
Features of the strapping of a solid fuel boiler
Classical heating scheme with one heat generator is well known to every owner of the house. However, combining gas and electric boiler in one system, you can achieve a much greater practical effect. They say that such a connection is much more economical than usual. It sounds tempting, isn’t it?
With logical reasoning, doubts arise: how electricity will help to save the budget, because its cost is much higher than gas? And why do this in terms of the advisability of strengthening the power of the units? Isn’t it easier to purchase just one productive boiler?

In fact, the project of such a combination is fully justified. We will tell you in detail how to collect heating with electric and gas devices. You will learn about the device of this system and its expediency. We will help you draw up a scheme and not miss important nuances of arranging a combined heating line.
Two heating gas boilers in the house
The comfort of a large house largely depends on the correct organization of the heating system. Difficulties are added as physical removal of heated rooms scattered along floors, with different functions and requiring various temperature conditions, as well as a variety of solutions used (radiators, warm floors).
The use of two (or even more) boilers for heating significantly increases the reliability of the system, gives the homeowner confidence and greater comfort in emergency situations. With a forced stop of one of the boilers, the system will continue to work, providing at least 50% of the calculated capacity. Although such “complacency” will cost 30-40% more. Two boilers are convenient in terms that each service can be carried out without stopping the entire system. And the spare parts themselves for lower power units are more affordable and cheaper.
Of the advantages of the paired system, it is worth mentioning an increase in the general resource of boilers. After all, practice shows that only a small part of the heating season of the boiler works with a load of more than 50%. The average for the heating season is the load in our climate is not more than 30-40%. If the boiler has been working for a long time for a long time, this leads to a decrease in its working resource. The power consumption ideally should correspond to the level of about 80% of the maximum. In this case, the best solution may be a cascade connection of several “small” boilers instead of one powerful. Using such a connection, the problem of the optimal ratio of the boiler room and the requirements of the house in the warmth is solved.
Cascade of boilers ensures the operation of the boiler room in the required power range, regardless of the time of year. The principle of operation of such a scheme is simple. The total required load is distributed between two, three or more independent control boilers. Each of them is a certain “step” in the overall performance of the boiler room.
In a certain period of time, only those boilers that are currently necessary and no more are included in the work. In this case, the temperature conditions of the building only improve, become more stable and comfortable. The cascade easily levels the influence of abrupt consumption, when one of the heating contours is involved inconsistently (for example, for heating the pool, bath, greenhouses and so on). With a sharp increase in the load, another boiler simply turns on. This provides their work in a more gentle mode.
Solomun Boiler Room DJ Set
Connection of boilers to a cascade using an electronic cascading unit is a comprehensive solution and has greater efficiency. The cascade control unit optimizes the operation of the system and provides inclusion depending on the required power of only the required number of boilers. When working with modulated burners, the cascading control unit seeks to ensure the operation of boilers in optimal mode of reduced power. This block provides alternating operation of all boilers and guarantees that each boiler will work the same number of hours.
Often, several boilers simply work together on one heating system through a hydraulic separator (“arrow”). This ensures the hydraulic and temperature balance of the primary (boilers) and secondary (load) contours.
The diagram with a hydraulic arrow allows you to attach any required number of boilers and heating zones or thermal load. That is, without much difficulties, a high.temperature heating zone (radiators), low.temperature (warm floors), and a boiler for hot water can be connected.
Such a scheme allows you to do without the use of additional complex blocks of cascading regulation and do not lower the temperature of the coolant in the heating system with a peak (at the request of the boiler) need for hot water.
Two heating boilers can be connected according to a simplified circuit, without additional devices and blocks. And use the built.in weather.dependent automation of the boilers and the automation of the priority of the hydraulic pump only one of the boilers. When organizing such a scheme, attention should be paid to the fact that each boiler individually should independently ensure the necessary circulation of the coolant in the entire heating system. If this is not possible, you will have to return to the circuit with a hydraulic shotgun and a separate pump in the secondary circuit of the heating system.
Arrangement of a heating system with a heat accumulator
The use of such an element in the scheme with two boilers in one heating system has several features depending on the installed units:
- Heat accumulator, gas boiler and heating devices form a single closed system.
- Solid fuel boilers operating on wood, pellets or coal, heat water, thermal energy is transmitted to the heat accumulator. He, in turn, warms the coolant circulating along the closed heating contour.
To independently create a heating scheme with two boilers, it is necessary to purchase the following:
- Boiler.
- Heat accumulator.
- Expansion tank of the corresponding volume.
- Hose for additional removal of the coolant.
- Cutting taps in the amount of 13 pieces.
- The pump for forced circulation of the coolant in the amount of 2 pieces.
- Three-way valve.
- Water filter.
- Steel or polypropylene pipes.
Such a scheme is characterized by work in several modes:
- The transfer of thermal energy from a solid fuel boiler through a heat accumulator.
- Water heating with a solid fuel boiler without using this device.
- Getting heat from a gas boiler connected to a gas cylinder.
- Connecting two boilers at the same time.
Parallel connection of boilers and minuses
The main boilers we examined above. Now consider the connection of backup boilers that should be in the system of any modern house.
If the backup boilers are connected in parallel, then this option has its pros and cons of.
The advantages of the parallel connection of the backup boilers are as follows:
- Each boiler can be connected independently and disconnected from.
- You can replace each heat generator with any other equipment. You can experiment with boilers settings.
Cons of parallel connection of reserve boilers:
- We’ll have to work more with the cauldron of boilers, solder polypropylene pipes more, cook steel pipes more.
- As a result, more materials, pipes and fittings, and locking reinforcement will leave more.
- Boilers will not be able to work together, in a single system, without the use of additional equipment. hydraulic shootings.
- Even after using the hydraulic shootout, the need for complex adjustment and coordination of such a system of boilers by the temperature of water supply to the system, and.
The indicated pros and cons of parallel connection can be applied to the connection of the main and backup heat generator, and to the connection of two or more backup heat generators on any type of fuel.
Two.fuel heating boilers
In an effort to obtain high indicators of the heating system, to avoid interruptions with voltage in the mains and in the operation of the unit, many turn to the installation of two.fuel boilers. Despite the large size and solid weight, combined boilers work properly through the use of different types of fuel and minimum maintenance costs.
A scheme, in which gas and firewood are used for heating the coolant, is considered the most popular and convenient, as it works with an open heating system. If you strive to install a closed system, then it is recommended to put an additional circuit for a heating system in a universal boiler tank.
Manufacturers of heating boilers are produced by several types of two.fuel combined boilers:
Solid fuel boiler and electricity
One of the financially justified and functionally convenient combined boilers is a solid fuel boiler with an electric heater that allows you to control and adjust the temperature regime in the house. Thanks to the use of heating, such boilers have a number of advantages and positive characteristics. Let us consider in more detail the principle of operation of the heating system of a combined boiler.
The combined boiler works only on one type of solid fuel. The water in the circuit begins to heat up when burning loaded raw materials. As soon as the fuel burned out, the thermostat is triggered and electric heaters are turned off, the water begins to cool down. As a result of a temperature reduction, the heating heating site is automatically turned on. The process of heating and cooling is cyclic, so the house is constantly maintained a comfortable temperature.
To optimize the operation of contours, manufacturers offer to use heat batteries in heating systems. Outwardly, they are a container with a volume of 1.5 to 2 meters of cubic. The principle of operation: through the battery container passes the circuit pipes and heat the existing water. After the end of the boiler, hot water slowly gives thermal energy to the heating system. Thanks to the batteries, the temperature regime is stable for a long time.
Summing up, it can be noted that to reduce the cost of heating a private house, ensure uninterrupted and stable operation of the heating system, the installation of a two.fuel boiler is an optimal and proven option.
The advantages of the system with two boilers
The main positive moment of installing two boilers in one heating system is continuous heat support in the room. The gas boiler is convenient because it does not need to be constantly maintained. But in case of its emergency shutdown or in order to save a wood boiler will become an indispensable heating addition.
The heating system of two boilers can significantly increase the level of comfort. The advantages of the double thermal device belong:
- selection of the main type of fuel;
- the ability to control the entire heating system;
- Increase in the operational time of equipment.
Connecting two boilers into one heating system is the best solution for heating buildings of any size. This decision will allow you to continuously keep warm in the house for many years.
Installation of a solid fuel boiler is the first step to effective and economical maintenance of heat in the house. The following steps are to regularly throw firewood or other types of solid fuel. Maintain the temperature of the heating system of the heating system within the working limits and at night. And even when the house is visited only on weekends, it is required to maintain a minimum temperature, in order to avoid the condensation of moisture on the internal surfaces in the room.
If the presence of condensate is not critical, then when leaving after the weekend, you need to wait for the boiler stopping and drain the water from the heating system in order to avoid freezing the system. In case of water drain, all metal elements are corroded when in contact with air.

The drain of the coolant is not needed if antifreeze is used instead of water. However, when using antifreeze, due to high fluidity, high requirements for threaded seals and shut-off valves are put forward.
The most common solution for maintaining temperature in the heating circuit is the installation of an electric boiler together with a solid fuel. The minimum amount of additional equipment will allow the electric boiler automatically to take on the functions of heating, and to solid fuel. disconnect, without risk of boiling. Also, the use of an electric boiler eliminates the need to carry out any manipulations with a heating system, leaving a country house until the next weekend. To track emergency situations and remote control of an electric boiler, there is. which controls the operating mode of heating equipment.
type of 2-pipe systems
Depending on the conditions for laying pipelines and further operation in private houses, the following options for two.pipe schemes are used:
- Gravitational or gravity with natural circulation of heated water.
- Classical dead end system of heating.
- Ring with the passing movement of the coolant, it is also the loop of the tichelman.
- Radiation with individual distribution of heat to radiators from the distribution collector.
The note. Warm floors can also be attributed to two.pipe heating. Hearing contours act as batteries, the role of the highways is played by supplying pipes and a comb with a mixing knot. In design, floor heating is close to the collector scheme.
In gravity, the system functions without excessive pressure, the coolant is in contact with the atmosphere through an open expansion tank. The remaining 3 options for schemes. closed, operating under pressure 1-2.5 bar and only with forced circulation of hot water. Now we will analyze each scheme on a specific example of a two.story house.
Summary heating
The principle of operation of the system with the natural movement of the coolant is based on the phenomenon of convection. hot and less dense liquid seeks to climb up the pipe, displaced by heavier cold layers. The boiler heats water, it becomes lighter and moves through a vertical riser at a speed of 0.1-0.3 m/s, then diverges through the highways and batteries.
Clarification. It is understood that the heated and cooled liquid is within one closed circuit, in this case, the heating network of a private house is such.
We list the characteristics of a two.pipe gravitational system of a two.story building shown in the drawing:
- The method of laying the highways is a horizontal upper wiring, originating from a common riser. The latter rises from the boiler, at the highest point there is an expansion tank communicating with the atmosphere.
- Horizontal areas are laid with a minimum slope of 3 mm per meter linear line. The feed is tilted towards radiators, the return. to the heat source.
- Pipes diameters are increased compared to pressure systems, since they are designed for a small speed of water flow.
An important nuance. To realize a stable itself, you need to use pipes Ø40-50 mm (internal). The minimum allowable diameter of distributing and collecting branches. DU25, is placed near the last batteries.
A similar scheme is used in a one.story house, but with a single connection of radiators. The supply collector of the upper wiring is laid in the attic or under the ceiling, the reverse. above the floor. It is impossible to make a lower wiring. the coolant according to the law of communicating vessels will start in batteries, but the speed and efficiency of heating will fall to a minimum.
The current gravitational schemes have become combined due to the installation of circulation pumps. The unit is mounted on bypas so as not to interfere with the flow of water in the case of disconnecting electricity.
Deadly heating branches
A two.pipe closed system of a shoulder (dead end) type is mounted in most country cottages and is often used in new apartment buildings. How the scheme works:
- The radiator network is one or more two.pipe branches. The coolant is sent to the heating devices along one highway, and returns by the second.
- The system works with excess pressure 1-2.5 bar, circulation provides a pump installed near the boiler.
- The expansion of the water compensates for a membrane tank located in the boiler room. The point of the insert. on the pipeline in front of the circulation pump (if you look along the fluid).
- Air discharge from the network occurs through the cranes of Maevsky on batteries and an automatic valve as part of the security group of the heating unit. There is also a pressure gauge and a safety valve.
- A common wiring option is the lower horizontal, when both pipes pass under the radiators in an open way.
Comment. If necessary, dead.end highways are laid without problems in a closed way. in the grooves of the floor screed, behind suspended ceilings or inside the walls.
If it is necessary to distribute the coolant into 2 wings of a two.story building, a division is carried out into 4 separate branches (shoulders) converging to a common riser. It is noteworthy that the length of the lines and the thermal load on the shoulders should not be the same at all. The number of batteries and the laying route is developed taking into account the features of a particular building.
Branches with different number of radiators are balanced by balancing. limiting the flow of adjusting reinforcement. Valves are always placed on the outputs of the batteries and if necessary. on the shoulder as a whole. How to correctly balance the contours, we read on another page of our resource.
Wiring dead end lines into 2 wings of a two.story building. Heat source-wall mini-boot
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Tichelman ring
The general principle of operation of this scheme is identical to dead end, but the method of distributing and returning the coolant differs by 3 signs:
- Each heating circuit is closed into the ring.
- The method of connecting batteries is as follows: the first radiator on the feed is the last for the back line. And vice versa, the final battery of the distribution line becomes the first to return.
- Water in both pipelines moves in one direction, hence the technical name of the system. a passing.
The device of the loop of the Tichelman involves horizontal lower wiring. hidden under the floor, less often. open on the walls. Another option: the ring can be made under the ceiling, hidden by the stretch ceilings or to the basement, and pipe eyeliners should be removed to the heaters.
The technological scheme of the boiler room
After the arrangement of thermal generators, there is a turn of the apparatus to connect to the engineering networks of the country house. heating, water supply, electricity. All possible schemes cannot be considered, but we will give the main options for the strapping of boilers and water heaters in the boiler room:

- The simplest option is to connect one double.circuit boiler of wall installation. Since the unit is originally equipped with its own pump, expanding tank and automation, it can be placed in the kitchen or in the corridor, and hid the communications in the walls. It is not necessary to separate or attach a room.
- The circuit of a boiler room with a solid fuel boiler provides for protection against cold “return” and condensate loss inside the fuel. The key role is played by a three.way valve, which does not let the coolant from radiators into the shirt, until the outline with bypass warms up to 50–55 ° C.
- The wagon with a heat accumulator increases the efficiency of TT KOTLA, which works in maximum mode, giving most of the energy of the buffer capacity. The second three.way valve limits the temperature of the water at the entrance to the radiator network, the balancing valve serves to configure the layout of the tank.
- Typical connection diagram of the wall heater with an indirect heating boiler. The temperature in the tank is monitored by the thermostat that supplies the signal to the controller of the boiler. Electronics switches a three.way electric valve and alternately directs the coolant to the coil of the water heater or heating battery.
- If necessary, an indirect boiler is included in the small circuit circulation of TT-KOTLA, as shown in the next picture.
- A scheme with two boilers. electric and wood. is often used when there is no gas in the house. The wood heat generator serves as the main source of heat, electric boiler. an auxiliary (automatically turns on after the burning of solid fuel).
- When it is required to combine several power plants and consumers in the boiler room, the scheme of primary and secondary rings is practiced. In residential buildings of Malaya and Medium Square, this option successfully replaces a more expensive hydraulic shotgun with a collector.
A more detailed description of each technological scheme is given in the relevant articles. methods of strapping heat generators and installing an electric boiler with your own hands.