Article outline

If you live in a private house, then installing a boiler indirect heating together with the boiler will allow you to kill two birds with one stone - heat the house and provide constant access to hot water. We have selected for you best models water heaters that can be found on sale today - choose!

Briefly about the main characteristics

In ordinary storage water heaters the temperature of the liquid increases due to the operation of heating elements, while in boilers heating is carried out due to the circulation of heated coolant in the system. It looks something like this: water is heated in one or double-circuit boiler and is supplied through pipes to a coil or other heat exchanger installed in the tank; at the same time, the tank receives from the main line cold water, which is subsequently heated due to heat exchange through the walls of the coil. Instead of a coil, a tank-in-tank design can be provided. In this case, the coolant is supplied to the outer tank, and the heated liquid is supplied to the inner tank. The presence of temperature and volume sensors of liquid inside the container, as well as automatic relays ensure smooth operation of the equipment. Some models are also equipped with additional electric heaters - even in case of force majeure you can use the boiler hot water. Everything seems simple, but before purchasing you need to understand the main technical characteristics of such equipment.

Reminder for upcoming purchases

Selection criterion	Varieties	Note
Volume of the tank	from 50 to 400 l and more	In the most popular models for household use Tanks with a volume of 80 to 200 liters are used. The volume is selected based on consumption hot water and the number of water points.
Power	from 2 to 60 kW and above	Together with the volume of the tank, the power determines the rate of heating of the liquid. The more powerful the equipment and the smaller the capacity, the faster the heating occurs.
Maximum water pressure	6-10 bar (0.6-1 MPa)	The pressure that the boiler can withstand in operating mode. It is advisable to install pressure reducers to prevent damage from water hammer.
Mounting method	Wall	Equipment with a small tank volume (up to 100 liters) is often mounted on the wall. The larger the volume, the more difficult it is to do this, so capacious water heaters are manufactured in a floor-standing design.
	Floor
	Combined
Heat exchanger design	Coil	The coolant from the boiler is supplied through a metal coil installed in a tank with heated water. The most common type.
	Coil within a coil	The heat exchange area is increased due to the use of two coils with different diameters spirals.
	Tank in tank	There are two steel tanks - one inside the other. The larger tank is supplied with coolant from the boiler, and the smaller tank is supplied with heated water.
Heat exchanger material	Stainless steel, brass	The vast majority are made from of stainless steel. However, this material may vary in quality. Therefore, you should not save money and buy products from an unknown brand.
Material and thickness of the thermal insulation layer	Foam rubber, mineral wool, polystyrene foam, polyurethane foam - thickness from 20 to 60 mm	The effectiveness of thermal insulation is determined by the value of thermal conductivity (the less, the better) and the thickness of the insulation layer (the more, the better). Today, a good solution is to use 50-60 mm of polyurethane foam insulation.
Maximum productivity in flow mode when heating at ΔT °C, l/min	where ΔT °C = 25, 45, 55, etc.	Determines the efficiency of the heater in flow mode. Depends on its power.
Heating time at ΔT °C, min.	where ΔT °C = 25, 45, 55, 60, etc.	Determines the heating rate of the entire volume of water in the tank. Depends on volume and power.
Options	heating element	Many models can be upgraded with tubular electric heaters, which are activated when the boiler is turned off.
	Recycling	The tank may be provided with a circuit connection for water circulation using a pump. This is necessary to ensure that water is supplied to the consumer at a constant temperature.
	Solar collectors	Using solar energy to heat the coolant and then transfer the heat to heat the water. Collectors are installed on the roof. In the CIS, this option is relevant only in the warm season.
	Heat pump	Possibility of connecting a heat pump to minimize the cost of heating cold water. A very rare option.

We omitted such a parameter as the diameter of the thread for connecting to pipes, because... If necessary, this issue can be resolved by installing adapters.

Calculation of water volume

Only you can determine the exact required volume, because... calculations are tied to water consumption conditions. Our task is to provide information that will somehow help in making a choice or give you ideas when making a calculation. For example, we open SNiP 2.04.01-85 and see that the standards set 7.9-10.9 liters of hot water (HW) per hour per person. Following some simple calculations, we get the following table.

These calculations can only be taken into account if water heated by the boiler is used sequentially and simultaneous work one water point (only one tap is open). In practice, the given values ​​​​need to be multiplied by 3-5. Why is this happening? Because the standards do not take into account the desire to warm up in the shower (+20 liters of hot water) and run a bath (+80 liters of hot water), wash a mountain of dishes (+20 liters of hot water), etc. and so on. Consider peak loads on the boiler - choose the volume that is most suitable for your needs.

• 50-60 liters is enough for 1 person;
• for 2-3 people you need to choose from models with 80-120 liters;
• for a family of 3-5 people, a boiler capacity of 120-200 liters is enough

To make it more convenient for you to choose suitable model equipment, we have identified four product groups depending on the volume of the storage tank: up to 100, 200, 300 and 400 liters. All specifications taken from open sources, and prices are provided for comparison purposes only.

Important! Please note that some water heaters are only suitable for certain models boilers In the description we will focus on this, but we recommend that you clarify all the nuances before purchasing.

Up to 100 liters

1. Baxi Combi 80 (80 l.) – from 52,500 rub.

A well-known Italian player specializing in heating and water heating equipment, Baxi has been maintaining a quality brand for decades. The Baxi Combi 80 small-volume boiler model is designed to work in conjunction with boilers of the LUNA-3 Comfort series from the same manufacturer. The placement is on the floor, the water heater can be installed directly under the boiler, saving space. One of the advantages of this system is its compact size. Corrosion protection is provided by the use of stainless steel and magnesium anode. Polyurethane foam is used as thermal insulation. Connection of a heating element is not provided.

2. Gorenje GBK80ORRNB6 (72.6 l.) – from 24,000 rubles.

When looking for a small model that can provide hot water for one or two people, pay attention to Slovenian equipment. This is a classic compact boiler with two tubular heat exchangers, the performance of which is sufficient for two water points at once. The device is equipped with an electronic control unit and allows you to change the DHW temperature in the range of 15-75 °C. Has outlets for connecting to a boiler with right side, two dry heating elements are installed as an additional heater. The model is equipped with several types of protection: against corrosion (magnesium anode), against freezing (effective thermal insulation), against overheating and heating without water. The manufacturer also provides a control function for legionellosis (a pulmonary disease whose pathogens actively multiply in hot water). One of the best combined solutions in terms of price/quality ratio.

* operating parameters in flow mode are not specified by the manufacturer. The power of the heat exchanger itself is not indicated - only for heating elements.

3. Protherm FS B100S (95 l.) – from 36,200 rub.

The Czech boiler is structurally linked to boilers of the same manufacturer - Medved. Compact, with a laconic but informative control panel, it easily fits into the kitchen interior as a built-in appliance. Enameled stainless steel, magnesium anode and antibacterial coating are all designed to protect against corrosion and microorganisms. The tubular heat exchanger provides a high heating rate of the entire volume of liquid: the water heats up by 50 degrees in 13 minutes. To keep warm, the product is protected by a polyurethane foam coat.

4. ACV COMFORT 100 (100 l.) – from 48,000 rub.

The Belgian manufacturer with almost a century of history offers interesting solution based on a “tank in tank” heat exchanger – model . The boiler consists of two stainless steel containers of different volumes, one of which is inserted into the other. Special attention It is worth paying attention to the inner container: its surface is corrugated, therefore, due to thermal expansion, a change in size occurs with the subsequent removal of the resulting deposit of hardness salts (scale). The equipment is installed on the floor by default, but with additional fastenings Can be mounted on a wall. The thermal insulation layer is made of polyurethane foam 30 mm thick. Kit standard features small, but an optional control panel can be installed. It is also worth considering the lack of recirculation and connection of the heating element.

Up to 200 liters

5. Baxi Premier plus 150 (150 l.) – from 50,600 rubles.

You can ensure full operation of two hot water collection points using. This series of heaters uses a tubular heat exchanger “coil in coil”. Due to its low weight, the device can be hung on the wall or placed on the floor. Parts of the structure in contact with water are made of DUPLEX stainless steel, minimizing heat losses is achieved by using polyurethane foam. The model is equipped with a thermostat and can be used in conjunction with any type of boiler. Optionally, it is possible to connect a tubular electric heater. The manufacturer has provided for the connection of a recirculation circuit. According to reviews, this is one of the best solutions value for money for a family of four.

6. BOSCH WSTB 160 (160 l.) – from 28,000 rub.

If your home has a gas boiler installed, then you should think about buying a water heater. Although there is no possibility of connecting a heating element here, there is a recirculation system. The model is adapted to the harsh conditions of use in the CIS, i.e. Suitable for hard water. To protect the steel from corrosion, the material is coated with a special glass-ceramic composition. There is a recirculation line, so you can always count on receiving water at a constant temperature. To minimize heat losses, a fur coat made of 50 mm polyurethane foam is provided, the lining is made of PVC, soft. The connection is frontal, it is possible to connect a temperature sensor. The entire volume is heated to ΔT=45°C in 37 minutes.

7. Protherm FE 200 BM (184 l.) – from 41,650 rub.

Many manufacturers offer storage heaters that are suitable only for their boiler models. If you have installed a Proterm boiler, then to satisfy your requests big family in DHW it is worth considering installation. This floor boiler indirectly heated stainless steel coated with enamel to protect against corrosion. The installed titanium anode serves the same purpose. To avoid the growth of bacteria on the walls of the container, they are coated with a layer of antibacterial substance. The productivity is high - with a delta of 25 degrees you can get more than 30 liters of water per minute. Without the possibility of connecting the recirculation line and heating element.

8. Gorenje GV 200 (188.9 l.) – from 25,800 rubles.

Floor-standing water heater of indirect type Combustion GV 200 - simplicity of design, reliability of design and laconic design. The product is an enameled steel tank with a tubular heat exchanger inside. Installed on the floor under the boiler. A relief valve is used as protection against overheating overpressure. The device is protected from corrosion by enamel and a magnesium anode. It takes up to 24 minutes to heat the entire volume of water in the tank from 15 to 75 degrees. For saving DHW temperature corresponds to a layer of thermal insulation with a thickness of 40 mm.

* the possibility of working in flow mode has not been announced by the manufacturer

Up to 300 liters

9. ACV COMFORT 240 (240 l.) – from 65,000 rubles.

Another representative of indirect water heaters, which use a “tank-in-tank” heat exchanger. The model is capable of providing hot water to up to three water points. The product is protected from corrosion due to the use of stainless steel and a special approach to the formation of the walls of the internal tank. Here it is corrugated, which has a positive effect on its work even with very hard water. At the same time, the equipment is characterized by the same features as products of the same series: a minimum of functions, a 30 mm thermal insulation layer, the inability to connect a tubular electric heater and a recirculation circuit.

10. Protherm FS B300S (295 l.) – from 63,000 rub.

This hydraulic accumulator is designed for use with Proterm Grizzly or Bison boilers. – capacious tank with a tubular heat exchanger. The tank has two flanges: for installing a heating element and for servicing the boiler. Enameled surfaces that come into contact with water, as well as the presence of a titanium anode, protect the equipment from corrosion. It should be noted that there is an antibacterial coating. A layer of polyurethane insulation is responsible for reducing heat loss. The device is characterized by high productivity in flow mode; it is possible to connect a recirculation line. The capabilities of this heater will be appreciated by owners of large private houses with more than three bathrooms.

11. Baxi Premier plus 300 (300 l.) – from 70,000 rubles.

Often the main criterion for choosing a boiler is not only its volume, but also the heating rate. In this case, it is important to consider models with a “coil-in-coil” heat exchanger. - exactly what is needed! Firstly, it is compatible with any boilers. Secondly, high-quality stainless steel is used for its production, which is perfectly protected from corrosion. Thirdly, with a fairly compact size and low weight, the equipment has universal placement and is equipped with an accurate thermostat. The model allows you to supplement the system with a recirculation circuit. Connecting a 2.7 kW heating element is optional.

Up to 400 liters

12. Drazice OKC 400 NTRR/1 MPa (380 l.) – from 68,000 rub.

The Czech boiler is equipped with two tubular heat exchangers, one of which is designed to connect to solar collector, and the second - to the boiler. This allows you to save a lot on heating water on sunny days, especially in summer. If necessary, for example, a malfunction of boiler equipment, you can install two auxiliary electrical heating elements. The enameled tank, as well as the presence of a magnesium anode, provide long-term protection of the tank from corrosion. 50 mm of solid polyurethane foam is used as a heat-insulating layer. There is a recirculation pipe.

The manufacturer does not provide information on the rate of water heating in flow mode. This is explained by the presence of two independent heat exchangers with different temperature conditions work.

13. Bosch SK 400-3 ZB (388 l.) – from 59,500 rubles.

Bosch's assortment does not include many indirect water heaters of the capacity we are interested in, but among them there is a special model - Bosch SK 400-3 ZB. This is an enameled tank with a stainless steel coil. Corrosion protection is provided by a magnesium anode, which has already become a natural phenomenon in such equipment. The device is quite simple: a built-in thermometer and a flange for easy maintenance. In this case, it is possible to connect a hot water recirculation line, as well as synchronize with the boiler if the latter has a connector for an NTC sensor (temperature sensor). Those. You can fine-tune the operation of water heating equipment. Separately, it is necessary to say about thermal insulation. Here it is not polyurethane foam, but made of rigid foam, which, with equal thickness, gives a lower heat-shielding effect.

14. BAXI UBVT 400 SC (395 l.) – from 58,100 rub.

If the prevailing part of boilers is designed to work in tandem with a boiler, then the model is an exception to the rule. It is adapted for connection to a solar collector, so its purchase will be advisable in two cases: in places with year-round sunny weather or for seasonal use. Additionally, it is possible to install electric heaters for heating. The container itself is made of steel coated with titanium enamel - the result is a corrosion-resistant and durable coating. The latter is also facilitated by the presence of a magnesium anode. The kit includes a thermometer for temperature control, and there are sockets for connecting sensors. The design provides a flange for monitoring the condition of the coil, as well as a built-in pipe for recirculation.

15. Hajdu STA 400 C (400 l.) – from 64,100 rub.

The model from a well-known Hungarian manufacturer is interesting in that, with one heat exchanger, fine-tuning of the equipment is possible. So, in the cold season, such an indirect heating boiler can be configured to work in tandem with a boiler, and in the summer it can be connected to a solar collector. In the latter case, if necessary, an additional heating element is connected. The tank and heat exchanger are protected from corrosion by a layer hot enamel and an installed magnesium anode. To minimize heat loss, the outside of the container is covered with a layer of polyurethane foam, protected by a plastic casing. A pipe is provided for connecting the DHW recirculation system.

On the next video this boiler presented in section.

Editor's Choice

For ease of comparison, let’s enter the main characteristics into the table and decide on the most successful models. To make it clearer, we choose a boiler for 1-2 people, 2-4 people, 4-6 people. (marked in the table below in bold from top to bottom, respectively). Because Not all manufacturers adhere to uniform standards when preparing technical documentation; for example, not all indicate the value of productivity in flow mode, then we introduce the characteristic N. It shows the ratio of a unit of power per 1 liter. water. Those. we simply took and divided the capacities indicated by the manufacturer by the usable volume of storage devices. The larger this value, the faster the heating occurs.

Rating of indirect heating boilers

Model name	Useful volume, l	power, kWt	N, kW/l	Accommodation	Heat exchanger	heating element	Rec-tion	price, rub.
80	31	0,3875	floor	coil	—	—	52500
72,6	2	0,027548	wall-mounted	coil	+	—	24000
	95	26,1	0,274737	floor	coil	—	—	36200
100	23	0,23	floor/wall	tank in tank	—	—	48000
	150	30	0,2	floor/wall	coil in coil	+	+	50600
160	20,8	0,13	wall-mounted	coil	—	+	28000
184	43,2	0,234783	floor	coil	—	—	41650
188,9	17,6	0,093171	floor	coil	—	—	25800
240	53	0,220833	floor/wall	tank in tank	—	—	65000
Gorenje KGV 300-2/BG	280	69,6	0,248571	floor	coil	+	+	83700
295	46	0,155932	floor	coil	+	+	63000
300	30	0,1	floor/wall	coil in coil	+	+	70000
380	57	0,15	floor	coil	+	+	68000
388	60	0,154639	floor	coil	—	+	59500

Life modern man who is used to comfortable conditions, it’s hard to imagine without hot water. Unfortunately, work central water supply leaves much to be desired. Hot water is supplied with constant interruptions, and some houses are not connected to central heating at all. In such cases, connecting an indirect heating boiler is a good solution.

What is an indirect heating boiler?

Separately, we note indirect heating boilers from European brand STOUT. These boilers are universal, sold with capacities from 75 to 200 liters - suitable for an apartment or house of almost any size. Each stage of the STOUT boiler production process meets European ISO standards, and at all stages the product is tested for leaks.

The brand closely monitors the product and audits every 50th boiler. Absolutely everything is checked, from the quality of packaging to testing of operating modes. Thanks to this, the STOUT indirect heating boiler is reliable, easy to operate and will serve for many years.

For details, go to stout.ru.

How does an indirect heating boiler work?

The inside of the boiler is usually steel or plastic, and the water heating container itself is made of heat-insulating material. Inside the tank there is a heat exchanger made of brass or steel, through which coolant from the heating boiler passes. It is usually made in the form of a coil to ensure the fastest and most efficient heating tank. To protect against corrosion, a magnesium anode is used to protect the tank from increasing pressure; a thermostat is installed inside the boiler and safety valve. The outer casing of the tank is usually made in the manufacturer's design style. Today on the market you can find other models of boilers with indirect heating - “tank-in-tank” water heaters or boilers with several heat exchangers. But it is extremely rare to find them on sale.

An indirect heating boiler is connected to the water supply system through an inlet for cold water and an outlet for hot water.

Cold water fills the heating tank, and at the outlet hot water reaches the consumer. Each indirect heating boiler is connected to a pipeline through which the coolant enters the boiler for the next heating. A pumping and mixing system must be installed on such a pipeline, which is responsible for water circulation.

Pros and cons of the work scheme

The main advantages of an indirect heating boiler:

• the operation of such a water heater does not overload the electrical wiring during the heating season, since the boiler depends on central heating And does not consume electricity;
• with proper design, the boiler has very high performance indicators and an optimal cost ratio;
• inner surface of the heater and coolant does not interact with running water , which ensures safe and long service life of the unit;
• Due to recirculation, hot water flows immediately after opening the tap;
• the indirect heating boiler can always be switched to alternative source heat or use several.

Unfortunately, each work scheme, in addition to positive ones, also has negative sides:

• to re-equip the system, you will need additional expenses;
• the cost of a boiler with indirect heating is much higher than gas or electric heaters;
• initial heating of water (volume more than 100 liters) lasts from 1 to 2 hours, this may negatively affect the quality of the heating system of the room;
• for a boiler with a volume of 100 liters or more a separate room is required due to the impressive size of the device.

What to look for when choosing an indirect heating boiler?

The most main characteristic boiler is its volume. You need to roughly estimate how much water your family needs to live comfortably. Based on average indicators, a person spends 5−15 liters per day on personal hygiene, 15−25 l/day on washing dishes, 50−100 l/day on showering, and 150−200 l/day on bathing.

It is believed that per resident it is necessary 80−100 liters of hot water, of course, this calculation is conditional, it all depends on the preferences and habits of the residents. For example, someone likes to shower twice a day, while others get by with a bath once a week. The larger the boiler volume, the higher its cost.

The next thing you need to pay attention to when purchasing is interior material water heater.

Preference should be given to boilers with a brass coil. It will heat water more efficiently than a steel coil, and it is much easier to clean a brass coil.
The water heating container must be protected from corrosion. In cheaper models, the tanks are covered with a layer of enamel or glass ceramics. Expensive devices are protected from corrosion by stainless steel.
In addition, do not forget about the thermal insulation of the unit; high-quality boilers are insulated mineral wool or polyurethane foam. Models with foam insulation are best avoided.

The boiler can be connected via a hydraulic or electrical system. The connection diagram with two pumps or hydraulic is considered the most effective.

One pump is used to heat the living space, the second is for indirect heating the boiler itself. Electrical diagram connection involves a mode switching system - a relay.

In a two-pump boiler connection scheme, coolant flows move in different directions due to the operation of circulation pumps. The hot water line (boiler and heating boiler) are connected in parallel to the pumps, and the operating mode of the pumps is regulated by the heater temperature sensor. A check valve is installed in the circuit after each pump so that the pumps operate autonomously, independently of each other. In the presented diagram, the heating circuit is turned off, but this has virtually no effect on the rate of heating of water in the batteries.

Typical connection errors

The first mistake that is most often encountered is the wrong location for installing the indirect heating boiler. You need to install it as close as possible to the heating boiler or to the outlet of the central water supply.

The next mistake is incorrect connection of the cold water supply. Serial connection coolant inlet and outlet provides effective work water heater. For optimal heating and heating results The coolant must enter the boiler from the top and come out from below.

Incorrect connection circulation pump entails many negative consequences:

• the motor axis must be positioned horizontally, this will help avoid early wear of the bearings;
• the pump must be protected from debris, you need to constantly monitor the condition of the mesh filters.

The modern heating systems market offers wide choose boilers and other water heaters, so everyone can find a model with an optimal price-quality ratio. For consultation you can always contact service center, where you will definitely receive assistance in the design, installation and maintenance of heating devices.

An indirect operator using the “tank-in-tank” technology is fundamentally different from its traditional “colleagues”. The basis for the difference lies in the design of the device, and as a result it was possible to achieve much higher efficiency indicators. This “trick” was developed by the ACV brand, which patented it and began to successfully use it in the production of water heating equipment powered by heating.

Indirect heating water heater with two tanks: design, heating principle, features

Double-wall models are fundamentally different from conventional boilers, which use a coil to transfer heat to the accumulated liquid. They do not have temperature exchangers at all, but can boast faster heating with less losses.

Design

A boiler of this type consists of containers placed one inside the other, with some distance between the walls. This cavity is completely filled with coolant, which is heated by the heating system and transmits thermal energy internal container. Thus, the area of ​​temperature return is maximized, which determines the high speed of achieving desired temperature in the tank.

Important differences from traditional models

Units with coils have a big disadvantage: their lower part has cold zones that are poorly heated by heat exchangers. Because of this, the time it takes to bring the liquid to the desired thermometer mark can be very long with a high capacity of the device. And the hygiene of the equipment is reduced. Double-wall indirects are free of these disadvantages.

Temperature exchangers are placed inside the working tank, so they come into contact with water and can become coated with scale, which reduces their efficiency and service life. In models with double walls, the liquid acts only on the surface of the tank, which is reliably protected from salt deposits and oxidation.

Advantages of double tank boilers

The ACV company produces its tanks from excellent stainless steel, so the advantages of the equipment include the following features:

• preservation of the structure of the material even when exposed to high temperatures;
• stability of units against mechanical stress;
• excellent resistance to rust formation;
• incredibly long service life;

The performance of units of this type is significantly superior to conventional models, since with the same volume, boilers with a double tank concept can serve a larger number of consumer taps. This is possible due to the complete absence of unheated areas: newly supplied cold water increases its temperature in record time and can be used for domestic and economic needs.

The ACV brand has in its assortment various water heaters: indirect, combined, direct. But it was precisely the two-capacity boilers that operated from heating that began to be in greatest demand among consumers.

Increasingly in heating systems alternative double-circuit boilers They use indirect heating boilers or the so-called “Tank in tank”. When a large supply of water is required, several tapping points become "tank-in-tank" indispensable assistants. Stainless steel boiler suitable for country houses, office and industrial buildings.
"Tank in tank" are becoming increasingly popular in the heating market. Working with heat generated by any other energy sources is the main advantage, since water is heated indirectly from electrical energy, solid fuel or gas. Indirectly heated boilers do not overload the electrical network and do not require a chimney.
Operating principle "Tank in tank"
The indirectly heated stainless steel boiler is manufactured according to the tank-in-tank principle. It works on the basis of two tanks. The first container is internal, filled with heated sanitary water, the second container, the outer one, contains a coolant - it is this that heats the sanitary water. Thus, the "tank in tank" eliminates a large number of disadvantages inherent in conventional water heaters with a coil.

The main advantages of an indirect heating boiler:
1. Larger number water points are provided with hot water due to the increased heat transfer area. It also takes a short time to heat up the newly received cold water.
2. Water heaters manufactured according to the tank-in-tank scheme have a smaller volume than was required when using a conventional water heater to ensure a given performance.
3.Sanitary requirements are ensured by the numerous advantages of stainless steel.
4.The use of reliable thermal insulation and the effect of self-cleaning from scale lead to savings in energy consumption
5. Possibility of regulating the heating of sanitary water due to the built-in thermostat.
6. Long term services

In rooms without a centralized hot water supply system, “Tank in Tank” boilers are an indispensable assistant.
Boilers can be divided into indirect and direct heating boilers.

Advantages indirect boilers(for example, boiler, WESTER or) use heat converted heating boilers, and are intended for economical hot water supply to apartments, office and industrial institutions, and cottages.

IN gas water heaters a direct heating circuit is used. The advantage of this type of boiler is stability and sometimes independence from electricity and other factors.
The advantages of indirect boilers (for example, an acv smart boiler) are the speed of heating and the ability to be used for several points of water consumption. During a water outage, the indirect supply ensures its continuous supply. The tank volume can reach 1000 liters. The energy savings are colossal!

You can buy indirect heating boilers in the section.