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Single-circuit boiler with boiler outlet. Gas boilers and indirect heating boilers

Single-circuit boiler with boiler outlet. Gas boilers and indirect heating boilers

Hot water is used every day in everyday life, and the central water supply does not fully satisfy this need.

In some places there is no possibility to connect to the public highway at all. In this regard, gas boilers have become widespread in everyday life.

A gas boiler is a heating equipment for heating the coolant, which operates by burning gas. Some types of boilers can provide both heating and hot water supply (DHW) at the same time - these are double-circuit boilers. Others are used only for heating - single-circuit.

Hot water supply using a double-circuit boiler

A double-circuit gas boiler heats cold water using a flow-through circuit, which ensures a continuous flow of hot water. Heating occurs due to direct heat from the flame.

Water consumption depends on the boiler power. On the one hand, this is a very effective way to provide hot water, but on the other hand there is a drawback.

Tap water is used for heating; it has a high hardness level (salt content). Therefore, when heated, scale formation occurs on the walls of the heat exchanger.

If you do not control the process of scale formation, this can lead to a malfunction of the gas boiler.

To reduce the hardness of heated water, special devices are used - softeners.

DHW using a single-circuit boiler

Despite the obvious advantage of double-circuit boilers, both types are popular. In fact, single-circuit boilers are also capable of heating hot water for the household, but this requires an additional water heater.

This heater is an indirect heating boiler.

Indirect heating boiler

A boiler is a tank inside which there is a heating element, most often electric. That is, the energy source is located inside the boiler itself. In our case, an indirect heating boiler is used.

“Indirect” means that there is no source of thermal energy inside the boiler. Heating occurs due to the heat from the gas boiler. Inside the boiler, as a heating element, there is a coil.

The same coolant that is used for heating enters this coil and heats the cold water that fills the boiler. In other words, the heating fluid heats cold water for domestic use.

The design of an indirect heating boiler includes two non-communicating water circuits:

Heating water circulation circuit – heating circuit. The flow pattern of the coolant begins in the gas boiler, then it enters the boiler coil, gives up its thermal energy to the cold water in the boiler and returns back to the boiler for heating. This cycle repeats continuously.
The domestic water flow circuit is a heated circuit. For heating, water from the water supply is used, it enters the boiler tank, coming into contact with the heat exchanger, the water heats up and at the exit from the boiler has a temperature of 45-65 ° C.

Types of indirect heating boilers

Due to the great demand for water heating equipment, indirect heating boilers have many different modifications.

A wall-mounted or hanging boiler has compact dimensions. Due to wall mounting, it takes up virtually no space. These types of boilers have found their application in apartments and small private houses.

A floor-standing or stationary boiler has a wide choice of sizes and capacities, and can also be made in a vertical or horizontal arrangement. This type of boiler can provide a constant large supply of hot water.

To heat water in an indirect type boiler, you can use any heat source: liquid fuel or solid fuel boiler, electric boiler, wall-mounted or floor-standing gas boiler.

There are types of indirect heating boilers that are equipped with additional electrical heating elements. If for some reason the gas boiler cannot function normally, you can always heat the water using an electric heater.

The tank is made of stainless steel with additional protective coatings. The heat exchanger is made of copper, as it has good thermal conductivity properties. To preserve heat, the boiler is packaged in thermal insulation material.

Main characteristics of an indirect heating boiler

Indirect heating boilers have the following characteristics:

tank volume;
water heating speed;
power consumption;
heat losses;
the presence of an additional heat source (TEH).

For the normal functioning of the boiler, heating and indirect heating boiler, it is necessary to correctly select the power of the gas unit.

The power of a gas boiler must be at least twice as large as the energy consumed by the boiler. Otherwise, the water in the boiler will not heat up quickly enough, and the heating system will not work efficiently.

The connection diagram for a gas boiler must provide for disconnecting individual coolant consumption circuits. So that it is possible to turn off the heating, but the boiler continues to function and vice versa.

For example, the power of a boiler for a house of 100 m2, with a rough calculation, can be 20 kW. (2 kW per 10 m2 area). In this case, the maximum boiler consumption should not exceed 10 kW. But it is best to have a reserve of boiler power.

Thus, with the correct selection of equipment, normal and continuous operation of heating and hot water can be achieved.

Gas boilers and indirect heating boilers

Gas boilers and indirect heating boilers: operating principle, installation, advantages and disadvantages. Heating and water supply using a gas boiler and boiler.

Indirect heating boiler or geyser: what to choose?

Both types of this equipment have a number of features, including both advantages and disadvantages. If you don’t know what is better to choose – an indirect heating boiler or a gas water heater, then we hope that our article will help you decide. So, a geyser is considered one of the most common methods of autonomous hot water supply. It is a flow-through water heater that heats cold water from the tap directly “on the fly.” Thanks to this, heating is carried out almost instantly, and the volumes of hot water supplied depend on the power of the column.

The gas water heater is compact and provides fast water heating. However, it requires that the house be connected to a centralized gas and, preferably, water supply. In many ways, the efficiency of such equipment depends on the pressure of the cold water supplied. Also, to install a gas water heater, a chimney is required, at least coaxial (for turbocharged models). In some cases, this may cause some inconvenience to the user.

As for the indirect heating boiler, it does not have a flow-through, but a storage principle of operation, accumulating hot water heated by a separate heating boiler in its container. Therefore, it is advisable to use this equipment (boiler + boiler) only in conjunction with each other. Some models of such water heaters have a built-in electric heating element that maintains a high water temperature. The advantage and, at the same time, disadvantage of this boiler is its bulkiness - it can store a large volume of liquid, but at the same time it requires a lot of space for its placement.

So, an indirect heating boiler or a gas water heater - which equipment will be more profitable? The column is intended exclusively for flow-through heating of hot water in relatively small, domestic volumes. At the same time, the house must have a stable, good pressure of gas and cold water. It does not have a tank, so if the cold water supply is turned off, you will be left without hot water too. A gas water heater is ideal for apartments or houses with central heating, as well as a stable water and gas supply.

In turn, an indirect heating boiler is much more economical than a gas water heater, since it receives water already heated by the boiler and spends a minimum of energy maintaining its temperature. It does not require a gas pipeline to heat water; the boiler can operate on electricity or completely autonomously (using coal, wood, pellets). In addition, it stores hundreds of liters of liquid in reserve in its container, which is ideal for cases where increased DHW consumption is required. Its disadvantages include its bulky dimensions, as well as the very high cost of a set of a heating boiler and an indirect heating boiler (which, however, soon pays off).

12 best boilers

A water heater or boiler is a device for constant heating of water connected to the water supply system. Structurally, it is a large container equipped with a heat source in various configurations. In another way, boilers are called storage-type water heaters. The use of such devices is advisable in rooms where there is no connection to the hot water supply line.

In specialized stores, every buyer will be able to find gas or electric water heaters, combined or indirect heating boilers. It is difficult to say which of them are the most popular and preferred for use in houses and apartments. Here, as in many other cases, everything depends on the tasks imposed by the consumer on the object.

In order to make your choice easier, a rating of the best boilers has been compiled based on user reviews, comparison of the characteristics of a large number of models and popularity among buyers.

The best gas boilers

Installation and startup of such heaters is carried out mainly in large-scale buildings and cottages, since they allow heating a large amount of water with minimal time and low fuel consumption. Considering that the prices for natural gas are relatively low, even in this case it can always be replaced with an alternative fuel.

The heater power is controlled by built-in regulators, which eliminates the occurrence of emergencies. Of the minuses, it should be noted that to install such a boiler, permission from competent government agencies is required, regulating both the correct installation and the presence of a separate hood for exhaust gas removal.

3 American Water Heater PROLine

Despite the rather high cost, the American Water Heater PROLine G-61-50T40-3NV storage water heater can rightfully be called one of the best gas boilers. The volume of the water tank is 190 liters, and the maximum thermal power for heating it to a temperature of 70 degrees Celsius is 11.7 kW. In order to prevent corrosion, a glass-ceramic coating is applied to the walls of the tank.

Since the exporter of boilers is the USA, the main disadvantage and inconvenience during installation is related to the indication of some parameters in the units of measurement adopted in this country. Like all gas heaters, the American Water Heater requires periodic scheduled maintenance. But, despite this, it is one of the most reliable boilers in its class, as confirmed by numerous customer reviews.

2 Baxi SAG3 80

An honorable second place in the ranking goes to Baxi SAG3 80, a compact wall-mounted boiler that is ideal for installation in both a large private house and a small apartment. The capacity of the heater tank is 80 liters, which is quite enough for moderate water consumption. To improve its performance, the tank is coated with durable enamel that protects it from corrosion.

The gas burner is equipped with a gas control system, and the design itself has a release valve that removes excess pressure from the tank. Temperature control is carried out mechanically. With reduced dimensions compared to floor-standing models, the Baksi boiler weighs an impressive 34 kilograms. However, compared to its competitors, it still remains the best gas wall heater.

Review and rating of the best boilers for the home. Rating categories: the best gas, electric, combined and indirect heating boilers.

Indirect heating gas boilers - advantages and disadvantages, connection options

Content:

Design and principle of operation

Indirect heating boilers are devices that accumulate hot water from an external heating device. Such equipment does not have a heating element in its design.

The main feature of the device is the presence of a heat exchanger, through the tubes of which coolant circulates, heated to a certain temperature by the boiler. It is usually made in a coil shape to increase the heat transfer surface.

The tank for these devices is made of two layers, inside of which there is thermal insulation that performs several functions:

Reduced heat losses,
Protecting people from burns,
Increasing the strength characteristics of equipment.

Temperature control is provided by a built-in thermostat, and a safety valve protects the device from pressure changes. Most models of this equipment are equipped with a magnesium anode, which protects the internal surface from the appearance and effects of corrosion.

Often, manufacturers of heating equipment develop and produce a series of devices that ideally interact in tandem boiler-boiler. But there are also universal water heating equipment suitable for most types of boilers.

Main technical characteristics

When choosing this type of heating device for certain parameters of the heating system, you should be guided by the following characteristics:

Volume of the tank. Depending on the need and operating conditions (domestic or industrial), equipment is presented on the market with a capacity of up to 2000 liters
The power of the coil is usually indicated in the product passport based on the temperature of the heating fluid coming from the boiler (approximately 77 degrees Celsius) and the temperature of hot water at the outlet (45 -60 degrees Celsius)
Boiler performance characterizes the average water withdrawal in flow mode over a certain time interval (l/min)
Ideally, the water pressure in the coil and at the outlet of the boiler should be the same. Typically the maximum permissible level is 10 bars.
The thickness of the thermal insulation depends on the total capacity of the tank.
Overall dimensions depend both on the volume of the boiler and on its internal design and design solutions of the manufacturer.

Connecting the boiler to a gas boiler

The operation of an indirect heating boiler can be controlled autonomously and independently of the central heating device. This is achieved by the presence of a progressive automation system and its own control panel.

Most models are completely dependent on a central automated heating device. Therefore, there are many options for connection schemes depending on the characteristics of the equipment and operating conditions.

When installing an autonomous heating system, there are 2 main connection schemes to central heating devices:

To a single-circuit boiler
To a double-circuit boiler.

Connection to a single-circuit boiler

There are 3 main schemes for connecting an indirect heating boiler to a gas heating boiler:

Using a 3-way mixing valve. This method is characterized by precise settings and operation of the boiler’s built-in thermostat. When the temperature drops, mainly when there is a large supply of hot water, a signal from the thermostat is sent to a 3-way valve, resulting in the supply of coolant to the coil. After the water temperature reaches the set value, the valve closes and the coolant circulates in the heating circuit.
Creation of parallel circuits using a pump group. This connection diagram involves installing check valves to prevent mixing of liquid flows.
For more complex systems that involve several central heating devices, as well as a large number of heating radiators, several water collection points, in addition to installing a pump group, it is advisable to use a hydraulic distributor. It serves to clearly separate the contours.

Connection to a double-circuit boiler

There are 2 types of connection of the device to a double-circuit boiler:

The first type involves a traditional sequential circuit for connecting the device to the boiler. The second type is characterized by parallel connection of equipment with the installation of additional devices that regulate the temperature of the coolant (thermal heads, controllers, etc.)

Pros and cons of indirectly heated gas boilers

Advantages

Saving on energy resources. Since this equipment is powered by a gas boiler and in most cases is energy independent, the consumer does not spend any money to operate it.
High performance due to constant circulation of hot coolant in the heat exchanger.
Reduction of scale and salt deposits due to prepared water entering the coil from the boiler
Longer service life compared to other types of equipment
Possibility of organizing several hot water collection points at a constant temperature

Flaws

High cost of a set of equipment
Requires large space for installation. The ideal option is to arrange a separate room
Providing hot water preparation only during the heating season

How to calculate and choose a suitable model - tips

An indirectly heated gas accumulator is designed for the needs of a relatively large family that requires a relatively large flow of hot water. Therefore, when purchasing this equipment, you should clearly define your needs. The volume of the tank and productivity, which are determining factors in its final cost, also depend on this.

You should also pay attention to the existing automation system of a particular model. Not only ease of use depends on this, but also the safety of people.

The versatility of connecting the device to various types and brands of gas boilers allows you not to depend on the model of the main equipment.

The materials of the main structural elements of the boiler affect its service life. It is preferable if the coil is made of brass.

The internal tank has a long service life if its material is stainless steel, and the fiberglass or enamel coating will quickly crack during operation. You should take into account the dimensions of the existing room in order to rationally arrange the equipment.

Indirect heating gas boiler - how to calculate, select, connect

Indirect heating gas boilers - advantages and disadvantages, connection options Contents: Design and principle of operation Indirect heating boilers are devices that

Hot water is used every day in everyday life, and the central water supply does not fully satisfy this need.

In some places there is no possibility to connect to the public highway at all. In this regard, gas boilers have become widespread.

A double-circuit gas boiler heats cold water using a flow-through circuit, which ensures a continuous flow. Heating occurs due to direct heat from the flame.

Water consumption depends on the boiler power. On the one hand, this is a very effective way to provide hot water, but on the other hand there is a drawback.

Tap water is used for heating; it has a high hardness level (salt content). Therefore, when heated, scale formation occurs on the walls of the heat exchanger.

If you do not control the process of scale formation, this can lead to a malfunction of the gas boiler.

On a note.
To reduce the hardness of heated water, special devices are used - softeners.

DHW using a single-circuit boiler

Despite the obvious advantage of double-circuit boilers, both types are popular. In fact, they are also capable of participating in heating hot water for the household, but this requires an additional water heater.

This heater is an indirect heating boiler.

Indirect heating boiler

A boiler is a reservoir inside which a heating element is located, most often. That is, the energy source is located inside the boiler itself. In our case, an indirect heating boiler is used.

“Indirect” means that there is no source of thermal energy inside the boiler. Heating occurs due to the heat from the gas boiler. Inside the boiler, as a heating element, there is a coil.

The same coolant that is used for heating enters this coil and heats the cold water that fills the boiler. In other words, the heating fluid heats cold water for domestic use.

The design of an indirect heating boiler includes two non-communicating water circuits:

Heating water circulation circuit – heating circuit. The flow pattern of the coolant begins in the gas boiler, then it enters the boiler coil, gives up its thermal energy to the cold water in the boiler and returns back to the boiler for heating. This cycle repeats continuously.
The domestic water flow circuit is a heated circuit. For heating, water from the water supply is used, it enters the boiler tank, coming into contact with the heat exchanger, the water heats up and at the exit from the boiler has a temperature of 45-65 ° C.

Types of indirect heating boilers

Due to the great demand for water heating equipment, they have many different modifications.

To heat water in an indirect type boiler, you can use any heat source: liquid fuel or solid fuel boiler, electric boiler, wall-mounted or floor-standing gas boiler.

Main characteristics of an indirect heating boiler

Indirect heating boilers have the following characteristics:

tank volume;
water heating speed;
power consumption;
heat losses;
the presence of an additional heat source (TEH).

Attention!
For the normal functioning of the boiler, heating and indirect heating boiler, it is necessary to correctly select the power of the gas unit.

Attention!
The connection diagram for a gas boiler must provide for disconnecting individual coolant consumption circuits. So that it is possible to turn off the heating, but the boiler continues to function and vice versa.

Thus, with the correct selection of equipment, normal and continuous operation of heating and hot water can be achieved.

A floor-standing gas boiler with a boiler is distinguished by the ability to quickly supply hot water in the required volume. The storage tank can hold from 40 to 500 liters.

Double-circuit gas boilers with a built-in boiler for hot water supply are essentially single-circuit units with an indirect heating tank, combined into one compact system. Such heating devices are equipped with a heat exchanger, which heats the water during breaks between heating support. Thanks to this design, the gas boiler will always have a supply of warm water. Examples of units are the Protherm Bear 30 KLZ models with a 90 l boiler, Baxi GALAXY 280 i with a 100 l capacity, Beretta Boiler 28 BAI with a 60 l boiler.

Note! A unit with a built-in boiler can provide up to 3 water intake points, depending on the volume of the container. The built-in boiler holds from 40 to 100 liters of liquid.

Advantages and disadvantages of units

The advantages of floor-standing gas boilers with a built-in boiler include:

possibility of constant supply of hot water supply;
compact dimensions;
Ease of use;
the presence of many additional functions.

The disadvantages of dual-circuit units are:

high price;
dependence on electricity;
complex installation.

Operation of a gas boiler with an indirect heating boiler

An indirect heating boiler is a separate container that can be equipped with both a single-circuit and a double-circuit gas boiler. Single-circuit units are equipped with an indirect heating boiler to ensure the production of hot water, since these devices are designed only for heating.

Additional capacity is connected to double-circuit gas heating boilers if the volume of the built-in boiler or the productivity of the flow-through heat exchanger is insufficient.

Advantages and disadvantages of boilers with indirect heating boilers

The advantages of gas floor boilers equipped with an indirect heating boiler are as follows:

possibility of installing a non-volatile system;
there is no need to purchase a full-fledged boiler.

The disadvantages of such heating devices include the following:

take up a lot of space;
Difficulties may arise when connecting the container to the boiler.

Selecting boilers with a boiler

A properly selected boiler will cover peak hot water needs. Floor-standing units differ in the type of combustion chamber:

Atmospheric - with an open combustion chamber. Installed in a specially prepared boiler room with a classic chimney.
Turbocharged - with a closed combustion chamber. Setting up a special room is not necessary. To remove smoke, it is enough to install a coaxial chimney.

When choosing a boiler with a boiler also take into account:

required power;
DHW capacity reserve;
amount of hot water consumed;
adaptation to domestic operating conditions;
Availability of service centers nearby.

The required power of a gas boiler is calculated on the basis that 1 kW of energy is needed to heat an area of 10 m². To heat the water you need to add about 30% additionally. The capacity ranges from 40-100 liters for household equipment and up to 500 liters in industrial devices.

Note! In order not to encounter difficulties when connecting an indirect heating boiler to your boiler, it is better to purchase a container from the same manufacturer as the gas unit.

Piping a gas floor-standing boiler with a built-in boiler

The piping scheme for a gas boiler with a built-in boiler includes five pipes: one gas and four water. Gas connections should only be made by a specialist; water pipes can be connected yourself. The gas line is connected using a ball valve. The rest are connected as follows:

heat exchanger pipe with heating supply pipe;
another main circuit pipe with a return pipe;
water supply with boiler pipe;
warm water supply tap with a second tank connection.

This connection scheme has two undeniable advantages compared to piping a conventional double-circuit boiler with an instantaneous water heater:

the heat exchanger does not become clogged with sediment that remains when the liquid is heated;
When using hot water, the heating does not turn off.

Which boiler to choose with a floor-standing boiler depends on the specific situation. If you already have a gas boiler with certain indicators of domestic hot water production, then it is advisable to supplement it with an indirect heating capacity for the missing volume. If you choose a new unit, then you should clearly calculate the expected need for hot water and select the appropriate boiler.

To install a hot water supply system (DHW), there is Several variants, some of them are double-circuit and single-circuit boilers with a separate boiler.

If in a dual-circuit device A small heat exchanger is already built in to heat water for domestic hot water, but in a single-circuit system with a boiler, the task of heating water for domestic needs is assigned to it.

Double-circuit boilers are usually equipped relatively small capacity for DHW, therefore they cannot provide the desired temperature for many consumers for a long time.

Types of gas boilers with indirect heating boilers

Eat two options water heaters for DHW:

indirect heating (IH);
direct heating.

The BKN is connected to the installed gas boiler. Inside it there is a heat exchanger (this can be a pipe twisted in a spiral or a “tank-in-tank” design).

Hot water from the heating system circulates through this heat exchanger, heating the water in the boiler. The latter is connected to the cold water supply network (CWS), and from the collapsible pipe the hot water supply is supplied to consumers.

Direct heating boiler can be compared with a conventional gas boiler heating. It also has a gas burner and a water tank. The burner heats the water in the tank independently of the central heating system.

Important! When installing a BKN, it is necessary to estimate the power that will be spent on DHW. If there are many consumers and use water frequently, The boiler power may not be enough for heating, and the temperature in the rooms will be lower than the set one.

In this case, it is advisable to replace the boiler with a more powerful one, or use a different type of water heater.

Schemes for connecting a boiler to a single-circuit boiler

Exists three ways connecting the boiler to the boiler.

Direct connection of the water heater to the heating system

In this embodiment, the BKN is included in the heating system, in series or in parallel with other radiators. The simplest and most ineffective scheme is not recommended for use and is given for reference.

Photo 1. Scheme of direct connection of a water-heating gas single-circuit boiler to the heating system.

If the boiler temperature is set below 60 °C, this scheme becomes even less economical, and the water takes a very long time to heat up.

Temperature increase

Added to the connection diagram three-way valve- a special device that switches the movement of coolant when the temperature in the water heater tank drops to DHW and vice versa.

Thus, if the DHW water cools down, The heating is temporarily switched off.

All boiler power is redirected to DHW.

The temperature on the device in this scheme is set higher ( usually 80-90 °C).

And the heating temperature is regulated by a three-way valve.

Reference! The boiler temperature must be set at 5 °C higher than the required water in the domestic hot water supply.

Using a thermostat in a water heater and automation

If a thermostat is installed in the BKN (a device that gives a signal when the set temperature is reached), and the boiler controller has contacts for connection boiler thermostat, then this circuit is the most preferable.

In this case, the boiler electronics know about the temperature of the water in the DHW system, and it decides itself where to direct its power: for heating water in the BKN or for heating.

Photo 2. Thermostat for a water heater in a heating system, with it you can find out data on the water temperature.

Materials and tools

Materials:

Pipes, shut-off valves, check valves— there are no special requirements for them: use the same materials as for working with hot water supply or heating systems.
Expansion tank— a separate one is required for the domestic water supply system; it serves to prevent sudden pressure changes when opening/closing taps.

Attention! The tank must be intended for use with hot water; such devices are usually designated special markings.

Circulation pump— as a rule, a separate pump is installed in the heat exchange circuit with the water heater.

In addition, in DHW systems with recirculation, a separate pump is required to circulate water in the DHW circuit.

This will eliminate the need to wait for hot water to arrive through long pipes from the installation site of the water heater: the water will immediately be hot.

Wires and small electrical wiring— if you plan to connect the water heater thermostat to the boiler automation.
Fasteners- especially in case of wall installation, also for securing pipes and pumps.
Standard plumbing set of sealants, seals, gaskets.

Tool:

gas key;
wrenches of various diameters;
Adjustable wrench;
building level;
hammer drill, screwdrivers, screwdriver;
Minimum set for an electrician: knife, wire cutters, electrical tape, phase tester.

Installation process: how to connect

Ideally, the boiler should be located as far as possible closer to the heating boiler to minimize heat loss.

Cold water is always supplied to the bottom pipe of the boiler, and hot water is drawn from the top.

Select a location for the water heater so that it does not interfere and is easy to maintain. Mount brackets, stands, and secure it to them.
Connect to the HVS network: make a tap, install a shut-off valve and a coarse filter.
Through a tee, take the cold water line to consumers, connect the second output to the boiler through a safety valve.
Connect the domestic hot water line to the boiler, not forgetting about the expansion tank on it. In addition, install bypass taps so that you can disconnect it from the circuit during maintenance.
Now connect the boiler to the gas boiler according to one of the given diagrams. Don't forget to turn off the boiler and shut off the system before connecting!
Connect electronics, sensors, pumps according to the instructions.

Startup and testing

Now we will figure out how to choose a gas boiler with a built-in boiler and what is the difference between single-circuit and double-circuit. In the end, let's see who produces the best models in this segment.

There are various ways to set up and equip a hot water supply system in your home. One option is to install a gas boiler with a built-in boiler.

You can find out the price and buy heating equipment and related products from us. Write, call and come to one of the stores in your city. Delivery throughout the Russian Federation and CIS countries.

Boiler with built-in boiler

Differences and advantages of single-circuit and double-circuit boilers

A single-circuit gas boiler is intended exclusively for heating a house - it does not have a built-in water heater that provides residents with hot water. If you connect a boiler to it, it will heat water for various domestic needs.

The mechanism of dual-circuit units is more complex and their price is higher.

The main advantage of a gas boiler with a built-in storage tank is that you do not have to additionally purchase and install. In addition, the water in it heats up much faster than in single-circuit boilers.

For devices with two circuits, you can connect a separate boiler to provide more hot water. If you already have a single-circuit boiler, then in addition to it you can buy a special one, which is equipped with a flow-through liquid heater.

If you are the owner of a small apartment and you need to save space, then the best option would be a single-circuit boiler with a built-in boiler.

To avoid all sorts of problems that may arise due to incorrect installation of equipment, installation should be carried out by specialists.

Currently you can find the following models of double-circuit boilers:

with a flow-through water heat exchanger;
with a built-in boiler for 40-60 l;
with built-in boiler for 80-599 l.

Main characteristics of wall-mounted instantaneous water boilers:

can simultaneously heat rooms with a total area of up to 300 m²;
they are compact, you can install them in a niche in the wall;
acceptable price;
are characterized by simple installation;
simple and convenient control.

Construction of a gas boiler with a built-in boiler

Advantages of gas heating boilers with a boiler capacity of 40-60 l:

can heat an area of up to 300 m² and simultaneously supply water to 4 water distribution points at once;
easy to operate;
have a self-diagnosis system.

Units with a boiler capacity of 80-500 l come in three types. The first two include devices that contain all the necessary parts, they are compact and allow you to fully control the system. The third type includes boilers for which you need to install additional equipment and purchase other parts. As a result, in order to purchase all the missing elements, you will have to spend a lot of money.

As already noted, most users prefer single-circuit gas boilers with a separate boiler.

Let us note the main advantages of such devices:

Large internal cross-section of the heat exchanger, due to which much less scale is formed.
They are reliable.
The mechanism and principle of operation of the device is simple.
Thermal energy is consumed expediently, as a result of which efficiency increases and fuel is consumed more economically.
They are easy to maintain.
With a gas boiler and boiler, you are guaranteed to be provided with hot water at any time of the day.

Manufacturers

Today, the leading manufacturers of gas boilers with built-in boilers are: Electrolux, Ariston, Viessmann, Baxi, De Dietrich, Vaillant, Wolf, Chaffoteaux, Biasi.

Manufacturer	Model	Characteristic
Electrolux	Electrolux GCB Magnum 28 Fi	Gas wall-mounted boiler with 60 liter boiler . Power: 28.70 kW. Efficiency: 92.4%. Voltage: 220 V. Combustion chamber: closed. Heat exchanger: separate. Dimensions (HxWxD): 900x600x460.
Ariston	Ariston Clas B Evo 24 FF	Wall-mounted gas boiler with built-in boiler. Power: 24.00 kW. Efficiency: 92.0%. Voltage: 220 V. Combustion chamber: closed. Number of circuits: dual-circuit (heating and hot water supply). Heat exchanger: separate.
Ariston	Ariston Clas B Evo 30 FF	Storage capacity: 8 liters. Power: 30.00 kW. Efficiency: 92.0%. Voltage: 220 V. Combustion chamber: closed. Number of circuits: dual circuit. Heat exchanger: separate. Dimensions (HxWxD): 943x600x460
Viessmann	Viessmann Vitopend 100-W WHKB025	Power: 25.10 kW. Efficiency: 90.0%. Voltage: 220 V. Combustion chamber: open. Heat exchanger: separate. Dimensions (HxWxD): 725x450x360
Viessmann	Viessmann Vitopend 100-W WHKB026	Storage capacity: 4 liters. Power: 30.00 kW, efficiency: 90.0%. Voltage: 220 V. Combustion chamber: open. Number of circuits: dual-circuit (heating and hot water supply). Heat exchanger: separate. Overall dimensions (HxWxD): 725x450x360
Baxi	Baxi Nuvola-3 B40 280 i	Designed for heating private houses, cottages, country houses, cottages with an area of up to 280 m², as well as for organizing hot water supply. Features: 40 liter boiler; separate heat exchangers; weather-compensating automatic; LCD display; push-button control; hydraulic group made of brass; advanced functionality; programming.
De Dietrich	De Dietrich MS 24	Wall-mounted gas boiler with a storage tank of 6 liters. Power: 24.00 kW. Efficiency: 91.0%. Voltage: 220 V. Combustion chamber: open. Number of circuits: single-circuit. Heat exchanger: separate. Overall dimensions (HxWxD): 730x400x299

Thus, by purchasing a gas boiler with a built-in boiler, you can achieve significant cost savings without losing functionality and ease of use.