Choosing a tankless water heater

Why is an electric model better than a gas model?

In city apartments, you don’t have to choose between the two types of devices, as they usually use electric, safer models.

The exception is apartments in which gas water heaters are installed during the process of equipping the premises upon delivery of the house. This applies to "Khrushchev", "Stalinka" and some types of panel houses built in the 60-70s of the last century.

Scheme of the gas column device. A necessary condition for its operation is a water pressure of at least 0.25-0.33 atm (approximately 1.5-2 l / min), otherwise the heating elements will not turn on

In country houses, water is often heated using a powerful floor-standing boiler, but some prefer to use a gas water heater out of habit.

Its use is appropriate for stove heating or in warm climates that do not require the installation of heating equipment.

Electric flowers are considered safer, although their operation is more expensive than using gas water heaters. In addition, with gas heating, an exhaust hood and reliable ventilation are required, otherwise there will be a risk of carbon monoxide poisoning. Savings are considered a plus, since gas prices are lower than electricity prices.

In old-built houses, it is not possible to use a powerful electric type appliance (above 3.5 kW), so you will have to get by with either a weak water heater or a gas water heater. Thus, if there is a choice, consider the condition of electrical networks and ventilation, water pressure, the cost of fuel (gas or electricity).

We invite you to familiarize yourself with the guidelines for choosing a water heater in the article devoted to these issues.

The best gas instantaneous water heaters

In buildings where there is gas, hot water can be equipped with a flowing gas water heater, popularly referred to as a gas water heater.Inside the housing there is a coil with circulating water, which is heated by burners. Now such equipment is equipped with automation and the flame is started when the tap is opened.

With the help of such a flow device, the liquid can be heated even up to 80 degrees, but installation requires a gas line and a chimney. Some models may also need an electrical network for ignition. Products from our rating in this category are optimal for apartments and houses in gasified settlements.

Mora Vega 13

Rating: 4.9

This is one of the simplest flow type gas water heaters with a capacity of 13 l / min. For convenience, a piezo ignition is provided (a sharp turn of the switch gives a spark). The device does not require electricity. Provides a good temperature with a strong jet.

In the reviews, the owners confirm its simplicity and reliability, which led to an honorable place in the ranking. If the connectors are hermetically connected, then maintenance in the form of a membrane replacement will be required no earlier than after 5 years. The gas control works autonomously and turns off the supply when the flame goes out, and there is nothing more to break in it. It is suitable for several sampling points, but with alternate use.

Advantages

• no electrical wiring required;
• automatic operation when opening the crane;
• protective functions in case of overheating or blowing out the flame;
• enough pressure of 0.20 atm to turn on.

Flaws

• large column dimensions 400x659x261 mm;
• buzzes at maximum mode;
• piezo ignition does not always work the first time;
• open combustion chamber.

Electrolux GWH 11 PRO Inverter

Rating: 4.8

Flowing gas heater with electronic control and display.Automatically maintains the desired outlet temperature and is equipped with electric ignition (no need to twist something, just press the start button). Productivity makes 11 l/min. The device is equipped with a thermometer and gas control. The start and screen are powered by a battery, the charge of which is shown on the display.

We rated the product because of the "smart" features. Among other things, the electronic unit is equipped with flame modulation, which automatically adjusts to the parameters of the jet. This is useful in homes where water pressure often changes, especially in the summer with seasonal watering of vegetable gardens. The gas water heater also received a lot of positive feedback due to increased protection - it will not turn on not only in the absence of water, but also if the draft in the chimney disappears.

Advantages

• touch control buttons;
• self-diagnosis;
• a good package of security systems;
• display for easy setup.

Flaws

• when two points are turned on at the same time, the pressure drops;
• after downtime, you need to drain the hot water heated from the heat exchanger;
• full dimensions 328x550x180 mm.

Zanussi GWH 12 Fonte

Rating: 4.7

Inexpensive flow model with a copper heat exchanger. Accompanied by an informative manual with a detailed description of all modes and safety features. Heats the flow of 11 liters per minute. In terms of heating output, this is comparable to 23.6 kW, which is suitable for several taps, for example, in the kitchen and in the bathroom. Inflammation occurs automatically when you turn the knob, but periodically you will have to change the batteries for this. The thermometer readings are shown on the display. The second handle adjusts the throughput.

We included the water heater in the rating due to the cheapness of the product with a good set of functions.The ideal value for money is complemented by a semi-closed combustion chamber protected by a fine mesh, which increases safety especially in a house with small children (so that they do not put anything there).

Advantages

• battery ignition;
• copper heat exchanger;
• there are no fluctuations in heating when the second tap is opened;
• the jet is hot after 10 seconds.

Flaws

• weighs 9 kg and can only be attached to a brick wall;
• noisy work;
• you need to hold the switch down a little to activate the gas control;
• dies when diluted with cold water.

Principle of operation, types and design features

A compact device, which at the core of its design contains a heating element powered by the mains (it heats running water), is called an instantaneous electric water heater.

Some flow models are very compact and almost invisible

The water “washing” the heating element acquires the desired temperature and is immediately ready for use.

"Protochnik" differ in structural elements:

• the heating element can be a heating element in a copper case (or have a tubular shape - be a spiral in a casing);
• may have a nickel-chrome heating coil.

Instantaneous water heater consists of a housing and a control lever

According to the control method, water heaters can be electronic or hydraulically controlled. The water pressure in the pipeline in each city and even in a detached house is different.

Given this, manufacturers produce devices with different design features. That is, if the pressure of the incoming cold water is strong, then a low-power water heater will not be able to produce well-heated water at the outlet.

And at extremely low water pressure (0.25 atm.), The device simply will not turn on.

In this regard, instantaneous water heaters are divided into:

• non-pressure;
• pressure.

Pressure water heaters for the crane are divided into single-phase and three-phase

Pressure water heaters: principle of operation

Pressure water heaters for a faucet are much more powerful (3-20 kW), so connecting them to two or three mixers is quite a common practice.

True, in order to provide hot water in your home, which in terms of temperature and pressure will be akin to a central water supply, you will need a device with a capacity of at least 10 kW.

It will cost more, but the comfort is worth it. Pressure water heaters are divided into single-phase and three-phase.

If you decide to install a running water heater, make sure that the wiring in your home can withstand it (in standard old apartments this limit is 3 kW).

A flowing water heater with a power of 3 kW is capable of "giving out" about 3 liters of hot water per minute. This is enough to fill a bathtub with hot water.

But this power is not enough to take a full shower. Such devices can be installed in houses where a three-phase power supply operates and are used for old houses with 16-ampere plugs.

The electrical wiring will only withstand a water heater with a power of up to 3 kW. In apartments where electric stoves are installed, or 32-40 ampere meters are installed, the maximum consumption of the water heater should not exceed 6 kW.

For such cases, manufacturers offer the so-called small flow heaters for a tap, with a power of 1.5-8 kW, and which are powered by the mains.They are also pressure and non-pressure.

Flowing water heaters have another interesting feature that is rarely talked about in a store when buying an appliance.

In summer and winter, from the same water heater (this applies to low-power models) at the outlet, you will get a different temperature. Of course, the device is equipped with a special sensor, and itself must “bring” the water to the desired temperature. But in the summer and winter periods, the device will do the same action, but with a different temperature of the incoming water.

For example, in summer the temperature of the water “incoming” to the heater is +15°С, the low-power system of the device will increase these 15 degrees by another 25, and the required 40°С will be obtained at the output. But in winter, the temperature of the incoming water can be about 5 degrees, and the power allows you to heat it by only 25 degrees. As a result, 30 ° C is still cold water, which is even difficult to wash dishes.

Why make such low-power devices? Firstly, this is consumer demand - they are cheaper and in the process of their use there are no problems with electrical wiring.

Secondly, a significant part of the manufacturers are firms from Asian countries, taking into account the climatic conditions of their native region.

As a result, it is worth thinking in advance - why you need a device. If as a “summer shower”, then a low-power device is quite enough, but if, as a full-fledged replacement for central hot water supply, purchase a more powerful water heater.

Non-pressure models and their features

Non-pressure instantaneous water heaters are devices with a power of 2-8 kW, they will provide hot water for the kitchen, but will be small for the bathroom.

At the same time, they have a significant plus - the electrical wiring of most apartments and houses will be able to withstand their work without damage.

Non-pressure instantaneous water heaters with a spout, as a rule, are mounted in the bathroom above the sink

Non-pressure instantaneous water heater can be made in any color

Popular Models

On our market there are taps-heaters for water of Russian, Chinese, European production. Firms offer models designed for all segments of the population. Regardless of the cost, all types do a good job of heating running water quickly and safely.

The most popular models of heated taps:

• Delimano;
• Sapretto;
• Aquatherm.

These are affordable and reliable devices presented on the Russian market.

Delimano

Instant heating taps Italian-Ukrainian firms are made in China. The power cord is connected at the back, the water temperature is regulated by the side knob. The blue and red markings show the operating mode. Lever swivels left and right, can be used for 2 sinks. Both hydraulic and electronic versions of the flow heater are available.

The compact vertical housing takes up little space, can be used as a backup heater, suitable for summer cottages, new buildings, as long as the central hot water supply system is not connected. The manufacturer offers various modifications designed for small and large volumes of water consumption.

The wall-mounted water heater with a display is equipped with a hose, a shower, a powerful heating element. In such samples, a reinforced heater, a more powerful system of protection against overheating, "dry" operation, water hammer. Flow models are equipped with electronics, the operating parameters are displayed on the screen.

supretto

The stylish heater is made in Hong Kong. The vertical case is shaped like a cylinder, white with a silver trim. Temperature adjustment is made by the side lever. The electrical cord is connected from below. Suitable for small volumes of hot water. Models are not equipped with a shower, installed on the countertop or on the sink. Dense plastic protects the body from water hammer, the flow rate of cold water is 1.5 l / min, heated to 50 ° C - 1.3 l / min. works from a standard network of 220-240 V, the wire length is 1 m, so you need to think about connecting to an outlet.

Supretto produce the same models as Delimano, but under their own brand. Like Delimano, there are more expensive models with a display.

Aquatherm

An overview of popular models is impossible without a representative of domestic production.

The flow device of a Russian company has a horizontal or vertical body. The buyer can choose the color of the heater. The manufacturer offers samples with a long and short drain, a hose with a shower head, electronic temperature control. Medium-power equipment heats water up to 60 ° C, operates from a 220 V network. The price of a faucet depends on the model - the consumer can choose a sample that is suitable for power and design. This is a good combination of affordable price and high quality.

How much water can be heated in a flow way

Let's try to calculate. For example, we have water in a water supply system with an initial temperature Тн = 10 ºС and we want to heat it up to Тк = 40 ºС. The desired power is calculated by the formula P \u003d Q * (Tk - Tn) / 14.3, where Q is the water flow (l / min). It is easy to calculate that with a water flow of 5 l / min (a fully open faucet in the kitchen or bathroom), you will need a 10.5 kW heater.A 5 kW heater is able to “give out” a stream of hot water at a flow rate of 2.5 l / min - this is enough to wash your hands or, say, for some kitchen needs, but it will be uncomfortable to take a shower. That is why heaters with a power of 3–5 kW are usually used in the kitchen.

Vaillant

Flowing water heater. Model of the miniVED series with top connection

Polaris

Flow heater model Polaris ORION 3.5 S (2 440 rubles)

Operation of instantaneous water heater

Before considering how a standard instantaneous water heater works, it is worth showing its predecessor - a storage water heater. His work is simple and clear. Water is poured into a large tank, where it is heated to the desired temperature and consumed as needed.

But such a drive has significant drawbacks. One-time consumption of hot water is limited by the volume of the storage tank. If this water has been used, you have to wait for the next portion to heat up. Therefore, it is desirable to have a larger storage tank, but then there are problems with its placement.

Plus, the heater constantly consumes electricity to maintain the desired temperature in the tank.

These shortcomings are deprived of a running water heater.

The principle of operation of any instantaneous water heater

As the name implies, the device heats the flowing water. When water is not being used, the heater does not work either.

The flow heater also has a container in which water is heated. But, unlike storage, the tank does not take up much space and can be installed in almost any convenient place.

Running water enters the tank, in which powerful heating elements are located. The heating power usually depends on the water flow rate and provides a continuous supply of water heated to 40–60°C at the outlet. All elements of the heater are located in a single housing, which is built into wall cabinets or mounted on the wall.

Instantaneous water heater mounted on the wall under the sink

How the instantaneous water heater is arranged inside is shown in the figure.

Scheme of the internal structure of the electric heating protochnik

Types of flow type water heaters

According to the heating methods, the devices are divided into:

• electrical;
• gas;
• liquid (diesel);
• solid fuel (wood, coal).

Liquid and solid fuel heaters are rare.

Gas heating devices find their application, especially in homes where gas water heaters are still installed. The undoubted advantage of gas heaters is the low maintenance cost - gas prices are low. But the disadvantages of gas heaters are also significant:

• gas appliances are inferior to electric in safety;
• Reliable ventilation is required to remove gas combustion products;
• the gas water heater turns on only when the water pressure exceeds 1.5 liters of water per minute;
• gas equipment requires regular inspections by a specialist.

But the most common are electric heaters. They are safe, they have several heating control modes available. In terms of accessibility, there are few residential premises that are not connected to electricity.

Therefore, further consideration of flow options will only apply to electric heaters.

Typical characteristics of flow type electric heaters

• Power - from 3 to 20 kW. But powerful devices require a three-phase electrical network with a voltage of 380 V. In houses with old wiring, it can be a problem to use heaters of even medium (4–6 kW) power. You may need to run a dedicated power line.
• The overall dimension of flow devices does not exceed 400 mm. Approximate dimensions - 350 x 200 x 100.
• The water heating temperature is 30–45°C. This is not the temperature of the water itself at the outlet of the heater, but an indicator of the change in temperature at the outlet, compared with the inlet. Please note that the cold water inlet temperature varies with the seasons.
• The performance of medium power flowers is 2-6 liters per minute of heated water

The principle of operation of instantaneous and storage water heater

These types of equipment, regardless of the source of heating, have fundamental design differences. This is what allows us to determine the best heater option for providing autonomous hot water supply to a house or apartment.

How flow heaters work

This equipment is available in electric and gas versions. The power of electrical equipment can reach up to 36 kW. This is a very high figure, which provides for connection to a 380V network. It is far from always available, and laying such a line is accompanied by high costs and the need to collect a lot of information, which is not suitable for everyone. Manufacturers offer an extensive range of devices for a standard 220V network.Since it is often a powerful consumer, it is necessary to lay a power cable from the electrical panel for it.

Scheme of an electric instantaneous water heater

The principle of operation of such a device, regardless of whether it works on gas or electricity, is the same. When the water is opened on the mixer, the automation is activated, as a result of which the flow passing through the body of the device begins to heat up intensively. It takes 3-5 seconds for the hot jet to come out. Even if you return from vacation when all the equipment in the house was de-energized and turn on the water heater, you will immediately be able to use warm water.

The automatic mechanism that ensures the activation of heating can be electric or hydraulic. The most durable is hydraulic. The device responds to pressure changes in the pipeline. That is, if you open the mixer, the pressure drops, which indicates the need for intensive heating. If the electronics break, then the repair will cost more.

Scheme of operation of a gas flow column

How storage heaters work

A storage electric water heater has a fundamental difference, since its design provides for a container in which the heating element is located. Such a device turns on, heats the liquid to the set temperature, and then constantly maintains it. When the mixer is opened, water flows out of the storage tank, while a portion of cold water takes its place. The new flow mixes with the existing hot accumulations. At the same time, when the temperature drops, the heating element turns on and quickly heats the water to the desired level. This design is very similar to a large teapot.

Scheme of operation of a gas electric boiler

A storage gas boiler has much in common with a pot and stove. Its hermetic container is connected to the water supply. Cold water enters it. Below is a burner, which, under the control of automation, periodically ignites and maintains the temperature of the liquid. When you open the hot tap on the mixer, there will be free space in the tank. To fill it, a cold stream will come in, which will cause the thermostat probe to cool. As a result, the boiler will light up again and restore the required temperature value.

Gas boiler diagram

Advantages and disadvantages of equipment

To make the right choice when purchasing a water heating device that will successfully cope with the task assigned to it, you need to know about all the positive and negative qualities of an electric instantaneous water heater tap.

Advantages:

1. The compactness of the device allows you to place it on a sink or sink, using it as a mixer with heated water, which makes it possible to reduce heat loss during liquid transportation.
2. Electricity is consumed only when hot water is consumed.
3. Unlimited amount of hot water to use, not as much as the boiler tank can hold.
4. Aesthetics. The appearance of the device will not spoil even the refined interior of the room.
5. Low purchase price (compared to storage water heaters equipped with a tank).

The domestic water heater is equipped with protection against pressure surges during drops and adjustment of the heating system depending on the volume of water consumed, which will reduce energy costs.

But besides the advantages, the water heater also has disadvantages:

• the main disadvantage of these units is high energy consumption, due to the fact that the task of the heating element is to heat a sufficient volume of water in a short period of time. When using flow models, where the power of the heating element is not less than 10-12 kW, the power consumption increases significantly.
• moreover, in order for the equipment to be as productive as possible, one condition must be met when it is connected to the plumbing system. This unit has a fairly high power, and on this basis it should be assumed that the load on the wiring will be very significant.

Following the recommendations of specialists, the electric instantaneous water heater for washing should be connected separately by a cable laid for this purpose, which is led to the junction box. A powerful electric water heater for an apartment with an energy consumption of more than 8 kW requires a three-phase connection to 380 V

These works, with their complexity, scare away buyers, forcing them to pay attention to other products.

How to install instantaneous water heater

Consider the installation method on the example of the Aquatherm model. In the package, as a rule, there is a nozzle on the faucet itself and the mixer itself, as well as a warranty card, operating instructions and technical specifications. The device operates from a voltage of 220 V, which allows you to connect the device directly to any outlet.

The flow type electric water heating faucet is a water heating system with a protective block against voltage drops and stabilization of the electric current level.The unit itself in the center of the structure has a heating element with a silicone gasket, which eliminates the possibility of breakage during freezing. A “spout” is mounted on top, through which liquid will be supplied.

After assembling the structure, you need to dismantle the old mixer. Unlike the old faucet, there will be only one water supply pipe - “cold”. A hose for connecting to the water supply system will need to be purchased separately, since it is not included in the package.

Next, the mount is removed from the bottom of the device, the device is inserted into the hole on the sink and fixed with fasteners. After that, a hose is connected to the “cold” pipe, and on the other side it is connected to the equipment. Check if there is pressure in the system by opening the supply and the mixer itself.

Next, plug the device into the socket, check the power supply, turn the handle to hot water and raise the lever or turn the valve. To regulate the temperature, it is enough to reduce the pressure by turning the knob towards cold supply.

VIDEO: How to install an instantaneous water heater Aquaterm

Buying and Operating Tips

Whatever you prefer, the main thing is to determine:

• degree of safety of installation of this or that equipment;
• take into account the voltage in the network and the presence / absence of grounding;
• weigh all the factors that indicate the appropriateness of the choice.

It is better to purchase a water heater flow tap at authorized points of sale. The secondary market is not the best place to buy, because no one will offer you a guarantee, and there is no return either.Such a device will be a great helper even if a water-heating boiler is already installed, because the heated and accumulated water is so quickly consumed when washing hands and dishes. And here again you have to wait several hours before you can take a bath.

Advantages of instantaneous water heaters

Positive points in favor of installing flow-through water heating taps

• do not imply the presence of mixers with the cold/hot option. Basically, they have different power levels, which allow you to immediately adjust the water temperature at the time of use;
• save time;
• ideal for rooms that do not have a large area;
• mobile - at any time you can take them with you to the country;
• savings on commissioning services;
• the cost is cheaper than that of massive boilers or gas water heaters;
• does not require constant heating, it is used at the time of water consumption.

Negative sides

• consumption from 5 kW per hour;
• you need to install a good outlet to prevent overheating of the wiring;
• extreme measure;
• the socket must be configured with a residual current device.

It is worth noting that such nozzles for cranes can not always boast of durability. Price and quality are not always the same

Pay attention to the body and material of manufacture of all components. Electricity and water, as a rule, are not friendly - when connecting, this factor should be taken into account and the wires should be removed from the source of risk as far as possible

VIDEO: What to choose - flow or storage (boiler)

Electric shower water heater

The choice of a water heater for a shower between a flow-through and storage type of device is not always unambiguous.Each of them has its pros and cons, and the solution in most cases depends on the capacity of the power supply system.

Advantages of flow type devices

The first advantage of the flow device is the significantly smaller dimensions. Placing it in the shower room and installing it yourself does not cause problems, while finding a place for a massive tank of a storage water heater and its installation create noticeable difficulties.

The second advantage is the significantly lower cost of a domestic instantaneous water heater designed for a single point of consumption. Depending on the configuration and brand, the price range of such devices is 1,700 - 8,000 rubles, while the price of a simple storage water heater with a tank capacity of 30 liters or more starts at 5,000 rubles.

Maintenance and repair of storage devices must be carried out more often, and it is more expensive. In addition, not every consumer can carry out their independent installation and connection, which incurs additional costs for paying for specialist services.

When using a storage water heater, the number of people must be taken into account when calculating the volume of the tank. However, in the event of the arrival of guests, it may not be enough. The flow analogue is devoid of such a drawback.

The problem of providing electricity

The only significant obstacle to making a decision in favor of an instantaneous water heater is the peak load on the electrical network. It exceeds the performance of the storage device several times.

Buying an instantaneous water heater significantly increases the requirements for electrical cable.Total power of typical bathroom appliances such as washing machine (with heating element 1.5 - 3.0 kW), towel warmer (0.4 - 0.6 kW) and lighting line (0.1 - 0.25 kW ) rarely exceeds 4 kW. To provide such a voltage, a wire with a cross section of a copper core of 1.5 or 2.5 mm2 is sufficient, which is often brought to such premises.

bathroom renovation

However, the presence of a flow heater increases the maximum power consumption of the circuit section to 6-10 kW, and then the cable will already be required with a cross section of 4 or 6 mm2. This means that before installing the device it is often necessary to replace the wiring, and it is better to separate it into a separate branch to the distribution (internal) electrical panel.

The second problem after wiring can be the load on the electrical outlet. They are marked with an indication of the permissible voltage and current strength. From these data, you can calculate the maximum possible power of the connected electrical appliance without the risk of damaging the outlet:

P=I*U

Where:

• P - equipment power (Watt);
• I - current strength (Ampere);
• U - mains voltage (Volt).

Household sockets for a network with a standard voltage of 220 Volts have a permissible current of 5, 10 and 16 amperes. Therefore, devices with a maximum consumption of 1100, 2200 and 3520 watts, respectively, can be connected to them. If a higher power heater is to be used, power outlets must be installed. They have the following standard options:

• 25 amperes (power of the connected device up to 5.5 kW);
• 32 amps (up to 7.0 kW);
• 63 amps (up to 13.8 kW);
• 125 amps (up to 27.5 kW).

In case of difficulties during the installation of the power outlet, you can connect the power cable to the terminal block.However, this procedure should only be performed by a professional electrician, since in the case of unskilled work, overheating of the connection and a short circuit may occur. In a room with high humidity, this should not be allowed.

If the existing electrical supply of the bathroom allows the alternate use of energy-intensive devices, then you can stop at this option. To exclude, due to forgetfulness, their simultaneous inclusion, it is enough to use one socket for two devices for this.

The last problem may be the maximum connected load of an apartment or house when connected to a common energy infrastructure. For gardening and private houses with old power lines, it can be as low as 4-6 kW. Then it is possible to use a flow-type water heater only if almost all other devices are turned off. But even with a standard 15 kW of permitted power, it is necessary to calculate the peak load.

Features and price

Model	Peculiarities	Maximum water temperature, ⁰ C	Consumed energy, kW	Price, rubles
Atlanta ATH-983	Compact, inexpensive, reliable model	+85	3	2100
Aquaterm KA-001	Easy installation, diversified design: marble, onyx, metal, etc., energy saving system	+60	3	4300
Delimano KDR-4C	Economical, convenient to use	+60	2	3900
Aquatherm 006 L	Many colors, shower set with tourmaline filter	+60	3	5490

Manufacturers set the service life of a faucet with a built-in electric water heater from 2 to 5 years, depending on the intensity and operating conditions.