Connecting a solid fuel boiler with plastic pipes. Tying a solid fuel heating boiler

Under the piping of a solid fuel boiler is meant the totality of all the necessary equipment, which forms the heating system. It consists of such important components as:

Selecting the right circuit, combined with important installation requirements, is a guarantee that the system will operate efficiently and safely throughout its entire operating life.

1. the heating device itself;
2. heated towel rails, batteries, "warm floor";
3. pipeline;
4. adjusting and control equipment;
5. fittings.

It is also worth noting that self-piping of a solid fuel heating boiler must necessarily be accompanied by compliance with a number of rules. Here are the main ones.

1. The difference in the temperature of the working fluid in the supply and "return" should be no more than 20 ° C. Otherwise, condensate may form inside the body, which will have a particularly negative effect on boilers made of steel.
2. The pressure of the heat carrier at the outlet, as well as its temperature, must be within certain values. To do this, it is recommended to use appropriate protective devices, as well as emergency connection options.
3. It is desirable that the system piping also consists of automatic devices that make it possible to adjust the power and maintain the required temperature of the working fluid.

How to make a solid fuel boiler with your own hands,

Note! All the described rules are much more convenient to follow in those heating systems in which the liquid moves forcibly, therefore, they are most popular among those who have a home boiler room.

Additional information on boiler piping,

Possible strapping schemes

There are several piping options, and the choice of one or another of them depends on factors such as the type of heating system, the number of circuits and the need for additional equipment. Let's briefly consider each of the options.

No. 1. Open type system, natural circulation

This strapping scheme is the easiest to perform, since the number of devices that need to be connected is minimal. And its main advantage is considered to be complete autonomy from electricity in the house.

But there are also disadvantages: in this case, it is impossible to regulate the temperature of the working fluid at the outlet, and air often enters the system from an open expansion tank. This can lead to the formation of rust on the internal surfaces of the piping and the boiler.

Also, such a scheme provides for special installation rules:

1. the boiler should be installed at least 0.5 mm below the installation level of the batteries, so that the natural circulation of the liquid is sufficiently stable;
2. the number of valves used in the system should be minimal - the same applies to various kinds of control devices, which, as you know, reduce the cross section of the line;
3. pipes should be installed at a slope in accordance with the movement of the liquid; they must also have a large diameter so that the hydraulic resistance is the smallest;
4. The open expansion tank must be fixed at the highest point of the entire heating system.

No. 2. Closed system, circulation is the same

Here the tank is closed and mounted, respectively, on the "return" line. It is characteristic that its minimum volume is 10 percent of the capacity of the system as a whole. In addition, in this scheme, a safety valve should be installed at the outlet to reduce pressure (it must be connected with a hose to the sewer system) and an air vent.

Note! These devices can either be installed individually or included in a “security group”, which is a separate device.

This device will consist of:

1. pressure gauge (it is necessary for monitoring "by eye");
2. a valve designed to release air from the pipeline;
3. pressure relief valve.

It is worth noting that in some models of solid fuel generators, these parts are already in the case.

Number 3. forced circulation

Such a scheme is distinguished by the presence of a circulation pump, which “drives” the coolant through the main. Often the pump is mounted on the "return", between the expansion tank and the heat generator inlet pipe.

The operation of the pump is controlled by a special temperature sensor installed on the same "return".

Note! The use of circulation pumps in heating significantly increases productivity through the use of temperature control equipment. But its operation requires electricity, which not only increases the cost of heating the room, but also makes the entire piping dependent on the supply of electricity.

No. 4. Collector connection

Another diagram of how a solid fuel heating boiler can be tied. A collector-type connection is used in combination with forced circulation and implies the presence of additional devices in the system - collectors (they are also called combs).

In fact, these are short tubes of considerable diameter with several outlets and only one inlet. They are connected to the input / output of the heat generator.

The main advantage of this scheme is that each radiator can be connected separately. Due to this, the coolant enters each of them with the same pressure and temperature. Moreover, the management of the functioning of the system will be much more efficient.

But there are, of course, disadvantages as well. First of all, this is a significant consumption of pipes, as well as the fact that laying requires significant labor and financial costs.

No. 5. Variant with hydraulic gun

In this case, the so-called hydraulic arrow is used in the piping - a tube of considerable diameter, fixed in a vertical position and connected to the outlet / inlet of the heat generator. It is characteristic that heating equipment can be connected to the output and input of this arrow at any height.

This piping scheme makes it possible to provide each of the devices with the optimum temperature of the working fluid.

No. 6. Scheme with indirect water heater

Let us make a reservation right away that this scheme is applicable to all systems with any type of fluid circulation.

The supply from the heat generator is connected simultaneously to the radiators and to the heat exchanger, which is built into the water heater and heats the water for the hot water supply system. At the same time, the capabilities of the boiler itself increase significantly, since it can provide the house not only with heat, but also with hot water.

Note! An automatic valve can be installed at the outlet, which will shut off the water supply if it is necessary to heat it in the boiler.

No. 7. Option with heat accumulator

Like the previous version, this scheme can be used in systems with any type of water circulation. After strapping, a pair of contours immediately appears:

1. between the heat accumulator and the system itself;
2. between it and the boiler.

During operation, hot liquid is supplied to this heat accumulator - a storage tank with an insulated housing. At the same time, the battery itself accumulates thermal energy and, as necessary, gives it to heating devices.

As soon as the fuel stops burning, the heated liquid flows from the battery to the devices for some time.

Note! Thanks to this scheme, it is possible not only to significantly reduce fuel consumption, but also to significantly increase efficiency. Moreover, this is a very effective protection of the heat generator, and the system as a whole, from possible overheating.

How the emergency system is connected - basic diagrams

We have already mentioned the emergency system, we will only talk about its main functions:

1. high pressure protection;
2. prevention of moisture condensation;
3. overheat protection.

No. 1. safety valve

This valve provides protection against increased pressure of the coolant and is installed at the outlet of the heat generator. As already noted, it can be installed separately or as part of an emergency group.

A drain hose is connected to a special pipe. When the valve is activated, excess water from the system is drained through this hose into the sewer system.

No. 2. emergency heat exchanger

This device protects the heating boiler and the entire system from possible overheating. The latter can happen if:

1. the boiler power has exceeded the demand of the system;
2. the pump stopped working due to a power outage or breakdown.

The device includes a special valve with a temperature sensor and a cooling module. Both elements can be installed both in the boiler itself and cut into the supply of the working fluid. If the temperature exceeds a certain value, the temperature sensor will work and the valve will open.

Further, water from the pipeline is supplied to the cooling module, where it “takes” excess heat from the working fluid. After that, the water goes into the sewer system. As you can see, this is a fairly effective piping of a solid fuel heating boiler.

Number 3. Auxiliary circuit

Another natural type liquid circulating circuit may be required to protect against overheating. It is characteristic that a storage tank for hot water supply must be connected to this building.

If the system is working correctly, then the pressure generated by the pump will close the auxiliary circuit through the valve, as a result, water will not circulate through it. But as soon as the pump stops working for one reason or another, the coolant begins to circulate in the auxiliary circuit. As a result, it cools down to the required value.

No. 4. thermostatic mixer

This device is necessary in order to maintain a minimum temperature at the inlet to the heater and thereby prevent moisture condensation. It is installed on the "return" and connected by means of a plumbing element - a bypass.

If the temperature of the working fluid in the "return" is low, then the thermal mixer will open and "add" hot water. When the temperature reaches the desired value, the appliance will close and the hot water supply will therefore stop.

Note! This scheme can be used in any type of heating system.

Video - Strapping schemes

What to pay attention to when installing?

1. Each connection must be of high quality.
2. The piping of a solid fuel heating boiler should take into account the off-season - this will avoid overheating in the house.
3. In most cases, schemes with 2 circuits are used.
4. The higher the quality of all the elements and parts used, the better the strapping itself will be. Cheap low quality parts are a sure way to waste.
5. Pipes made of combustible materials must not be used! Polypropylene is possible only if it is certified.
6. Pay attention to the dimensions of the expansion tank - the larger the piping, the larger they should be.
7. Thanks to regular maintenance, the system will always work properly.
8. Natural circulation is advisable only for small areas.
9. The working fluid must be clean, without any impurities.
10. It is recommended to use paronite in the connections in order to prevent possible leaks.
11. The use of an air vent will prevent air from entering the line.

As a conclusion

As you can see, tying a solid fuel heating boiler is an extremely time-consuming and complex process that requires not only specific skills, but also appropriate education. And only in the case of a professional approach, the system will be durable, efficient and, most importantly, safe! Therefore, it is better to entrust this work to a professional, because amateur performance in such cases can not only not bring results, but also be dangerous for you and those around you.

The main principles for choosing a heating system for a home are economy, efficiency, and ease of use. Consider how it will look with solid fuel boilers and what rules must be observed during installation.

Features of solid fuel boilers

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

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

Heating with a solid fuel boiler has several advantages:

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

Now for the cons:

• fire hazard. But this drawback is present in both gas and diesel models. And in case of problems with wiring - even with electric ones;
• the need to monitor the amount of firewood / coal in the firebox. A solid fuel boiler will not work just “turn it on and forget it”. Less often, it is required to put fuel in pellet and long-burning boilers, but they are not too autonomous in this regard;
• it is difficult to control the combustion process of solid fuel (for other units, it is enough to turn off the gas valve or turn off the electricity). The inertia of solid fuel boilers is high, and the whole system, respectively, too.

Types of solid fuel boilers

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

• firewood;
• coal;
• pellets and briquettes;
• peat;
• woodworking waste;
• universal boilers for two or more fireboxes.

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

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

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

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

Solid fuel boiler piping

The package of a solid fuel boiler rarely includes a circulation pump, automation, and a security group. The owner buys all this himself, guided by the peculiarities of his heating system.

Regardless of the type of wiring, the pipeline should be equipped with safety devices (see below). The second stage is to ensure the functionality of the system and comfort when using it. A couple of devices should be mentioned here:

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

Whether or not to purchase a pump if hot water is not provided depends on the wiring. Consider its main types.

Open system with natural circulation

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

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

Advantages of open systems:

• since there is no pump, the heating is not dependent on the mains. In suburban conditions, problems with power grids are common: interruptions due to wire breaks, power surges;
• strapping equipment will cost less (there is no pump, an open tank is cheaper than a membrane tank).

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

Closed circuit with natural circulation

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

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

When choosing this type of wiring, consider:

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

Scheme of installation of a solid fuel boiler with a circulation pump

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

• high speed of movement of the coolant, uniform heating of all rooms;
• large diameter pipes are not required;
• there are no difficulties in the installation of the pipeline: it is not necessary to observe the slope, the height of the membrane tank is unprincipled.

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

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

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

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

Collector wiring

In a long, highly branched pipeline of a large cottage, one pump may not be enough. In this case, they are installed two or even more, for each circuit its own. Separate underfloor heating, radiators, hot water. Since the temperature of underfloor heating is initially low (within 50 degrees), you can install the pump at the inlet to the circuit.

The best wiring option for a large house with several circuits is collector (beam). The coolant enters each circuit from the boiler through its own pipe. Heat is distributed evenly, the liquid does not cool down, sequentially passing through the entire system.

The collector includes at least two combs, direct and reverse. The corresponding lines from the boiler are suitable for the ends of the combs, and direct / return pipes of the circuits are connected in parallel to the fittings on their bodies - radiators and underfloor heating, different floors, utility rooms, hot water supply - each with its own temperature regime.

At the inlet to the collector, a pressure gauge and a safety valve are installed, on the opposite side on the "hot" comb - an air vent, on the "cold" - a tap for draining the coolant from the system. Pipes are equipped with control valves - this is one way to set different temperatures in the circuits. A large house may have several pairs of combs.

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

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

Functions of control and safety devices:

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

This group of devices includes:

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

Mounting Features

Solid fuel boilers are not among the environmentally friendly equipment; a boiler room is needed to install them. During installation, a number of rules are observed:

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

In the chimney pipe, inspection hatches should be provided for cleaning soot. At the junction with the boiler, a condensate collector is arranged. Parts of the metal pipe located in cold rooms (unheated attic, etc.) must be wrapped with heat-insulating material to protect against condensation and icing.

Heat-insulating material for chimneys - basalt wool. All other heaters are flammable to one degree or another.

The efficiency of its further operation and service life depend on how correctly the binding of a solid fuel boiler is made. In operation, wood and coal heat generators differ from units using other types of fuel, therefore they require a special approach.

It is proposed to consider in detail how, after installing the heating wiring, connect a solid fuel boiler, including with your own hands. You can find a description of the various schemes for connecting a TT boiler to a heating system in this material.

What is the difference between solid fuel boilers

In addition to burning various types of solid fuels, heat generators have a number of differences from other heat sources. These features should be taken for granted and always taken into account when tying a solid fuel boiler with a water heating system. What are they:

1. High inertia. At the moment, there are no ways to abruptly extinguish a burning solid fuel in a combustion chamber.
2. Formation of condensate in the firebox during warm-up. The peculiarity is manifested due to the entry of a coolant with a low temperature (below 50 ° C) into the boiler tank.

Note. The phenomenon of inertia is absent only in one type of solid fuel units - pellet boilers. They have a burner, where wood pellets are dosed, after the supply is stopped, the flame goes out almost immediately.

Scheme of the device of a TT-boiler of direct combustion with forced air injection

Inertia creates a danger of overheating of the water jacket of the heater, as a result of which the coolant boils in it. Steam is formed, which creates high pressure, tearing the body of the unit and part of the supply pipeline. As a result, there is a lot of water in the furnace room, a lot of steam and a solid fuel boiler unsuitable for further operation.

A similar situation may arise when the heat generator is connected incorrectly. After all, in fact, the normal mode of operation of wood-burning boilers is the maximum, it is at this time that the unit reaches its passport efficiency. When the thermostat responds to the heat carrier reaching a temperature of 85 ° C and closes the air damper, combustion and smoldering in the furnace still continues. The temperature of the water rises by another 2-4°C, or even more, before its growth stops.

In order to avoid excess pressure and a subsequent accident, an important element is always involved in the piping of a solid fuel boiler - a safety group, more about it will be discussed below.

Another unpleasant feature of the operation of the unit on wood is the appearance of condensate on the inner walls of the firebox due to the passage of an unheated coolant through the water jacket. This condensate is not God's dew at all, since it is an aggressive liquid, from which the steel walls of the combustion chamber quickly corrode. Then, having mixed with the ash, the condensate turns into a sticky substance, it is not so easy to tear it off the surface. The problem is solved by installing a mixing unit in the piping circuit of a solid fuel boiler.

Such a deposit serves as a heat insulator and reduces the efficiency of a solid fuel boiler.

It is too early for owners of heat generators with cast-iron heat exchangers that are not afraid of corrosion to breathe a sigh of relief. They can expect another misfortune - the possibility of destruction of cast iron from temperature shock. Imagine that in a private house the electricity was turned off for 20-30 minutes and the circulation pump, which drives water through a solid fuel boiler, stopped. During this time, the water in the radiators has time to cool down, and in the heat exchanger - to heat up (due to the same inertia).

Electricity appears, the pump turns on and sends the cooled coolant from the closed heating system to the heated boiler. From a sharp temperature drop, a temperature shock occurs at the heat exchanger, the cast-iron section cracks, water runs to the floor. It is very difficult to repair, it is not always possible to replace the section. So even in this scenario, the mixing unit will prevent an accident, which will be discussed later.

Emergencies and their consequences are not described in order to scare users of solid fuel boilers or encourage them to purchase unnecessary elements of piping circuits. The description is based on practical experience, which must always be taken into account. With the correct connection of the thermal unit, the likelihood of such consequences is extremely low, almost the same as for heat generators using other types of fuel.

How to connect a solid fuel boiler

The canonical scheme for connecting a solid fuel boiler contains two main elements that allow it to function reliably in the heating system of a private house. This is a safety group and a mixing unit based on a temperature sensor, shown in the figure:

The always open outlet of the mixing valve (left connection in the diagram) must be directed to the pump and the heat generator, otherwise there will be no circulation in the small boiler circuit

Note. The expansion tank is not conventionally shown here - it must be connected to the return line of the heating system in front of the pump (in the direction of the water flow).

The presented diagram shows how to connect the unit correctly and is used with any solid fuel boilers, including pellet ones. You can find various general heating schemes - with a heat accumulator, an indirect heating boiler or a hydraulic arrow, on which this unit is not shown, but it must be there. The method of protection against moisture loss in the furnace is discussed in detail in the video:

The task of the safety group, installed directly at the outlet of the solid fuel boiler inlet pipe, is to automatically relieve the pressure in the network when it rises above the set value (usually 3 bar). It does this, and besides it, the element is also equipped with a pressure gauge. The first releases the air that appears in the coolant, the second serves to control pressure.

Attention! On the section of the pipeline between the safety group and the boiler, it is not allowed to install any shutoff valves. If you have installed a ball valve for cutting off and repairing group parts, remove the handle from the stem.

How the scheme works

The mixing unit, which protects the heat generator from condensate and temperature extremes, operates according to the following algorithm, starting from kindling:

1. Firewood is just flaring up, the pump is on, the valve on the side of the heating system is closed. The coolant circulates in a small circle through the bypass.
2. When the temperature in the return pipeline rises to 50-55 °C, where the remote-type overhead sensor is located, the thermal head, at its command, begins to press the three-way valve stem.
3. The valve slowly opens and cold water gradually enters the boiler, mixing with hot water from the bypass.
4. As all the radiators warm up, the overall temperature rises and then the valve closes the bypass completely, passing all the coolant through the unit heat exchanger.

An important nuance. Paired with a 3-way valve, a special head with a sensor and a capillary is installed, designed to regulate the water temperature in a certain range (for example, 40 ... 70 or 50 ... 80 degrees). A conventional radiator thermal head will not work.

This piping scheme is the simplest and most reliable, you can safely install it yourself and thus ensure the safe operation of the solid fuel boiler. Regarding this, there are a couple of recommendations, especially when tying a wood-burning heater in a private house with polypropylene or other polymer pipes:

1. Make a section of the pipe from the boiler to metal, and then lay plastic.
2. Thick-walled polypropylene does not conduct heat well, which is why the overhead sensor will frankly lie, and the three-way valve will be late. For the unit to work correctly, the area between the pump and the heat generator, where the copper bulb stands, must also be metal.

Connection with copper pipes will not protect polypropylene from destruction in case of overheating of the TT boiler. But it will allow the temperature sensor and the safety valve on the safety group to work correctly

Another point is the installation location of the circulation pump. It is best for him to stand where he is shown in the diagram - on the return line in front of the wood-burning boiler. In general, you can put the pump on the supply, but remember what was said above: in an emergency, steam may appear in the supply pipe.

The pump is unable to pump gases, therefore, when the chamber is filled with steam, the impeller will stop, the circulation of the coolant will stop. This will accelerate the possible explosion of the boiler, because it will not be cooled by the water flowing from the return.

Way to reduce the cost of strapping

The condensate protection scheme can be reduced in cost by installing a three-way mixing valve of a simplified design that does not require the connection of an attached temperature sensor and a thermal head. A thermostatic element is already installed in it, set to a fixed mixture temperature of 55 or 60 ° C, as shown in the figure:

Special 3-way valve for solid fuel heating units HERZ-Teplomix

Note. Similar valves that maintain a fixed temperature of mixed water at the outlet and are designed for installation in the primary circuit of a solid fuel boiler are produced by many well-known brands - Herz Armaturen, Danfoss, Regulus and others.

The installation of such an element definitely allows you to save on piping a TT boiler. But at the same time, the possibility of changing the temperature of the coolant with the help of a thermal head is lost, and its deviation at the outlet can reach 1-2 °C. In most cases, these shortcomings are not significant.

Binding option with buffer tank

The presence of a buffer tank is highly desirable for the operation of the boiler on solid fuels, and here's why. In order for the unit to function efficiently and produce heat with the efficiency stated in the passport (from 75 to 85% for different types), it must operate at maximum mode. When the air damper is closed in order to slow down combustion, there is a lack of oxygen in the furnace and the efficiency of burning wood decreases. At the same time, emissions of carbon monoxide (CO) into the atmosphere increase.

For reference. It is precisely because of emissions that in most European countries it is forbidden to operate solid fuel boilers without a buffer tank.

On the other hand, at maximum combustion, the temperature of the coolant in modern heat generators reaches 85 ° C, and one laying of firewood lasts only 4 hours. This does not suit many owners of private houses. The solution to the problem is to put a buffer tank and include it in the piping of the TT boiler so that it serves as a storage tank. Schematically it looks like this:

By measuring the temperature T1 and T2, you can adjust the layer-by-layer loading of the tank with a balancing valve

When the firebox burns with might and main, the buffer tank accumulates heat (in technical terms, it is loaded), and after attenuation it releases it to the heating system. To control the temperature of the coolant supplied to the radiators, on the other side of the storage tank, a three-way mixing valve and a second pump are also installed. Now it is not at all necessary to run to the boiler every 4 hours, because after the attenuation of the firebox, the buffer capacity will provide heating for the house for some time. How long - depends on its volume and heating temperature.

Reference. Based on practical experience, the capacity of a heat accumulator can be determined as follows: a private house with an area of ​​200 m² will need a tank with a volume of at least 1 m³.

There are a couple of important nuances. In order for the piping scheme to work safely, a solid fuel boiler is needed, whose power is enough for simultaneous heating and loading of the buffer tank. This means that the power required is 2 times higher than the calculated one. Another point is the selection of pump performance in such a way that the flow rate in the boiler circuit slightly exceeds the amount of water flowing in the heating circuit.

An interesting option for docking a TT-boiler with a home-made buffer tank (it is also an indirect heating boiler) without a pump was demonstrated by ours in the video:

Joint connection of two boilers

To increase the comfort of heating a private house, many owners install two or more heat sources that operate on different energy carriers. At the moment, the most relevant combinations of boilers are for:

• natural gas and firewood;
• solid fuel and electricity.

Accordingly, a gas and solid fuel boiler must be connected in such a way that the second one automatically replaces the first one after burning the next portion of firewood. The same requirements are put forward for piping an electric boiler with wood burning. This is quite simple to do when a buffer tank is involved in the piping scheme, since it simultaneously plays the role of a hydraulic gun, which is shown in the figure.

The supply lines of the boilers are connected to the upper branch pipes of the heat accumulator, the return lines - to the lower ones.

Advice. You will find information on calculating the volume of the buffer tank.

As you can see, due to the presence of an intermediate storage tank, 2 different boilers can serve several heating distribution circuits at once - batteries and underfloor heating, and in addition load an indirect heating boiler. But not everyone puts a heat accumulator with a TT boiler, since this is not a cheap pleasure. In this case, there is a simple scheme, and you can mount it yourself:

The scheme takes into account the peculiarity of the electric boiler - the built-in circulation pump always works

Note. The scheme is valid for both electric and gas heat generators operating together with solid fuel.

Here the main source of heat is a wood-burning heater. After the firewood load burns out, the air temperature in the house begins to fall, which registers the room thermostat sensor and immediately turns on the heating with an electric boiler. Without a new load of firewood, the temperature in the supply pipe decreases and the overhead mechanical thermostat turns off the pump of the solid fuel unit. If after some time it is ignited, then everything will happen in the reverse order. Details about this method of joint connection are described in the video:

Tying with the method of primary and secondary rings

There is another way to jointly tie a solid fuel boiler with an electric one to provide a large number of consumers. This is a method of primary and secondary circulation rings, which provides for hydraulic separation of flows, but without the use of a hydraulic arrow. Also, for reliable operation of the system, a minimum of electronics is required, and the controller is not needed at all, despite the apparent complexity of the circuit:

The trick is that all consumers and boilers are connected to one primary circulation ring by both the supply and return pipelines. Due to the small distance between the connections (up to 300 mm), the pressure drop is minimal compared to the head of the main circuit pump. Due to this, the movement of water in the primary ring does not depend on the operation of the secondary ring pumps. Only the temperature of the coolant changes.

Theoretically, any number of heat sources and secondary rings can be included in the main circuit. The main thing is to choose the right pipe diameters and the performance of pumping units. The actual performance of the main ring pump must exceed the flow in the most "gluttonous" secondary circuit.

To achieve this, it is necessary to perform a hydraulic calculation and only then will it be possible to choose the right pumps, so an ordinary homeowner cannot do without the help of specialists. In addition, it is necessary to link the operation of solid fuel and electric boilers by installing shut-off thermostats, as described in the following video:

Conclusion

As you can see, it is not so easy to properly piping a solid fuel boiler. The issue must be taken responsibly and before performing installation and connection work, additionally consult with a specialist whose qualifications are beyond doubt. For example, with someone who gives explanations in the videos presented.

The boiler piping is all devices and elements that are connected to a heat source, and which together form one heating system. The piping scheme for a solid fuel device consists of:

1. Shut-off and control valves.
2. Control and automation devices.
3. pipelines.
4. Heating devices (radiators, warm floors, heated towel rails).

Strapping requirements

Tying can be done according to many schemes, which must take into account the rules:

1. Temperature of water or any other liquid, which comes out of the head unit of the system, should not exceed the normative values. This applies to the pressure under which the coolant is supplied.
2. The temperature of the heat carrier entering the long-term combustion boiler should not be less than 20 °C from that of the water leaving the heat exchanger. Otherwise, in the middle of the body begins.
3. There should be automatic devices that are able to control the power of the long-burning unit and ensure a stable liquid temperature.

Best of all, such requirements are met by schemes that provide for the presence of circulation pumps.

Open system with natural circulation

Such a scheme is the simplest among all harnesses because it consists of a minimum number of elements. Thanks to this, it is completely autonomous. Flaws:

1. It is not possible to control the temperature of the water leaving the heat exchanger.
2. Air can enter the coolant through the open expansion tank. This accelerates the corrosion of panel and bimetallic radiators, steel pipes and heat exchangers.

This type of harness includes:

1. Long burning boiler.
2. Hot water supply line.
3. Open expansion tank.
4. A certain number of heating radiators.
5. Return water line.

Installation rules:

1. The water supply pipe from the boiler must be more than 0.5 m below the heating radiators. Otherwise, the natural circulation of the coolant will be unstable.
2. Pipes are installed inclined in the direction of water movement. To reduce the resistance to movement, it is recommended to use pipes with a larger diameter.
3. The expansion tank must be placed in the place whose height is the greatest when compared with the height of the placement of all trim elements.
4. Since shut-off and control valves reduce the flow area of ​​the pipes (this increases the resistance of the liquid), its number should be minimal.

Read also: Frequent breakdowns of electric boilers and their repair

Closed system with natural circulation

This piping of the pellet device involves the use of a closed-type membrane tank. It is better to place it on the return pipe at the lowest point. At the same time, a tank is optimal, in which more than 10% of the water used in the entire system is placed.

The composition of the scheme is presented:

1. Heating boiler.
2. Security group.
3. Feed line of heated liquid.
4. Heating radiators.
5. membrane tank.
6. Return water supply line.

The safety group is a separate device, which must consist of at least radiators and a safety valve. The latter is connected to the sewerage using a drain hose. Its function is to relieve excess pressure. This device may include a pressure gauge that allows you to visually assess the pressure in the system.

The first two elements of a security group can also be set individually. Often it is already included in the design of the device. The rules for installing the main piping elements are almost the same as the rules for installing the components of the above diagram.

Piping with forced circulation

It has almost the same structure as a closed system with a natural movement of the coolant. In this case, an additional element appears in the form of a circulation pump. In most cases, it is mounted on the return supply line after the membrane tank and before the inlet fitting of the heat exchanger.

Thanks to this pump, you can more flexibly control the operation of the system. It becomes possible to install shut-off and control valves on each radiator. Now water is able, under the pressure created by the circulation pump, to easily pass through narrower sections of the pipeline made of polypropylene.

The use of such a pump makes the system dependent on the power supply.

Collector system

Such a piping of a solid fuel unit includes:

1. Solid fuel boiler.
2. Security group.
3. Supply line manifold.
4. Heating radiators.
5. Towel dryer.
6. Underfloor heating system.
7. Return manifold.
8. Membrane tank.
9. Circulation pump.

Read also: Solid fuel boiler with hob

The new elements in this system are collectors. Known as combs. They are a wide pipe with a large number of nozzles. One of them is the input, the rest are the output. A pipe with a safety group is connected to the first. Hot liquid is supplied through it, which, leaving various nozzles, is distributed among user groups: radiators, underfloor heating and a heated towel rail. The second collector collects water together and directs it through the outlet.

Hydraulic gun system

Very similar to the collector circuit. Instead of two collectors hydraulic gun is used, which is a vertical pipe with a large diameter, and which is connected to the supply and return lines. It has many fittings to which individual groups of users are connected.

Branch pipes to which radiators, underfloor heating, etc. can be connected are located at different heights of the hydraulic gun. In this case, the placement height corresponds to the water temperature. Due to this, coolant with a certain temperature can be supplied to various devices.

Thermal storage system

The piping of a solid fuel heating boiler, the scheme of which includes, differs in that it can have two coolant movement circuits:

1. The first occurs between the device and the heat accumulator.
2. The second is formed between the heat accumulator and radiators.

The scheme is this:

1. Boiler.
2. Security group.
3. Heat accumulator.
4. Heating devices.
5. Main circulation pump. It is included in the pipe, which departs from the heating radiators and goes to the heat accumulator.
6. membrane tank. Located after the heat accumulator.
7. Additional circulation pump. It is located between the membrane tank and the return pipe of the heat exchanger.

Accumulates heat in itself, at the same time giving the necessary amount of it to radiators. It always supplies a normalized amount of heat, absorbing all its excesses. As a result, the radiators do not overheat. In this mode, the coolant circulates throughout the system.

If you need to stop the supply of heated water to the radiators for a while, it begins to circulate between the boiler and the heat accumulator. When the fuel in the boiler runs out and the fire goes out, the coolant circulates only between the heat accumulator and the heating radiators.

Wiring diagram for a solid fuel boiler and a gas boiler

Very simple is the strapping, which provides parallel connection of a gas and solid fuel boiler. It is used for systems with natural circulation.

Content

1. What is strapping, its tasks and types
2. Tying according to the scheme with natural circulation
3. Forced circulation heating system
4. Piping using a backup boiler

Introduction

The heating system, in addition to a solid fuel boiler, contains many more elements. Correctly connecting and configuring all the elements of this system is not an easy task. In this article, we will analyze various connection schemes, weigh the advantages and disadvantages of each of them, and analyze the various nuances and subtleties. I hope this article will help you safely and effectively tie a solid fuel boiler with your own hands.

What is strapping, its tasks and types

So what is a harness? This is the name of the process of the most efficient and safe connection of a solid fuel boiler to a house heating system.

To prolong the service life and ensure the safe operation of a solid fuel boiler, it is necessary to control parameters such as pressure and temperature in order to avoid overheating. Steel heat exchangers, among other things, are sensitive to the temperature of the coolant in the return line, which should not be lower than 50-65 degrees Celsius. The use of colder water in the return line is fraught with condensation, which reduces the life of the heat exchanger.

So, how to properly tie a solid fuel boiler? There are several basic schemes:

• with natural circulation;
• with forced circulation;
• using a backup heating source.

Photo 1: Tying a solid fuel boiler and a spare electric boiler

Let's take a closer look at each of them, determine the list of devices necessary for organizing each of the schemes, as well as the pros and cons inherent in these schemes.

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Tying according to the scheme with natural circulation

The easiest way is to tie a solid fuel heating boiler - a scheme with natural circulation. It does not require a power supply. The circulation of water is carried out by means of the force of gravity. That is why it is also called gravity.

Photo 2: Gravity type piping scheme

The solid fuel boiler is located at the lowest point of the circuit, and the heating device (for example, a radiator) is located at the top. The boiler heats water, which rises through pipes to the radiator, where it gives off part of its heat to the room and at the same time cools. The cooled coolant goes down and the circle closes. The specific gravity of the cooled coolant is greater than that of the hot one, so it tends to go down. Thus, pressure appears and the water cycle in the heating system is carried out.

The more the temperatures in the forward and reverse lines differ, the higher the speed of water movement along the circuit. But unfortunately it is difficult to achieve a big difference, since the temperatures in the supply and return lines are limited, as well as the safe conditions for its operation. Therefore, larger diameter pipes are used to ensure better circulation.

To protect against overheating, a special circuit is used, which ensures the circulation of the coolant and heat consumption in any case.

An expansion tank provides protection against overpressure. There are two types: open and membrane type. The disadvantage of using open tanks is that the water in it is enriched with oxygen, which in turn causes corrosion of the steel parts of the solid fuel boiler. That is why, most often, open tanks are used in conjunction with cast-iron boilers and radiators. When using a membrane tank, it becomes necessary to connect additional equipment, such as: an air vent, a relief valve and a pressure gauge to control pressure.

Photo 3: Self-piping of a solid fuel boiler

To provide hot water, a heating tank is used. For safety reasons, it must be equipped with a thermostatic mixer at the hot water outlet. The function of the mixer is to bring the temperature of the water to the values ​​that exclude burns. The requirements for the location of the heater are the same as for other heating devices - i.e. above the level of the solid fuel boiler.

The main advantages of such a scheme are the simplicity of its design and energy independence. The main disadvantage is that during a cold start, until all the water in the circuit is completely warmed up, the temperature in the return line will be below the allowable one. This negatively affects the service life, for example,. Also, the disadvantages include poor handling and low energy efficiency.

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Forced circulation heating system

The circulation of the coolant is carried out using a circulation pump. This solves the problem of low return temperature by adding hot water from the supply line. Also, more comfortable heating conditions are achieved, thanks to the possibility of adjusting the temperature in the heaters. However, there are also significant disadvantages:

• The chance of overheating increases if the room heaters are set to low heat consumption.
• In the absence of power, the circulation pump will no longer be able to perform its function, and therefore the movement of the coolant will stop. This can also lead to overheating.

For example, to reduce the risk of an emergency rise in temperature in the heating system, they are equipped with external or built-in emergency heat exchangers.

The inclusion of storage tanks in the piping scheme allows you to accumulate excess heat and, if necessary, give it to the heating system. This solves several problems:

• In case of low heat consumption, excess hot heat transfer fluid is stored for later use.
• With low heat consumption, the solid fuel boiler still operates at rated power.
• Allows you to use devices with higher power.

The figure shows the piping of a solid fuel boiler with a heat accumulator and a circulation pump:

Photo 4: Piping according to the forced circulation scheme

Many owners of private houses designing a heating system are interested in the question, is it possible to tie a solid fuel boiler with polypropylene? The use of polypropylene pipes imposes certain requirements on the temperature of the coolant. When using polypropylene pipes in a heating system, experts advise that the first 1-1.5 meters of the supply line be made of metal, as well as use a larger pipe diameter and a thermostatic valve. Naturally, overheating of a solid fuel boiler should be avoided in every possible way.

When performing this type of piping, it should be borne in mind that the cost of additional equipment can be equal to and even exceed the cost of the solid fuel heating device itself. This is not suitable for those who decide to buy a TT boiler for home heating, focusing on its relatively low price.