Solid fuel stoves with electricity. Combined boilers for wood and electricity: the best solution for heating a country house. Choosing the type of heating in a private household

Recently, more and more often you can find universal combined heating boilers in private homes that can operate simultaneously on two types of fuel. The combination of electricity and firewood is an excellent choice: such a boiler is very compact, practical and reliable. In the event of a power outage or lack of fuel, you will not be left without heat and hot water in winter.

Externally, the combined boiler is practically no different from a conventional solid fuel unit. In principle, this is the same wood-burning heating boiler, in which a heating element is installed in the heat exchanger. Another important difference is the design of the water jacket. One of the walls of the furnace of such a boiler has a complex configuration and is made by cold stamping. Heating elements are mounted between the walls of the jacket, and there is a special contact hole to which the contacts of the electrical wiring wires are connected.

Combined boilers that run on wood and electricity are designed very competently and thoughtfully, the main working units are:

• solid fuel loading hatch - solid fuel is loaded into it, the volume of fuel loaded at a time depends on its size;
• ash pan - supplies oxygen for burning fuel and collects ash;
• burners allow you to switch from one type of fuel to another;
• draft damper - regulates the intensity of fuel combustion. The chain drive opens or closes the ash chamber damper;
• heat exchanger - provides warm water supply;
• temperature sensors - automatically regulate the operation of heating elements, which ensures the continuity of heating.

The automation system allows you to adjust the operating mode of the boiler, as well as its power. There are models of boilers that have hobs for cooking, they are installed above the firebox. Boilers with two circuits allow you to connect the "warm floor" system, for this there are special outlets for installation.

They produce boilers with one circuit and with two circuits. In the first case, the boiler is used only for heating, in the second case it will provide hot water for household needs. Also on sale are units with a manual control system and with an automatic one. Boilers with a manual control system are cheaper, and automatic control makes maintenance and the life of the owner easier.

Advice. When choosing a boiler for heating a house, it is necessary to correctly calculate the power of the device based on the area of ​​\u200b\u200bthe room. This will affect fuel consumption.

Principle of operation

The principle of operation of a combined heating boiler is quite simple. The heat generator, powered by the mains, starts the electric heater. Pipe electric heaters begin to heat the coolant (water) in automatic mode according to the principle of a boiler. This process is automated by a special device, only firewood is loaded into the firebox manually.

While the heater is heating the water, you need to fill the combustion chamber with firewood and set it on fire. The combustion chamber is located below and transfers heat from burning firewood to the heat exchanger. When the temperature of the coolant reaches a predetermined level, the heating element turns off, and then only firewood generates heat. The burning power of firewood can reach 30 kW, which is enough to heat the house.

When the firewood burns out, the heating element turns on again and maintains the set temperature. You can only heat with firewood, and turn on the heating element only for safety. If firewood runs out, then only the heating element will provide heat. But often electricity and firewood are used simultaneously, this is especially convenient at night, when it is not possible to constantly put firewood in the firebox. Then firewood is laid in the evening, and the heating element is turned on to maintain heat not at full capacity.

If electricity is used as a priority for heating, and firewood is used only as a reserve, then boiler maintenance is simplified to a minimum. The desired temperature is set automatically and the heating element is responsible for maintaining it. When the electricity is turned off, as is often the case in our country, you put firewood in the furnace, and the boiler starts to work on solid fuel.

Important. When operating the boiler on wood, make sure that the damper on the chimney is open. When working on electricity, the valve can be closed.

Advantages of combined boilers

Advantages of boilers firewood and electricity compared to single-fuel devices are obvious.

1. Versatility. You can use one of the two types of fuel as you wish.
2. Profitability. Electrical energy is the most affordable type of fuel, and so is wood. In addition, coal and waste from the woodworking industry can be used as an alternative. It turns out the perfect union: wood - electricity.
3. Thoughtful design. Heat is intelligently distributed and energy losses are minimal, which makes these boilers very efficient.
4. Long service life. With proper operation, such a boiler will serve you faithfully for a very long time, at least 20 years.
5. Autonomy. There is no need to constantly monitor the process - automation will do everything for you. Especially when working on electric fuel, the heating mode with the help of a heating element is limited by an uninterrupted supply of electricity.
6. There are models with pre-built pipes for connecting the "warm floor" system.

Important. Combined boilers that run on wood and electricity work efficiently even in low-power modes.

disadvantages

And yet, with all the advantages, combined boilers have their drawbacks, like any other heating equipment.

1. It is necessary to equip a separate room - a boiler room, it is also necessary to store fuel reserves.
2. Weight. Devices made of cast iron can weigh several hundred kilograms; before installing such a boiler, a concrete pad may be required to reinforce the subfloor. Due to the significant weight of the product, there are no models for wall mounting, only models for floor mounting.
3. The design of combined boilers is more complex, which affects the cost of installation and service repairs.
4. Another disadvantage is the low power of the electrical component. The power of electric heaters should not exceed the power of the wood burning chamber. The power range of a wood-burning firebox is within 6 - 25 kW.
5. The cost of models of combined boilers is 20-40% more expensive than similar solid fuel boilers, but their purchase is much more justified than installing one type of boiler and then replacing it with another.

The manufacturer offers combined heating boilers powered by electricity and wood of various capacities, configurations and performance. When purchasing such equipment, pay attention to such moments.

1. Power - depends on what kind of fuel is used. Decide in advance on what type of fuel the priority units will operate.
2. The size of the combustion chamber - the volume of the combustion chamber depends on how often you need to load fuel.
3. Noiselessness - installation of a special valve ensures quiet operation of the unit.
4. Number of circuits - for some models, water is heated only by a heating element. More economical than models in which the coolant coil is mounted in the combustion chamber.
5. Heat exchanger. It can be made from cast iron or steel. Cast iron devices are resistant to corrosion, heat up for a long time, but they also give off heat for a long time, have a significant mass and can crack with a sharp temperature drop. Steel is subject to faster oxidation and corrosion, lighter in weight and resistant to temperature extremes.
6. Grids. They are made from various materials. It can be cast iron or ceramic. Cast iron is more heat resistant and suitable for the combustion of any solid fuel. They use honeycomb cast iron grates with ceramic coating, they are suitable for bulk materials that use more oxygen during combustion.
7. The weight and dimensions of the boiler. It may be necessary to reinforce the surface area on which the unit will be installed with a concrete screed.

Among multi-fuel equipment, boilers for heating a private house on wood and electricity are especially popular due to their simple and reliable design. The transition between firewood and electricity is carried out automatically.

How does a wood-fired boiler work with a heating element

Almost all heating boilers for a private house on wood and electricity work in the manner described above. There are differences related to the design and the combustion principle used.

Boilers with built-in heating element

It is impossible to use the heater as a full-fledged electric boiler, due to its insufficient power. In most boilers, a heating element is installed, with a capacity of up to 6 kW.

The consumer is offered models with a cast-iron and steel heat exchanger. Holes for the heating element are cut out by laser welding or, in the case of cast-iron analogues, are provided during the casting of the heat exchanger.

Floor combined heating boilers wood-electricity, factory assembled, have the following advantages:

1. Possibility to choose any type of heat exchanger.
2. Full automation of the combustion process, turning on / off the heating element.
3. Compliance with safety requirements.
4. Convenient adjustment of the operation of the heating element and the selection of a suitable mode.
5. The anti-freeze mode is provided.

Modifiable boilers

• Steel boiler - heating element and thermostat, inserted directly into the heat exchanger. Installation requires welding. After installation, the holes are hermetically sealed.
• Cast iron boiler - the design of the heat exchanger is somewhat different. In the body there is a water jacket surrounding the combustion chamber. Independent production of holes for the installation of a thermostat and a heating element will lead to an increase in the load on the cast-iron heat exchanger. During the work, microcracks appear, which eventually leads to the failure of the boiler. For this reason, it is not recommended to remake a cast-iron boiler for the installation of an electric heating element.

How to choose a heating boiler on electricity and wood

• The principle of operation - the most profitable and economical, are pyrolysis boilers that operate 6-12 hours from one tab. During operation, heat is extracted in two ways: during the combustion of firewood and the afterburning of gases.
  A gas-fired boiler is more expensive than a classic model, but the costs are paid off by reducing the consumption of firewood, better efficiency and heat output.
• The number of circuits - single-circuit units are characterized by high performance, they are able to heat large areas. The design provides for connection only to the heating system. Water heating becomes possible only after modification (indirect heating).
  Double-circuit combined boilers, simultaneously work to heat the coolant of the heating system and hot water.
• Heat exchanger - There are two types of wood-fired boilers. Cast iron units are heavy, inconvenient during installation, but at the same time, they are distinguished by a long service life and high heat transfer.
  Steel boilers are cheaper, sensitive to excessive overheating of the coolant, cool down quickly after the firewood has burned down. Most manufacturers focus on the manufacture of steel boilers, since production is cheaper, and they are in constant demand from consumers.

When choosing a mixed-type boiler, from electricity and firewood, it is important to calculate the required power, select equipment by manufacturer and cost.

How to calculate the power of an electric wood boiler

Accurate calculations, taking into account the characteristics of a residential building, are carried out only after an audit of heat losses. The approximate power of a combined wood and electricity boiler is calculated using an online calculator or a special formula.

Calculations are performed as follows:

1. The total heated area of ​​the building is calculated.
2. The amount of heat required for heating is calculated. Use the formula 1 kW = 10 m².
3. When calculating, for a universal double-circuit boiler, taking into account the need for heat for hot water supply, 15-20% is added to the result obtained.

Heating systems with electric wood-fired boilers are equipped with an electric heating element with a power of up to 6 kW. The performance of the heater is sufficient to prevent freezing of the coolant or full heating of 60 m² of the building.

Manufacturers of combined electric-wood boilers

• - German boilers, characterized by high build quality, long service life and high cost, 3-5 times higher than what the Russian manufacturer asks for their products. In the case of Buderus, the price is fully justified. The boiler consumes fuel economically and has sensitive automation that controls the combustion process. In an additional complete set the storage boiler is offered. Productivity up to 350-400 kW.
• - the consumer is offered steel boilers with a capacity of up to 18 kW and a built-in electric heater of 6 kW. Suitable for full-fledged heating of rooms with a total area of ​​up to 200 m². In addition to the boiler Mister Hit AOTVC, a remote control unit is offered that allows you to control the combustion process using the remote control.
• - one of the largest domestic manufacturers offering products that meet European standards of quality and reliability. Products are offered in the Master series. Zota boilers provide a place and a hole for installing a thermostat and an electric heater. The heating element and sensors are purchased separately and are not included in the basic package. One of the main advantages of the model is the ability to install a heating element for 9 kW, instead of the traditional 6 kW.
• – the company offers heating equipment with power from 8 to 30 kW. Boilers are distinguished by low cost, minimal equipment, small dimensions and "omnivorousness". You can pick up a Karakan boiler with a hob, which is especially convenient when heating a country house.
• Kupper OVK - boilers offered by Teplodar are presented in two power sizes of 10 and 18 kW. Models are equipped with a cast-iron hob, able to work on any type of solid fuel. If necessary, they are equipped with a pellet and gas burner. Kupper HVAC is the optimal solution for heating a house with a maximum area of ​​up to 200 m².
• Stoker Aqua is a brand promoted on the domestic market by Ermak. Four standard sizes are presented, in terms of performance 12, 14, 16, 18 kW. Built-in electric heater, power 1.5 - 3 kW. The automatic draft regulator is installed separately, as an option. The model has a capacious combustion chamber. The Stoker Aqua series offers boilers exclusively with a steel heat exchanger.

The main advantage of Russian heating boilers running on wood and electricity is unpretentiousness to fuel quality. In Western counterparts, heat efficiency drops sharply if the moisture content of firewood is more than 20%.

The cost of wood-electricity boilers

Buderus offer luxury boilers, to purchase a universal boiler, even of low power, will cost about 150-250 thousand rubles. Domestic boilers are cheaper. Models similar in their characteristics are offered on the Russian market for 15-45 thousand rubles, depending on the manufacturer and configuration.

Where and how to install electricity-firewood boilers

• Models with built-in heating elements do not require an installation permit, provided that the maximum power consumption rate does not exceed 3 kW. Heating element 6-9 kW, creates an additional load on the power grid. A separate voltage line is allocated for connection.
• Boilers, with a capacity of up to 40 kW, are installed anywhere in the house. A boiler over 40 kW is best placed in a separate room used exclusively for the needs of the boiler room.
• The connection of the electric wood-burning boiler is carried out through separate machines located on the control room. The electric heater is not afraid of power surges in the network, but if a remote control controller is used, voltages are set.
• As a boiler room, for heating a house on wood and electricity, a dry heated room is chosen, with a total area of ​​​​at least 8 m². Be sure to have natural lighting and ventilation.
• Universal combined boilers powered by wood and electricity are located in such a way that there is at least 50 cm to the walls lined with combustible material. Installation is carried out on a fire-resistant base. The chimney, when passing through floor slabs and roofs, is placed in a special box filled with thermal insulation material.

Dual-fuel combined solid fuel boilers for heating wood-electricity, connected to the water circuit. To replenish the coolant, it is recommended to connect a water treatment and filtration system. Additionally, a safety group is connected that automatically relieves pressure in the system.

The electricity parameters for electric heaters, with a maximum power of 9 kW, do not require the use of a three-phase power supply. The connection is made to a regular 220 V household network.

Recently, more and more often you can find universal combined heating boilers in private homes that can operate simultaneously on two types of fuel. The combination of electricity and firewood is an excellent choice: such a boiler is very compact, practical and reliable. In the event of a power outage or lack of fuel, you will not be left without heat and hot water in winter.

Externally, the combined boiler is practically no different from a conventional solid fuel unit. In principle, this is the same wood-burning heating boiler, in which a heating element is installed in the heat exchanger. Another important difference is the design of the water jacket. One of the walls of the furnace of such a boiler has a complex configuration and is made by cold stamping. Heating elements are mounted between the walls of the jacket, and there is a special contact hole to which the contacts of the electrical wiring wires are connected.

Combined boilers that run on wood and electricity are designed very competently and thoughtfully, the main working units are:

• solid fuel loading hatch - solid fuel is loaded into it, the volume of fuel loaded at a time depends on its size;
• ash pan - supplies oxygen for burning fuel and collects ash;
• burners allow you to switch from one type of fuel to another;
• draft damper - regulates the intensity of fuel combustion. The chain drive opens or closes the ash chamber damper;
• heat exchanger - provides warm water supply;
• temperature sensors - automatically regulate the operation of heating elements, which ensures the continuity of heating.

The automation system allows you to adjust the operating mode of the boiler, as well as its power. There are models of boilers that have hobs for cooking, they are installed above the firebox. Boilers with two circuits allow you to connect the "warm floor" system, for this there are special outlets for installation.

They produce boilers with one circuit and with two circuits. In the first case, the boiler is used only for heating, in the second case it will provide hot water for household needs. Also on sale are units with a manual control system and with an automatic one. Boilers with a manual control system are cheaper, and automatic control makes maintenance and the life of the owner easier.

Advice. When choosing a boiler for heating a house, it is necessary to correctly calculate the power of the device based on the area of ​​\u200b\u200bthe room. This will affect fuel consumption.

Principle of operation

The principle of operation of a combined heating boiler is quite simple. The heat generator, powered by the mains, starts the electric heater. Pipe electric heaters begin to heat the coolant (water) in automatic mode according to the principle of a boiler. This process is automated by a special device, only firewood is loaded into the firebox manually.

While the heater is heating the water, you need to fill the combustion chamber with firewood and set it on fire. The combustion chamber is located below and transfers heat from burning firewood to the heat exchanger. When the temperature of the coolant reaches a predetermined level, the heating element turns off, and then only firewood generates heat. The burning power of firewood can reach 30 kW, which is enough to heat the house.

When the firewood burns out, the heating element turns on again and maintains the set temperature. You can only heat with firewood, and turn on the heating element only for safety. If firewood runs out, then only the heating element will provide heat. But often electricity and firewood are used simultaneously, this is especially convenient at night, when it is not possible to constantly put firewood in the firebox. Then firewood is laid in the evening, and the heating element is turned on to maintain heat not at full capacity.

If electricity is used as a priority for heating, and firewood is used only as a reserve, then boiler maintenance is simplified to a minimum. The desired temperature is set automatically and the heating element is responsible for maintaining it. When the electricity is turned off, as is often the case in our country, you put firewood in the furnace, and the boiler starts to work on solid fuel.

Important. When operating the boiler on wood, make sure that the damper on the chimney is open. When working on electricity, the valve can be closed.

Advantages of combined boilers

Advantages of boilers firewood and electricity compared to single-fuel devices are obvious.

1. Versatility. You can use one of the two types of fuel as you wish.
2. Profitability. Electrical energy is the most affordable type of fuel, and so is wood. In addition, coal and waste from the woodworking industry can be used as an alternative. It turns out the perfect union: wood - electricity.
3. Thoughtful design. Heat is intelligently distributed and energy losses are minimal, which makes these boilers very efficient.
4. Long service life. With proper operation, such a boiler will serve you faithfully for a very long time, at least 20 years.
5. Autonomy. There is no need to constantly monitor the process - automation will do everything for you. Especially when working on electric fuel, the heating mode with the help of a heating element is limited by an uninterrupted supply of electricity.
6. There are models with pre-built pipes for connecting the "warm floor" system.

Important. Combined boilers that run on wood and electricity work efficiently even in low-power modes.

disadvantages

And yet, with all the advantages, combined boilers have their drawbacks, like any other heating equipment.

1. It is necessary to equip a separate room - a boiler room, it is also necessary to store fuel reserves.
2. Weight. Devices made of cast iron can weigh several hundred kilograms; before installing such a boiler, a concrete pad may be required to reinforce the subfloor. Due to the significant weight of the product, there are no models for wall mounting, only models for floor mounting.
3. The design of combined boilers is more complex, which affects the cost of installation and service repairs.
4. Another disadvantage is the low power of the electrical component. The power of electric heaters should not exceed the power of the wood burning chamber. The power range of a wood-burning firebox is within 6 - 25 kW.
5. The cost of models of combined boilers is 20-40% more expensive than similar solid fuel boilers, but their purchase is much more justified than installing one type of boiler and then replacing it with another.

The manufacturer offers combined heating boilers powered by electricity and wood of various capacities, configurations and performance. When purchasing such equipment, pay attention to such moments.

1. Power - depends on what kind of fuel is used. Decide in advance on what type of fuel the priority units will operate.
2. The size of the combustion chamber - the volume of the combustion chamber depends on how often you need to load fuel.
3. Noiselessness - installation of a special valve ensures quiet operation of the unit.
4. Number of circuits - for some models, water is heated only by a heating element. More economical than models in which the coolant coil is mounted in the combustion chamber.
5. Heat exchanger. It can be made from cast iron or steel. Cast iron devices are resistant to corrosion, heat up for a long time, but they also give off heat for a long time, have a significant mass and can crack with a sharp temperature drop. Steel is subject to faster oxidation and corrosion, lighter in weight and resistant to temperature extremes.
6. Grids. They are made from various materials. It can be cast iron or ceramic. Cast iron is more heat resistant and suitable for the combustion of any solid fuel. They use honeycomb cast iron grates with ceramic coating, they are suitable for bulk materials that use more oxygen during combustion.
7. The weight and dimensions of the boiler. It may be necessary to reinforce the surface area on which the unit will be installed with a concrete screed.

Combined boilers are designed for space heating and are distinguished by the fact that they can operate on different types of fuel. These are electricity, liquid gas, firewood and coal. Such a design adds efficiency to the heating system and makes it independent of the presence of some type of fuel resource. If electric solid fuel boilers for some reason can no longer work on electricity, solid fuel is used: firewood, coal.

There are various modifications of combined heating devices. They can be two-chamber, that is, they have compartments for gas and liquid fuel, and the device can be operated on these two types of fuel at the same time. Varieties of combined boilers differ in combinations of types of fuel. Gas is combined with solid fuel or liquid fuel, that is, diesel fuel, and sometimes all three types are used.

These are universal boilers used for heating country houses and other premises with unstable centralized heat supply. Combined heating devices eliminate dependence on one type of combustible material as a heating source. If there is coal, then you can save on diesel fuel or gas. At the same time, coal or wood has to be heated manually, and if this is not possible, gas is used. Devices only require regular maintenance for their long-term operation.

Combinations of fuels in boilers

The combination of solid fuel and electricity helps to quickly turn on the heating in the room. Solid fuel combined boilers, which also work on electricity, have so-called heating elements in the heat exchanger tank - tubular electric heaters. The device is adjustable, having switches for fuel modes and for changing power. As a rule, there are temperature sensors that perform the alarm function when the power of the solid fuel unit decreases.

In this case, the heating elements turn on automatically. Like any other boiler that uses wood, peat and coal, this device needs a chimney that provides draft when burning. The design consists of a furnace, above which heat exchangers are placed, containing liquid inside. Water is heated by burning fuel or by means of electricity to the desired level.

After that, it passes through the heating system. If no one is at home, then such a heater can operate at low power, while preventing the batteries from freezing for an extended period. Such boilers are economical, safe enough, but the disadvantage is the large size of the unit. Solid fuel boilers when combined with electricity are very popular, as they are convenient and reliable to use.

If solid fuel and gas are combined in the heating unit, then the device requires attention to safety. It has no automatic systems to ensure safe operation.

With a combination of gas and liquid, that is, diesel fuel, heating is effective. To switch to another type of fuel, it is necessary to change the burner. This boiler can heat large rooms.

Gas and diesel heat up quickly, but if electricity is included in the combination, it will be possible to maintain the set temperatures.

Solid, liquid fuel and gas combined makes the boiler versatile. The heating system acquires reliability and independence from fuel problems. If you supply a country house with such a boiler, then it is not entirely easy to operate it, but the device will be multifunctional.

A combined boiler for four types of fuel: solid, liquid, gas and electricity is not only universal, but also allows you to save on heating your home.

Advantages of universal boilers

• If the gas supply to the house is not regular, and there are also problems with electricity, then with a combined universal boiler, it is possible to use other available fuels.
• Sometimes the transition between modes occurs automatically, but sometimes it is necessary to adapt a different type of burner.
• There is the prospect of saving a more expensive energy resource by using a cheaper variety of fuel when it is available in abundance.
• The installation is inherent in durability, as well as reliable equipment. It can be repaired and do all kinds of prevention, extending the service life.

All this list of advantages allows you to give preference to combined boilers in comparison with other types.

Solid fuel and electricity boiler

A combined solid fuel boiler, which also runs on electricity, is not much different from a conventional heating solid fuel boiler. You can heat with the help of firewood, coal, peat in the form of briquettes, combustible household waste. Under the firebox there is a cavity for ash, and in the upper part of the firebox there is a heat exchanger tank. The heat during combustion is transferred to the heat exchanger. Water has the ability to expand in a highly heated form and rises to the pipeline, and then to the heating circuit.

There is also a return pipeline, through which water with a lower temperature returns to the heat exchanger. So, by means of circulation, the operation of a solid fuel boiler is carried out. But the fuel supply eventually comes to an end, the temperature transmitted to the heat exchanger decreases and the circulation becomes slower. At a certain value of the reduced temperature, an automatic sensor in the tank starts the heating process with the help of electricity.

To do this, tubular-type electric heaters are built into the heat exchanger.

Even if the power decreases, the heating efficiency, the heating continues to function for a long period. This thermostatic switch and heaters distinguish the combined boiler from a conventional solid fuel boiler. And since their price is low, the cost of these two types of boilers is almost the same, modification in design does not require large expenses. Switching to another type of heating occurs automatically.

The electric heater helps to set the mode of maintaining a specific temperature in the heating system. As a rule, this is the permissible minimum temperature, but this does not replace the unit with full electric heating. For the heating mode, a box is equipped with a solid fuel unit in a building structure, filling it with basalt wool. This is a chimney that should be galvanized with the exception of flammable materials, wood.

Good draft in the chimney improves the combustion process. A pipe with this function is commercially available. It is connected to the boiler through an additional part - an adapter. Since the heating unit is massive, it will be correct to install it on a separate foundation. The distance from the walls should be more than fifty centimeters, and the walls near the boiler must be galvanized.

A solid fuel electric boiler with a long burning mode is characterized by high efficiency, a duration of several days with one laying of firewood or coal. In addition to electric heating elements, it often has an electronic control unit that regulates air supply, ventilation, power, and can compare temperatures over periods of time. Such combined boilers are safe to use. For example, during power outages, the system is transferred to the appropriate mode.

Some models have room temperature sensors. Electric and at the same time solid fuel boilers differ from other combined designs with two types of fuel in terms of cost, which is much lower. In fact, you have to pay for one boiler, which often amounts to no more than 15 thousand rubles. The electrical components are of negligible cost compared to a second boiler or switching device. Circulation pumps are also not needed in some modifications of the type of combined boiler in question, because circulation occurs naturally.

Are there disadvantages?

• The high cost of electricity consumed during heating. This problem is offset by the fact that in solid fuel mode, savings can be made by using wood or coal, resulting in a low total fuel cost.
• Bulky and heavy, as a result of which only floor versions are produced. It is impossible to hang the boiler on the wall.
• For buildings with more than two floors, a solid fuel boiler is not suitable due to the inability to equip a chimney. It is also impractical to heat too small houses with a bulky unit.
• Regarding the use of electricity, a three-phase connection is required and coordination with the electricity service regarding increased power.
• For preventive maintenance, it is necessary to contact professional specialists and do it regularly.

To install this type of boiler at home, it is best to allocate a separate room, as well as a place to store firewood or other solid combustible material. This method of heating is gaining popularity, being an autonomous system with which it is possible to heat a cottage or a country house, regardless of the regularity of fuel supply by centralized services.

Until quite recently, the owners of private houses did not even think about what fuel the heat source would operate on to heat their homes. The question was considered rhetorical, and the answer was clear - it was natural gas. However, the time has come for non-standard solutions, since energy carriers are constantly becoming more expensive, and it is not known which of them will be beneficial for use tomorrow. That is why there has been a massive interest in such heating installations as an electric wood-burning boiler.

What are the advantages of combined installations?

The solution is really non-standard, and it makes it possible to kill several birds with one stone:

• find an alternative to natural gas for heating;
• play it safe for the future, having in stock as many as two additional energy carriers;
• at the same time, ensure comfortable operation of the heater, eliminating the need to fiddle with firewood in the furnace at night.

Arranging heating with electric wood-fired boilers is also relevant in new buildings, for the same reasons. At the same time, it is possible to recall the old-fashioned methods and mount a gravity-flow heating system in order to maximize independence from external influences. Although the convection system is not the best solution in terms of efficiency, it is affordable at the cost of installation. And in the event of a power outage, you can always safely switch to firewood.

Unit design features

Externally, the device of an electric wood-burning boiler practically does not differ from a traditional solid fuel heat generator. Only in one place, where the water jacket of the unit is located under the casing and thermal insulation, there is a special hole from which contacts for connecting electrical wires are visible. In reality, the combined plant has a solid fuel combustion chamber, an ash chamber with a damper through which the combustion air passes, and a grate.

Household combined boilers for wood and electricity can be equipped with both a water-tube heat exchanger and fire tubes. Some models are also equipped with hobs located in the upper part of the combustion chamber. That is, these are full-fledged solid fuel installations with an efficiency of 75-85%. But they have one design feature: one of the furnace walls, which is the inner lining of the water jacket, has a complex profile made using cold stamping. Thanks to this profile, one or more heating elements are placed in the space between the inner and outer skin of the jacket. This is a special case of the scheme according to which electric wood heating boilers are made, heating elements can be built into the boiler tank in other ways.

When for some reason the boiler cannot operate on the main fuel - wood, it automatically switches to electricity and vice versa, when the furnace is ignited, the electric heaters are turned off.

Description of the boiler

The heating elements are controlled by an electric unit, and the intensity of solid fuel combustion is regulated by an air supply thermostat, opening the ash chamber damper at a certain angle by a chain. That is, the control functions of the electric and solid fuel parts of the heater are separated. If air is forced into the furnace by a fan, then both parts are controlled by automatics for a wood-burning boiler. In the first case, the algorithm of work is as follows:

After connecting the heat generator to the network, the electric heater is switched on. The temperature of the coolant is set on the control panel and the heating element starts to heat the water in automatic mode. It is better to set the temperature 10-15 ºС below the working one.

At this time, fuel is loaded into the combustion chamber and it is ignited. From this point on, the heating of the coolant occurs jointly, unless the electric heaters are forcibly turned off.

Having reached the water temperature set on the remote control, the heating elements turn off and the heat carrier is heated by firewood to the operating temperature. The intensity of combustion is controlled by a thermostat with a chain drive, and as soon as the water reaches the operating temperature, it shuts off the air supply.

When the combined boiler burns out its main fuel and there is no new load, the coolant will begin to cool down and at a certain moment the sensor of the electrical unit will work and it will turn on the heaters, which will maintain the temperature of the water until the next laying of firewood.

The algorithm for working with an air supply fan and a single electronic unit is similar to that described above, only the process of setting up the equipment is simplified. In this case, the energy independence of the solid fuel part of the unit is lost.

Due to their design and principle of operation, electric wood heating boilers for a private house acquire some advantages that are not characteristic of conventional solid fuel units:

1. Condensation does not occur on the inner walls of the furnace due to the flow of cold water from the return pipeline, since the boiler tank is constantly heated by the heating element.
2. As a result, the heating system of the building can be connected directly to the heat source, without the organization of a small circuit and a mixing unit with a three-way valve.
3. Theoretically, the efficiency of a combined water heater increases to 97-99% when the electric heating is on and the main firebox is not operating.

At the same time, the versatility of the unit does not eliminate the shortcomings inherent in both types of heaters separately. This is inertia, which is expressed in the impossibility of immediately stopping the heating of the coolant when the maximum temperature is reached.

Another drawback is the relatively low power of the electrical part, which will not be significantly increased by a water jacket device, it is impossible to build many electric heaters into it. For this reason, the power of electric heaters is equal to the power of a wood combustion chamber in the range of 6-25 kW. If a higher rate is required, then the electricity will only serve as heating and will be able to maintain the temperature of the coolant at a certain level.

Conclusion

The use of universal electric power - solid fuel installations for heating a small private house is a fairly rational solution that provides a lot of advantages over a separate system. Yes, and the issue of cost plays a role, at the price of a combined heater, it will not be possible to buy solid fuel and electric heating boilers separately.