Heating a private house with a wood-burning solid fuel boiler. Solid fuel boiler wiring diagrams

In country houses and cottages where there is no gas pipeline nearby, heating units that burn wood and coal are often used. But the connection diagrams for solid fuel boilers may differ from each other, since pyrolysis devices require the presence of electricity, and such an installation itself has some fundamental differences.

Solid fuel boilers and their connections

Some requirements for installing TT boilers

• The correct operation of the heating system depends, first of all, on the system itself, since it is possible to connect it correctly or not only if the wiring of pipes and radiators is done professionally. After all, in fact, a water heating device of this type has only an input and an output, into which the rest of the circuit fits.
• In order for a solid fuel boiler to work with maximum efficiency and have the longest uninterrupted service life, the operating instructions suggest a minimum outlet temperature of 55⁰C, and an inlet (return) temperature of 45⁰C. Otherwise, condensation on the cold walls of the unit will reduce its temporary performance, destroying the metal. This can be avoided by using different schemes for connecting the boiler to the heating system.

• The installation of the unit is no less important, because the boiler must stand strictly vertically, on a rigid foundation, and this implies a cement screed of at least 5 cm thick with a bedding (half-layer) of the same thickness. The open type expansion tank must be located above the entire heating system and for this purpose it is most often placed in the attic.
• The boiler's chimney must be equipped with a stainless steel valve, and a condensate collection tank must be installed in its lower part. To be able to clean the channel from soot, small, easily accessible hatches can be made along its length. In the unheated part of the room through which the soot removal pipe passes, you should insulate it yourself to extend its service life.

Warning Tips: Operation without a safety valve is strictly prohibited. The use of TT units is only possible in a water circuit with a pressure of about 2 MPa or 2 kg/cm2, and the permissible temperature should not exceed 90⁰ C.

Connection diagrams for TT boilers

• There are many schemes for connecting a solid fuel boiler, and all of them in one case or another are the most acceptable, and sometimes even irreplaceable. But, nevertheless, it is not at all necessary to memorize all the drawings in order to achieve the most optimal result - it is enough to know well the principle of operation of solid fuel units, their advantages and disadvantages.

• To calculate the ideal heating scheme, you need to combine the operation of a solid fuel unit with a thermal energy storage tank as best as possible. The fact is that the operating temperature of a water heating device constantly fluctuates around 60⁰C-90⁰C and it is almost impossible to keep it constant. After all, a boiler running on wood or coal is an inert device, unlike similar gas, electric and even diesel installations (see this material).

• It is not always possible to install a water pump for forced circulation of coolant and the reasons for this may be the most trivial. One of them is frequent voltage drops in the network, which are difficult to equalize with a stabilizer, or even the complete absence of power lines near the house. Of course, the price of such a system will be lower due to the lack of additional equipment, but its installation will require special care to maintain slopes.

• Between the boiler and the tank in the heating system, it would be useful to have safety lines on the inlet and outlet pipes, as close as possible to the water heater. Also, the connection of the boiler to the expansion tank should take place in the shortest possible way, in which taps or safety valves cannot be cut in.
• Pay attention to the distance h in the diagram, which determines the rise of the expansion tank above the top point of the heating system. If for some reason it is impossible to lift the tank, the circulation pump should be cut into a straight pipe. Otherwise, you will open up the possibility of air being sucked into the upper radiators.

There are many different schemes for connecting a solid fuel boiler for heating systems. It all depends on the system and its type, and of course the boiler; the most important thing in all this is the selection of the required technical installation system for a specific connection. Of course, the project can be ordered from licensed organizations that have a lot of experience and education, but finances do not always allow this, so many people draw boiler connection diagrams on their own. First of all, the efficiency of a solid fuel boiler depends on the correct connection. Installation of a heating system for a wood-burning boiler differs from installation of an electric or gas boiler. What is the difference? The fact is that the operating temperature of a wood-burning boiler is 60 - 90 degrees, and this temperature is almost impossible to accurately regulate, because all solid fuel boilers are inert boilers. Few people know all the intricacies of the operation of such a boiler, and they make the mistake of using these boilers at temperatures below 55 degrees, this temperature is the dew point, which will lead to the appearance of condensation that will flow out of the boiler.

At low temperatures, a lot of soot is formed in the chimney and heat exchanger, which will lead to difficulty in maintenance and to a decrease in efficiency. To avoid all these problems, you need to install a buffer tank, also called a heat accumulator. If everything is calculated correctly, then the heat will be transferred with maximum efficiency to the buffer tank, which will serve as a thermos, and the heating system itself will extract heat as needed. With this connection, the solid fuel boiler will produce maximum efficiency, will never overheat, it can be used with maximum efficiency, while fuel will be saved, that is, firewood, there will be less need to burn soot, and there will also be minimal condensation.

How to install a boiler safely, reliably and get maximum comfort.

In order to comfortably use a solid fuel boiler, and also to keep the house warm, the boiler needs to be loaded several times a day, at least twice, of course, all this directly depends on the correct selection of the boiler power and the use of a buffer tank. When choosing a boiler, you need to take into account the height of the ceiling, the thickness of the walls, whether the house is insulated or not, the presence of heated floors and the temperature zone.

Systems using a solid fuel boiler and a buffer tank are not cheap, but at the same time, they are in great demand in European countries. This gives the advantage of independence and efficiency over other heat sources such as electricity or gas.

The connection diagrams for a solid fuel boiler, which are presented on our website, are suitable for almost every home, and it is they that most manufacturers recommend using when connecting a wood-burning boiler to a heating system. The thermo-mixing valve adds cold water to hot water, which prevents cold water from entering the boiler body, this protects the boiler from thermal shock and corrosion; when using such a valve, your boiler will work for a very long time. The change in water volume will be compensated by the expansion tank, and the boiler safety group, also called the “burst valve,” will operate at the moment of excess pressure. The STS-20 valve will supply cold water to the cooling coil from the water supply system at the moment when the temperature in the boiler body reaches 95 degrees, with this scheme the boiler will operate as safely and economically as possible. Another important element in the operation of solid fuel boilers is the correct installation of the chimney. If the chimney is installed incorrectly, many troubles may arise that will lead to a decrease in efficiency, the formation of tar and condensate in the boiler body and smoke in the house or boiler room.

Connection diagrams for a solid fuel boiler in a place with a gas or electric boiler:

Diagram with a buffer tank diagram of a solid fuel boiler and gas diagram with a buffer capacity
connection diagram for a solid fuel boiler; diagram with a boiler; connection diagram for a solid fuel boiler

What kind of boiler room should there be for a solid fuel boiler?

Based on the requirements of regulatory documents, “How to connect a solid fuel boiler,” all boilers over 30 kW must be installed in a separate room.

If the boiler is less than 30 kW, it can be installed in a house or basement; for convenience, you can store fuel for it in one room, but not less than 1 m from the boiler. Before deciding where the boiler will be installed, you need to prepare the base for its installation, it must be made of non-combustible materials, everything in the boiler room must have a fire resistance limit of 0.75 hours. The boiler must be installed so that it can be accessed from all sides, There should be a distance of at least 1 meter from the front of the boiler to the wall, which will ensure trouble-free maintenance of the boiler and its loading with firewood.

The ventilation in the room must be supplied, the minimum diameter of the ventilation duct is 14 cm, and it must be located under the ceiling of the room, preferably above the boiler.

If the boiler is connected to the sewer, then before releasing the water into the sewer system, it is necessary to install a floor drain; if for some reason it is impossible to connect the drain, you need to make a container or well in which the water will be cooled before being discharged into the sewer, You also need to install a pump in this well to pump out water.

Video instructions for installing a solid fuel boiler:

» » » How to connect a solid fuel boiler - Instructions

Due to their considerable size and weight, heating units that burn solid fuel are available in only one version - floor-standing. But before installation you do not need to obtain any permits; the main thing is to follow basic safety rules and ease of maintenance. We will discuss this issue in this publication: we will look at how to correctly install a solid fuel boiler and connect it to the water heating system of a private house.

Wood boiler installation instructions

Regardless of what type of TT boiler you bought - direct combustion, pyrolysis or pellet, the installation procedure remains the same and consists of the following steps:

1. Selecting a specific location in a private house for placing a heat generator.
2. Preparing the premises for installation.
3. Supply and exhaust ventilation device.
4. Installation of heating unit and chimney.
5. Connection to the heating system (piping) and test run.

Note. Depending on the model of a wood-burning or coal-fired boiler, it may be necessary to connect to the electrical network.

The first 3 items on the list relate to preparatory work, which does not at all detract from their importance. If you choose the location of the unit incorrectly and do not provide for normal ventilation, then you will have to solve the problems that arise during operation, in the middle of the heating season. So we suggest looking at each point separately.

To correctly select a heat source based on power, we recommend calculating the heat load for heating using.

Where is the best place to install a TT boiler?

It is noteworthy that to this day no country of the former USSR has developed a specific regulatory document regulating the installation of solid fuel boilers in private and apartment buildings. The main part of the requirements is set out in SNiP “Heating and Ventilation”, certain standards are found in the document SNiP 31–02-2001 “Single-apartment buildings” (for Russia) and in other scattered acts.

Reference. Many online resources send us to read the huge SNiP “Boiler Installations”, without taking into account that its effect extends to heat generators with a capacity of over 360 kW (clause 1.2). Others suggest that we follow the rules for gas heaters. Both options are wrong: the requirements for the placement of domestic TT boilers are not so stringent.

We analyzed the regulatory documentation regarding the placement of wood-burning hot water heaters, added to them the practical experience of our experts and compiled a list of recommendations for the location of the unit:

1. The use of firewood, coal and even briquettes with pellets involves increased dust, and during the combustion process smoke enters the room in different quantities. Therefore, it is extremely undesirable to install a boiler in the house, although the norms allow placement in the kitchen, hallway and other rooms except bedrooms.
2. The best places for a solid fuel heat generator: a boiler room on the street (separate or attached to an existing building), a technical room inside the house, a basement or garage. The last option is a well-ventilated corridor.

   A good solution is to attach a solid fuel boiler room made of foam blocks to the wall of a residential building

3. It is advisable to install the unit closer to the external wall, so as not to lay a long horizontal section of the chimney or bring it out through the ceilings.
4. To maintain and clean the heat exchanger of a TT boiler, ensure access to it from the right sides. Ideally, there should be at least 1 m of free space in front, and 60 cm on the sides and back (minimum 25 cm).

   Installation diagram with permissible distances to the walls and ceiling of the boiler room

5. Do not expect to connect the flue duct of a wood-burning heater to brick ventilation ducts inside the walls, this is strictly prohibited.

Advice. Before purchasing and installing a long-burning boiler of the Stropuva type, compare its height with the premises. Consider the location of other large equipment - a heat accumulator, a buffer tank and an indirect heating boiler.

In small-area furnaces, move the boiler with the unattended side to one of the walls (minimum distance - 10 cm), and leave an opening at the back with a width of at least 250 mm, as shown in the photo.

About preparing the premises

What needs to be done before installing a TT boiler in the intended room of the house:

• provide a foundation and, if necessary, cast a concrete foundation;
• punch holes in the wall for the chimney and ventilation;
• walls and floors built from flammable materials should be protected from fire with sheets of metal, asbestos cement, basalt cardboard or mineralite.

It is not necessary to tear off the wooden cladding of walls and floors. If the boiler is moved closer to a combustible wall than 38 cm, cover the latter with one of the materials listed above. Place the same sheet on the floor below and in front of the TT boiler with a protrusion of 80 cm. This is protection against heat particles flying out of the open door.

Regarding the foundation required by all manufacturers in the operating instructions, we will give the following recommendations:

Advice. Small TT boilers can be placed on a wooden floor. But first you will have to strengthen this area with your own hands by installing additional logs from timber with a minimum cross-section of 100 x 50 mm.

If you plan to install a tank - battery and other heavy equipment in the boiler room, there is no point in pouring foundations for each unit. Make industrial floors - a concrete screed 12 cm high with reinforcement with metal rods with a diameter of 8-14 mm. Tie a mesh with wire with mesh dimensions of 20 x 20 cm and lay it on a bed of compacted crushed stone, as shown in the video.

How to make ventilation in a boiler room

Air exchange in the combustion chamber is organized for the purpose of:

• provide the solid fuel boiler with the required amount of combustion air;
• throw out flue gases that accidentally enter the room from the firebox;
• compensate for the removed air with the same amount of inflow.

For reference. To completely burn 1 kg of wood, it is necessary to supply about 4.6 m³ of air. Combustion of 1 kg of coal will require from 8 to 9 m³, depending on the type and quality.

The following recommendations will help you organize exhaust ventilation in a boiler room with a solid fuel unit:

Calculate the cross-section of the hood enlarged: multiply the heat output of the heater by 8 and get the opening area in cm².

Example. For a 25 kW boiler, the cross-section will be 25 x 8 = 200 cm² or 0.02 m². The dimensions of the exhaust opening are easy to determine - 10 x 20 cm (0.1 x 0.2 m). For inflow, take a 15 x 20 cm grid.

Video: options for placing a heating unit

We install the heat generator and chimney

As such, installing a heating boiler on the floor or foundation is not difficult - the unit must be placed in the design position and aligned vertically using adjustable legs or metal pads. It is not necessary to scrupulously maintain the alignment of the chimney pipe and the hole in the wall: they can be combined without problems by turning the knees.

Important point. To avoid problems with the formation of condensation during operation, it is strongly recommended that the chimney of a wood-burning heater be assembled from insulated pipes - sandwiches. The second option is to make a chimney with your own hands: take an ordinary pipe and cover it with basalt fiber.

The easiest way is to install an external chimney duct of an attached type. That is, attach the pipe vertically to the wall and connect the gas duct from the TT boiler through a tee. In a wooden house, the passage through the outer wall or ceiling for access to the roof is carried out in compliance with fire safety rules using the following technology:

Note. A chimney is laid through a wall made of brick or foam block using a steel liner and seal.

The correct installation and assembly of a modular chimney is reflected in two connection diagrams, which show external and internal installation through the ceiling.

Important note. Make sure that the head of the chimney duct does not end up in the area of ​​wind support on the roof of your or a neighboring house. To ensure stable traction, raise the pipe to the mark shown in the diagram above.

Connecting to the heating system

When the installation of the solid fuel unit and the installation of the chimney are completed, proceed to piping the boiler. The main rule applies here: cold water should not get into a working heat generator (especially with a cast iron heat exchanger). Then, condensation forms on the walls of the firebox due to the temperature difference, which turns into a viscous crust after mixing with soot.

For reference. Sticky deposits are difficult to clean off, and in addition, it significantly reduces the efficiency of a solid fuel installation.

The release of condensate during operation of a solid fuel boiler is minimized using a standard piping scheme with a bypass and a three-way valve set to a fixed coolant temperature of 50 or 55 °C. The water circulates in a small circle until it heats up to the specified temperature, then the valve begins mixing in cold water from the heating system.

Advice. When piping the pellet boiler, pay attention to the connection of the control unit and burner. In products of European manufacturers, there is an automatic fire extinguishing system powered from the water supply network. To avoid making mistakes, before installing a TT pellet boiler, you should consult with a technical specialist of this brand.

Your task is to install shut-off valves, an expansion tank for a closed heating system and a circulation pump in accordance with the diagrams, fill the pipeline network and create it. Next is trial lighting and performance testing. The full range of work on installing a wood-burning boiler is reflected in the next video:

Conclusion

On the one hand, installing a solid fuel hot water boiler is a fairly simple procedure to perform; there are no strict requirements for it and no permission from officials is required. On the other hand, the process is troublesome and time-consuming, associated with a thousand small nuances. However, the homeowner always has a choice: to do all the work themselves or to give some part (for example, piping) to the trained personnel of a specialized company.

Installing a solid fuel boiler now will no longer mean smoke, soot and soot throughout the house. Now such systems have undergone many changes and are worthy of your attention. Why? Let's figure it out together.

This heating device is made mainly of cast iron or heat-resistant steel. Energy is released through the combustion of solid fuel. The materials used are wood, coal, and peat. Modern designs of solid fuel boilers are completely different from the first examples of such boilers. Thanks to the enlarged combustion chamber, it became possible to add a large amount of fuel at once. With today's boilers, you can ensure even 12-hour operation of the equipment without your supervision.

The firewood loading pattern can be vertical or frontal, depending on the design. There are systems with automatic loading. Other similar boilers can be non-volatile, in which the circulation of liquid occurs due to the slope of the pipes, and energy-dependent. The latter will be more economical; in them, water moves through the system under pressure, due to the operation of a special pump. True, in this case, the operation of the equipment depends on the voltage in the network, and the circuit is no longer completely autonomous.

Photo of a solid fuel boiler with automatic loading

Such equipment has a lot of advantages, although it is not without minor disadvantages. Let's look at them all in order. The main advantage is that you can install a solid fuel boiler yourself. Also, unlike gas wiring, you don’t have to run around to different services, wait in queues, obtain the appropriate permits, etc. The next significant advantage is cost-effectiveness.

Compared to a gas solid fuel system, it is 4 times cheaper, and with diesel fuel equipment it is 8 times cheaper. And what can we say about electric boilers, heating a house with them will cost as much as 17 times more than with solid fuel ones.

In the photo - a boiler with a solid fuel system

In addition, such equipment has a long service life, for example, for cast iron boilers it reaches 50 years. Steel units, however, can last you only 20 years, but this is also a lot. Modern devices are equipped with an electronic system, which greatly simplifies control. And don’t forget about maintainability. The operating scheme of such boilers assumes operation without the participation of gas or electricity, so another of their advantages includes partial or complete autonomy.

Now let's talk a little about the cons. Firstly, you will have to put firewood, coal and other fuel into the firebox yourself. It's not difficult, but it will take a little time and effort. Secondly, you will have to constantly monitor the condition of the boiler and, if necessary, clean it of ash formed on the walls and grate.

Correct connection of solid fuel boilers is, of course, necessary, but in order for the equipment to function properly and serve for a long time, it needs proper care. Very often, there are remains of combustion products in the firebox, for example, ash, soot. All this significantly reduces power. Therefore, it is necessary to regularly (at least once a week) clean these deposits from the walls of the firebox. The grate also needs cleaning. To remove unwanted ash, you just need to stir the coals using a special lever. By the way, this simple device will allow for emergency coal discharge if necessary.

Photo of connecting a solid fuel boiler

For proper functioning, you also need to monitor the draft in the chimney and the circulation of liquid throughout the system. For this purpose, the chimney is cleaned once a year. It is very important to properly insulate all its areas located in unheated rooms. Otherwise, condensation will form in them, which will not allow combustion products to escape freely. And to improve the circulation of fluid in the system, you should install a pump. It is placed directly in front of the entrance to the boiler when the water returns to it. This will not only have the best effect on thermal characteristics, but will also allow you to save a little. The liquid will move faster and return to the boiler hot, which means less energy will be spent on its next heating.

Boiler installation diagram and procedure

Please note that installation is a very important matter, and any mistake will result in at least incorrect functioning of the system. But if you are not afraid to take risks, let’s turn to our step-by-step instructions.

How to install a solid fuel boiler - step by step diagram

Step 1: Select a location

Such equipment should be placed in a separate room. Basements or ground floors are most often used as a boiler room. Hot coals from the firebox can fall onto the floor, so the base under the boiler must be perfectly level and non-flammable. A concrete slab is perfect. Be sure to ensure that the body is in a strictly vertical position. Its distortions are unacceptable.

You also need to maintain the following distances. There should be more than half a meter between the back surface of the heating unit and the wall. And from the front side of the boiler to other objects and surfaces, a distance of at least 125 cm is maintained. The ceiling height cannot be less than 250 cm, and the volume of the room in which the heating equipment is located must be more than 15 cubic meters. Treat the floor and walls of the boiler room with special fire-fighting agents and take care of a good exhaust system.

Step 2: Preparing components

The circuit consists of a radiator, a pipe, a circulation pump, an expansion tank and the heating unit itself. The kit also includes a heat accumulator, air and safety valves, a pressure gauge and a thermostat. Be sure to check the serviceability of all elements when purchasing and give preference only to reliable manufacturers.

Step 3: Hardware Installation

We display the unit in the boiler room, adhering to all the above requirements. Pay special attention to the position of the body; it should be positioned strictly horizontally. Therefore, check the prepared area again with a level to see if it is level enough. Then we connect all electric heaters, if any are included in the package. In principle, there is nothing complicated about this, since there is a special place in the boiler itself where the heating element will be located, and next to this element there is a thermostat.

Step 4: Install Piping and Electronics

Connection diagrams for solid fuel boilers assume the presence of pipes. It is best to connect them through shut-off valves. The joints are additionally sealed with flax fibers or special plumbing tape. If we are talking about volatile units, then they, accordingly, should be connected to the network. Don't forget about grounding. Next, we install all the devices responsible for the safe operation of the equipment. This is a thermostat, valves, pressure gauge, draft sensor.

Step 5: Installation of the chimney

Today it is not at all necessary to lay a chimney out of brick; you can assemble it from special plastic elements. Wherein The diameter of the components is selected depending on the power of the equipment. Therefore, be sure to follow the recommendations given in the operating instructions for the selected boiler. Moreover, this stage is especially important, because the key to high-quality operation of a thermal unit is good traction.

Step 6: Filling the Outline

First, we fill the heating circuit with water so that the pressure is slightly higher than the working pressure, and carefully inspect the entire system, especially the joints. This way you will identify all leaks, if any. Then we carefully check whether the internal elements of the firebox are positioned correctly. These include the ignition valve, grates, fireclay stones and plugs.

Step 7: Connection

If the entire circuit is in order, no leaks are detected, then you need to relieve the pressure to operating pressure, adjust the position of the dampers and begin directly operating the heating device. To do this, add and light the fuel, and after 10 minutes close the damper. As soon as the temperature reaches 80 degrees, set the thermostat to the desired level. All that remains is to add firewood in time and enjoy the comfortable microclimate.

The main principles for choosing a heating system for a home are cost-effectiveness, efficiency, and ease of use. Let's consider what it will look like with a solid fuel boiler and what rules must be followed during installation.

Features of solid fuel boilers

Gas supply and centralized electricity supply are still not available everywhere in Russia. Gas is cheap only in capital cities, and even there it is becoming more expensive. Electricity is expensive everywhere.

Communication networks leave much to be desired: power outages and sudden voltage changes are commonplace outside the city. It is not always possible to connect to the main gas, and purchasing liquefied gas in cylinders is an energy-intensive business.

Heating with a solid fuel boiler has several advantages:

• you can choose the type of fuel that is cheapest in your area - firewood, peat, coal, wood waste, etc.;
• solid fuel boilers are the cheapest in the category. Long-burning models are more expensive, but their thermal efficiency is higher;
• a large assortment. Automation and auxiliary strapping elements can be purchased separately if necessary;
• Unlike gas units, the installation of a solid fuel boiler does not require permission from the local administration.

Now about the cons:

• fire hazard. But both gas and diesel models have this drawback. And in case of problems with wiring - even electrical ones;
• the need to monitor the amount of wood/coal in the firebox. A solid fuel boiler cannot be simply “turned on and forgotten”. It is less often necessary to add fuel to pellet and long-burning boilers, but in this regard they are not very autonomous;
• The combustion process of solid fuel is difficult to control (for other units it is enough to turn off the gas valve or turn off the electricity). The inertia of solid fuel boilers is high, and so is the entire system.

Types of solid fuel boilers

Types of solid fuel heating boilers differ in the type of fuel:

• firewood;
• coal;
• pellets and briquettes;
• peat;
• wood processing waste;
• universal boilers with two or more fireboxes.

In addition, there are combined models for two or more energy sources: wood + electricity, wood/diesel/gas, etc. Their purchase is justified if:

• In your area, the two energy sources are equally available and inexpensive. If you run out of firewood, switch to gas; if there are power outages, switch to firewood, and so on;
• in order to save money. For example, if you have a two-tariff payment for electricity, heat with wood during the day, and at night (when electricity is cheap) switch to fully automated electric heating.

There are classic and long-burning t/t boilers. Types of the latter:

• with top ignition. When the flame spreads from top to bottom, the filling burns out more slowly;
• with an extended firebox and limited air supply. Horizontal flame propagation is also slower. By reducing the oxygen needed for combustion, you reduce the intensity of the flame;
• pyrolysis chambers are equipped with two chambers: in one the fuel burns, in the second the gases released during combustion are burned. The thermal efficiency of these units is the highest, but they are also more expensive than others.

Solid fuel boiler piping

A solid fuel boiler rarely includes a circulation pump, automation, or a safety group. The owner purchases all this himself, guided by the characteristics of his heating system.

Regardless of the type of wiring, the pipeline should be equipped with safety devices (see below). The second stage is to ensure the functionality of the system and comfort during its use. A couple of devices worth mentioning here:

• heat accumulator. Thanks to its operation, there will be no sudden temperature changes in the house during the boiler reboot process. This is a large volume tank that is installed between the boiler and the system on the supply pipe. To regulate the temperature at the outlet of the tank, install a mixer with a three-way valve;
• an indirect heating boiler for domestic hot water is connected in parallel to the heating system. They are equipped with a mixer and their own pump so that when moving from the boiler to consumers, the water does not have time to cool down.

Whether or not to purchase a pump if DHW is not provided depends on the wiring. Let's consider its main types.

Open system with natural circulation

This installation scheme is considered the safest for a solid fuel boiler: even with a sharp increase in pressure and temperature, an accident is unlikely. Differences between an open system and others:

• the circuit uses an open expansion tank (it is installed at the highest point of the pipeline);
• There is no circulation pump. Water moves through pipes due to natural gravity. For this design, pipes of a larger cross-section are selected and installed at a slight angle so that the water moves by gravity.

Advantages of open systems:

• Since there is no pump, the heating does not depend on the mains. In suburban conditions, problems with electrical networks are common: interruptions due to broken wires, power surges;
• equipment for piping will cost less (there is no pump, an open tank is cheaper than a membrane one).

• installation is technically more difficult - you need to maintain the required slope of the pipes, install the piping elements at a certain height;
• oxygen inevitably enters the system, which leads to corrosion of pipes and metal fittings;
• for the same reason, airing of the circuit is inevitable;
• the coolant partially evaporates, it has to be replenished;
• even with large pipe diameters, natural circulation is slower than forced circulation. It is necessary to equip all heating devices with control valves, to minimize the number of shut-off valves, but even in this case, heating of the circuit will be uneven.

Closed circuit with natural circulation

There is no pump, but the expansion tank is different - a closed (membrane) type. The system configuration will be the same as in the previous case (large cross-section pipes installed at an angle), but some of the disadvantages of an open circuit can be avoided:

• oxygen does not enter the pipeline through the tank, i.e. slower airing and development of corrosion of internal walls;
• you will not have to regularly restore the amount of coolant in the circuit.

When choosing this type of wiring, consider:

• the tank capacity must contain at least 10% of the coolant volume;
• A safety valve is required on the supply pipe. When the pressure in the system exceeds critical (i.e. more than three atmospheres), the valve discharges excess coolant;
• An air vent is installed at the top point of the circuit.

Installation diagram of a solid fuel boiler with a circulation pump

A system with a pump can only be closed. The advantages of forced circulation are obvious:

• high speed of coolant movement, uniform heating of all rooms;
• large diameter pipes are not required;
• There are no difficulties in installing the pipeline: there is no need to maintain a slope, the height of the membrane tank is not important.

Since the pressure in a system with forced circulation is higher, the requirements for the safety group are also increased.

Installation of such a circuit provides the possibility of switching to natural circulation in the event of a pump breakdown or power outages: the pump is connected in parallel, on a bypass with shut-off valves.

Most often, the pump is inserted into the pipeline in the return pipe section near the boiler; this is where the temperature is lowest. This allows you to save the resource of the device and is safer for the entire system: when installed on the supply pipe, if the water in the boiler boils, the vapors will block the circulation, which can lead to an accident.

On the return side, a filter is installed in front of the pump.

Collector wiring

In a long, highly branched pipeline of a large cottage, one pump may not be enough. In this case, two or even more of them are installed, for each circuit. Separately heated floor, radiators, hot water supply. Since the temperature of heated floors is initially low (within 50 degrees), you can install a pump at the entrance to the circuit.

The optimal wiring option for a large house with several circuits is collector (radial). Each circuit receives coolant from the boiler through its own pipe. The heat is distributed evenly, the liquid does not cool down, consistently passing through the entire system.

The collector includes at least two combs, forward and reverse. The corresponding lines from the boiler are connected to the ends of the combs, and the forward/return pipes of the circuits are connected in parallel to the fittings on their bodies - radiators and heated floors, different floors, utility rooms, DHW - each with its own temperature regime.

A pressure gauge and a safety valve are installed at the entrance to the manifold, an air vent is installed on the opposite side on the “hot” comb, and a tap is installed on the “cold” side to drain the coolant from the system. The pipes are equipped with control valves - this is one way to set different temperatures in the circuits. A large house may have several pairs of combs.

Another way to set different modes is a hydraulic arrow. A vertically placed section of large cross-section pipe is connected to the direct pipe and the return pipe of the boiler, and circuits are connected to the body at different heights. The higher the connection, the hotter the coolant.

In small circuits, the temperature can be adjusted as follows: the free ends of the combs are connected by a bypass to a shut-off valve. When the valve opens, cool water from the return pipe is mixed into hot water from the supply pipe.

Functions of control and safety devices:

• protection of the pipeline from depressurization due to a sharp increase in pressure;
• protection against overheating of the boiler itself;
• temperature control;
• preventing condensation formation. This usually happens due to too large a temperature gap between the supply and return. The optimal temperature delta is 20 degrees.

This group of devices includes:

• safety valve for releasing excess pressure/excess coolant;
• control pressure gauge;
• air vent;
• emergency heat exchanger;
• control fittings, incl. thermostatic valves.

Installation features

Solid fuel boilers are not environmentally friendly equipment; their installation requires a boiler room. During installation, a number of rules are observed:

• At least 1 meter of free space should be left from the firebox to the wall;
• Ventilation ducts must be installed half a meter from the floor and a maximum of 40 centimeters from the ceiling;
• there should be no flammable substances in the boiler room;
• a metal or asbestos sheet of at least 50 by 70 cm in size should be laid in front of the firebox;
• a chimney is installed above the boiler. Recommended chimney parameters are in the boiler instructions.

Inspection hatches should be provided in the chimney pipe to remove soot. A condensate collector is installed at the junction with the boiler. Parts of a metal pipe located in cold rooms (unheated attic, etc.) must be wrapped with thermal insulation material to protect against condensation and icing.

Thermal insulation material for chimneys is basalt wool. All other insulation materials are flammable to one degree or another.