Electric instantaneous water heater: device, selection criteria, review of models

Readers have probably heard about such a device as a heated water mixer. An increasing number of craftsmen and homeowners prefer to use faucets with a similar device in their homes.

What is this design, what determines the popularity of the mixer and how justified is its use at home? We will try to answer the most important questions for users and try to determine how profitable it is to use such devices in your own home.

Typical design

In a heating tap, the heating element is located in the mixer body. Typically the design includes the following:

• cold water connection,
• ceramic cartridge mixer for cold and hot water,
• housing with spout and cartridge control handle and switch,
• spiral heater, but in powerful 380 V devices it is possible to use several heaters.
• electric heat switch paired with a control handle.

This is a basic mechanical control based on the “on-off” principle.

But for powerful 380V models, it is also possible to adjust the heating power, usually in steps, according to the number of heaters simultaneously turned on. This means that the water temperature is also regulated at the same flow rate.

More expensive models can also be equipped with an electronic display indicating the water temperature and sensors for turning on the heaters, depending on the actual water consumption.

Instant water heating taps can be designed to work with a 220 V or 380 V network. The power of the first is in the range of 2.5 - 6.0 kW, and the power of the second three-phase can reach 25 kW.

What is the temperature of the water from the heating tap, is it sufficient for running a bath?

Faucet manufacturers indicate abstract heating temperatures of +60 degrees and 80 degrees, without notifying either the initial temperature or the amount of heated water per unit of time. The main characteristic of flow-through heaters remains heating performance - the number of liters of water heated to 25 degrees. For example, the inlet temperature is 8 degrees, the outlet temperature is 33 degrees, with a flow rate of 3 liters per minute. But you can get a higher temperature, for example, a hot 40 - 50 degrees, simply by reducing the flow rate by a third or half...

In fact, the popular 3kW cheap water heater taps provide only a thin warm stream, a small shower for washing dishes. It is impossible to draw a hot bath with them; the water will simply cool down during the drawing.

To set up a bath, you need a minimum 15 kW flow-through heater with three-phase power, but preferably even more powerful...

Next, we compare the advantages of a heating tap and a storage boiler.

A hot water tap has the following advantages

• The minimum price of the equipment and minimum dimensions - it’s just an ordinary mixer with a slightly larger body, inside of which there is a heating element.
• Extremely easy installation that does not require reworking the system - just dismantle the faucet on the sink and install a heater tap in its place, and also connect it to the electrical network, for 3 kilowatts - just plug the plug into the socket.
• Better energy savings compared to a boiler. Almost all the energy from electricity will be used to heat water, which is immediately supplied to the consumer. With a boiler, when it cools down, it can waste 30% of the energy (spent on heating the home) from each heating.
• Hot water is generated immediately at will, and its quantity is conditionally infinite - as long as there is a supply of cold water and energy. The boiler is running out of warm water; its not so powerful heater cannot heat it up on the go. To get the first heating with a boiler you need to wait a long time, usually at least an hour.

Purpose, advantages and disadvantages of an electric tap for heating water

The main purpose of an instant water heating faucet is to provide the consumer with hot water at any time when the need arises. The advantages of this design are:

• compactness, allowing the device to be placed directly at the point of water collection;
• the ability to instantly heat water immediately after opening the tap;
• ease of installation and maintenance;
• the ability to maintain water temperature in a given range;
• high efficiency of use;
• variety of models - allows you to choose a device in accordance with the design style of the room where it is installed;
• relatively low cost compared to other types of water heaters.

A flow-through tap-water heater can be placed in any room where there is a need for hot water

Among the disadvantages of devices of this type, the following should be noted:

• significant electrical power requires the installation of a separate group for connection to the electrical network;
• Possibility of use for only one water collection point;
• the volume of heated water is limited and determined by the throughput of the tap;
• the difficulty of performing repair work at home on your own.

A flow-through tap-water heater is convenient to use and is used in situations such as:

• For seasonal use - when the centralized hot water supply (DHW) is turned off.
• To create local hot water networks (country house, dacha, etc.).
• For ease of use when the house (apartment) is equipped with gas heating appliances, and it is not advisable to turn them on for a short period of time.

Instantaneous water heater - electric for faucet with shower

Homemade designs

Long before the appearance of non-freezing taps in retail chains, many users solved the problem on their own. To do this, they used two interconnected ball valves installed on opposite sides of the wall. The internal one was connected to the water supply system, and the external one served as a point of delivery.

This kit worked as follows:

• the internal tap opens;
• The tap opens from the outside and water is drawn in;

• after the water has been collected and is no longer needed, close the internal tap;
• When the remaining water drains, close the external tap.

It is necessary to install such a dual system with a slight slope outward so that the remaining water completely drains from the pipe. Similar devices are still used today. They are simple and cheap, but have a drawback - to work with them you have to walk and open/close taps on opposite sides of the walls.

Design features and principle of operation

The principle of operation of a flow-through electric tap-heater is similar to the operation of an ordinary boiler, when water, in contact with the heating element, which is an electric heating element, is heated, after which, under the influence of pressure in the water supply network, it flows out of the open tap. The design of such a device is shown in the following figure.

Design of an electric tap-heater: 1 – tap body; 2 – heating element (electric heating element); 3 – faucet spout equipped with a mesh filter; 4 – temperature sensor of outflowing water; 5 – temperature regulator; 6 – cartridge 7 – pressure sensor; 8 – light indicator of heating element operation.

For your information! The body of such products can be made of metal or plastic, and the flask in which the heating element is located can be made of copper or composite material.

The electrical power of different models can vary greatly and range from 3 to 27 kW, which should be paid special attention to when choosing a specific device, because The ability to connect to an existing electrical network depends on this indicator. The presence of significant electrical power allows you to heat water in a short period of time, a few seconds, after which the water temperature is maintained at a given level and is controlled by a temperature sensor, and is regulated by a special regulator and the amount of water passed per unit time. When the tap is closed, the pressure sensor turns off the power supply circuit of the heating element and its operation stops.

Water heater attachment for faucet

Related article:

Storage water heater: which company is better? A separate publication provides an overview of popular brands and models with prices, as well as device characteristics.

Varieties

Antifreeze taps of imported and domestic production are available for sale.

They can be made in different design types:

for wall installation

These are models designed to remove the spout from the room to the outside (faucet in the wall);

hydrants

These are models for vertical installation. They are connected to underground insulated pipelines and act as an external outlet with a valve for water supply.

In addition, the working part of the crane can be made of different materials:

cast iron

These are inexpensive and reliable models that are not afraid of corrosion;

brass

Such models are considered the best among analogues made from other materials;

stainless steel

High-quality and durable devices.

There are also low-quality crafts from Southeast Asian countries on the market. They are made of silumin - a weak and low-quality metal. The service life of such cranes is short. It’s not easy to distinguish them - they have the same chrome coating and look no different from high-quality models.

Therefore, the only way to verify the origin of the crane is to read the documents and check for a certificate. Usually, sellers present all documents without any questions asked. If there are problems with them, it is better to look for a suitable model in another store.

Types of electric flow-through water heater taps

Instantaneous water heaters, made in the form of a tap, come in several types:

• attachment on the crane;
• mixer;
• separate device mounted on the wall.

Nozzle for heating water on the faucet

Such a device is installed on a water tap or mixer installed in the cold water supply system of a house, apartment or other building where the presence of warm water is necessary during its operation (domestic, administrative and other facilities). Distinctive features of this type of equipment are: ease of installation and use. In addition, the advantages of nozzles for heating water on the tap include such indicators as:

• low cost;
• compactness.

Among the disadvantages of the design, low performance due to the low electrical power and throughput of the device should be noted.

Instant water heater Delimano

Mixer – water tap with instant water heating function

A mixer tap equipped with a heating element can be used in two operating modes:

• cold water supply - when the heating element does not turn on and cold water flows from the tap;
• hot water supply - the heating element is turned on and heated water flows from the tap.

For your information! The temperature regime on devices of this type is regulated by changing the water pressure, while the heating error is 0.5-1% of the set values.

Stand-alone wall-mounted unit

This type of device, which provides instant water heating, has in its design a container that serves to increase the volume of water heated per unit time.

The presence of a storage capacity is the main difference between this type of device and the designs discussed earlier.

Instantaneous water heater, made in the form of a separate block mounted on the wall

In addition, such devices are distinguished by a high degree of protection and significant electrical power, which allows connecting more than one water intake point, as well as greater productivity than similar devices of this type (nozzle, mixer). Depending on the method of connection to the water supply network, wall-mounted devices are of two types:

• pressure - heated water is supplied under pressure to the hot water system, where it is disassembled;
• non-pressure - heated water after the storage tank immediately flows to the tap.

Expert's point of view

Kirill Mikhailov

Head of the Water Supply and Sanitation Group, GRAST LLC

Ask a Question

“Pressure models have significant electrical power and can be connected to a single- or three-phase network, and there can be several water collection points. Gravity models can only serve one water intake point.”

Installation options for a wall-mounted flow-through heater of a non-pressure type

Related article:

Flat storage water heater 50 liters. Advantages and disadvantages, device, connection, review of brands and models, recommendations from experts - in our publication.

Installation subtleties

The tap-heater of running water is installed on a cold water supply. Certain models can also be connected to hot water supply, then the tap can be used both as a regular mixer and as a heater, depending on the prevailing conditions. Technically it looks like this :

1. Grounding and a separate branch of electrical wiring are done. The required cable size is at least ½ inch.
2. A connecting coupling is screwed to the pipeline, the coupling is brought to the sink or bathtub, and a heater tap is screwed into it.

Criterias of choice

When the question arises about creating a local hot water system for a country house or apartment and to solve it the choice fell on a water heater tap, then the selection criteria in this case will be such indicators as:

1. Electric power. The possibility of placement in a particular installation location depends on the amount of power. This is due to the permissible load currents of the electrical network, both in relation to the group line through which the heating element is connected, and the general house line, regulated by the electricity supply contract.
2. Performance. This indicator characterizes the ability of the device to heat and pass through its structure a certain amount of water per unit of time.

   An indicator light informs you that the heating element is working

3. Type of heating element. Heating elements can be made in the form of a coil or spiral, as well as a straight or curved tube through which water circulates, washing the built-in heating element. In their manufacture, ceramic elements and spiral blocks protected by glass are used, as well as copper and other metals that are resistant to corrosion.
4. Degree of protection. This indicator characterizes the device according to the degree of protection against external influences and corresponds to the standard scale for all electrical devices (IP). In addition, this indicator reflects the protection class of the device against the possibility of electric shock during its use (electrical safety - grounding, insulation class).
5. Extra options. These indicators include: the material used in the manufacture of the case and the method of controlling the device, as well as the presence of additional functions.

Premium segment models are equipped with an LCD display informing about the temperature of the supplied water

For your information! Water heater taps are equipped with a mechanical or electronic type of control, while mechanical models are lower in cost and are not able to independently maintain the temperature, while electronic ones belong to the premium segment and provide automatic operation.

Among the additional options available, as a rule, on more expensive models, the following should be noted: backlighting of the jet and light indication, LCD display and programming capabilities, as well as working with different electrical power and limiting temperature operating conditions.

Budget models are characterized by simplicity of design, mechanical control and the absence of electronics in the control circuit

Related article:

Boiler for heating water. Application, design and principle of operation, selection criteria, overview of manufacturers and models, average prices, details of installation on your own - read in our publication.

Benefits of use

If initially such shut-off elements had a strictly limited scope of use, today they are successfully used by owners of private houses and summer residents, who, with the help of such simple devices, have completely solved the problems with using water outside the house. At the same time, freezing of pipes during the cold season is prevented.

The advantages of such anti-freeze taps include the following:

• versatility of use;
• simplicity of design;
• reliability and durability;
• ease of installation.

Today on sale you can find non-freezing outdoor taps from domestic, Chinese, American and European manufacturers. Italian and American plumbing fixtures are considered the best , but they have a high cost, which somewhat limits their popularity on the Russian market. The best outdoor water taps today are “Merrill” and “Woodford”. These are the largest manufacturers that offer the entire line, including for wall and underground installation, shut-off valves are distinguished by excellent build quality, reliability and durability.

If initially such hydrants for installation on the street from domestic manufacturers did not differ in workmanship, today their design has improved significantly, and they traditionally have a low price, which makes them popular with buyers. With equal success, such taps and hydrants can be used both in winter and in summer; mixers are especially popular, which allow summer residents and gardeners to water their gardens with water at the desired temperature.

On average, the cost of Russian hydrants and non-freezing taps is 2-3 thousand rubles. But products from Italian or American manufacturers will cost 5-8 thousand rubles. Provided the correct selection and proper installation, such shut-off valves will last for decades without requiring any maintenance, repair or replacement.

Review of popular models

Flow-type water heater taps, which have an electric heating element in their design, are produced by many enterprises operating in this segment of plumbing fixtures, but the most popular brands in our country are:

“Aquatherm” (Russia) and “Delimano” (Italy-Ukraine), “ Supretto ” and “Rapid” (China). The following table shows the models most in demand among users, their prices are indicated as of the beginning of the third quarter of 2022.

The table does not show all models of the Aquatherm brand; in total, the company offers for sale more than 10 models of faucet-water heaters, differing in design style, location and purpose (kitchen, bathroom, etc.).

Which water heater tap is better, according to the editors of HomeMyHome.ru

Having studied the technical characteristics of the most popular brands, specialists from the editorial staff of the online magazine HomeMyHome.ru came to the conclusion that, in their opinion, when choosing an electric faucet-water heater, it is better to pay attention to the product, and there are several reasons for this, namely:

• a variety of models allows you to choose the one you need both in terms of design style and purpose;
• The color range of devices is also presented very widely. Thus, the KA 001 model has 9 different solutions from white to black, and the KA 25 has four color options;
• models of this brand “lie” in the middle price range of the line under consideration - they are more expensive than their Chinese counterparts and cheaper than their European counterparts;
• The manufacturer provides a 5-year warranty on its products.

The variety of models of the Aquatherm brand allows you to choose the one you need in terms of design style and color scheme

Operating principle of a heated mixer

In the flow-through, water is heated in the most common way - using a tubular electric heater (TEH), which converts electrical energy into thermal energy due to the high resistance of the nichrome spiral located inside it.
But unlike a boiler, this device does not heat water gradually, but immediately, that is, the outlet stream flowing through it already has the required temperature.

You can change the heating level in two ways:

• adjusting water flow:
• by changing the voltage at the contacts of the heating element (there is a special regulator).

The more water flows through the water heater, the lower its temperature will be.

The nuances of installing a water heater nozzle on a faucet

The use of a water heater nozzle allows you to meet the user’s needs for hot water in small volumes without making changes to the water supply system of an apartment or country house, because in this case, there is no need to replace plumbing equipment and perform installation work. However, when installing such devices at the site of use, it must be remembered that:

1. The body of the nozzle must be grounded, for which a 3-wire electrical network is used, in which the third wire is grounding.
2. The design of the device, its mounting hole, must correspond to the spout of the water tap or shower on which it is intended to be used.
3. The cross-section of the power supply line must correspond to the load current of the device used.

Option for a faucet attachment used as a shower

What to do if the sides are mixed up?

Incorrect placement of water supply hoses to the mixer causes great discomfort to many people. A hose with blue spots is used only for installing cold water supply. With red ones - for hot.

To resolve incorrect installation, it is recommended:

1. Close the riser valve.
2. Remove the nut from the distribution socket.
3. Change hoses.
4. Reinstall the hoses.
5. Install new gaskets under the nuts.
6. Check connections for leaks.
7. Open the tap and check the flow.

The tubes must be swapped under the sink. The hot water supply is connected to the left socket. To the right - cold. The system can install universal hoses with blue and red shades. They are suitable for supplying both warm and cold flow.

Features of operation of instantaneous electric water heater

When using such devices, the main features of their operation that should be remembered are:

• the use of filters installed in the water supply network will ensure longer periods of use of the water heater;
• if the water pressure in the supply pipeline is low, you should not use the device at full electrical power;
• The water temperature at the outlet of the water heater tap depends on the pressure and heating mode set by the user.

Models from German manufacturers are distinguished by the presence of a programming system, but are much more expensive than the most popular analogues discussed in this article

Difficulties of winter water supply

Being at the dacha or living in a private house, sooner or later every person is faced with the need to use a water hose on the street. For example, the garden is being watered, a small skating rink in the garden area may be filled in winter, or a car may be washed in an open area. Of course, you can constantly go home and carry water in buckets, but this is not very convenient and does not allow you to take advantage of all the benefits of your own autonomous water supply.

An effective solution to this problem will be a non-freezing outdoor faucet, which has a fairly simple design. This is a reliable locking element, the installation and subsequent use of which does not present any particular difficulty. Depending on their type, size and design, such hydrants can be made exclusively for street use or require a combined installation, when part of the structure with the locking mechanism is kept warm in the house, and the valve with the spout is located directly on the street.

Consumer reviews of instantaneous electric water heater faucet

Thanks to the Internet, complete strangers can communicate and leave their feedback on the use of this or that equipment and household appliances.

This fully applies to plumbing fixtures, which include the water heater taps discussed in this article, and here’s what real users write about them.

Review of the Aquatherm RSKJ-006C model:

More details on Otzovik: https://otzovik.com/review_6533435.html

Review of the Aquatherm KA 001 model:

More details on Irecommend: https://irecommend.ru/content/problemy-s-goryachei-vodoi-bolshe-net

Review of the Delimano model:

More details on Otzovik: https://otzovik.com/review_1405694.html