Faucet water heater: advantages and disadvantages, principle of operation

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

Comparison of different heaters

Shutting off the centralized hot water supply, called preventive, has become a common occurrence for city dwellers. For those who live in a country house or in a temporary country house, choosing a convenient and effective way to establish hot water supply has always been relevant.

A gas boiler with a supply of heated water in a storage tank seems to be the right choice for a cottage. Where there is no gas supply and for a large number of water points, it is more reasonable to install an electric storage water heater of the required volume. Flow-through heaters of only higher power can serve several consumers - the kitchen and the bathroom - at the same time.

A device in the form of a mixer with a built-in instantaneous electric water heater is appropriate where a small amount of hot water flowing from one tap is sufficient. Usually this is a country house. It will also come in handy as a means of surviving the summer periods when the hot water supply is turned off in a sparsely populated city apartment, provided that electricity prices are not critical.

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.

How to choose?

Before buying a device, they determine for what needs it is being purchased, how much water is planned to be heated? When choosing an instantaneous electric water heater for a tap, pay attention to the following items:

• power;
• availability of a certificate;
• what the body is made of;
• manufacturer country;
• drain diameter;
• the presence of a mesh on the outlet tap;
• the ability to install a reliable filter in the device;
• temperature control method;
• availability of protection against water hammer;
• fastening method;
• design.

The adjustment lever can be located on the side or built into the body. There is no fundamental difference in this. Which option to choose depends on personal preference.

For a small family, low and medium power models of 2-3 kW are suitable. Dachas, new buildings, offices, apartments with intermittent central hot water supply can also be equipped with a device with average performance.

For a family with small children or for using a flow-through tap-heater during the winter, more powerful samples are selected, with a power of 5-7 kW, capable of quickly heating cold water and working with large volumes. These are wall-mounted models with a large stainless steel body.

Self-respecting companies provide their products with quality certificates. Although such faucet heaters are a little more expensive, they have a greater margin of safety and durability.

There is no need to chase affordable Chinese flow-through devices. Cheap heaters can quickly fail and repair or purchase of new equipment will cost more.

Manufacturers offer various configurations:

• faucet only;
• rotating tap;
• faucet + shower;
• shower only.

In samples that have 1 tap, different lengths and shapes of the drain are possible.

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.

Design, operating principle, protection levels

An electric water heater tap is a design similar to a regular mixer tap.

He has:

1. a housing made of metal or heat-resistant plastic that holds:
   heater design,
2. electronics elements,
3. control lever with three positions:
   turning to the right turns on the water in cold mode,
4. the position of the lever directly turns off the tap,
5. turning to the left turns on the heater and after a few seconds heated water runs out of the tap.

Faucet design
An electric instantaneous water heater on a faucet combines an electrical component and running water, which can be dangerous. Therefore, high-quality water heaters have a high degree of protection.

It may consist of the following positions:

• To minimize contact between water and the electrical part of the faucet, the electrical equipment has special waterproof protective shells.

• The tap has a built-in device called an RCD. It will turn off the electric heater if the voltage in the network exceeds the norm or a breakdown occurs in its electrical part. This function protects the user from electric shock and the device itself from burnout.
• If, when opening the tap, the water pressure is too low (less than 0.4 atm.) or no water is supplied at all, the automation will turn off the heater. The same will happen if the water pressure is too high (7 atm.).
• When heating water, its temperature does not rise above the set parameter, usually 60 °C. This function is monitored by a special sensor. When the limit value is reached, it turns off the heating; when the temperature drops, the heating element turns on. This protects the water from overheating.
• The silicone damper in the crane design provides protection against water hammer.

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.

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 2021.

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.).

Description and selection of models for kitchen, bathroom, shower

This device is capable of providing autonomous hot water supply. Of course, there is a certain model range here. But the most popular brands are Aquatherm and Delimano. The Delimano brand can offer elegant devices that will easily fit into your home interior. Metal, plastic on the outside, and ceramic parts on the inside help to operate the device reliably.

These water heating taps have enough power within 3.5 kW. The devices have the functionality required by the consumer, which is perfectly applicable both in the kitchen area and in the bathroom.

However, the Aquatherm water heater can heat water up to 60 degrees. Can maintain a stable temperature in any environment. Therefore, this device is often chosen for country and garden conditions.

Also, the brands “Supretto” and “Kruss” are still popular. These devices may not boast the best performance, but their diverse range of designs is impressive. For example, heat-resistant plastic allows the client to count on long-term use of the product.

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

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

Installation and connection

Installing a faucet with a heater is no different from installing a mixer. The main difference is the cable for connecting the power supply. Designers have provided fastening elements that make it invisible and do not interfere with the use of the sink or shower.

The combination of water and electricity is deservedly considered deadly, so you should reduce the risk to nothing: buy heaters from certified sellers, carry out installation strictly according to the manufacturer’s instructions. It is important to check that the electrical network complies with the necessary requirements of the flow-through heater manufacturer; when connecting the power, be sure to ground it .

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

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