Heating system for two houses with one boiler. Increasing the total power of wall-mounted boilers. The feasibility of using automatic and manual switching between two boilers

Can water in a well freeze? No, the water will not freeze, because... both in sandy and artesian well the water is below the freezing point of the soil. Is it possible to install a pipe with a diameter greater than 133 mm in a sandy well of a water supply system (I have a pump for a large pipe)? It does not make sense when installing sand well install a pipe larger diameter, because Sand well productivity is low. The Malysh pump is specially designed for such wells. Can a steel pipe in a water supply well rust? Quite slowly. Since when constructing a well suburban water supply It is sealed, there is no oxygen access into the well and the oxidation process is very slow. What are the pipe diameters for an individual well? What is the productivity of a well with different pipe diameters? Pipe diameters for constructing a water well: 114 - 133 (mm) - well productivity 1 - 3 cubic meters / hour; 127 - 159 (mm) - well productivity 1 - 5 cubic meters ./hour; 168 (mm) - well productivity 3 - 10 cubic meters/hour; REMEMBER! It is necessary that...

The most efficient heating system is one in which the coolant becomes hot due to the operation of two or three boilers. However, they can be the same in power and type. This rationality is explained by the fact that one heat generator operates on full power only a few weeks a year. At other times, you need to reduce its productivity. And this leads to a drop in its efficiency and an increase in heating costs.

Several combined ones allow you to more flexibly control the operation of the piping without loss of efficiency, since it is enough to turn off one or two devices. In addition, if one of them breaks down, the system continues to raise the temperature in the house.

Types of connection of two or more boilers

Usage more identical boilers require a special connection diagram. You can combine them into one system:

1. Parallel.
2. Cascade or sequentially.
3. According to the scheme of primary-secondary rings.

Features of parallel connection

The following features exist:

1. The hot coolant supply circuits of both boilers are connected to the same line. These circuits must have safety groups and valves. Latest can be closed manually or automatically. The second case is only possible when automation and servos are used.
2. join another line. These circuits also have valves that can be controlled by the above-mentioned automation.
3. The circulation pump is located on return line in front of the junction of the return pipes of two boilers.
4. Both lines are always connected to hydraulic collectors. There is an expansion tank on one of the collectors. In this case, a make-up pipe is connected to the end of the pipe to which the tank is connected. Of course, at the junction there are check valve and shut-off valve. The first does not allow hot coolant to enter the make-up pipe.
5. Branches extend from the collectors to the radiators, heated floors, . Each of them is equipped with its own circulation pump and coolant drain valve.

Using such a piping arrangement without automation is very problematic, since it is necessary to manually close the valves located on the supply and return pipes of one boiler. If this is not done, the coolant will move through the heat exchanger of the switched off boiler. And this turns out:

1. additional hydraulic resistance in the water heating circuit of the apparatus;
2. an increase in the “appetite” of the circulation pumps (they must overcome this resistance). Accordingly, energy costs are rising;
3. heat losses for heating the heat exchanger of a switched-off boiler.

Read also: Features of automatic coal boilers

Therefore, it is necessary to correctly install the automation, which will cut off the switched-off device from the heating system.

Cascade connection of boilers

The cascading boiler concept provides distribution of heat load between several units, which can work independently and heat the coolant as much as the situation requires.

Can be cascaded like boilers with stepped gas burners, and with modulated ones. The latter, unlike the former, allow you to smoothly change the heating power. It is worth adding that if boilers have more than two stages of gas supply regulation, then the third and remaining stages make their productivity less. Therefore, it is better to use units with a modulating burner.

With a cascade connection, the main load falls on one of two or three boilers. The additional two or three devices turn on only when needed.

The features of this connection are as follows:

1. The wiring and controllers are designed so that in each unit it is possible to control the coolant circulation. This allows you to stop the flow of water in disconnected boilers and avoid heat loss through their heat exchangers or casings.
2. Connecting the water supply lines of all boilers to one pipe, and the coolant return lines to the second. In fact, the connection of boilers to the mains occurs in parallel. Thanks to this approach, the coolant at the inlet of each unit has the same temperature. This also avoids the movement of heated fluid between disconnected circuits.

Plus parallel connection is preheating the heat exchanger before turning on the burner. True, this advantage occurs when burners are used that ignite the gas with a delay after turning on the pump. Such heating minimizes the temperature difference in the boiler and avoids the formation of condensation on the walls of the heat exchanger. This applies to a situation where one or two boilers have been turned off for a long time and have had time to cool down. If they have recently turned off, then the movement of the coolant before turning on the burner allows you to absorb the residual heat that is preserved in the firebox.

Read also: Types and principle of operation of a steam boiler

Piping boilers with cascade connection

Its scheme is as follows:

1. 2–3 pairs of pipes extending from 2–3 boilers.
2. Circulation pumps, check valves and shut-off valves. They are on those tubes that are designed to return the coolant to the boiler. Pumps may not be used if the unit design includes them.
3. Shut-off valves on hot water supply pipes.
4. 2 thick pipes. One is intended for supplying coolant to the network, the other for return. Corresponding tubes extending from the boiler devices are connected to them.
5. Security group on the coolant supply line. It consists of a thermometer, a calibration thermometer sleeve, a thermostat with manual release, a pressure gauge, a pressure switch with manual release, and a reserve plug.
6. Hydraulic delimiter low pressure . Thanks to it, pumps can create proper circulation of coolant through the heat exchangers of their boilers, regardless of what the flow rate of the heating system is.
7. Heating network circuits with shut-off valves and a pump on each of them.
8. Multi-stage cascade controller. Its task is to measure the coolant at the output of the cascade (often temperature sensors are located in the safety group area). Based on the information received, the controller determines whether to turn on/off and how the boilers combined into one cascade circuit should operate.

Without connecting such a controller to the piping, operation of boilers in a cascade is impossible, because they must work as a single unit.

Features of the scheme of primary-secondary rings

This scheme provides primary ring organization, through which the coolant must constantly circulate. Heating boilers and heating circuits are connected to this ring. Each circuit and each boiler is a secondary ring.

Another feature of this scheme is the presence of a circulation pump in each ring. The operation of a separate pump creates a certain pressure in the ring in which it is installed. The assembly also has a certain effect on the pressure in the primary ring. So, when it turns on, water comes out of the water supply pipe, entering the primary circle and changing the hydraulic resistance in it. As a result, a kind of barrier appears on the path of coolant movement.

The two-boiler circuit is very widely used in Lately, and there is quite a lot of interest. When two heating units appear in one boiler room, the question immediately arises of how to coordinate their operation with each other. Let's try to answer the question of connecting two boilers into one heating system.

This information will be of interest to those who are going to build their own boiler room, who want to avoid mistakes, and for those who are not going to build with their own hands, but want to convey their needs to those people who will assemble the boiler room. It is no secret that each installer has his own ideas about what a boiler room should look like and often they do not coincide with the customer’s needs, and in this situation the customer’s desire takes priority.

Let's look at examples of why in one case the boiler room operates in automatic mode (the boilers coordinate with each other without the participation of the consumer), while in another it is required that it be turned on.

Nothing is required here except shut-off valves. Switching between boilers is carried out by manually opening/closing two taps located on the coolant. And not four, in order to completely cut off the idle boiler from the system. Both boilers most often have built-in ones and it is more profitable to use them both at the same time, because the volume of the heating system very often exceeds the capabilities of one expansion tank taken separately. To avoid the useless installation of an additional (external) expansion tank, there is no need to completely isolate the boilers from the system. It is necessary to block them according to the movement of the coolant and leave them simultaneously included in the expansion system.

Connection diagram for two boilers with automatic control

Important! The valves must work towards each other, then the coolant from the two boilers will move only in one direction, towards the heating system.

For automatic system simultaneous operation of two boilers will require an additional part - a thermostat that will turn off the circulation pump if the system has a wood-burning boiler or any other boiler with non-automated loading. It is necessary to turn off the pump at the boiler. Because when the fuel burns out in it, there is no point in wasting coolant through this boiler, interfering with the operation of the second boiler. Which will pick up the work when the first one stops. With the maximum diameter and the highest brand of thermostat to turn off the pump, you will spend no more than 4,000 rubles and get an automatic system.

Video of the implementation of two boilers in one boiler room

The feasibility of using automatic and manual switching between two boilers

Let's consider the following five options with various units in conjunction with electric boiler, which is in reserve and must turn on at the right moment:

• Gas + Electric
• Firewood + Electric
• Liquefied gas + Electro
• Solar + Electro
• Pellet (granular) + Electro

Pellet and electric boiler

Combination of connecting two boilers - pellet and electric boilers– best suited for automatic activation and manual operation is also allowed.

A pellet boiler may stop because it has run out of fuel pellets. It got dirty and wasn't cleaned. The electric one must be ready to turn on to replace the stopped boiler. This is only possible with automatic connection. Manual connection in this option is only suitable when you permanently live in a house where such a heating system is installed.

Diesel boilers fuel and electricity

If you live in a house with such a system for connecting two heating boilers, a manual connection is quite suitable for you. The electric boiler will operate as an emergency boiler in case the boilers fail for some reason. They didn’t just stop, they broke down and require repairs. Perhaps the same automatic switching on, as a function of time. An electric boiler can operate in pairs liquefied gas and a solar boiler at the night rate. Due to the fact that the night tariff is cheaper per 1 kW/hour than 1 liter of diesel fuel.

Combination of electric boiler and wood boiler

This combination of connecting two boilers is more suitable for automatic connection and less suitable for manual connection. A wood boiler is used as the main one. It heats the room during the day, and turns on the electricity to add heat at night. Or if you are not living in the house for a long time, an electric boiler maintains the temperature so as not to freeze the house. Manual operation is also possible to save electricity. The electric boiler will turn on manually when you leave and turn off when you return and start heating the house using a wood-fired boiler.

Combination of gas and electric boilers

In this combination of connecting two boilers, the electric boiler can act as both a backup and a main one. In this situation, a manual connection scheme is more suitable compared to an automatic one. The gas boiler is a proven and reliable unit that for a long time can work without breakdowns. At the same time, connecting an electric boiler to the system for backup in automatic mode is impractical. If the gas boiler fails, you can always manually turn on the second unit.

Comfortable accommodation in a private two-story house completely depends on the complex of communications, among which one of the main places is occupied by the heating network. Is not it? It is she who is responsible for maintaining optimal temperature regime and the safety of the building itself. Agree, room temperature is one of the main components of ensuring comfortable living.

The choice of heat source and its correct connection directly determines whether you can maintain the temperature necessary for living. Here we will help you understand how the heating system works two-story house, and which wiring schemes are considered the most effective.

Here you will find information about the types of coolants, methods and features of their connection. For clarity, the material is accompanied by connection diagrams, as well as videos that will help expand knowledge about heating systems in private houses.

It is quite difficult to independently select the equipment necessary to assemble a heating system. To do this, you need to have special engineering knowledge, be able to navigate detailed calculations and installation nuances.

If you have the appropriate education or you already have experience installing heating in a two-story house, then you can choose the heating circuit option yourself by using useful information and developed skills.

Selecting a thermal energy source

The heart of the heating network is the heat generator, which heats the coolant to optimal temperature and, if allowed technical capabilities, maintains the specified parameters around the clock.

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Among modern heat sources in private two-story houses, almost all are used, sometimes 2-3 types are combined.

Possible types of heat generators:

• heating boilers;
• infrared emitters;
• stoves (Russian, Dutch, Canadian);
• fireplaces;
• solar collectors, thermal pumping units and other types of alternative equipment.

Heating boilers are actively used, which can be classified by type of fuel:

• liquid or solid fuel;
• gas;
• electric.

The second and third options are more economical, and if gas or electricity is supplied to the house, then you should prefer them.

Wall-mounted gas boiler with a power of 28 kW with two independent circuits, a closed combustion chamber and convenient electronic ignition - great option for a 2- or 3-story house

If the cottage is built on a non-gasified site, the electric boiler becomes the main one, and a fireplace or infrared heating is used as a backup source.

The sequence of operation of an electric boiler: the coolant is heated to a temperature set by the user, moves through a pipeline to radiators located on two floors, is partially cooled and, under the action of a circulation pump, is sent back to the boiler (+)

The use of alternative heat generators largely depends on climatic conditions region, besides, the minimum set is relatively expensive equipment(For example, solar collectors) will pay off in at least 3 years.

The diagram shows the advantage of an infrared heating system: IR radiation provides comfortable temperature in the lower part of the room, with convective heating, on the contrary, warm air always rises to the ceiling

Which coolant is better?

The heat generated by a gas boiler or other heat generator cannot by itself spread throughout all rooms. For this purpose, you need a substance that moves freely through the pipes and has the necessary technical characteristics.

There are technologies for using heated air, especially relevant in houses with a stove, fireplace or electric heating. But, unfortunately, to ensure effective functioning it has insufficient parameters of heat capacity, density and heat transfer.

Layout diagram air system heating in a two-story residential building. The arrows indicate the movement of cold and warm air, which is provided by ventilation and air conditioning systems (+)

Unlike gaseous substances, liquid substances have an excellent ability to absorb heat, release it and maintain a given temperature for some time. In this sense, the ideal “conductor” is ordinary water. When heated, it fills pipes and radiators, gradually releasing heat to living spaces, and circulation ensures the consistency of the process.

For houses with permanent residence systems with water as a coolant are optimal. To ensure that heating equipment lasts longer without repairs and that the pipeline does not become coated with plaque, water is passed through filters and enriched with special additives and inhibitors.

Antifreeze HotPoint 65 is used in heating and air conditioning systems, designed for 10 heating seasons or 5 years of continuous operation

If the house is a temporary shelter or serves as a vacation spot on weekends, it is better to use antifreeze instead of water. This is a liquid solution with chemical composition, one of the components of which is propylene glycol or ethylene glycol.

The chemicals prevent the coolant from freezing even when the building freezes and constantly maintain the network functionality in operating mode.

Convector and radiator heating of premises

When drawing up a heating project for a two-story or three-story house as heating devices Both radiators and convectors can be used.

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Convectors have more open design, consist of copper tubes and heat exchangers. The air enters the heat exchangers, heats up, rises, making room for a new portion of not yet heated air. The device is protected from cooling by a voluminous casing.

In heating circuits two-story houses Both radiators and convector heaters are used; the choice of devices is large due to the variety of designs, sizes and shapes.

Global Style Extra sectional bimetallic radiators are made of steel (internal structure) and aluminum (external frame), operating pressure– 35 atm

Brief description of household radiators

All types of home heating radiators can be classified according to the material from which they are made. Modern models Heating devices are made from the following metals:

• cast iron;
• aluminum;
• steel.

Cast iron radiator for heating a living space, made in retro style. Metal surface covered with heat-resistant paint and painted with floral designs

Previously, sectional radiators made of cast iron were common, and they can still be found on sale. Cast iron is valued for its wear resistance and undemanding characteristics of the coolant, however heavy weight is considered a minus. Weight should be taken into account if the project involves mounting the radiator on a light wall.

Sectional, that is, prefabricated, models are also made of aluminum. They are lightweight and aesthetically pleasing appearance, but do not come into contact with copper parts and react negatively to some types of coolants.

Royal Termo Revolution aluminum heating radiators are ideal for private systems. Special shape sections provides maximum heat transfer. The cost of 1 section is 500 rubles.

Steel radiators can be panel, made from pieces of sheet steel, or sectional, consisting of several modules. The first option is considered more reliable due to the simple double-sided threaded connection. Steel perfectly tolerates any heat carriers; it is lighter in weight than cast iron, but heavier than aluminum.

Any type of radiator is suitable for a two-story house; when choosing, you need to focus on the type of coolant, features of the system installation and interior design.

Efficiency of forced circulation schemes

The prevailing part of modern heating systems can only when created, that is, one in which the coolant moves within the network due to the operation of the circulation pump.

Diagram of a heating system with a gas boiler in a 2-story house: equipment and metering devices are installed on the first floor (in the basement, in the basement), in a specially equipped room with good sound insulation (+)

For device forced circulation A building with several floors has its own prerequisites:

• installation of a pipeline with a smaller diameter, which facilitates the assembly of the wiring as a whole;
• providing zonal regulation (along with or instead of general regulation);
• the presence of 2nd and higher floors does not affect the heating efficiency;
• reducing the coolant temperature without changing heat transfer parameters;
• possibility of using inexpensive plastic pipes.

The disadvantages include the availability of power supply - interruptions are possible, but they can be easily avoided by using backup UPSs. The problem of louder noise can also be solved by installing a layer of sound insulation in the boiler room.

Scheme of water heating with forced circulation: 1 – gas or electric boiler; 2 – riser; 3 – pipe to the expansion tank; 4 – riser for draining; 5 – top horizontal wiring; 6 – expansion tank; 7 – circulation pump; 8 – return line

Most appropriate place inserting a circulation pump where the temperature drops to a minimum, that is, directly in front of the boiler, on the return line.

Natural circulation as an alternative

Now autonomous heating networks with gravitational circulation, that is, acting according to natural physical laws, can be found extremely rarely.

The principle of operation is explained by the difference in density of cold and heated water and the presence of an additional control device - an expansion tank, which is installed in the upper part of the hot water riser.

Diagram of the heating system in a two-story house with natural circulation: the accelerating vertical riser crosses both floors and ends in the attic, at the expansion tank, and the lower circuit is located in the basement or on the first floor (+)

A special feature is the inclined position horizontal pipes(return and distribution) and the location of the boiler - it is installed at the lowest possible level. The coolant is supplied through the expansion riser, and the cooled water (or antifreeze) is discharged through the return riser.

The advantages of the gravitational scheme are independence from electrical supply, ease of installation, no noise emitted by the circulation pump.

Features of a single-pipe heating system

The choice of one- or two-pipe heating does not depend on the number of floors of the house - both types are suitable, but for buildings with 2 or more floors, the installation of a circulation pump is required.

Heating with liquid coolant (water or antifreeze) is considered the most effective, while for small one-story houses, For example, summer cottages, you can consider other options.

Operating principle and distinctive features

Heating radiators are connected in series, that is, the coolant first enters one device closest to the boiler, from it through a pipeline to another, etc. The looped circuit, which is a network, is also suitable for a 2-story house, since it is conveniently located along the perimeter walls.

The simplest single-pipe heating scheme for a 2-story building: from the supply riser the coolant flows into heating radiators, connected in series order

The presence of shut-off valves can improve the use of the system. For example, Mayevsky’s crane is designed to remove air “locks” that often occur during downtime, that is, in summer period. In addition to it they use various models balancing valves, ball valves, special regulators.

The forced circulation method in a single-pipe structure in the event of a temporary absence of electricity can be replaced by a natural one, but this requires the installation of a membrane tank and the placement of horizontal pipes at an angle of up to 5º.

Assessing disadvantages and advantages

The main advantage of single-pipe networks is considered to be easier drafting of the project and the installation itself. A minimum of pipes allows you not to rely on a complex room layout, but simply lay the pipeline strictly along the perimeters of both floors. Savings on purchasing fewer elements for a single main line - pipes, taps - are also appreciated.

One pipe takes a lot less space, than two, so it can be disguised as flooring, unnoticed to lay in doorways, that is, to carry out installation without disturbing the interior.

One of the main disadvantages of a single-pipe system, relevant for a house with 2 floors, is the rapid cooling of the coolant during sequential movement through the radiators (+)

The disadvantages include the need to purchase a more powerful electric pump, as a result of which the cost of electricity increases. Regulate the temperature level in the structure with serial connection more complicated: when the heating intensity in the nearest radiator decreases, the temperature in the entire line will automatically decrease.

Common connection options

If you decide to install a single-pipe system, you will have to choose between two types:

• simple circuit without regulation;
• "Leningradka" with the ability to turn off individual radiators.

In terms of control method, the first option is clearly inferior to the second; its only advantage is its budget cost.

Installation of a simple single-pipe system of horizontal or vertical type is simple and reliable, but temperature control in the network is impossible (+)

Installing the Leningradka will cost a little more, since in addition to the pipes you need to purchase a set of shut-off valves. Using bypasses and valves, you can reduce/increase the amount of coolant supplied to the radiator.

Diagram of the Leningradka device: using shut-off valves, you can temporarily turn off individual unnecessary radiators without changing the functional qualities of the entire system as a whole (+)

Leningradka is recognized by professional heating engineers the best option single-pipe system for a 2-story residential building.

Complete set and installation of equipment

Standard equipment for system assembly:

• circulation pump;
• gas or electric boiler (power depends on the size of the house, characteristics of the coolant, etc.);
• expansion tank;
• pipes 20 mm and 25 mm;
• adapters, gaskets, plugs;
• set of radiators;
• Mayevsky cranes.

Along with steel pipes Polymer or metal-plastic can be used, with the latter being preferred.

In heating circuits with closed expansion tanks air is bled using automatic vents equipped with shut-off valves and floats, or Mayevsky taps, supplying each radiator

First, they find a suitable place for the boiler and install it, then assemble the pipeline leading to the radiators. Tees are fixed in places of radiator branches and bypasses. The pump is installed on the return line, next to the inlet to the boiler, and connected to the power supply.

The installation location of an open expansion tank is the highest point of the system; a closed one can be mounted in any convenient location, for example, in a boiler room. Radiators are hung from the walls using special fastenings, equipped with plugs and taps.

Two-pipe heating system for a 2-story house

For real comfortable conditions residence can only be achieved with installation. Its design allows you to regulate the temperature in individual rooms and save energy resources.

How does a two-way circuit work?

Unlike the one-pipe circuit, the two-pipe circuit consists of a pair of lines with for various purposes: one of them supplies the coolant, the second takes it back. The radiators are connected not in series order, but in parallel. One circuit, with heated coolant, extends from the riser to the radiators of both floors, the second is mounted to the boiler outlet and is also distributed to both floors.

Radiators are equipped with thermostatic valves that allow you to set a comfortable temperature. If desired, you can reduce the heating intensity partially or completely block the flow of water into the device.

Some devices are fundamentally embedded in the return line, for example, they are traditionally installed in front of the boiler membrane tank, pressure regulating, circulation pump and safety valve

In modern 2-story houses, two-pipe structures are used, since they are much more efficient than single-pipe ones:

• reduce pressure loss;
• do not require a powerful pump;
• keep the coolant temperature the same for each radiator;
• allow you to use many different thermal devices within one system (for example, radiators, convectors and “warm floors”);
• make it possible to repair and replace parts without compromising overall functionality.

The main disadvantage is the complexity self-installation– during assembly, consultation and supervision of professionals is mandatory.

Successful solutions for installing a two-pipe system

There are many incarnations of various schemes, but when drawing up a project you should start from individual requirements.

The simplest diagram for arranging a heating system in a 2-story house. It is characterized by the following points: 2 circuits for heating and hot water production, liquid coolant, forced circulation (+)

A number of universal schemes are suitable for providing heat to homes various sizes and number of storeys.

Detailed diagram of two-pipe wiring for one-story house with fully equipped ground floor. The problem of thermal insulation of the floor in the basement was solved by connecting a water-based “warm floor” system

If you install additional equipment, such as a membrane tank, the capabilities of the heating system will expand.

A and B – two variants of the wiring device, upper and lower type. Additional equipment: expansion tank, Mayevsky taps, overhead line (+)

The following diagram combines the three most popular wiring diagrams.

Level 1 – dead-end wiring with parallel installation of both circuits; Level 2 – counter wiring, characterized by two-way radiator connection; 3 – collector wiring with improved balancing

All of the above schemes are suitable for heating a 2-story building.

Conclusions and useful video on the topic

Informational videos will expand your knowledge about heating systems in 2- and 3-story buildings.

Video #1. Connection diagram for a double-circuit radiator heating system with “warm floors”:

Video #2. Option for wiring a heating system in a 3-story building (using Leningradka):

Video #3. Practical use systems with natural coolant circulation (on a solid fuel boiler):

Thus, the most effective can be considered two-pipe systems heating systems with liquid coolant, equipped with a gas or electric boiler and a circulation pump. Combined systems are more effective, the selection of heat sources depends on the number of storeys and design of the house.

In any case, to compile individual scheme We recommend consulting with heating engineers and designers.

In the block below you can leave a comment, if you have any questions, you can give valuable advice or found errors in the text. Your opinion is important to us.

One house - one boiler. This simple rule is true in the vast majority of cases when designing and installing a heating system. country house. And, given the reliability of modern boilers, this approach is completely justified.

However, despite this, a significant number of owners of private houses, before starting work on designing a heating system in own home, the question of the need for a second boiler arises. In our experience, every second Customer asks it. The initial motivation is usually concern about possible exit boiler out of order at the height of heating season when the outside temperature is below zero. It must be admitted that such fears may be fair, given the not very mild climate in the Chelyabinsk region. And modern gas boilers, although quite reliable, but not absolutely.

How to proceed? In what case is the use of two boilers for heating one house justified and how much will you have to pay for it? The material of this article is devoted to the answers to these questions.

The use of two (or several) boilers for heating a private house may be necessary in the following cases:

• For redundancy - in case one of the boilers fails, the second will provide heating for the house, even if not in full;
• For achievement required power, if you need to use it for heating the house only wall-mounted boilers, and the required power exceeds maximum power one wall-mounted boiler;

Heating boiler operation backup

An increasingly popular solution among installation and design organizations is the use of several boilers for one heating system. This solution is justified with a heat load starting from 40 kW. This can be either a large heated area or the presence of thermal loads in the form of swimming pools, garages, bathhouses, greenhouses, etc.

Using several boilers for one heating system has a number of advantages compared to one boiler with the same total power. Let's list some of these advantages.

• Firstly, several small boilers of smaller size and lighter weight are much easier and cheaper to transport to the boiler room and install there instead of one large and heavy boiler. It becomes especially relevant this moment when installing roof or semi-basement boiler rooms.
• Secondly, the reliability of the system is significantly increased. If one of the boilers is forced to stop, the system will continue to operate, providing at least 50% of the power (if two boilers are installed).
• Thirdly, maintenance is easier due to the smaller size of each boiler. Maintenance of each boiler can be carried out without stopping the entire system.
• Fourthly, the total service life of boilers increases. In autumn-spring, you can operate only part of the boilers by turning off part of the boilers manually or using cascade automation.
• Fifthly, if in the future it becomes necessary to replace any part of the boiler, then it is known that parts for boilers of lower power are more accessible and cheaper due to greater serial production.

Do you need this or can you get by? In the end, everyone decides for themselves, but to make a decision you can be guided by the following arguments:

• Additional redundancy provides “peace of mind” and greater comfort of life in emergency situations.
• Additional comfort and “peace of mind” will cost 30-40% more (boiler installation).
• The use of cascade automation will significantly increase the service life of the system due to the alternating operation of boilers in the off-season.

If you need to reserve boilers, you need to take into account that everything described above applies to cases of redundancy against breakdowns of boiler equipment.

If you want to get fuel reservations, then it is better to use one boiler, but a combined one (gas/diesel, gas/solid fuel). Most common problem With fuel, power outages are considered; gas outages are unlikely.

System redundancy for electricity

If you need to obtain redundancy (independence) for electricity, you should pay attention to the use of non-volatile boilers. When using energy-independent boilers, one very important thing to consider is important feature: they can realize their main property (working without electricity) only when used in gravitational heating systems.

Those. in those that operate on a natural flow of fluid, without the use of pumps. This condition applies only to one-story houses with a small area.

In other cases, when the heating of the house operates on forced circulation (pumps are used), a power outage will cause the pumps to stop and the heating will not function, even with the boiler running. If power outages occur rarely and a short time

- no need to worry, a well-insulated house can keep warm for a couple of days. If you need more confidence and peace of mind, then we recommend having a diesel (gasoline) generator in your home. Which can be started manually during a prolonged power outage and warm up the house. The power of the generator must be selected according to your heating system, plus the power for lighting must be provided.

Increasing the total power of wall-mounted boilers

• Using wall-mounted boilers gives you a number of useful advantages (compared to floor-standing ones):
• Possibility of placing a boiler room in a small room; Ease of implementation of the chimney (there are many models with closed cameras
• combustion). There is no need to organize a massive chimney on the roof; you can make a plastic chimney “through the wall”;

If you are very attracted to these properties (or you have restrictions on the use of boiler equipment), and the area of ​​your house is more than 400 square meters, it makes sense to use two (or more) wall-mounted boilers, considering the maximum power of most models is 35 kW. In this case, in addition to saving space, you also automatically receive the function of reserving the reliability of boiler equipment.

The comparison results show that you will have to pay 10% more to save space and other “amenities”. The difference is much more moderate than in the case of floor-standing boilers, but the service life of wall-mounted boilers is significantly inferior to floor-standing ones - 2 - 2.5 times.

What should you consider when choosing a system of two wall-mounted boilers? When making your choice, take into account the following arguments:

• Saving space is achieved;
• There is no need for a bulky chimney;
• Boiler redundancy is provided;

The service life of wall-mounted boilers is 2 - 2.5 times lower than that of floor-standing boilers;

• Two wall-mounted boilers “in cascade” will cost 10% more than one floor-standing boiler.

When choosing a model of wall-mounted boilers for a two-boiler installation, you must pay attention to whether they are intended for cascade connection.

Typical scheme for using two Baxi SLIM floor-standing boilers

In Fig. 1 two boilers operate on a single heating system. In this case, the built-in automation of one of the boilers is used to heat the boiler for hot water supply.

In addition to the above advantages of using several boilers for one heating system, this scheme allows:

• do without the use of additional complex cascade control blocks;
• use built-in weather-dependent automation of boilers;
• do not change the temperature of the coolant in the heating system if there is a request from the boiler for hot water;*
• use the built-in automatic DHW priority on one of the boilers.

* - when the water temperature in the boiler drops below the set point, the boiler turns off the heating system pump NK1 and turns on the boiler circuit pump NB (DHW priority mode). If the need for hot water large - the boiler can work for several hours to heat water in the boiler without heating the water in the heating system.

Bottom line: this recipe does not exist for all cases, but the information provided will help you make right choice, if you still have doubts, our specialists will help you dot the i’s.