram it is not difficult to determine how much hot water a family needs for comfortable living in the house

electric, instantaneous, water, heater, choose

To find out your family’s hot water needs, you can make simple practical calculations using a bucket of known capacity, such as 8, 10 or 12 liters. Run the water at a normal pressure and time the bucket is full.

Dividing the number of liters by the resulting number of seconds and multiplying the result by 60, determine the hot water requirement for that particular point of consumption. You can immediately divide the liters into minutes, so that you do not have to additionally multiply by 60, but if the number of minutes will not be a whole, you should correctly convert additional seconds in tenths / hundredths of a minute. For example:

The same practical measurements and simple calculations should be carried out for each point of hot water consumption, and then sum up the result.

Information about the flow-through water heater performance is contained in the product data sheet, and usually this indicator is specified in the product description on the websites of manufacturers, online stores, in flyers, etc. п.

To determine the capacity of the flow heater, you can use a quite scientific formula that uses data on the hot water demand of the point of consumption/house/apartment. Calculate the capacity of the device using the following formula:

P. flow heater capacity, W;

Q. required hot water flow, l/min.;

t1. necessary temperature of hot water arriving to the point of consumption, 0 C;

t2. temperature of water entering the device for heating, 0 C;

0,073. correction factor.

Here is a rough calculation of the power flow heater for the conditional situation, when the consumption of hot water is 15 l / min, the water temperature at the outlet should be equal to 400C, and at the inlet water operating temperature is on average 100C.

In this case, the flow heater capacity should be P = 15×(40-10)×0.073 = 32.85 kW. It is enough high power, the purchase of such a device is not cheap.

Before you choose a suitable flow-through water heater, you should assess the forthcoming 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 temperature of water that can be obtained with such a device. It all depends on the needs and specific conditions.

For example, if in the cottage hot water is needed only for dishwashing or showering, the model with a capacity of up to 8 kW is enough. Such a device is quite enough to solve these small household tasks.

If you need hot water for a large house, especially throughout the year and not just in the summer, you have to consider devices with a capacity of 18 kW or more.

Evaluate also the location of hot water consumption points. Usually, if the shower stall and the kitchen are located next to each other, it is possible to use a single low-power device for these two points.

True, the hot water will go to only one consumer: either in the shower or in the kitchen.

The diagram clearly shows the features of the flow heater installation. With the location of the device and the order of its connection should be decided before buying

If funds allow, you can increase the comfort in the house with two small capacity water heaters. One in the kitchen and one in the bathroom or shower.

They do not occupy much space, so the presence of two devices will not create big problems. For the shower, it makes sense to buy a water heater, equipped with a remote control unit. However, the device can be placed directly in the shower.

These devices are usually designed to work in conditions of high humidity, so it is not afraid of splashing.

Some models of flow-through water heaters are equipped with a block for remote control. Such devices are very convenient to use in a shower cabin

Overview of popular manufacturers and models

Manufacturers offer a wide range of flow-through water heaters with different design, purpose and technical characteristics.

The non-pressurized model is suitable for country houses. The device is sensitive to the temperature of the incoming water. The manufacturer does not recommend feeding the iced liquid directly from the well. It is desirable that the incoming water is heated to at least 15 o C. Inside the water heater is built a safety valve, as well as protection against overheating. The power of the heating element. 3,5 kW. Includes shower head with flexible hose. Water flow rate. 1,9 l / min.

The device flow electric water heaters

All flow-through electric water heaters work according to the same scheme: the flow of cold water moves through an electric heating element, where it is heated to a predetermined temperature. This characterizes the similarity of pressure and non-pressure type devices:

  • The heating element is the heating element. It turns on during the start of the water draw. Heating time depends on the power of the heating element and varies from three seconds to two minutes.
  • The pressure switch is actuated at the start of water extraction. At this time, voltage is applied to the heating element.
  • The regulator allows the user to set the temperature. The unit will continuously maintain the set parameter until a change is made.
  • The breaker protects the heating element from overheating. Power supply is cut off at a critical temperature.
  • Pressure stabilizer protects the appliance against water pressure fluctuations.
  • The water hardness value in all regions is abnormal. An activator helps to prevent the formation of limescale on the heating element. Magnetic treatment of the flow of liquid through the appliance.

A slightly different scheme, in which the role of the reservoir for water is played by a copper tube with a heating element inside. This is how the Themex System, Etalon System, Edisson System, etc.п.

The device flow-through water heater a certain model can differ only in type of heating element, control system and the ability to work with the required water pressure.

Rating of the best instantaneous electric water heaters

What flow-through water heater would you recommend??

The editorial team of the site has prepared a list of the top 10 models of flow-through water heaters, working with electricity. It can be found below. The list was formed based on the analysis of ratings and reviews that customers gave this or that model on popular product-aggregator sites. We remind you that you should not take this list as the absolute truth in the last instance. But it is quite possible to be guided by the editorial choice when making a purchase. So, what water heaters more often write good words about?

Timberk WHEL-6 OSC

Timberk WHEL-6 OSC

Small and handy heater, which is great for a rental apartment or a small family. The device is suitable for installation on a single point of water intake.

This model has a capacity of up to 4 liters per minute and consumes 5.5 kW. Its dimensions are quite small. only 271611 cm. Convenient overheat protection and heating temperature limitation feature will prolong the life of the model and prevent it from failing during constant use. It comes with a hose, shower head and faucet. Can be installed on the wall.

As users write about the model, this water heater is an ideal option for a rental apartment or in the conditions of a limited budget, as it costs very inexpensive. But at the same time the device performs its functions perfectly, it is quite convenient to use. In addition, it is easy to install during the period when you need to heat water, and remove it when the need for the heater is eliminated. Ideal for having hot water at home even during a summer water outage.

  • inexpensive model
  • easy to install and remove
  • small dimensions
  • heats water well
  • overheat protection
  • neat design

Ariston Aures SM 7.7

Ariston Aures SM 7.7

A budget option for a compact but reliable water heater. Mounted on the wall, easy to control and protected from overheating.

Can heat up to 4.5 liters of cold water in a minute and consumes 7.7 kilowatts of energy. Max. heat up to 55 degrees. Enough to comfortably take a shower or wash the dishes. Dimensions are small 301810 cm. Installation is done with the bottom feeder, installation. on the wall. The model has overheat protection, indicators that tell you whether the heater is on and ready for use.

As customers note, this heater is very easy to install and heats water quite well. But it is necessary to connect it to the network carefully and correctly, according to the instructions, otherwise you can ruin the device. The appearance does not spoil the design of the bathroom at all. Water flows at a sufficiently large pressure, so you feel comfortable.

  • inexpensive model
  • small dimensions
  • Warms water well
  • good water pressure
  • Availability of various indicators that inform you about the condition of the heater

Atmor Lotus 5 shower faucet

Atmor Lotus 5

Slightly less powerful heater than the above described, but heats water better and performs its functions perfectly. The device is designed for one water intake.

The capacity of this version. 3 liters per minute, and the heating of the liquid is made to 65 degrees. The heater consumes 5 kW of power and must be connected to a standard 220 V mains supply. Dimensions are compact. 312610 cm. Everything you need for comfortable use is included. a hose, a tap and a shower head. Can be mounted horizontally on the wall. Convenient mechanical control allows you to easily turn on and off the heater. There are also protection programs against overheating and operation without water.

As buyers write, the device copes with its tasks perfectly, but has certain design flaws. for example, the plastic thread, which is not reliable. It can be under tightened and leave a leak or over tightened and break, overdone with force. There are several operating modes, and the water pressure is sufficient to comfortably use the device. The device heats water quickly.

  • inexpensive model
  • small dimensions
  • heats water quickly
  • easy assembly
  • ample water pressure
  • water heating up to 65 degrees

What’s The Best Water Heater Sold At Lowe’s?

Zanussi 3-logic 5,5 TS (dushkran)

Zanussi 3-logic 5,5 TS

electric, instantaneous, water, heater, choose

Small compact reliable model with mechanical control, which will provide you with warm and even hot water at the time of shutdown. The device is reliable. it is made by a company whose products can be trusted and has all the necessary safety features.

European manufacturers

There are several manufacturers of electric boilers:

  • Electrolux. the Swedish giant manufacturer of household appliances. Produces high-quality electric equipment designed to work with tap water. Electric flow-through water heaters models are of high quality, but at a very “biting” price.
  • Aeg is a company from Germany that started its business back in 1887. So among other companies on the list AEG is the oldest of all. In 1996, due to a number of circumstances, the company was absorbed by Daimler AG, but the company still continues to produce, although already as one of the subsidiaries, which managed to maintain its world-famous brand.
  • Thermex is a relatively young company, which will specialize in flow-through water heaters. Most of this brand’s lineup is, of course, filled with similar water heaters for homes and apartments, but there are also storage boilers that will take the place of the former if necessary.
  • Timberk is one of the youngest manufacturers of quality boilers. This Scandinavian company is about 20 years old. The quality of products from the company Timberk initially high, for this reason there are and will be hopes for a long period of its use.
  • Zanussi is an Italian company that was founded in 1916. Initially it was focused on a completely different sector. ovens, washing machines, as well as household appliances. In 1984, the company was unexpectedly sold to the concern Electrolux, under which they now continue to operate. Zanussi products are distinguished by their high quality, ease of operation and reliability
  • Polaris, LG, Bosh are two famous companies that produce high-powered devices. They have a common minus. very strict, almost impossible requirements for the electric network and laid cables.
| Denial of responsibility | Contacts |RSS