Instantaneous electric water heater on tap: selection tips + review of the best brands

Amir Gumarov
Checked by a specialist: Amir Gumarov
Author: Oksana Chubukina
Last update: April 2019

To quickly solve problems with hot water supply, a technical device was created - a flow-through electric water heater on a tap. A useful device at home differs from its predecessors in affordable cost, compactness and ease of installation.

The efficiency of the device will be appreciated if its technical characteristics correspond to the needs of the user and operating conditions.

Feasibility of using a heated crane

Instantaneous water heater for a tap is the most compact electrical appliance providing hot water supply. The feasibility of using a compact device depends on the intensity and operating conditions.

To determine whether the mini-heater is suitable for your own needs, you should compare the arguments for and against.

The main advantages of a compact water heater on the tap:

  1. Compactness. This argument becomes decisive for small rooms. The heater takes up the space reserved for the mixer for mounting on the sink in the bathroom, kitchen sink or countertop.
  2. Heating rate. Depending on the model’s power, the warm-up time to a comfortable temperature ranges from 10-30 seconds. They cannot boast of this quality. storage water heaters - the boiler must be turned on in advance, at least 30 minutes before use.
  3. The constancy of temperature. In technically advanced heaters, the heating process is monitored by electric sensors that control the incandescent level of the heater.
  4. Aesthetics. The variety of the model range allows you to choose a water heater for a certain interior style.Manufacturers offer specimens of different colors with a glossy or matte effect, unusual shapes of the spout and valves of the original geometry.
  5. Easy installation. The technology is almost identical to the installation of a conventional crane. The difference lies in the need to supply power and ground the device.
  6. High efficiency. The thermo-faucet functions in fact - it carries out heating only in the process of using the mixer. At rest, electricity is not consumed.

The advantage of a small-sized module is its cost. The price of a water faucet is less than a full-sized electric or gas flow, especially on a storage boiler.

Instantaneous water heater
The choice between the storage tank and the water faucet is based on an assessment of needs: the required volume and temperature of water heating, mode of use, availability of free space, etc.

However, manufacturers of flow-through devices declare the efficiency of devices, focusing on the consumption of electricity exclusively at the time of use of water. Whereas the storage boiler operates in the mode of maintaining the set temperature - the unit turns on every 20-30 minutes.

Power consumption
The main minus of the flow path is high energy intensity. The average power of the heating element is about 2.5-4.5 kW. With regular use of the water heater, electricity bills will increase significantly

Additional disadvantages of a crane water heater:

  1. Limited bandwidth The volume of heated water is 4-6 l / min. For comparison, the performance of the gas column is approximately 1.5-2 times higher.
  2. High network load. Installing a groover in a building with old wiring requires a separate cable. Regardless of the state of the power supply network, the streamer is necessarily connected through a reinforced outlet connected to an RCD.
  3. Maintenance of one water intake point. It is not possible to divide the incoming volume of heated water into several streams. To organize hot water supply of several points, it is better to purchase a storage heater or a wall groove.
  4. The complexity of the repair. In the event of a breakdown, it is problematic to restore the operability of the portable module - in the distribution network of repair kits for such models is an order of magnitude smaller than for a wall-mounted electric heater.

Pondering a purchase shower groove or for a kitchen faucet, it should be noted that low-power appliances can increase the temperature of water by 25 °. This indicator is enough in the warm season. With the onset of cold weather, with a significant decrease in the temperature of tap water, it is unrealistic to obtain the desired 35-40 ° C.

Pressure dependent
Modifications of the flow driver without adjustment perceive the low pressure of water as its complete absence - the flow module simply does not turn on

Despite the indicated drawbacks, it is advisable to install mini-heaters in the following situations:

  • instability of centralized hot water supply, when interruptions in the network are short-term - not more than a month;
  • seasonal water consumption - inherent in country houses, country cottages;
  • organization of water supply in the summer kitchen of a private household;
  • in hairdressing salons, beauty salons;
  • in kitchens in buildings with individual gas heating - turning on the boiler for washing dishes is not profitable.

In a word, the installation of a heated tap is fully justified if hot water supply is not required continuously and in a limited volume.

Features of the device and the work of the “protochnik”

A miniature water heater looks similar to conventional mixer, a distinctive feature is increased dimensions. A water-heating element and many equipment responsible for the safe operation of the heat nozzle are hidden in a heat-resistant housing.

Water heater device
The main working parts of a heated crane: a powerful heater, a sealed cylinder with holes, a thermostat, a water intake relay, hydraulic protection, a control lever and a spout. Some models are complemented by an electronic display and temperature indicators

Inside the module there is a cartridge mechanism for adjusting the flow of water and a tank with a powerful electric heater. It is the small internal volume of the tank and the high power of the heating element that explains the ability of the heater to reach the desired temperature in a matter of seconds.

The principle of operation is extremely simple. Water enters the heating cylinder, contacts a heated coil and is already heated is supplied to the mixer spout.

In the design of the instantaneous electric water heater for the faucet, the so-called “safety group” is provided.

The complex includes the following elements:

  1. Head sensor. Disables the heater if network pressure does not exceed 0.004 MPa and blocks the operation of the module when the value increases above 0.7 MPa. Excessive pressure is dangerous for internal elements.
  2. Flow sensor and thermal relay. Provide protection of the tubular heater from combustion when the water supply is cut off. In addition, the flow sensor is responsible for instantaneous heating after the tap is opened.
  3. Auto fuse. In the event of a power surge in excess of normal or with a short circuit inside the module, the current supply is interrupted.

Most groovers are equipped with protection against water shocks - elastic plastic and a silicone damper are placed in the device case.

RCD of a flow heater
Responsible manufacturers complement the products with built-in RCDs for maximum user safety and preventing electric shock during the breakdown of the heater

Types of compact electric heaters

Modules of hot water supply for a crane are usually divided into two types: a removable heating nozzle and mixers with a built-in heating element. Universal wall grooves are often used to supply warm water to the sink of the wash zone and to the kitchen sink.

Separate nozzle for crane

The module is installed on the spout of a previously mounted mixer. The main advantages of the mini-block: low cost, the ability to connect to an existing crane, compactness. The disadvantages are obvious - as a rule, the thermo-block has a small capacity and productivity (about 4 l / min).

Attachment on the crane
Small sizes do not allow to equip the nozzle with a full-fledged security system and a more or less powerful heating element. The efficiency and reliability of the device is quite low

As a protective element, the module is equipped with a temperature sensor that prevents overheating of the internal elements.

Instant water mixer

Heated taps occupy a large part of the segment of flowing miniature water heating units. The device operates in three modes:

  1. Hot water supply. Mixer handle turned to the right. The electrical system comes into action, providing an influx of warm water.
  2. Cold water supply. Turning the lever to the left side disables the electric part of the tap - cold water runs from the mixer.
  3. Shutdown. Joystick handle in the central lowered position - the heating valve is idle. The circuit is de-energized, water supply is cut off.

In most flow-type models, the water temperature is controlled by changing the pressure. Moving the lever vertically allows you to choose a heating mode with an error of 0.5-1 ° C.

Heated faucet
A water faucet costs more than a separate nozzle. But the price difference pays off with increased instrument performance and a high degree of security

Wall-mounted “groove”: pressure and non-pressure model

A universal water heater can be connected to the tap.

The electrical module has a number of distinctive features:

  • the ability to service several water points at the same time;
  • high degree of protection;
  • productivity is up to 7-9 l / min that is more in comparison with nozzles on the crane and mixers heaters;
  • wall mounting.

The case is made in the form of a capacious box. The increased area of ​​the heating element explains the improved heating characteristics of the device.

Wall mounted
The unit is attached to a wall nearby a crane. In order not to clutter up the space for a mirror or a spacious shelf, the module can be placed under the sink

There are two types of wall grooves:

  1. Pressure Hot water from the heater is supplied to the distribution network, and then to the water intake points. The power of the units is 3-20 kW, one-and three-phase connection is possible.
  2. Pressureless. Designed to service one point of water consumption - water from a mini-boiler is immediately transmitted out through a tap. Power devices - 2-8 kW.

When falling sharply pressure in the water system the water flow through the non-pressure module will slow down - there is a high probability of receiving very hot water at the outlet. In devices with a temperature sensor, this problem is solved.

Criteria for choosing an electric heater for a tap

Having decided on the type of device, you should calculate the appropriate module power and compare the technical and operational characteristics of different models.

Unit power and performance

The decisive factor in choosing a flow path is its power indicator. The required value is determined based on the priority purposes of use: a kitchen sink, a sink in the bathroom, etc.

Calculation of heater power
When using a flowing electric heater for several points of water consumption, the total power is selected according to the maximum water intake. The table shows the estimated water flow for different needs

Power is determined by the formula:

W = V * (T2-T1) /14.3where:

  • W is the calculated power of the portable heater, kW;
  • V - water consumption or unit capacity, l / min;
  • T2 - the desired temperature, depending on the needs, ° C;
  • T1 - temperature of tap water (summer value - about 15 ° С, winter - about 5 ° С);
  • 14.3 is a constant.

If simultaneous consumption from several water points is planned, the total figure increases by 1.5 times.

Calculation example. It is required to choose a groove for a kitchen sink, the optimum temperature for use is 45 ° С. Based on the table, a model with a capacity of 4 l / min is suitable for a sink for washing dishes. For the objectivity of the calculation, it is better to use the average annual water temperature in the highway - about 10 ° C.

W = 4 * (45-10) / 14.3 = 9.79 kW.

Heater performance
The performance of the hot water module is calculated using the inverse formula. The greater the power of the unit, the more warm water it will give out. However, the load on the network will increase significantly.

Having picked up the power of the heater, an important question arises: are there enough wiring options? In buildings of an old construction with traffic jams on 16 A it is impossible to establish a groover more than on 3,5 kW. New homes with 32 A and 40 A meters will pull a water heater up to 6 kW.

Type of heating element

The heart of the flow module is TEN. In the classic version, the heating element is assembled in the form of a spiral to increase the contact area of ​​water.

A heating element
The operation of the heating element in “standing” water is unacceptable - the absence of continuous washing with a cooling fluid stream and the accumulation of hot water will lead to its burnout

In addition to the spiral shape, the heater can be made as a curved or straight tube with an electric heater enclosed inside. Water circulates through the coil. Closed heating elements better cope with the formation of scale.

The efficiency and durability of the heating element is largely determined by the material of its manufacture.

Possible options:

  • TEN with a copper or anodized shell - provide good heat transfer and protection against scale;
  • ceramic tubular heater - highly efficient, durable and expensive;
  • spiral blocks protected by glass - belong to the premium segment, are not demanding in maintenance, when scale is formed, the heat transfer rate is partially changed.

The most technological solution is spiral induction heat exchangers. In addition to efficient heating, eddy currents induce vibration in the central core. Such an effect is the prevention of scale formation.

Degree of electrical safety of the device

In addition to the presence of built-in elements of the “protection group”, the outer shell must also comply with safety standards.

Two indicators should be noted:

  • protection class of an electric device against electric shock;
  • IP index - marking the protection of the case from external influences.

The protection class displays the requirements for connecting the heating module and the way to prevent electric shock. A flowing water heater is characterized by a protection class of 1. Safety is ensured by the obligatory grounding of the conductive parts and the main insulation.

Electrical Appliance Protection Index
Interpretation of the IP index: the first value is the enclosure's protection against penetration of solid particles, the second figure is the resistance of the outer shell to liquids. For water taps, IP25 is considered sufficient.

Accounting for additional parameters

In addition to the listed characteristics, when choosing a hot water supply module, you should consider:

  • management method;
  • case material;
  • minor functionality.

The whole variety of flow paths is divided into mechanical and electronic units. The former are otherwise called hydraulic. The mechanics are typical for budget-class modules and mid-range devices.

Type of control
Usually, a three-stage switching of operating modes with the possibility of adjusting the pressure and water temperature is provided. Manual control by lever

The disadvantages of the method: the inability to fine-tune the temperature and save the selected parameters. The electronic mechanism with the help of sensors and microprocessors independently supports the specified settings, adjusting the operating mode to the current indicators of network pressure and temperature.

The product is regularly exposed to high temperatures, the chemical composition of the passing fluid. Therefore, the housing must have heat resistance and sufficient strength. Enamelled, polypropylene and copper “shells” have proven themselves well - materials are resistant to aggressive environments and temperature extremes.

Body material
Costly models are equipped with internal anti-scale protection. The role of the barrier is performed by the "anode", the life of the element is about 6-7 years

Some built-in secondary functionality provides comfortable use of a water faucet.

Useful options include:

  • the presence of an informative display, indication of the operating mode;
  • limiting the temperature of heating and cooling;
  • programming ability;
  • work with different power;
  • color illumination.

Also, some manufacturers equipped their products with a practical function - locking the heater from children.

Brand Model Overview

Water heating taps of well-known brands are in special demand:

  • Delimano (Ukraine / Italy);
  • Supretto (China);
  • Aquatherm (Russia);
  • Rapid (China).

Delimano The company offers an instant water heater "Aquasystem". The module is presented in the form of a cylindrical block with a crane-regulator and spout.

Water heater Aquasystem.
Specifications: gander length - 22 cm, dimensions - 12.5 * 7 * 7 cm, case material - plastic / metal, pressure - 0.04-0.6 MPa. In addition to the thermo-tap, the kit includes: connection insert, support ring, gasket and fixing nut

Distinctive features of Aquasitem:

  • fast heating up to + 60 ° С;
  • the presence of a temperature controller;
  • indicator light;
  • connecting the cord to the back of the case;
  • Warranty - 365 days;
  • estimated cost - 25-30 cu

Supretto. The crane is made of heat-resistant high-strength plastic, the internal elements are metal. The device is equipped with the necessary safety system - the construct suggests grounding, protection against overheating.

Supretto Crane
Supretto performance is dependent on heating temperature. Without the heating function, the throughput of the device is 1.5 l / min, when heated to + 50 ° C - 1.3 l / min

There is an indicator on the front wall of the case, the control lever is located on the side. The cost of a miniature electrical appliance is about 30 cu

Aquatherm. Single lever heating valve of Russian assembly. It features a high arcuate spout, the presence of a water filter and plastic aerator with the option "Anti-Calcium".

Aquatherm Heater
Additional features: ceramic cartridge, crane turning angle - 360 °, protection against overheating. Mains parameters: frequency 50 Hz, single phase

The model is available in 4 colors: blue, burgundy, white, beige. The issue price is 50 cu

Rapid Brand-name water heaters have multi-level protection. In economy models, the temperature is controlled by the joystick. In more expensive options, the heating mode is controlled by an electronic sensor.

Features of Rapid flow-through crane modules:

  • TEN from heat-resistant polymer;
  • heating ceramic disc can function continuously up to 5000 hours;
  • heating temperature - 30-60 ° C;
  • grounding of the main body.

In all models, the heating elements are protected by an insulating layer.

Rapid Water Heater
Features of the heated crane RLD-01 from Rapid: weight - 1 kg, heating speed - 5 seconds, voltage - 220-240 V. Estimated cost - 55-60 cu

Among wall-mounted groovers are popular models of firms: Kospel, Electrolux, AEG, Bosh, Termex.

Conclusions and useful video on the topic

To summarize and generalize the theory presented, we give visual video reviews on the installation, practicality and effectiveness of thermo-taps.

Step-by-step installation and testing of the Delimano heater:

Test drive Rapid heated mixer, heating rate rating:

A water faucet in some situations is the best and only possible option for organizing hot water. In order not to make a mistake in the choice, you should really evaluate your own needs and calculate the required power. Important purchase criteria are the safety of the device and the reputation of the manufacturer.

Please write comments in the block below. Tell us about how a faucet with a water heater works in your home or at the cottage. Ask questions, share useful information with visitors to the site, publish photos on the topic of the article.

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Visitors Comments
  1. And I had previously been biased towards these instantaneous mini-water heaters. And now I read the article more closely, but never imagined the real situation when they are needed. The only cases where systematic fan cut-offs of hot water systematically occur, but even then you need to take a boiler, and not this toy. Cons for me: the need for a separate power supply, a separate RCD, aesthetically not very, an extra charge for electricity. I did not see the pluses.

    • Expert
      Amir Gumarov
      Expert

      Each thing has its own niche. Not everyone can afford to buy a boiler for a summer cottage. And they are very lacking warm water. In this situation, this flow heater is applicable. The cost of it, in comparison with the boiler, is simply ridiculous. Connect is no more difficult than a conventional mixer.

  2. Valentine

    In the cold season, such a device on the crane has become a real salvation. The water is very cold, and the dishes have to be washed every day. We installed a special water heating nozzle. Now I can’t get enough, I open the tap, and hot water is running from it. Perfect for those with interruptions in hot water. It is compact, does not take up much space, looks pretty, does not spoil the overall design of the kitchen.

  3. Vladimir

    And to think of making such a faucet but with weak hot and cold water? This is exactly what you need for a period of shutdown of hot water. And so it makes no sense. Really the brains of the engineers do not work. There is hot - it works with a mixer, no - it heats for two weeks. Is it really that hard to implement.

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