Scheme of installation of a heating system with a solid fuel boiler. Tying a solid fuel boiler: more about the rules of operation and basic schemes

A heating boiler operating on various types of solid fuels differs in operation from gas and electric boilers. Here there are heating and cooling cycles associated with firewood loads, the danger of overheating of the coolant and low-temperature corrosion. Accordingly, the scheme for connecting a solid fuel boiler to the heating system of a building has its own characteristics. The purpose of this article is to show how to properly include the unit in the heating system, including in conjunction with other boiler plants.

The basic scheme of piping a solid fuel boiler

For a better understanding of the processes that occur during the operation of the heat generator, we will show its piping in the figure, and then we will analyze the purpose of each element. In the event that the heating unit is the only source of heat in the house, then it is recommended to use the following basic scheme to connect it:

Note. The basic scheme, where there is a small boiler circuit and a three-way valve, shown in the figure, is also mandatory for use when working with other types of heat generators.

So, the first on the path of movement of the coolant from the boiler plant is the safety group. It consists of three parts mounted on one manifold:

• pressure gauge - to control the pressure in the network;
• automatic air release valve;
• safety valve.

When operating a solid fuel boiler, there is always a risk of overheating of the coolant, especially in modes close to maximum power. This is due to some inertia of fuel combustion, because when the required water temperature is reached or the electricity is suddenly turned off, it will not be possible to immediately stop the process. Within a few minutes after the air supply is stopped, the coolant will still heat up, at which point there is a risk of vaporization. This leads to an increase in pressure in the network and the danger of destruction of the boiler or bursting of pipes.

To exclude emergency situations, the piping of a solid fuel boiler must necessarily include. It is adjusted to a certain critical pressure, whose value is indicated in the heat generator passport. As a rule, the value of this pressure in most systems is 3 bar, when it is reached, the valve opens, releasing steam and excess water.

Further, in accordance with the scheme, for the correct operation of the unit, it is necessary to organize a small coolant circulation circuit. Its task is to prevent cold water from entering the house heating system into the heat exchanger and the water jacket of the boiler. This is possible in 2 cases:

• when heating is started;
• when the pump stops due to a power outage, the water in the pipelines cools down, and then the power supply resumes.

Important! The power outage situation is particularly dangerous for cast iron heat exchangers. A sudden supply of cold water from the system by the pump can lead to cracking and loss of tightness.

If the furnace and heat exchanger are made of steel, then connecting the solid fuel boiler to the heating system through a three-way valve protects them from low-temperature corrosion. The phenomenon occurs if condensation forms on the inner walls of the combustion chamber due to temperature differences. Mixing with volatile fractions and ash, moisture forms a layer of scale on the steel walls, which is very difficult to remove. In this case, the metal is exposed to corrosion and the service life of the product as a whole is reduced.

The scheme works according to this principle: while the water in the boiler jacket and in the system is cold, the three-way valve allows it to circulate along the small circuit. After reaching a temperature of 60 ºС, the unit starts mixing the coolant from the network at the unit inlet, gradually increasing its consumption. Thus, all the water in the pipes warms up gradually and evenly.

Scheme with a heat accumulator

In a number of EU countries, rules have been introduced, according to which schemes for connecting solid fuel boilers to a heating system must necessarily include a heat accumulator. Without it, the operation of such heaters is simply prohibited. The reason is the high content of carbon monoxide (CO) in emissions during the restriction of oxygen supply to the furnace to reduce the intensity of combustion.

With normal access to air, harmless carbon dioxide (CO2) is formed, so the furnace must operate at full capacity, giving energy to the heat accumulator. Then the CO content will not exceed environmental standards. In the post-Soviet space, there are no such requirements yet, respectively, we continue to block the access of air in order to achieve slow decay of wood, for example, in.

Thermal accumulators are commercially available as a finished product, although many craftsmen make them themselves. By and large, this is a tank covered with a layer of thermal insulation. In the factory version, it can have a built-in DHW circuit and a heating element for heating water. This solution allows you to accumulate heat from a wood-burning boiler, and at times of its downtime, provide heating for the house for some time. The connection diagram of the boiler with a heat accumulator is shown in the figure:

Note. In the scheme, instead of a mixing unit consisting of several elements, a ready-made device is installed that performs the same functions - LADDOMAT 21.

Piping with an electric or gas boiler

Often, homeowners purchase a solid fuel boiler as their main source of heat, leaving an existing gas or electric unit in reserve. Usually it looks like this: while the owner of the house is awake, he devotes time to a wood-burning heat generator, but another type of heater is turned on at night. It is a sin not to connect these two boilers in such a way that the system works automatically, that is, when the firewood in the furnace dies out, an electric heater comes into play.

Of course, the scheme of parallel connection of a gas and solid fuel boiler through a buffer tank will work most efficiently. The latter will simultaneously perform 2 functions: to serve as a hydraulic separator and a heat accumulator.

While all heating systems operate from a heat generator on wood or coal, the gas boiler is in standby mode. But when the fuel in the chamber burns out, the temperature of the water in the buffer tank will decrease. This will automatically start the burner of the gas unit, since its circulation pump is constantly running. It will deliver the cooled water to the temperature sensor, which will start the main burner through the controller. When the furnace is ignited, the reverse process will follow, the gas burner will turn off due to the high temperature of the coolant.

It should be noted that the scheme for connecting a solid fuel boiler with an electric boiler through a buffer tank will be absolutely identical. But it has a significant drawback - the high cost. Such a device of the heating system is relevant for private houses of a large area, for small buildings there are simpler solutions:

Both boiler installations are connected in parallel, while check valves are installed at the outlet of each. Since the pump in the electric boiler is built-in, it works constantly and it is impossible to turn it off, it is necessary to choose the right pump for the solid fuel heat generator. The pressure of the latter must be higher so that when working together it has priority over the electric boiler.

This connection of the electric boiler to the solid fuel boiler will function automatically if two devices are installed:

• a thermostat that controls the operation of the biomass heat generator pump;
• room temperature sensor that controls the electric boiler.

During the burning of firewood, the room sensor will record the normal temperature in the house, so the electric heater will not turn on. But as soon as the fuel burns out, the air in the room will begin to cool, as well as the coolant in the pipes. The pump thermostat will turn it off when the water temperature drops, and the sensor will turn on the electric heat generator. For more information, please watch the video:

Conclusion

So, the scheme of the heating system with a solid fuel boiler should ensure its correct, and most importantly, safe operation. At the same time, it is necessary to provide for all individual installation conditions and tie the basic scheme in place, preferably with the recommendations of specialists.

In country houses and cottages where there is no gas pipeline nearby, heating units that run on wood and coal are often used. But the connection schemes 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 connection

Some requirements for the installation of 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. Indeed, in fact, a water heating device of this type has only an input and output, where the rest of the circuit crashes.
• In order for the solid fuel boiler to work with the greatest efficiency and have the longest uninterrupted service life, the operating instructions assume a minimum outlet temperature of 55⁰C, and an inlet (return) temperature of 45⁰C. Otherwise, condensate on the cold walls of the unit will reduce its time indicators, destroying the metal. This can be avoided by using various 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 base, and this implies a cement screed of at least 5 cm thick with a bedding (half bed) of the same thickness. An open-type expansion tank must be located above the entire heating system and for this, most often it is determined in the attic.
• The chimney at the boiler must be equipped with a stainless steel valve, and in its lower part it is necessary to arrange a condensate collector. 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 pipe for removing soot passes, you should insulate it with your own hands in order to extend the service life.

Cautionary advice: It is strictly forbidden to operate without a safety valve. The use of TT units is possible only in a water circuit with a pressure of 0.2 MPa or 2 kg / cm2, and the allowable 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 way 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 the principle of operation of solid fuel units, their advantages and disadvantages well enough.

• To calculate the ideal heating scheme, it is necessary 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 the water heating device constantly fluctuates around 60⁰C-90⁰C and it is almost impossible to keep it in a constant mode. After all, a boiler that runs on wood or coal is an inert device, unlike similar gas, electric and even diesel installations (see this article).

• It is not always possible to install a water pump for forced circulation of the coolant, and the reasons for this can be the most banal. One of them is frequent voltage drops in the network, which are difficult to equalize with a stabilizer, or in general, 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 comply with the slopes.

• Between the boiler and the tank in the heating system, safety lines on the inlet and outlet pipes, as close as possible to the water heater, will not be superfluous. Also, the connection of the boiler with the expansion tank should be made in the shortest way, where no taps or safety valves can be inserted.
• 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 not possible to raise the tank, the circulation pump must be inserted into a straight pipe. Otherwise, you will open the possibility for air to be sucked into the upper radiators.

Solid fuel boilers (wood, coal, peat, etc.) are usually used to heat private houses that are not connected to mains gas. The installation of such systems, due to the danger of an open combustion process, requires compliance with some simple rules that allow you to provide reliable protection against a fire.

In this article, we will describe the basic requirements for a room for a solid fuel boiler and the sequence of its connection to the heating and chimney line.

A solid fuel boiler is a heat unit with an open type combustion chamber. It is clear that the rest of the heating equipment connection scheme should be developed taking into account the requirements for open systems:

• The outlet for the combustion products of the boiler must be connected to a natural draft chimney;
• At the top of the heating circuit, it is imperative to install an expansion tank that ensures contact of the coolant with the atmosphere;
• Such a system can only work on water.

Recently, indoor heating systems have become much more popular among owners of suburban real estate. However, connecting a solid fuel boiler to closed systems is strictly prohibited. The fact is that when water is heated, there is a serious increase in its volume and pressure.

In gas models of boilers, to prevent uncontrolled expansion of the coolant, there is a thermostat that instantly turns off the burner in a dangerous situation. The combustion process in the chamber of a solid fuel boiler is much more inertial: even after a complete shutdown of the oxygen supply to the furnace (for this you also need to connect a thermostat), the water temperature in the heating circuit can rise for quite a long time. This is due to the greater heat capacity of wood compared to gas. So in case of severe overheating, excess water in an open system will simply pour out through the outlet pipe of the expansion tank. If a closed circuit is used, excessive pressure in the pipes can lead to their rupture.

Where can I install a solid fuel boiler

To accommodate boilers with an open firebox, including solid fuel ones, it is necessary to equip a separate room - a boiler room.

Most often, a place is allocated for it in the basement or on the basement floor. Unlike gas heating systems, the installation of a solid fuel boiler can be done independently, without coordination with the supervisory services. However, the installation of such equipment must be carried out in full compliance with the requirements that are given in building codes and regulations:

The main stages of installing a solid fuel boiler

The solid fuel boiler connection scheme includes the heating unit itself, heating pipes and radiators, an expansion tank, a circulation pump, a heat accumulator and automation elements: a safety and air valve, a thermostat, a pressure gauge. The installation of the boiler and the necessary connections of peripheral equipment are carried out in the following order:

After performing all these operations, you can start starting the solid fuel boiler. To do this, you need to ignite the fuel, and after 10–15 minutes, close the ignition damper. When the temperature reaches 80–85 °C, it is recommended to set the thermostat to the required level of heat supply. Now it is enough to put firewood in the firebox at the right moments, and a comfortable climate in the house will be ensured.

Recommendations for the safe and efficient use of a solid fuel boiler

Unlike gas boilers, during the operation of their solid fuel counterpart, part of the combustion products remain in the furnace. They must be periodically removed, as well as other measures to improve the efficiency of the combustion process:

Solid fuel boiler and closed heating system

As we have already noted, the installation of a conventional solid fuel boiler in a closed-type heating system is prohibited.

There are special models of boilers, the execution scheme of which provides for increased strength, resistance to high pressure and the presence of a built-in container for removing excess liquid.

Before such a boiler is approved for installation, it must pass a series of tests, which only specialists can correctly carry out. Therefore, it is not worth making a decision on the use of solid fuel thermal units in closed systems on your own, even if it is recommended by experienced installers who claim that they have already implemented more than a dozen similar solutions at other facilities.

The only possible way to combine this equipment is to use a heat exchanger, which allows you to divide the system into two circuits: open, with a boiler and an expansion tank, and closed, including radiators and a closed membrane tank.

Unlike electric and gas heating units, solid fuel boilers are almost never equipped with circulation pumps, a safety group, adjustment and control devices. Everyone solves these issues on their own, choosing a heating device piping scheme in accordance with the type and features of the heating system. Not only the efficiency and productivity of heating, but also its reliable, trouble-free operation depends on how correctly the installation of the heat generator is carried out. That is why it is important to include components and devices in the circuit that will ensure the durability of the heating unit and its protection in case of emergency.

In addition, when installing a solid fuel boiler, you should not give up equipment that creates additional convenience and comfort. it is possible to solve the problem of temperature difference during the reboot of the boiler, and the indirect heating boiler will provide the house with hot water. Thinking about connecting a solid fuel heating unit in accordance with all the rules? We will help you with this!

Typical piping schemes for solid fuel boilers

The opinion that a solid fuel boiler is an obsolete unit covered with dirt and soot is erroneous, isn't it?

The complexity of controlling the combustion process in solid fuel boilers leads to a large inertia of the heating system, which negatively affects the convenience and safety during operation. The situation is further complicated by the fact that the efficiency of units of this type directly depends on the temperature of the coolant. For efficient operation of heating, the piping must ensure the temperature of the heating agent in the range of 60 - 65 ° C. Of course, if the equipment is not properly integrated, such heating at a positive temperature "overboard" will be very uncomfortable and uneconomical. In addition, the full operation of the heat generator depends on a number of additional factors - the type of heating system, the number of circuits, the presence of additional energy consumers, etc. The ones presented below take into account the most common cases. If none of them meets your requirements, then knowledge of the principles and features of the structure of heating systems will help in the development of an individual project.

Open type system with natural circulation in a private house

First of all, it should be noted that gravity-type open systems are considered the most suitable for solid fuel boilers. This is due to the fact that even in emergency cases associated with a sharp increase in temperature and pressure, heating is likely to remain airtight and efficient. It is also important that the functionality of the heating equipment does not depend on the availability of power. Considering that wood-fired boilers are installed not in megacities, but in areas remote from the benefits of civilization, this factor will not seem so insignificant to you. Of course, this scheme is not without drawbacks, the main of which are:

• free access of oxygen to the system, which causes internal corrosion of pipes;
• the need to replenish the coolant level due to its evaporation;
• uneven temperature of the heat agent at the beginning and at the end of each circuit.

A layer of any mineral oil 1-2 cm thick poured into the expansion tank will prevent oxygen from entering the coolant and reduce the rate of evaporation of the liquid.

Despite the shortcomings, the gravitational scheme is very popular due to its simplicity, reliability and low cost.

Scheme of installation of a solid fuel unit in an open-type heating system

When deciding to carry out installation in this way, please note that for normal circulation of the coolant, the boiler inlet must be at least 0.5 m below the heating radiators. The supply and return pipes must have slopes for normal circulation of the coolant. In addition, it is important to correctly calculate the hydrodynamic resistance of all branches of the system, and in the design process, try to reduce the number of shut-off and control valves. The correct operation of the system with natural circulation of the coolant also depends on the installation location of the expansion tank - it must be connected at the highest point.

Closed system with natural circulation

Installation on the return line will avoid the harmful effects of oxygen and eliminate the need to control the level of the coolant.

Diaphragm expansion tank design

When deciding to equip the gravity system with a hermetic expansion tank, consider the following points:

• the capacity of the membrane tank must contain at least 10% of the volume of the entire coolant;
• a safety valve must be installed on the supply pipe;
• the highest point of the system must be equipped with an air vent.

Additional devices that are included in the boiler safety group (safety valve and air vent) will have to be purchased separately - manufacturers very rarely complete units with such devices.

The safety valve allows the coolant to be discharged if the pressure in the system exceeds a critical value. The normal working indicator is considered to be a pressure from 1.5 to 2 atm. The emergency valve is set to 3 atm.

Learn more about this system from our next article:.

Features of systems with forced movement of the coolant

In order to equalize the temperature in all areas, a circulation pump is integrated into a closed heating system. Since this unit can provide forced movement of the coolant, the requirements for the installation level of the boiler and compliance with slopes become negligible. However, you should not give up the autonomy of natural heating. If a bypass branch is installed at the outlet of the boiler, then in the event of a power outage, the circulation of the heating agent will be provided by gravity forces.

The use of a bypass will allow, if necessary, to switch to the natural method of circulation of the coolant

The electric pump is installed on the return line, between the expansion tank and the inlet fitting. Due to the low temperature of the coolant, the pump operates in a more gentle mode, which increases its durability.

Video: Solid fuel boiler piping

Proper installation of a solid fuel boiler in a closed-type heating system

A huge advantage of solid fuel boilers is that no permits are required for their installation. Installation is quite possible to carry out with your own hands, especially since this does not require any special tools or special knowledge. The main thing is to approach the work responsibly and observe the sequence of all stages.

Arrangement of the boiler room

The disadvantage of heating units used for burning wood and coal is the need for a special, well-ventilated room. Of course, it would be possible to install a boiler in the kitchen or bathroom, however, the periodic emission of smoke and soot, dirt from fuel and combustion products make this idea unsuitable for implementation. In addition, the installation of burning equipment in living rooms is also unsafe - the release of fumes can lead to tragedy.

Solid fuel boilers are best installed outdoors

When installing a heat generator in a boiler room, several rules are observed:

• the distance from the furnace door to the wall must be at least 1 m;
• ventilation ducts must be installed at a distance not higher than 50 cm from the floor and not lower than 40 cm from the ceiling;
• the room should not contain fuel, lubricants and flammable substances and objects;
• the base platform in front of the ash pan is protected with a metal sheet measuring at least 0.5x0.7 m.

In addition, at the installation site of the boiler, an opening is provided for the chimney, which is taken out. Manufacturers indicate the configuration and dimensions of the chimney in the technical data sheet, so you don’t need to invent anything. Of course, if the need arises, then the requirements of the documentation can be deviated, however, in any case, the channel for the removal of combustion products should provide excellent traction in any weather.

How to properly install a chimney

When installing a chimney, all joints and gaps are sealed with sealing materials, and windows are also provided for cleaning the channels from soot and a condensate trap.

Preparing to install the heating unit

Before installing the boiler, a piping scheme is selected, the length and diameter of pipelines, the number of radiators, the type and number of additional equipment and shut-off and control valves are calculated.

Despite all the variety of design solutions, experts recommend choosing combined heating, which can also provide natural circulation of the coolant. Therefore, when calculating, it is necessary to consider how a parallel section of the supply pipeline (bypass) with a centrifugal pump will be installed and provide for the slopes necessary for the operation of the gravity system. Do not give up on the buffer capacity. Of course, its installation will entail additional costs. However, this type of accumulator will be able to even out the temperature curve, and one bookmark of fuel will last for a longer time.

Connecting the boiler to a heating system with a dual-use buffer tank

A heat accumulator with an additional circuit, which is used for hot water supply, will provide special comfort. Given the fact that due to the installation of a solid fuel unit in a separate room, the length of the DHW circuit increases significantly, an additional circulation pump is mounted on it. This will eliminate the need to drain cold water while waiting for hot water to come out.

Before installing the boiler, it is imperative to provide a place and do not forget about devices designed to reduce pressure in the system in critical situations. A simple strapping scheme that can be used as a working draft is shown in our figure. It integrates all the equipment discussed above and ensures its correct and trouble-free operation.

You will learn more information about the arrangement of the boiler room and the installation of equipment from our article:.

Installation and connection of a solid fuel heat generator

After carrying out all the necessary calculations and preparation of equipment and materials, installation begins.

1. Install in place, level and fix the heating unit, after which a chimney is connected to it.
2. They fix heating radiators, install a heat accumulator and an expansion tank.
3. Mount the supply pipeline and bypass, on which a centrifugal pump is installed. In both sections (direct and bypass), ball valves are installed so that the coolant can be transported by forced or natural means.
   

   We remind you that a centrifugal pump can only be installed with the correct orientation of the shaft, which must be in a horizontal plane. The manufacturer indicates the schemes of all possible mounting options in the instructions for the product.

4. The pressure line is connected to a heat accumulator. I must say that both the inlet and outlet pipes of the buffer tank must be installed in its upper part. As a result, the amount of hot water in the tank will not affect the readiness of the heating circuit. Be sure to note the fact that the cooling of the boiler during the reboot period will reduce the temperature in the system. This is due to the fact that at this time the heat generator will work as an air heat exchanger, transferring heat from the heating system to the chimney. To eliminate this shortcoming, separate circulation pumps are installed in the boiler and heating circuits. By placing a thermocouple in the combustion zone, it is possible to stop the movement of the coolant through the boiler circuit when the fire is extinguished.

   

   Installation of separate pumps on the boiler and heat exchange circuit can solve the problem of heat leakage through the boiler when it cools down

5. A safety valve and an air vent are installed on the supply line.
6. They connect the emergency circuit of the boiler or install shut-off and control valves, which, when the water boils, will open the line for its discharge into the sewer and the channel for supplying cold liquid from the water supply.
7. Mount the return pipeline from the heat accumulator to the heating unit. Before the inlet pipe of the boiler, a circulation pump, a three-way valve and a sump filter are installed.
8. Separately, an expansion tank is mounted on the return pipeline.
   

   Note! On pipelines that are connected to protection devices, stop valves are not installed. These areas should have as few connections as possible.

9. The upper outlet of the heat storage tank is connected to a three-way valve and a heating circuit circulation pump, after which radiators are connected and a return pipeline is mounted.
10. After connecting the main circuits, they begin to equip the hot water supply system. If the heat exchanger coil is built into the buffer tank, then it will be enough just to connect the cold water inlet and the outlet to the “hot” main to the corresponding pipes. When installing a separate indirect water heater, a circuit with an additional circulation pump or a three-way valve is used. In both cases, a check valve is installed at the cold water inlet. It will block the path for the heated liquid to the "cold" water supply.
11. Some solid fuel boilers are equipped with a draft regulator, the work of which is to reduce the flow area of ​​the blower. Due to this, the air flow into the combustion zone is reduced and its intensity, and, accordingly, the temperature of the coolant decreases. If the heating unit has such a design, then they mount and adjust the drive of the air damper mechanism.

    

    Installing an automatic draft regulator will allow you to control the process of fuel combustion

The places of all threaded connections must be carefully sealed with sanitary flax and a special non-drying paste.

After the installation is completed, the coolant is poured into the system, the centrifugal pumps are turned on at full power and the places of all connections are carefully inspected for leakage. After making sure that there are no leaks, they kindle the boiler and check the operation of all circuits at maximum modes.

Features of the integration of a solid fuel unit into an open heating system

The main feature of open heating systems is the contact of the coolant with atmospheric air, which occurs with the participation of an expansion tank. This capacity is designed to compensate for the thermal expansion of the coolant, which occurs when it is heated. The expander is cut in at the highest point of the system, and in order to prevent hot liquid from flooding the room when the tank overflows, a drain pipe is connected to its upper part, the second end of which is led into the sewer.

Expansion tank structure of open type

The large volume of the tank forces it to be installed in the attic, so additional insulation of the expander and the pipes suitable for it will be required, otherwise they may freeze in winter. In addition, it must be remembered that this element is part of the heating system, so its heat loss will lead to a decrease in temperature in the radiators.

Since the open system is not hermetic, there is no need to install a safety valve and connect emergency circuits. When the coolant boils, the pressure will be released through the expansion tank.

Special attention should be paid to pipelines. Since the water in them will flow by gravity, the circulation will be influenced by the diameter of the pipes and the hydraulic resistance in the system. The last factor depends on turns, narrowings, level drops, etc., so their number should be minimal. In order to initially give the water flow the necessary potential energy, a vertical riser is mounted at the outlet of the boiler. The higher the water can rise along it, the higher the coolant speed will be and the faster the radiators will warm up. For the same purpose, the return inlet must be located at the lowest point of the heating system.

Finally, I would like to note that in open systems it is preferable to use not antifreeze, but water. This is due to a higher viscosity, reduced heat capacity and rapid aging of the substance upon contact with air. As for water, it is best to soften it and, if possible, never drain it. This will increase the service life of pipelines, radiators, heat generators and other heating equipment several times.

Pay attention to the article on the choice of coolants for heating systems:.

Video: Connecting a solid fuel boiler with your own hands

As you can see, the choice of a boiler integration scheme depends on many factors, including the features of the heating system and the need to install additional equipment. If you have successfully figured out all the nuances, then you can safely get to work. Finally, I would like to note that heating is one of the most complex and responsible engineering systems. If you do not have self-confidence, do not experiment. Remember that installation errors will sooner or later result in serious problems, so do not hesitate to ask the experts for advice.

Heating units operating on various types of solid fuels differ significantly in operation from electric, gas and liquid fuel heat generators. In this regard, the connection of a solid fuel boiler has a number of features. Consider how to properly install the heating unit so that its operation is efficient and safe, as well as how a heating system with two boilers is installed.

Solid fuel boiler in the heating system

Features of solid fuel boilers

The difference between a solid fuel heat generator and boilers operating on other energy carriers is based on the characteristics of the combustion of wood, coal and other types of solid fuels.

1. Inertia. Solid fuel that has ignited in the combustion chamber cannot be abruptly extinguished, so there is always a risk of overheating of the coolant. Boiling water in the boiler jacket leads to an abrupt increase in pressure in the system and its depressurization. To avoid an emergency, it is mandatory to include an automatic valve designed to relieve pressure in the piping of a solid fuel boiler.

Due to the inertia, it is more difficult to control the heating of the coolant - after the thermostat is triggered, the valve closes, reducing the air flow into the combustion chamber, but for some time the combustion continues in the same mode and the temperature of the liquid in the circuit has time to rise by at least 2-3 degrees more before stabilizing.

Attention! The pellet boiler is deprived of such a disadvantage as high inertia, since the design provides for the supply of fuel into the combustion chamber in small portions. The cessation of supply leads to a rapid extinction of the flame.

2. Condensation of moisture in the firebox. Condensation is formed if a very cool coolant with a temperature below 50 degrees enters the water jacket of the unit. Condensation is fraught with rapid corrosion of the metal from which the walls of the combustion chamber are made, since this moisture is an aggressive environment. In addition, condensate mixed with ash forms a sticky substance that is difficult to clean from the inside of the firebox.

The connection diagram of a solid fuel boiler should include a mixing unit, due to which the liquid heated by the boiler is mixed into the cooled return coolant.

Attention! Cast iron solid fuel boiler is resistant to corrosion and is not afraid of condensate. However, a mixing unit is also added to the piping of such a unit, since the flow of cooled coolant into the water jacket of a hot boiler can lead to the destruction of cast iron due to temperature shock.

Basic principles for connecting a solid fuel unit

When considering how to properly connect a solid fuel boiler, it is necessary to pay attention to the basic piping elements that ensure the safety of the heat generator. We are talking about the safety group and the mixing unit.

The safety group, which includes a pressure gauge, as well as a safety valve and an air vent, mounted on one manifold, is installed directly on the outlet pipe of the boiler unit. The pressure gauge helps to monitor the pressure in the system, the air vent is used to remove air plugs, and the safety valve dumps excess steam-water mixture when the pressure exceeds the specified parameters.

Important! It is forbidden to install a circulation pump or stop valves between the branch pipe and the safety group.

A mixing unit based on a three-way valve with a thermal head is installed together with a bypass (jumper) connecting the supply and return pipes, thereby forming a small circulation circuit.

The system that protects the boiler from condensate and temperature shock operates according to the following scheme:

1. While the fuel flares up, the valve blocks the flow of the cooled coolant from the large circuit of the heating system. As a result, the circulation pump drives a limited volume of coolant in a small circle.
2. A sensor is installed on the return pipe, connected to the thermal head of the three-way valve. When the coolant in the return pipe heats up to 50-55 degrees, the thermal head works and presses on the valve stem.
3. The valve opens smoothly and the cooled coolant begins to gradually enter the boiler jacket, mixing with the heated one from the bypass.
4. When all radiators warm up and the return temperature rises to values ​​that are safe for the boiler, the three-way valve closes the bypass, completely opening the passage for the coolant flow through the return pipeline.

The basic scheme for connecting a solid fuel boiler to the heating system is as simple and reliable as possible; you can install the piping yourself.

It is important to know how to connect a solid fuel boiler using polymer pipes in order to avoid common problems:

• Polymer pipes are not safe to use for piping the boiler - they may not withstand an emergency increase in temperature and pressure. Therefore, it is recommended that the piping be made with steel or copper, and the polymer pipes should be connected to a collector that distributes the coolant through the heating circuits. In extreme cases, a metal pipe is mounted only between the boiler supply pipe and the safety group.
• The use of a thick-walled polypropylene pipe for the return pipeline in the area between the three-way valve and the boiler nozzle leads to the fact that the overhead temperature sensor reacts to the heating of the coolant with a noticeable delay. It is better to install a metal pipe.

Connecting a solid fuel installation with a hydraulic boom

The pump for the heating system with forced coolant supply is installed on the return pipe between the three-way valve and the boiler. This arrangement allows it to circulate water or antifreeze in a small circle. It is impossible to put a circulation pump on the supply pipe, since the device is not designed to work with a steam-water mixture, which is formed when the coolant is overheated. Stopping the pump will accelerate or provoke an explosion of the heating boiler, since the cooled coolant will no longer flow into it.

How to make strapping cheaper

The basic scheme for connecting a solid fuel boiler provides for the use of a three-way mixing valve equipped with a thermal head and an attached sensor. This equipment is quite expensive, and it can be replaced with a cheaper option - a three-way valve with a built-in thermostatic element. Such a device is distinguished by a fixed setting - the valve is activated when the temperature of the medium reaches 55 or 60 degrees (depending on the model).

Installing a valve that maintains a fixed temperature reduces the financial costs of installing the protection of a solid fuel unit from condensate and thermal shock. The ability to flexibly control the temperature of the coolant is lost, deviations from the set value can reach 1-2 degrees, but this is not critical.

Tying with a heat accumulator

In order for the solid fuel unit to operate in optimal mode and its efficiency to approach the passport values, it is necessary to use a buffer tank, which serves as an accumulator of excess thermal energy remaining after heating the coolant in the heating circuit to operating temperatures.

If a wood or coal boiler works without a heat accumulator, the draft must be reduced so that the wood does not burn too hot and the coolant does not overheat. But due to the lack of oxygen, an increased amount of carbon monoxide is formed, which enters the atmosphere. In advanced European countries, for this reason, it is forbidden to operate solid fuel heaters without mounting a buffer tank.

The installation of a heat accumulator has another advantage: the fuel that burns with an optimal supply of oxygen gives off maximum thermal energy, and its excess does not fly into the chimney, but accumulates in a buffer tank. This allows you to maintain a high temperature of the coolant in the heating circuit for several hours after the fuel load burns out.

The piping of a solid fuel boiler with a heat accumulator provides for the connection of a buffer tank as follows:

Scheme of piping a heat accumulator with a solid fuel boiler

To control the temperature of the coolant that is supplied to the radiators, a second three-way valve and a second circulation pump are installed on the supply line after the heat storage tank connected to the system.

The cooling time of the coolant in a system with a heat accumulator after the attenuation of the boiler depends on the volume of the reservoir and the heating temperature. For a private house with an area of ​​150-200 sq. m requires a buffer capacity of 1 cu. m. You can purchase a ready-made heat accumulator of a suitable volume or make it yourself - it is a rectangular or cylindrical container made of steel sheet, equipped with reliable thermal insulation.

Important! The installation of a heat accumulator should be provided for at the stage of developing a heating system project. In order for the boiler to simultaneously heat water in the heating circuit, the DHW system and in the buffer tank, its capacity must be twice the calculated one.

Installation with electric or gas unit

Two heat generators can be installed in one heating system, the main of which is a solid fuel unit, and the additional one is a boiler running on gas or electricity. This option is convenient because at night you can turn on the boiler, which operates in automatic mode. Bottled gas is inconvenient to use as the main energy carrier due to the need to take care of regular fuel supplies. Electricity is the most expensive energy carrier and it is most profitable to operate such a boiler unit only at night, if the region has a system of cheap night tariffs.

How to connect solid fuel and gas boilers in one system for heating a large house? The simplest option is to connect two heat generators in parallel through a heat accumulator, which will additionally perform the function of a hydraulic separator.

The gas boiler operates in standby mode while the water in the buffer tank is heated by a solid fuel unit. After the fuel burns out, the coolant begins to cool down, and as soon as the temperature sensor transmits the appropriate signal to the gas unit controller, it automatically turns on. When a solid fuel heat generator is restarted, the reverse process occurs - heating the coolant above a certain temperature leads to the shutdown of the gas burner.

A system with an electric boiler in large-area houses is mounted according to a similar principle. But for small private houses, a simpler and cheaper option for connecting a TT and an electric boiler is relevant (see diagram).

Scheme of connection of solid fuel boiler and electric boiler

Boiler units are connected in parallel with the installation of check valves at each outlet. The electric boiler is equipped with a built-in circulation pump, which cannot be turned off, therefore, for a solid fuel heat generator, it is necessary to select a more powerful pump so that the TT boiler has an advantage over an electric one when operating together.

The system is complemented:

• a thermostat that turns off the circulation pump TT of the boiler when the coolant cools down;
• room temperature sensor, which turns on the electric boiler when the room temperature drops after the fuel burns out in the TT unit.

Method of primary and secondary rings

How to connect two boilers in one system using a minimum amount of electronics? The use of the method of primary and secondary circulation rings allows you to perform a joint piping of the CT of the unit and the electric boiler. Hydraulic separation of flows is carried out without the installation of a hydraulic switch.

Option to connect two types of boilers to one heating system

Both boilers, the DHW boiler, as well as all heating circuits, are connected by both the supply and return pipelines to a single circulation ring - they are primary. The minimum pressure difference is ensured due to the small distance between each pair of connections (no more than 300 mm). The pressure of the pump installed on the main circuit ensures the movement of the coolant along the primary ring, while the flow rate is not affected by the pumps of the secondary circuits (to which heat consumers are connected).

For the system to function properly, it is necessary to perform complex hydraulic calculations and select the optimal diameter of pipelines for all circuits. It is also important to calculate the performance of the pumps. The actual performance of the pumping unit on the main circuit must exceed the flow rate of the coolant on the most "volumetric" secondary circuit. Both boilers are equipped with shut-off thermostats so that they can work replacing each other.

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Basic requirements for the boiler room

Household solid fuel heat generators are installed in separate dry rooms, outbuildings or separate buildings. The dimensions of the boiler room are determined by the dimensions of the unit, as well as the features of its maintenance, however, the smallest allowable area is 7 sq.m. At the same time, it is necessary to provide a place protected from atmospheric influences for storing the fuel supply - it must be dry before loading.

If the walls of the boiler room are made of combustible materials, they must be covered with a 2.5-3 cm layer of plaster or thermal insulation in the form of an 8 mm layer of asbestos and sheet iron. In the absence of fire protection of the ceiling, the distance from it to the boiler body must be at least 120 cm.

The normal operation of a solid fuel boiler is ensured by a stable air supply. Therefore, in the boiler room it is necessary to perform supply and exhaust ventilation. The channel of the first with dimensions of 30x30 cm should go to the lower part of the wall opposite the chimney, and the exhaust hole, the dimensions of which should be 40x40 cm, is located no more than 40 cm from the ceiling. The ventilation of the boiler room must provide normal draft. With its lack, the performance of the boiler decreases, and with an excess, it becomes difficult to regulate the process of fuel combustion.

The solid fuel boiler must be installed on a strictly horizontal fireproof (concrete or brick) platform with a thickness of about 7 cm. On a wooden floor, such equipment can only be installed with an intermediate brick layer covered with a 3-4 mm metal sheet or at least 5 cm cement screed . The base of the solid fuel boiler should be 10-20 cm wider than the outer dimensions of the body, but the sides of the firebox should additionally be equipped with a safety zone with a width of at least 40 cm.

Installation standards

Requirements for the installation of solid fuel heating boilers are regulated by the Fire Safety Standards (NPB) and Building Codes and Rules (SNiP). It is very important to follow the provisions of these regulatory documents, since not only the efficiency of the heating system being equipped, but also the safety of the residents of your home directly depends on this.

Basic standards for the installation of solid fuel boilers:

• the distance from the body of the heating boiler to the walls of the boiler room must be at least 0.5 m;
• there should be no gaps between the bottom of the boiler and the screed;
• the distance from the firebox door to the opposite wall of the boiler room must be at least 1.3 m;
• if the heating system is designed for natural circulation of the coolant, the boiler should be placed in such a way that its heat exchanger is lower than radiators and other heating devices;
• the first meter of the inlet and outlet pipes is made of steel pipe;
• the inner walls of the chimney are protected by stainless steel sheet;
• the section of the branch pipe through which flue gases are discharged from the boiler must be not less than the section of the chimney;
• the vacuum at the outlet of the boiler is regulated by the height and configuration of the chimney - it should be 10-80 Pa;
• the junction of the flue pipe and the chimney is sealed and sealed;
• the chimney must have a minimum number of elbows;
• the temperature of the water entering the heat exchanger from the heating system must have a temperature of at least 60 ° C;
• when equipping the heat exchanger with a heating element, the boiler is grounded without fail;
• the connection of the flue pipe of the boiler with the chimney must be collapsible;
• if the roof of the building is made of combustible materials, the chimney must be equipped with a spark arrester;
• the chimney channel must be equipped with valves, as well as a hatch for cleaning soot.

Connecting a solid fuel boiler from various angles in the photo

What do you need to install a solid fuel boiler with your own hands?

If you are not going to involve specialists for the installation of a solid fuel boiler, you will have to prepare for work yourself.

First of all, you will need overalls and tools:

• overalls, leggings and a welding mask;
• welding machine;
• circular saw with cutting discs for metal;
• building level and square;
• a set of open-end wrenches;
• wrenches;
• screwdriver with a set of various nozzles;
• tape measure and marker;
• sealant gun.

To connect the boiler to the heating system, you must additionally purchase:

• 2 ball valves with a drive and double-sided (external and external) thread with a diameter of 50 mm;
• safety group (pressure gauge, safety valve, automatic air vent and a pair of ball valves with a diameter of 15 mm);
• 3 steel couplings with a diameter of 50 mm;
• steel adapters 57-32 mm;
• steel bends with a diameter of 50 mm;
• chimney with slide gate valve;
• metal pipes for connecting the boiler;
• thermal sealant;
• sanitary winding;
• circulation pump (installed on the return line and provides forced circulation of the coolant in case of natural obstruction).

The most important thing when installing a heat generator is to follow the manufacturer's instructions. Before starting installation work, it is necessary to assemble the heating system and check it for leaks, as well as organize ventilation and smoke exhaust systems in the boiler room.

Heating systems based on solid fuel boilers should be equipped with open expansion tanks, the function of which is to protect communications from breaking due to overheating of the coolant.

The subtleties of installing solid fuel boilers

The boiler piping scheme is adopted in accordance with the characteristics of the heated object.

It can be implemented using one of the following options:

• boiler in an open heating system with natural circulation and radiators;
• boiler in a closed system with forced circulation and radiators;
• boiler with thermal accumulator in a closed forced system with radiators;
• boiler with a thermal accumulator in a closed system with forced circulation and underfloor heating;
• boiler with radiators and underfloor heating as part of a forced circulation system.

The piping of a solid fuel boiler must be equipped with a security system. The latter includes:

• thermal accumulator or buffer tank;
• three-way valve for mixing cold water;
• thermostat in the control system.

The safety group of a solid fuel boiler is installed at the outlet, i.e. on the hot water line.

Immediately before installing a solid fuel boiler, it is necessary to carry out its visual inspection and test firing in the open air for about 1 hour at the maximum load of the combustion chamber.

According to the requirements of SNiP, after connecting the boiler, a hydraulic test of the system under pressure with a holding time of 24 hours should be carried out.

For this you need:

• connect water, open all taps and valves;
• raise the pressure in the system to 1.3 atm (control valve);
• make sure that there are no leaks, especially in the places of welded and threaded connections.

If the installation, piping and connection of the boiler are performed correctly, there will be no pressure loss and no leakage of the coolant. In this case, you can proceed to the revision of the boiler itself:

• checking the installation of grate and fireclay;
• setting the ignition damper to the extreme position to ensure optimal traction;
• checking the quality of installation of plugs, combustion chamber doors and other structural elements of the boiler.

First start of the heating system

Before the first kindling of the boiler, the pressure in the system should be about 1 atm. Don't forget to open the damper on the chimney. The kindling material is placed on the grate, after which fuel can be loaded into the combustion chamber. After 10-15 minutes from the moment of ignition, the ignition damper should be closed. When the temperature of the coolant in the system reaches 85 ° C, you should adjust the thermostat, and then set the minimum (about 5 cm) gap between the primary damper and the furnace door.

The dampers allow you to adjust the volume of secondary air and thus increase the efficiency of the heating boiler.

Installing a solid fuel boiler is not an easy task, but it is quite solvable. It is important not only to comply with the requirements of regulatory documents, but also to follow elementary logic. And do not forget to use the successful experience of those who have already dealt with the organization of heating systems based on solid fuel heat generators. The most important thing is to ensure the optimal operation of the heating equipment. After all, its reliability and durability and, of course, the microclimate in the premises of your home directly depend on this.

Proper installation and connection of a solid fuel boiler on video

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Solid fuel heating boilers and their features

Solid fuel boilers are the cheapest way to equip the heating in the house, although this is not an easy task. Companies producing boilers of this type are producing more and more consumer-friendly models that emit a minimum of harmful gases into the environment. However, obsolete models are still being produced, although their number is decreasing every year, and professional, modern, efficient, easy-to-use and safe boilers are coming out of the place.

Solid fuel boilers can be of upper and lower combustion. If the main intended fuel for the boiler is wood, then you should choose a lower combustion model. The efficiency of such a boiler will be higher than that of the upper combustion model, since these boilers are designed for coal combustion.

The lower combustion boiler consists of two or three combustion chambers, which makes it possible to completely burn all fuel particles. The result of this principle is that there is a significant reduction in fuel consumption and harmful substances enter the atmosphere in a smaller amount (the opposite situation is observed with boilers with upper combustion, in which unburned particles enter the atmosphere along with smoke).

Boilers with bottom combustion open up possibilities for controlling the combustion process and adjusting productivity, dosing portions of the air that enters the furnace compartment. This is possible thanks to a draft regulator or a fan with a control system.

Solid fuel boilers made of cast iron and steel

Cast iron boilers are more resistant to corrosion than steel ones. This is an important point, since during the ignition of a solid fuel boiler, until the temperature in the combustion chamber exceeds the dew point temperature, condensate forms in the combustion chamber. This dew is not just water, when coal burns, it turns into a very aggressive environment. For this reason, corrosion on a steel boiler will appear earlier than on a cast iron one.

A steel heat exchanger will burn out much earlier due to the fact that cast iron has a higher fire resistance. However, a cast iron kettle is more brittle than a steel one and can break if it is hit accidentally. For cast iron boilers, temperature fluctuations are detrimental - the temperature of the heated liquid should not exceed the return flow temperature by more than 20 ºC.

Cast iron boilers are divided into sections, and this makes it possible to transport in parts. If a fault is found in one section, then the entire boiler will not have to be replaced. These options are not available on steel boilers, which are one piece. A steel cauldron is much easier to manufacture, while a cast iron cauldron requires special casting techniques.

The configuration of steel boilers can be completely different, while cast iron boilers are very similar. The reason for this is the peculiarities of the sectional design. Since cast iron boilers are difficult to optimize, their efficiency is slightly underestimated compared to steel ones.

Battery tank in the home heating system

The battery tank in the heating system can also be called a buffer tank. Today, they are increasingly beginning to be used in heating systems. Let's take a closer look at what it is.

A tank accumulator or heat accumulator is almost the central element in a heating system powered by several heat sources. A non-permanent heat source, such as a solid fuel boiler or solar system, heats the water in the storage tank cavity, and can meet the moderate heat demand of the heated space. And the share of other sources of thermal energy, which have higher operating costs, will be much less.

An electric boiler in multi-tariff mode also works much more economically if it is used in tandem with an accumulator tank, which makes it possible to save electricity as much as possible at night.

Heating systems in which there are heat pumps are also often equipped with storage tanks.

The heating system, powered by a solid fuel boiler in the presence of a heat accumulator, operates in the optimal mode. The coolant comes from the boiler to the capacity of the accumulator tank as hot as possible. And already from the heat accumulator charged by the boiler, the coolant is transferred into the system as needed, and does not depend on whether the boiler is working.

A person using a heat accumulator significantly increases his comfort in terms of heating, even outdated heating systems equipped with a buffer tank are comparable to modern ones in terms of quality. You can load fuels and service the boiler at any time. An opportunity is formed for the complete automation of the heating system after the installation of the accumulator tank. Thermal energy from the tank will be taken in the amount in which it is necessary. The battery tank will protect the boiler from excessive overheating. Installing a heat accumulator makes it possible to use materials made of polymers, and if the tank is not installed, then this cannot be done.

Boiler heating scheme

The boiler heating scheme, or rather its compilation, is a task that requires the right approach. The owner of the building is obliged to choose the most optimal option for heating his home, based on his material capabilities and fuel, which can be easily found.

Adjustable heating system in a two-story house

In this case, a diagram of the heating system of a two-story house is presented. Most often, a water heating system is installed, although air-type heating systems are becoming increasingly popular. The presented scheme can be taken as a basis for more voluminous objects, taking into account the correct adaptation to a specific situation. The scheme can be implemented independently, although the best option would be installation by highly qualified specialists. This is due to some nuances that may occur during the implementation of the heating system, and during its further operation.

• metal-plastic pipes of the required diameter;
• boiler;
• several throttles;
• gas convectors;
• several cranes;
• heating batteries;
• brackets.

Heating a house with a solid fuel boiler

Heating a house with a solid fuel boiler is an urgent task today. This is due to the fact that energy carriers are becoming more expensive every day, and they are not always affordable, which cannot be said about solid fuels.

Since cottage construction is on the rise, people are increasingly wondering how to heat their cottages. Gas is not supplied to houses of this type immediately, and sometimes it is delayed for a long time, and diesel fuel or electricity is quite expensive.

Naturally, you can use a conventional wood-burning stove or fireplace, but they have minimal heat output, and you will have to keep an eye on them all the time. Installing a solid fuel boiler is the best solution to this problem. Solid fuel boilers can be fired with coal, wood, peat or special wood pellets. Heating a house with a solid fuel boiler is very easy in terms of maintenance and time costs associated with it. All you need to do is add fuel from time to time.

Solid fuel boilers are classic and pyrolysis. In a traditional type boiler, water acts as a heat carrier, which heats up during the combustion of fuel. After that, the already heated coolant is distributed through the heating system, thereby heating the house. In pyrolysis boilers, they are also called gas generators, the principle of operation is the dry distillation of fuel.

Under the action of high temperature (200 - 800 ºC) in a low-oxygen environment, wood decomposes and pyrolysis gas is released. When this gas comes into contact with oxygen, it ignites, and this is accompanied by the release of a large amount of heat. In a gas-generating boiler, there is an increase in the interval of throwing fuel twice, compared with a conventional one, and the efficiency can reach 90%. In addition, in such a boiler, the fuel burns completely.

The boiler may also depend on a third-party influx of energy, or it may not depend. Volatile boilers need an external source of electricity as they may be equipped with an electrical control panel and may have a fan installed to blow air. Thanks to this, the air circulation system is greatly simplified.

Summing up, we can say that a solid fuel boiler can be used both as the main source of heat and as a backup one. Despite the fact that such a boiler requires constant maintenance, it may be the only solution available in remote parts of our country. And affordable and inexpensive fuel for it allows the use of such boilers in all types of country houses.

Solid fuel boiler in operation - video

The heat accumulator is a necessary element of the heating system with a solid fuel boiler of a private house. The previous article describes a heat accumulator - a kind of analogue of a Russian stove in a modern house - “Heating a house with a solid fuel boiler”.

To heat a private house with underfloor heating with a solid fuel boiler, it is necessary to use a forced heating scheme, in which the circulation of the coolant - water, is provided by pumps. In addition, the forced heating scheme with a solid fuel boiler must ensure a decrease in the temperature of the boiler water supplied to the underfloor heating pipelines.

Boiler manufacturers, in the operating instructions attached to the boiler, often publish schematic diagrams of heating systems that are recommended for connection to the boiler. In addition, the instructions contain requirements for technical parameters:

• chimney;
• heating system equipment;
• systems that ensure safe operation (fire and explosion safety);
• elements of control and management of the operation mode of the boiler and other equipment of the heating system;
• water supply;
• power supply;
• fuel preparation;
• operating modes in various conditions (heating season, hot water heating in the off-season);
• operational maintenance (frequency and order of boiler firing, cleaning of deposits from the ash pan, furnace, chimney, checking security systems).

Building and other state norms and rules also contain certain requirements for the design and safe operation of boilers and heating systems.

When designing heating, they calculate, take into account and select the hydraulic resistance of various sections of the system, pump performance, equipment placement elevations, building heat losses and many other parameters.

It is obvious that the design of forced heating with a solid fuel boiler, the choice of a boiler and other elements of the system for a particular facility is a complex engineering task, which should involve specialists.

In this article, using a specific example, we will consider a forced heating scheme with a solid fuel boiler.

Scheme of connection and piping of a solid fuel boiler

For heating the premises of the house with underfloor heating, a system with forced circulation of the coolant is required. In the diagram, we see two coolant circulation circuits:

1. boiler circuit consists of boiler "Atmos", pumping and mixing unit "Laddomat" and boiler of hot water supply system (DHW);
2. IN heating circuit includes a mixing three-way valve, a circulation pump and heating appliances (warm floor) in the premises.

Mode of circulation of the coolant in the boiler circuit regulated by the pump-mixing unit “Laddomat”. The unit is specially designed to work with a solid fuel boiler. Blocks of a similar purpose are produced by different manufacturers under their own trademarks.

Boiler firing mode. When the boiler is fired up, at the signal of the thermostat sensor, the circulation pump of the mixing unit is started. The valves of the block direct the circulation of the coolant only through the block in a small circle, in addition to all other elements of the heating system.

There is a rapid heating of the coolant in the boiler and the surfaces of the boiler, the chimney to the operating temperature. This acceleration of heating contributes to the reduction of soot deposits, resins released from the fuel, reduces the amount of condensate and corrosion of the boiler metal, and increases the efficiency of the boiler.

Coolant heating mode. After the boiler is fired up, when the temperature of the water circulating in the small circle rises to 70-80 ° C, the valves of the mixing unit begin to turn on the water circulation in the heating system. At the first stage, in the mixing unit, cold water is mixed, coming through the return pipe from the heating system, and hot water circulating in a small circle.

Mixing of water in the mixing block occurs gradually, so that the temperature of the water supplied to the boiler does not decrease below the set value (65 ° C). After heating the water in the heating system to a predetermined temperature, water mixing stops. The circulation pump of the unit continues to ensure the movement of the coolant in the boiler circuit. The heating mode ends after the combustion of the fuel loaded into the boiler. The temperature of the water at the outlet of the boiler decreases and, at the signal of the thermostat sensor, the circulation pump of the unit is turned off. The valves of the mixing block switch the circulation of the heat carrier in the boiler circuit to the mode of natural circulation of the heat carrier.

Room heating mode. After increasing the water temperature at the outlet of the boiler to the operating temperature, at the signal of the thermostat, the circulation pump of the heating circuit is turned on. Through the mixing valve, hot water taken from the boiler circuit begins to circulate in the heating appliances of the premises of the house.

The mixing valve mixes the water cooled in the radiators with the hot water at the inlet to the heating circuit - in this way the temperature of the water in the room heaters is regulated. The mixing valve can be adjusted manually or by an automatic controller.

Overheating protection mode (water boiling in the boiler). The process of burning solid fuel in the boiler cannot be stopped instantly. Therefore, in case of a sudden stop in the circulation of water in the system (lack of electricity, breakdowns) or low heat removal, the water in the boiler may boil.

Boiling water leads to an increase in pressure in the system, an increase in temperature, destruction of system elements, injury to people and other consequences that are dangerous for equipment and people.

The boiler is equipped with an overheating protection system. This is a heat exchanger built into the boiler, connected to the water supply. When water boils in the boiler, the TS-130 valve opens on the signal of the sensor. Cold water from the water supply enters the boiler heat exchanger, cooling the boiler, and drains into the sewer.

The forced heating circuit with a solid fuel boiler is very sensitive to the shutdown of the circulation pumps. To ensure their operation in the event of a power outage, it is recommended to install uninterruptible power supplies (UPS). Such devices receive electricity from the battery and convert it into the alternating voltage necessary for the operation of the pump.

For a closed heating system, boilers are required that are specially designed for operation in this mode - designed to work with increased pressure and equipped with an overheating protection device.

Through an open expansion vessel, the heating system is connected to the atmosphere (open system), that is, it operates under atmospheric pressure. The operation of the system under atmospheric pressure has its advantages and disadvantages.

Calculation of the volume of the membrane expansion tank

More advantages have a closed heating system, the coolant in which is under pressure above atmospheric. In this case, to compensate for the thermal expansion of water, instead of an open expansion tank, a closed membrane expansion vessel is used (shown in the diagram as a dotted line to the left of the boiler).

The expansion tank is divided into two parts by an elastic movable membrane. The coolant from the heating system enters one part of the tank. On the other side of the membrane in the tank is compressed air. Air pressure balances the pressure of the coolant in the heating system. With an increase in temperature and volume of the coolant, the membrane in the expansion tank moves, increasing the volume occupied by the liquid. The air on the other side of the membrane is compressed even more.

The expansion membrane tank can be horizontal or vertical. There are also those in which the membrane can be replaced and there is no such possibility.

How to choose the correct volume of the expansion tank

The volume of the membrane expansion tank is calculated by the formula: V = (VLхE) / D;

VL is the total volume of liquid in the heating system;

E is the expansion coefficient of the liquid, for water at a temperature of 85°C=0.034;

D is the efficiency of the membrane tank, calculated by the formula: D= (PV-PS)/(PV+1).

Where PV is the maximum operating pressure of the system, usually 2 bar is sufficient, PS is the charging pressure of the membrane tank, equal to 0.5 bar.

Thus, D=(2-0.5)/(2+1)=0.5

If, for example, the volume of the coolant - water in the heating system of the house is about 450 liters, then the volume of the expansion tank will be equal to:

V \u003d (450x0.034) / 0.5 \u003d 30.6 liters.

Selecting the right boiler size, i.e. its heating output is a very important condition for economical operation and correct functioning of the boiler. The boiler must be selected so that its rated heating output corresponds to the heat losses of the heated object. Selecting a boiler with a too large rated output can lead to increased formation of deposits (soot, tar). Therefore, you should not use a boiler that has a significantly higher power than the heat loss of the object.

The approximate heating output of the boiler can be calculated as follows - for every 10 m2 heated area of ​​the house with an average insulation of the building and a ceiling height of up to 3 m. 1 kW of power is required.

It is useful to get acquainted with the instruction manual for the solid fuel boiler. Operating instructions for solid fuel boilers "Atmos" (Czech Republic) can be read and downloaded by clicking on this link. To download, in the window that opens, in the menu, at the top left, select “file” –> “download”.

Heat accumulator with insulation

Solid fuel heating equipment today is an excellent alternative to gas. A well-thought-out and professionally designed piping significantly increases the life of the unit. Among the various connection options, the connection of a heat accumulator for a solid fuel boiler has become very common. Such a scheme allows significant savings and relieves stress from the heater at peak loads.

Functionality of heat accumulators

The principle of operation of the equipment is that during the operation of the boiler part of the heat is used to heat the coolant from an additional tank. The connected tank has good thermal insulation and perfectly retains the heat received. After the boiler is turned off, the water in the heating system cools down, and the control devices turn on the pump that supplies hot water from the storage tank.

These cycles continue as long as the temperature of the water in the additional tank remains high enough. The total duration of the system operation without turning on the boiler depends on the volume of the additional tank. In practice, it allows you to heat the premises from several hours to 2 days.

The heat accumulator performs the following functions:

1. Accumulates the heat coming from the boiler of the system and releases it over time to heat the rooms in the room.
2. Prevents the possibility of boiler overheating by removing excess heat from the exchanger.
3. Allows you to easily combine different heating devices (electric, gas, solid fuel) into a common system.
4. Helps to improve the operation of heating equipment, reducing fuel consumption and improving efficiency.
5. In systems with solid fuel boilers, it allows you to exclude constant monitoring of the state of heating equipment. By heating the coolant in an additional tank, homeowners can forget about the need to constantly load fuel into the boiler.
6. It is a source of hot water for domestic needs.

Heating system diagram

How profitable a heating system with a heat accumulator can be seen in this example.

Assume that a boiler with a capacity of 10 kW is installed in the heating system. Firewood needs to be loaded every 3 hours. This does not fit into the plans of homeowners. To lengthen the breaks between loads, it is necessary to use a larger boiler. But in this case, boiling of the coolant is possible, since the system will not have time to take away all the generated heat.

Connecting a heat accumulator with a capacity of about 200 liters easily solves the problem. The equipment allows you to accumulate 110 kW of energy, subject to full and frequent boiler loads. Subsequently, the accumulated heat will maintain a comfortable room temperature for about 10 hours. Loading the boiler with fuel all this time is not necessary.

The use of heat accumulators

There are several methods for calculating the volume of a tank. Practical experience shows that, on average, 25 liters of water are additionally needed for each kilowatt of heating equipment. The efficiency of solid fuel boilers, which includes a heating system with a heat accumulator, increases to 84%. Due to the leveling of combustion peaks, up to 30% of energy resources are saved.

When using tanks for supplying domestic hot water, there are no interruptions during peak hours. At night, when the needs are reduced to zero, the coolant in the tank accumulates heat and in the morning again provides all the needs in full.

Reliable thermal insulation of the device with foamed polyurethane (polyurethane foam) allows you to save the temperature. Additionally, it is possible to install heating elements, which helps to quickly “catch up” with the desired temperature in case of emergency.

Sectional heat accumulator

• high demand for hot water. In a cottage where more than 5 people live, and two bathrooms are installed, this is a real way to improve living conditions;
• when using solid fuel boilers. Accumulators smooth out the operation of heating equipment during the hour of greatest load, take away excess heat, preventing boiling, and also increase the time between laying solid fuel;
• when using electric energy at separate tariffs for day and night;
• in cases where solar or wind batteries are installed to store electrical energy;
• when used in the heat supply system of circulation pumps.

This system is perfect for rooms heated by radiators or underfloor heating. Its advantages are that it is able to accumulate energy received from different sources. The combined energy supply system allows you to choose the most optimal option for obtaining heat in a given period of time.

Advantages of heat accumulators

The mechanism of operation of the heat accumulator

The heat accumulator can fully replace the hot water boiler. At the same time, both devices are comparable in price.

However, the heat accumulator will not only provide hot water supply, but also solve a whole range of additional tasks. Using a solid fuel boiler with a heat accumulator, you can get many advantages:

• the service life of heating equipment is increased several times;
• the boiler will never operate in extreme load modes or idle;
• the temperature of the heat supply to the house is equalized. In the case when the water in the boiler does not have time to heat up, the hot coolant is automatically supplied from the reserve tank. Conversely, excess carrier temperature will be taken and accumulated;
• a properly selected container continues to take heat from the boiler even with complete combustion of the fuel;
• resource savings up to 30%.

The advantages of batteries have been appreciated by many manufacturers of solid fuel boilers. And now they provide their equipment warranties only if additional tanks are installed.

Features of installing heat accumulators

All installation work is carried out according to a previously approved project in accordance with the recommendations of the heating equipment manufacturer.

Wiring diagram

In this case, the features of the installation work should be taken into account:

If you are the owner of a solid fuel boiler and have not yet purchased a heat accumulator, think about it. You will not only extend the life of your heating equipment, but also significantly save on fuel.

Installation of a solid fuel boiler

When installing a solid fuel boiler, there are certain rules necessary for safe and durable operation. In this article we will try to analyze the main aspects so that installing a solid fuel heating boiler with your own hands is a simple and understandable task for you. Where and how to properly install a solid fuel boiler, this is our article. Today, climatic conditions (which, by the way, change every year) in our latitudes simply require the installation of a boiler in the house and a full-fledged heating system. Of course, this is a responsible matter, in which, if you do not do everything yourself, then at least you need to understand the process in general terms in order to avoid problems in the future. How long and how reliably your heating system with a solid fuel boiler will work depends on the correct installation of the boiler. Perhaps later you will need to add additional equipment (for example, a solid fuel boiler), which means you need to think about the area around the boiler. Also, if we talk about the reserve of space, it is necessary to consider a place for distributing heating pipes from the boiler. It is quite possible to carry out such an installation of heating pipes with your own hands, the main thing is to think over and calculate everything in advance. But more on that below.

For your convenience, the article is divided into subsections:

Requirements for the installation site of the boiler and standards for the installation of a solid fuel heating boiler.

First, you need to deal with the boiler room. There must be good ventilation in the boiler room, which is necessary for the correct combustion process. The floor must be concrete no thinner than 5 cm.

The installation of a heating boiler primarily consists in choosing the right place for the boiler room and the boiler. Of course, the correct equipment that is needed to install the system also plays an important role. Such equipment, if it is professional, costs a lot of money, and therefore it is better to entrust the installation to competent companies. Although, of course, it all depends on the scale of your heating system. Whatever it was, it will be necessary to perform the following installation work:

• Placement in the boiler room of the heating boiler
• House piping
• strapping
• Boiler start

You can watch a detailed video "how to install a solid fuel boiler":

Now regarding the standards and requirements for connecting the boiler and the system as a whole. after all, how well these recommendations will be implemented depends on how reliably and for a long time your system will work without outside interference.

If we are talking about connecting the entire system, then it must be carried out taking into account all the standards, so that, God forbid, something breaks somewhere and does not cause serious damage to you in the future. Consider the basic requirements for the safety of boiler equipment:

The area of ​​the boiler room must be not less than 7m² Boiler room must be equipped with forced ventilation. The cross section of the ventilation channel should be from 80 millimeters per 1 kW of solid fuel boiler power. Standard safety distance from the equipment to the walls should be from half a meter. The floor must be paved with non-combustible building materials, a list of which you can find on the pages of our website. In front of the firebox, as in a furnace, a sheet of non-combustible material, such as metal, should be placed. Chimney diameter from the calculation of the boiler flue, but separately about the requirements for the chimney, you can read below. Many indicators are not an axiom and are calculated based on the documentation attached to the boiler. fire safety above all. Both the electrical connection and the water supply must be carried out in accordance with fire safety regulations. efficiency your heart of the heating system, the boiler, directly depends on the correct choice and installation of the type of chimney.

Of course, it is better to seek help with installation from professionals. but if you still decide to install a solid fuel boiler yourself, then you need to understand that you can not count on warranty obligations from the manufacturer. Depending on the dimensions and power, the volume of the furnace part, the boiler can be unloaded either manually or using a mobile crane. In this case, it is better to take care of the installation before the completion of construction, so that there are no problems with doorways, roofs. In general, the calculation of the power of a solid fuel heating boiler deserves a separate word. as this is a rather complicated procedure, which should also be carried out by a specialist installer. Also, if you do not know which solid fuel boiler to choose. our site will help you with the choice.

What is required to install a solid fuel boiler?

So: how to install a solid fuel boiler, what is required for installation? Here I would like to immediately note that the competent creation of a heating system is a long and meticulous task, the implementation of which requires experience and a special tool. Whether it is a long burning wood boiler or some other type. Therefore, doing this on your own is highly discouraged. Before installing the system, it is necessary to calculate the parameters of the boiler room, based on the peculiarities of the principle of operation of the boiler, to consider slopes. Then make the wiring of pipes with the coolant and soldering the connecting elements, not to mention the membrane expansion tanks for heating. boilers and more. All this requires special equipment, a special soldering iron for plastic pipes, or a welding machine, pipe cutters and much more.

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