A boiler is an indispensable attribute of any modern home that is not connected to central heating. During the construction or renovation process, many people wonder what type of heating is best to choose for their home, so that it is more economical, cheaper and more durable. The second important question is how to connect all this stuff?
The article was prepared with the information support of specialists from the Teplodar company https://www.teplodar.ru/catalog/kotli/ - Production of heating boilers and stoves for baths.
Boiler review - advantages and disadvantages
There are several types of heating boilers: electric, gas and the well-known solid fuel boiler. It is up to you to decide which type of heating to choose for your home, based on the area and the availability of certain heating materials. The most practical and used in our time is the electric boiler. It has many advantages, but also has its disadvantages.
The electric type of boiler is characterized by simple and quick installation at minimal cost. This type of heating does not require connecting a gas line or purchasing firewood, and also uses electricity economically. With a detailed calculation of all heating costs, you will probably find that in our time electricity is the cheapest source of heat.
Gas boilers are much cheaper, but to buy a good quality boiler, you need to spend a lot of money. When buying a boiler, it is best to buy imported ones; they are more practical and of better design. But installing heating boilers of this kind is quite a labor-intensive task. During operation, they require constant supervision.
Electric boilers require constant voltage in the network, so they require at least a stabilizer, and at maximum an electricity generator that will provide voltage during power outages. If you look at it, all boilers according to the scheme use electric pumps, which ensure the movement of water through the heating system. Therefore, a generator is by no means a luxury, but a necessity.
Nowadays, wall-mounted double-circuit heating boilers are very popular. This scheme is advantageous in that the boiler simultaneously provides heating in your home and is responsible for the supply of hot water. It is especially beneficial to use such boilers in a gas heating system.
We buy slowly - what do you need to know when buying?
Depending on the type of installation and installation, boilers can be floor-mounted or wall-mounted. The very scheme for connecting boilers to the heating system is not very different, so which type of boiler to choose depends on the availability of space for installation, as well as the area that needs to be heated. Floor-standing boilers require a large area for installation and operation, often requiring an entire room. Wall-mounted ones do not take up much space and can be installed regardless of the size of the room.
The advantage of this type of boiler is much lower energy consumption. However, it cannot heat a very large area, so it is only suitable for small houses. After determining the type of boiler for your home, you need to competently approach the issue of purchasing it. To do this, it is better to compare boiler manufacturers, listen to the opinions of people who are already using them; fortunately, numerous forums allow you to learn about all the disadvantages and advantages of the products. If possible, try to get professional advice.
You should not buy cheap boilers, as they are of poor quality and are unlikely to last you long. It is better to entrust the installation and connection of the boiler to specialists in this matter, for whom any scheme is tough. When installing a gas boiler, you need to obtain the necessary permits for work and connection to the central pipe.
DIY connection diagram - if you are confident in your abilities
Installation of boilers is divided into several stages. First of all, you need to decide on the installation location. Next you need to install the fastenings for the boiler. It is different for each type. Installing a mount for a boiler is not a complicated process in itself - at this stage, the main thing is to correctly mark and calculate the pipe supply and connection system, as well as take into account the dimensions of your boiler in the room. The next stage is connecting the heating system of your home and looping the pipes with the boiler circuit according to the connection diagram.
The last stage, which is relevant only for the installation of gas and solid fuel boilers, is the supply to the chimney system. Well, and, of course, checking the heating system after all types of work have been carried out. Now in more detail. After marking and securing the boiler, we begin to determine the location of the chimney. If you do not have a chimney system in your house, then you will have to punch a hole in the ceiling and install it. In houses with ready-made chimneys, you need to make a hole in the wall; such systems are usually called turbocharged. The most reliable chimney system is the so-called “pipe in pipe”.
Particular attention should be paid to the angle of inclination of the pipe. If it is placed incorrectly, condensation may form in it, which, if it enters the boiler, can lead to failure of the entire unit. If your chimney system is located in the ceiling, then you need to provide a special condensate drain for it. This process is labor-intensive, but it will save you from possible breakdowns.
The heating boiler connection diagram is described in detail in the installation instructions, and during operation you must follow all the points. Even if this is not indicated in the connection diagram, it is necessary to install filters for water purification in the boiler piping circuit. This is especially true for an electric boiler, since the presence of filters significantly prolongs the operation of heating elements. Filters also prevent pipes from becoming contaminated with various materials.
When connecting a gas boiler, it is necessary to install a shut-off valve, with which you can shut off gas access to the installation if you need to leave the house for a long time. After it there must be a gas filter, the installation of which is required by all authorities. All gas pipe connections must be carefully sealed. Regular tapes and other materials used for other pipe connections will not work here.
You can install an electric boiler yourself if you have sufficient technical skills. Connecting this type of heating will not take much time. For installation and further use of the installation, it is best to connect yourself to another power supply line. Grounding must be done to prevent electric shock.
To correctly connect the power supply circuit and grounding connection, it is necessary to invite special services or an experienced electrician. Among the main devices in the power supply network, in addition to the stabilizer, there is also an automatic switch, which will protect the system from sudden voltage drops, and will also allow you to turn off the boiler for future work. The circuit breaker must be selected depending on the voltage supplied to your boiler.
Standard mistakes - avoiding the rake
The main mistake of most homeowners is incorrectly calculating the boiler power for the square footage of the house. The average value for a private house is considered to be consumption of 1 kW per 8–10 m2. This counting system should be used for small houses.
For houses in which the square footage exceeds 400 m2, you need to use a slightly different calculation - 1 kW per 10–15 m2.
When installing a heating boiler, it is very important to correctly calculate the thickness of the system circuit pipes, as well as the average liquid pressure inside the pipes. Incorrect calculation can lead to pipe rupture and failure of the entire system. Today, most homeowners use plastic pipes for heating - this material is relatively inexpensive, durable and easy to install. In the process of connecting pipes, soldering of individual elements is used.
In metal-plastic pipes, various fittings are used for connection, which, under the influence of high temperatures, can allow water to pass through. Valves must be installed at all pipe connections at the inlet and outlet of the boiler, which can be closed if necessary.
When calculating yours, you need to take into account the square footage of all rooms and for each make a separate calculation of the required amount of coolant. After completing all the work, it is necessary to check your heating system. It is recommended to do this for several days in a row to ensure its practicality. Then you will definitely not have problems when starting and operating the heating in winter.
Despite the variety of heating equipment, solid fuel boilers are still in great demand, especially in places where gas supply is difficult, there are difficulties in organizing the storage of liquid fuel, and power outages often occur. Let's consider the principle of operation and piping diagrams of solid fuel boilers.
Features of solid fuel boiler operation
This heating system generates heat by burning solid fuel (wood, coal, peat, pellets). It is distinguished by its features, which directly affect its effectiveness and safety:
- Inertia. A solid fuel boiler cannot be stopped immediately. After the oxygen supply is stopped, the system continues to operate until the oxygen inside the firebox runs out, or until the fuel burns out. This can lead to overheating of the coolant and the formation of a large amount of steam. The result is destruction of the boiler body or parts of the heating system.
- Condensate. Appears when the boiler is connected directly, low-temperature coolant passes through the boiler tank. Leads to corrosion of the steel walls of the fuel tank. At the same time, when mixed with ash, it turns into a sticky mass that is difficult to clean off.
To eliminate the problems listed above, it is necessary to properly organize the boiler piping with the obligatory inclusion of a safety group in it. Let's take a closer look at why the piping of a solid fuel heating boiler is needed and the basic installation diagrams.
Piping of a solid fuel heating boiler. Purpose. Elements
The most important purpose of the piping is to ensure efficient, safe, economical operation of the boiler. This means:
- protect equipment from overheating, sudden pressure changes, maintain the most acceptable temperature;
- control the amount of coolant in the system, remove excess liquid, excess steam;
- remove air from the system;
- distribution function - to divide the coolant between all heat consumers in the system.
The piping elements of a solid fuel boiler and their correct installation in one way or another work to ensure the safety of heating equipment. The main ones include:
- safety group (pressure gauge, air vent, safety valve);
- expansion tank;
- heat accumulator;
- three-way mixing valve.
Heating boiler Wiring rules that must be followed when independently connecting a solid fuel heating system:
- to avoid the appearance of condensation, the temperature difference between the supply and return should not exceed 20 ⁰C;
- protective devices should be installed that will regulate the coolant pressure throughout the entire circuit;
- It is also recommended to include automatic devices in the piping that are responsible for regulating power and fluid temperature in the system.
These rules work best in systems with forced coolant movement. Let's briefly look at the wiring diagrams for solid fuel boilers. But before that, a few words about the safety group in the heating system.
Security group
Includes elements:
— pressure gauge (shows the pressure level in the system)
— safety valve (automatically relieves pressure if it exceeds the permissible value of 2 Bar, usually triggers at 3 Bar),
— automatic air vent (removes air from the coolant).
Heating scheme It is installed on the supply pipe of the boiler itself, immediately at the outlet. It is important to remember that no locking mechanisms should be installed between the safety group and the boiler. These devices must be installed in any heating system piping circuit.
Open type with natural circulation
The simplest wiring with a minimum number of devices, complete independence from electricity. The movement of fluid through the system occurs naturally due to the general arrangement of the pipes at a slight slope. The boiler is installed half a meter below the level of the radiators. Minimum number of locking mechanisms, control devices, etc.
This type of piping is effective for a small house with a small number of heat consumers. An open type expansion tank is installed as high as possible, in the attic, for example.
In this case, the coolant temperature cannot be adjusted. And air often enters through an open expansion tank, which has a detrimental effect on the inner surface of the pipes.
Closed type with natural circulation
Also a fairly simple strapping scheme with a small number heat consumers. The scheme is very similar to the open type. It is distinguished by the inclusion of a closed expansion tank with a membrane, which is installed on the return pipe. In addition, do not forget about the security group. Some models are already equipped with it in production.
The expansion tank is designed for a volume of more than 10% of the total coolant volume.
There are several important points when lining a heating boiler with polypropylene. Pipe from heat generator up to the safety group it is made of metal, then it is laid from polypropylene. Also, the section of the return pipe with an installed three-way valve and sensor is made of metal. Polypropylene has low thermal conductivity. If you install a three-way valve on it, it will respond with a delay to an increase in temperature, and the sensor will provide information incorrectly.
In general, the polypropylene piping system for a heating boiler is beneficial and quite practical.
Closed type with forced circulation
A simple circuit with a circulation pump that moves coolant throughout the system. The slope as such is no longer required to be observed. The pump, as well as a temperature sensor (controls the operation of the pump) are installed on the return line (between the expansion tank and the boiler) and connected to the electrical network.
This harness is more productive due to the use of the device thermoregulatory. Can be used where the power supply is stable. Otherwise, if there is a power outage, the heating system will stop.
Manifold piping with forced circulation
Circulation pump + collectors. This is a characteristic difference between the manifold piping system.
The pump moves liquid through the pipes. Collectors (so-called combs) are connected to the heating system. They are pipes with a large cross-section. They have one common input and several outputs for connecting the required number of heating elements (for example, radiators, underfloor heating system, heated towel rail). Connect to the supply and return pipes of the system.
The specificity of such a connection is characterized by a separate supply of coolant to each element of the system with the same temperature and pressure. It features more efficient regulation of the heating system.
It should be taken into account that such piping will take a lot of time, effort, and material costs (high pipe consumption, financial expenses).
Harness with hydraulic arrow
The piping system uses a large-section vertical pipe - a hydraulic arrow. This element is connected to the boiler by supply and return pipes. It is installed in the same place as the collectors: after the expansion tank, in front of the heating elements (radiators, heated towel rail, etc.).
It differs from collectors in that it can be connected to the hydraulic arrow at different heights. This directly affects the temperature of the coolant, and with it the temperature of each heating element in the house. Thus, using a harness with a hydraulic arrow, you can create an optimal thermal regime for each device separately.
Connecting a solid fuel boiler with heat accumulator
For equipment operating on solid fuel, it is recommended to install heat accumulator. It is a buffer tank for accumulating and then storing the heat generated by the boiler.
A very profitable device, because it allows you to increase the efficiency of solid fuel equipment and at the same time save heating material.
The wiring diagram for a solid fuel boiler with a buffer tank is as follows. Inlet and outlet pipes heat generator are connected to the heat accumulator, and from it to the heating elements. Now two contours are formed at once:
- between the heat buffer and the boiler;
- between the buffer and the heating devices of the house.
As the coolant passes through the heating system, it fills the buffer tank. In this case, cooled liquid from the heating elements passes below, and hot liquid from the boiler passes above. The buffer accumulates heat when the firebox is operating at full power. After the fuel burns out, the accumulated heat from the tank is released through the heating system for a certain period of time. After the storage buffer, a pump and a three-way valve are installed to adjust the temperature of the heating fluid.
The wiring diagram of a solid fuel boiler with a battery tank saves fuel, allowing you to add coal and firewood much less frequently. It must be taken into account that with such piping, the boiler power should be sufficient for heating and warming up the buffer tank.
Wiring a solid fuel and gas boiler (electric boiler)
This harness is relevant and in demand among residents of country houses. It allows you to organize year-round comfort in the house, including several heating sources in the overall system. As a rule, steam from a gas heating boiler with a solid fuel device is installed, as well as solid fuel equipment with an electric boiler.
Solid fuel boiler+electric The wiring diagram for gas and electric devices with wood is the same, is quite simple because it uses heat accumulator at the same time and as a hydraulic gun. This allows you to efficiently supply heat to a large number of heating points at once (radiators, heated floors, boiler, heated towel rail, etc.). In this case, the heat from the gas heating boiler (electric) and wood-burning boiler charges the buffer tank, and then it supplies thermal energy to the heating end points.
There is also another option for connecting a gas heating boiler (electric boiler) and a solid fuel boiler together, without using a buffer tank, because it is quite expensive. Here the main source of heating is a wood-burning boiler, with a gas boiler as an auxiliary one.
Operating principle. After solid fuel burns out, the air temperature decreases. This detects the sensor installed in the room and immediately starts the gas boiler. When the main boiler cools down, it switches off automatically. The gas one operates until the wood-burning unit begins to process the next portion of fuel. Now, in reverse order, the room temperature sensor turns off the gas heating device.
The scheme with such a harness is simple, you can install it yourself.
Piping with connection of an indirect water heater
The wiring diagram for a solid fuel boiler with a boiler is quite common due to its cost-effectiveness and efficient operation. This is especially relevant during the heating season, when you can save a significant amount on electricity.
This piping is designed in such a way that the heated liquid is supplied simultaneously to the boiler and radiators. In this case, the boiler circuit is connected to the heat exchanger of the water heater, which heats the water indirectly.
Heating a country house with a diesel boiler. Briefly about the important How to make a solar water heater for your home with your own hands? Choosing wood stoves for baths and saunas: firebox, power, heater Wood stove for a country house: choosing heating options
Content
Heating units operating on various types of solid fuel differ significantly in operation from electric, gas and liquid fuel heat generators. In this regard, connecting a solid fuel boiler has a number of features. Let's consider how to properly install a heating unit so that its operation is efficient and safe, as well as how to install a heating system with two boilers.
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 sources is based on the combustion characteristics of wood, coal and other types of solid fuel.
1. Inertia. Solid fuel that has flared up in the combustion chamber cannot be quickly extinguished, so there is always a risk of overheating of the coolant. The boiling of water in the boiler jacket leads to an abrupt increase in pressure in the system and its depressurization. To avoid an emergency, an automatic valve designed to relieve pressure must be included in the piping of a solid fuel boiler.
Due to inertia, it is more difficult to control the heating of the coolant - after the thermostat is activated, the valve closes, reducing the air flow into the combustion chamber, but for some time combustion continues in the same mode and the temperature of the liquid in the circuit manages to rise by at least another 2-3 degrees before stabilizing.
Attention! A pellet boiler does not have such a disadvantage as high inertia, since the design provides for the supply of fuel to the combustion chamber in small portions. Stopping the supply leads to a rapid extinction of the flame.
2. Moisture condensation in the firebox. Condensation forms when a very cool coolant with a temperature below 50 degrees enters the water jacket of the unit. The loss of 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, condensation 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 must include a mixing unit, thanks to which the liquid heated by the boiler is mixed into the cooled return coolant.
Attention! The cast iron boiler, which runs on solid fuel, is resistant to corrosion and is not afraid of condensation. However, a mixing unit is also added to the piping of such a unit, since the entry 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, you need to pay attention to the basic piping elements that ensure the safe operation of the heat generator. We are talking about a safety group and a 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 monitor the pressure in the system, the air vent serves to remove air pockets, and the safety valve releases excess steam-water mixture when the pressure exceeds the specified parameters.
Important! It is prohibited to install a circulation pump or shut-off valves between the 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 condensation and temperature shock operates according to the following scheme:
- While the fuel flares up, the valve blocks the flow of cooled coolant from the large heating circuit. As a result, the circulation pump circulates a limited volume of coolant in a small circle.
- A sensor is installed on the return pipe, connected to the thermal head of a three-way valve. When the coolant in the return pipeline heats up to 50-55 degrees, the thermal head is activated and presses on the valve stem.
- The valve smoothly opens slightly and the cooled coolant begins to gradually flow into the boiler jacket, mixing with the heated coolant from the bypass.
- When all radiators warm up and the return temperature rises to values safe for the boiler, the three-way valve closes the bypass, completely opening the passage of coolant flow through the return pipeline.
The basic diagram 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 to avoid common problems:
- It is unsafe to use polymer pipes for piping a boiler - they may not withstand an emergency increase in temperature and pressure. Therefore, it is recommended to make the piping with steel or copper, and connect the polymer pipes to the manifold that distributes the coolant through the heating circuits. As a last resort, a metal pipe is installed 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 pipe leads to the fact that the surface-mounted temperature sensor responds to the heating of the coolant with a noticeable delay. It is better to install a metal pipe.
Connecting a solid fuel unit with a hydraulic boom The pump for a heating system with forced supply of coolant 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 install the circulation pump on the supply pipe, since the device is not designed to work with a steam-water mixture that is formed when the coolant overheats. Stopping the pump will speed up or provoke an explosion of the heating boiler, since cooled coolant will no longer flow into it.
How to reduce the cost of harness
The basic connection diagram for a solid fuel boiler involves the use of a three-way mixing valve equipped with a thermal head and an overhead 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. This device has a fixed setting - the valve is activated when the ambient temperature reaches 55 or 60 degrees (depending on the model).
Installing a valve that maintains a fixed temperature reduces the financial costs of installing protection for a solid fuel unit from condensation and thermal extremes. 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.
Connection with heat accumulator
In order for the solid fuel unit to operate in optimal mode and its efficiency to approach the rated 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 operates 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 a lack of oxygen, an increased amount of carbon monoxide is formed, which enters the atmosphere. In advanced European countries, for this reason, it is prohibited to operate solid fuel heaters without installing a buffer tank.
Installing a heat accumulator has one more advantage: the fuel, which burns with an optimal supply of oxygen, releases maximum thermal energy, and its excess does not fly away 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 has burned out.
Connecting a solid fuel boiler to a heat accumulator involves connecting a buffer tank as follows:
Wiring diagram for a heat accumulator with a solid fuel boiler To control the temperature of the coolant supplied to the radiators, a second and second circulation pump is 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 boiler is extinguished 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 tank with a volume of 1 cubic meter. 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 design stage of the heating system. In order for the boiler to simultaneously heat water in the heating circuit, the DHW system and in, its power must be twice the design power.
Installation with electric or gas unit
Two heat generators can be installed in one heating system, the main one 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. Gas in cylinders 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 source 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 into one heating system for a large house? The simplest option is to connect two heat generators in parallel through a heat accumulator, which will additionally serve as a hydraulic separator.
The gas boiler operates in standby mode while the water in the buffer tank is heated by the solid fuel unit. After the fuel burns out, the coolant begins to cool, and as soon as the temperature sensor transmits the corresponding 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 gas burner turning off.
A system with an electric boiler in large houses is installed 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).
Connection diagram for 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, so for a solid fuel heat generator it is necessary to select a more powerful pump so that the TT boiler has an advantage over the electric one when operating together.
The system is being supplemented:
- a thermostat that turns off the boiler’s TT circulation pump when the coolant cools down;
- a 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 into one system using a minimum amount of electronics? The use of the method of primary and secondary circulation rings allows for joint piping of the CT of the unit and the electric boiler. Hydraulic separation of flows is carried out without installing a hydraulic arrow.
Option for connecting two types of boilers to one heating system Both boilers, the DHW boiler, as well as all heating circuits, are connected by both supply and return pipelines to a single circulation ring - they are the primary one. The minimum pressure drop is ensured by 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 intensity is not affected by the pumps of the secondary circuits (to which heat consumers are connected).
In order for the system to function properly, it is necessary to perform complex hydraulic calculations and select the optimal pipeline diameter for all circuits. It is also important to calculate the pump performance. The actual performance of the pumping unit on the main circuit must exceed the coolant flow rate on the “volumetric” secondary circuit itself. Both boilers are equipped with shut-off thermostats so that they can operate instead of each other.
Conclusion
Before proceeding with the independent installation of the solid fuel boiler piping, it is recommended to contact professionals who will perform a competent calculation of the system and give advice on the correct arrangement of its elements. The connection diagram must ensure the safe operation of the solid fuel boiler and create optimal conditions for efficient fuel consumption.
Unlike electric and gas heating units, solid fuel boilers are almost never equipped with circulation pumps, a safety group, or adjustment and control devices. Everyone solves these issues independently, choosing a heating device piping scheme in accordance with the type and features of the heating system. Not only the efficiency and performance of heating, but also its reliable, trouble-free operation depends on how correctly the heat generator is installed. That is why it is important to include in the diagram components and devices that will ensure the durability of the heating unit and its protection in the event of emergency situations.
In addition, when installing a solid fuel boiler, you should not give up equipment that creates additional convenience and comfort. you can solve the problem of temperature differences when rebooting the boiler, and an indirect heating boiler will provide the house with hot water. Have you thought about connecting a solid fuel heating unit according to all the rules? We will help you with this!
Typical wiring diagrams for solid fuel boilers
The opinion that a solid fuel boiler is an obsolete unit covered with dirt and soot is wrong, isn’t it?
The complexity of controlling the combustion process in solid fuel boilers leads to high 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 heating operation, the piping must ensure the temperature of the thermal agent is within 60 - 65 ° C. Of course, if the equipment is not integrated correctly, such heating at above-zero temperatures “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 structural features of heating systems will help in developing an individual project.
Open type system with natural circulation in a private house
First of all, it should be noted that open gravity-type 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, the heating will most likely remain sealed and operational. It is also important that the functionality of the heating equipment does not depend on the availability of power. Considering that wood-burning 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 its drawbacks, the main ones being:
- 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 thermal agent at the beginning and 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 its shortcomings, the gravity scheme is very popular due to its simplicity, reliability and low cost.
Installation diagram of a solid fuel unit in an open heating system
When deciding to install using this method, keep in mind that for normal coolant circulation, the boiler inlet must be at least 0.5 m below the heating radiators. The supply and return pipes must have slopes for normal coolant circulation. In addition, it is important to correctly calculate the hydrodynamic resistance of all branches of the system, and during the design process try to reduce the number of shut-off and control valves. The correct operation of the system with natural coolant circulation 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 coolant level.
Design of membrane expansion tank
When deciding to equip a gravity system with a sealed 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 equip units with such devices.
The safety valve allows the coolant to be discharged if the pressure in the system exceeds a critical value. A normal operating indicator is considered to be a pressure of 1.5 to 2 atm. The emergency valve is set to 3 atm.
You will learn more about this system in our next article:.
Features of systems with forced coolant movement
In order to equalize the temperature in all areas, a circulation pump is integrated into the closed heating system. Since this unit can provide forced movement of the coolant, the requirements for the level of installation 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 thermal agent will be ensured by gravitational forces.
The use of a bypass will allow, if necessary, to switch to the natural method of coolant circulation
The electric pump is installed on the return line, between the expansion tank and the inlet fitting. Thanks to the lower coolant temperature, the pump operates in a more gentle mode, which increases its durability.
Video: Tying a solid fuel boiler
Correct installation of a solid fuel boiler in a closed heating system
A huge advantage of solid fuel boilers is that their installation does not require any permits. It is quite possible to carry out the installation yourself, especially since this does not require any special tools or special knowledge. The main thing is to approach the work responsibly and follow the order of all stages.
Boiler room arrangement
The disadvantage of heating units used to burn 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, periodic emissions of smoke and soot, dirt from fuel and combustion products make this idea unsuitable for implementation. In addition, installing burning equipment in living rooms is also unsafe - the release of fumes can lead to tragedy.
A solid fuel boiler is best installed outside residential premises
When installing a heat generator in a boiler room, several rules are followed:
- the distance from the combustion door to the wall must be at least 1 m;
- ventilation ducts must be installed at a distance no higher than 50 cm from the floor and no lower than 40 cm from the ceiling;
- There should be no fuel, lubricants or flammable substances and objects in the room;
- The base area in front of the ash pit is protected with a metal sheet measuring at least 0.5 x 0.7 m.
In addition, at the location where the boiler is installed, an opening is provided for the chimney, which is led outside. Manufacturers indicate the configuration and dimensions of the chimney in the technical data sheet, so there is no need to invent anything. Of course, if the need arises, you can deviate from the documentation requirements, but in any case, the channel for removing combustion products must provide excellent traction in any weather.
How to properly install a chimney
When installing a chimney, all connections and cracks are sealed with sealing materials, and windows are also provided for cleaning the channels from soot and a condensate catcher.
Preparing to install a heating unit
Before installing the boiler, select a piping scheme, calculate the length and diameter of the pipelines, the number of radiators, the type and quantity of additional equipment and shut-off and control valves.
Despite all the variety of design solutions, experts recommend choosing combined heating, which can also provide natural circulation of the coolant. Therefore, when making calculations, it is necessary to consider how a parallel section of the supply pipeline (bypass) with a centrifugal pump will be installed and to provide for the slopes necessary for the operation of the gravity system. You shouldn’t give up on buffer capacity either. Of course, its installation will entail additional costs. However, a storage tank of this type will be able to level out the temperature curve, and one load of fuel will last for a longer time.
Connecting the boiler to a heating system with a dual-purpose buffer tank
Particular comfort will be provided by a heat accumulator with an additional circuit, which is used for hot water supply. Considering the fact that due to the installation of a solid fuel unit in a separate room, the length of the hot water circuit increases significantly, an additional circulation pump is installed on it. This will eliminate the need to drain cold water while waiting for hot water to flow.
Before installing the boiler, it is imperative to provide space and not forget about devices designed to reduce pressure in the system in critical situations. A simple strapping diagram that can be used as a working design is shown in our drawing. It combines all the equipment discussed above and ensures its correct and trouble-free operation.
You will learn even more information about the arrangement of the boiler room and installation of equipment from our article:.
Installation and connection of a solid fuel heat generator
After carrying out all the necessary calculations and preparing the equipment and materials, installation begins.
- The heating unit is installed in place, leveled and secured, after which the chimney is connected to it.
- Heating radiators are mounted, a heat accumulator and an expansion tank are installed.
- A supply pipeline and a bypass are installed, on which a centrifugal pump is installed. Ball valves are installed in both sections (direct and bypass) so that the coolant can be transported by forced or natural means.
We remind you that the centrifugal pump can only be installed with the correct orientation of the shaft, which must be in a horizontal plane. The manufacturer indicates diagrams of all possible installation options in the product instructions.
- The pressure line is connected to the heat accumulator. It must be said that both the inlet and outlet pipes of the buffer tank must be installed in its upper part. Thanks to this, the amount of warm water in the container will not affect the readiness of the heating circuit. We definitely note the fact that cooling 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, you can stop the movement of coolant through the boiler circuit when the fire dies out.
Installing separate pumps on the boiler and heat exchange circuits can solve the problem of heat leakage through the boiler when it cools down
- A safety valve and an air vent are installed on the supply line.
- Connect the emergency circuit of the boiler or install shut-off and control valves, which, when the water boils, will open the main line for its discharge into the sewer and the channel for supplying cold liquid from the water supply.
- Install a return pipeline from the heat accumulator to the heating unit. A circulation pump, a three-way valve and a settling filter are installed in front of the boiler inlet pipe.
- An expansion tank is mounted separately on the return pipeline.
Note! Shut-off valves are not installed on pipelines that are connected to protection devices. These areas should have as few connections as possible.
- The upper outlet of the heat storage tank is connected to a three-way valve and the circulation pump of the heating circuit, after which the radiators are connected and the return pipeline is installed.
- After connecting the main circuits, they begin to install a hot water supply system. If the heat exchanger coil is built into a buffer tank, then it will be enough to simply connect the cold water inlet and the outlet to the “hot” line to the corresponding pipes. When installing a separate indirect heating water heater, use a circuit with an additional circulation pump or three-way valve. In both cases, a check valve is installed at the cold water supply inlet. It will block the path for heated liquid into the “cold” water supply.
- Some solid fuel boilers are equipped with a draft regulator, the function 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 is reduced. If the heating unit has this design, then install and adjust the drive of the air damper mechanism.
Installing an automatic draft regulator will allow you to control the fuel combustion process
The places of all threaded connections must be carefully sealed using plumbing flax and a special non-drying paste.
After installation is completed, coolant is poured into the system, centrifugal pumps are turned on at full power and all connections are carefully inspected for leaks. After making sure that there are no leaks, fire up the boiler and check the operation of all circuits at maximum modes.
Features of integrating 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 container is designed to compensate for the thermal expansion of the coolant that occurs when it is heated. The expander is installed at the highest point of the system, and in order to prevent hot liquid from flooding the room when the tank is overfilled, a drain tube is connected to its upper part, the other end of which is discharged into the sewer.
Open type expansion tank design
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, you must remember that this element is part of the heating system, so its heat losses will lead to a decrease in the temperature in the radiators.
Since the open system is not sealed, there is no need to install a safety valve or 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 changes, etc., so their number should be minimal. In order to initially impart the necessary potential energy to the water flow, a vertical riser is installed 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 purposes, the return inlet should 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 water rather than antifreeze. This is due to higher viscosity, reduced heat capacity and rapid aging of the substance upon contact with air. As for the 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 choosing coolants for heating systems:.
Video: Connecting a solid fuel boiler with your own hands
As you can see, the choice of 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 understood 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 critical engineering systems. If you don't have confidence in your own abilities, don't experiment. Remember that installation errors will sooner or later result in serious problems, so do not hesitate to ask specialists for advice.