Wood-burning stoves, gas and electricity burning. Combined boilers for heating on wood and electricity. Combined heating boilers

Our units run on solid fuel and are designed for wood heating of cottages and private country houses low storey. The area of premises heated by firewood is from 80 to 320 squares.

The design of the wood burning apparatus allows additional use of electric heating of the coolant. To do this, a threaded sleeve for the heating element is provided on the rear or side wall of the housing.

This is a useful option for wood-fired boilers, which allows you to avoid temperature fluctuations in the heating system between fires. When using water as the heating medium, electrical heating will protect the system from freezing in case of long downtime during the cold season.

A tubular electric heater with a control panel will automate the process of controlling the unit and expand the functionality of a simple wood-fired boiler.

Heating element installation

The heating element is not included in the sale of the wood-burning boiler, but is an option that must be purchased separately. For combi wood boilers of low power up to 18 kW, a tubular electric heater of 1-3 kW is suitable; for devices of 18-32 kW, a heater with a rated power of 6 to 9 kW is recommended.

The control panel with a thermostat automatically maintains the temperature within the specified range by turning the electric heater on and off. The block is equipped with protection against boiling and a light signal.

Heating elements with a power of 1 to 3 kW are single-phase and are powered by household electrical network with a voltage of 220 V, and heating elements with a power of 6 to 9 kW are three-phase and are powered by a network with a voltage of 220/380 V. When installing the unit, connect the ground.

All in our time, you can increasingly see universal combined for a private house heating boilers operating simultaneously on two types of fuel. Combining firewood and electricity together is a pretty smart solution, such a boiler is quite reliable, compact and practical. And if there is a power outage or a lack of fuel, you will not experience discomfort from the cold or lack of hot water during the cold period.

Modern heating boilers use solid fuel, combining it with both gas and electricity, which is more relevant for consumers. When purchasing a heating boiler that works both on wood and on electricity, several problems are solved at once:

For heating, two alternative energy carriers relative to natural gas are used at once.
The issue of cooling down the premises is being solved in the case when everything in the firebox has completely burned out, and a new portion of fuel has not yet been loaded.
Makes more comfortable water heating, since you no longer need to get up in the middle of the night and go to the boiler room to load fuel.

Combined electro wood boilers heating systems of the latest generation with a large firebox are made in such a way that switching to electric heating occurred automatically when the water temperature in the boiler falls below a certain level. Naturally reverse the transition to combustion solid fuel occurs through external actions.

The design of the electric wood boiler

Externally, the combined TT firewood boiler is in no way different from a conventional solid fuel unit. In fact, this is the same wood-burning heating boiler, the only difference is that it has a heater installed in the heat exchanger. Another important difference from the standard configuration is the presence of a water jacket.

One of the walls of such a boiler is made by cold stamping and has a complex configuration. Heating elements are installed between the walls of the shirt and there is a special contact hole to which the electrical wiring contacts are connected.

This type of heater device is similar in design to a standard solid fuel boiler, which consists of the following main elements:

firebox (combustion chamber), a place for loading solid fuel;
outside it is washed by the coolant, which is inside the water jacket;
a water-tube or fire-tube type heat exchanger, where the combustion products most heat is transferred to water before being released into the chimney;
at the bottom of the firebox there is a grate, and under it there is an ash chamber;
firebox and ash pan in front equipped with doors;
to regulate the intensity of combustion, there is a mechanical draft regulator or an air blower fan (if not manual control air damper).

Household combined heating boilers are distinguished by the design of a water jacket, where a place is provided for the installation of a block of tubular electric heaters - heating elements. Their contacts are brought out and connected to the control panel with the help of an electric cable, and the heating part is immersed in the coolant.

How a combi boiler works

The principle of operation of a solid fuel heater, in which electric heaters are installed, is as follows:

Kindling and heating of the boiler are carried out in the usual mode. When burning solid fuel, the temperature of the coolant is maintained using a mechanical thermostat or a fan together with a sensor, and the heating elements are turned off at this time.
After the contents of the fuel chamber burn out, the coolant temperature in the system gradually drops to certain value, reaching which the heating element (one or several) is switched on by the signal of the temperature sensor. At this point, the boiler starts to work on electricity.
After the next portion of firewood or coal is loaded, the water in the system begins to be heated from the side of the combustion chamber, the electrical part automatically turns off until the temperature of the coolant drops to a certain value.
Electrical equipment is auxiliary.
The heater control unit is used to maintain a certain water temperature, based on the readings of the air or water sensor.

Continuous heating of water is provided by switching from one mode to another, which ensures comfortable conditions in a private house.

Advantages of universal boilers

After installing a combined wood-electricity heating boiler, you will receive the following bonuses:

Versatility. You will have the choice of which of the two fuels to use and when.
Due to the built-in heating elements, the coolant will retain set temperature even after the fuel is given burned out in the loading chamber. This will maintain a comfortable temperature inside the room, and in case of your long absence, it will prevent pipes and radiators from freezing.
Comfort. Maintaining the temperature with electricity will be of great service, helping to get rid of the problem of night trips to re-load fuel into the combustion chamber.
If electricity is metered according to a multi-tariff scheme, then in addition to convenience, you can also save on the night operation of heating elements.
Thoughtful device. The heat is distributed in such a way that the loss of thermal energy is close to a minimum, thanks to which the boilers are quite efficient.
Long period of operation. If properly maintained, such a boiler can serve you for at least 20 years.
Autonomy. You do not need to constantly monitor the process - for this the unit is equipped with automation. Especially in the case of operation from electricity, the operation mode using a heating element is limited to an uninterrupted supply of electricity.
You can find models with pre-built pipes in order to be able to connect the "warm floor" system.

Heating combined boilers, which work both on wood and on electricity, cope with their task even in low-power mode.

Disadvantages of combined units

Electric heaters of a universal boiler assume only maintaining the temperature of the water in the system; they cannot completely replace the combustion of solid fuel. The reason for this is low power block of heating elements, which are mounted by manufacturers on solid fuel boilers. This feature, unfortunately, is one of the serious drawbacks of combined boilers for heating a private house on wood.

Heating a private house with a combined boiler that runs on both electricity and firewood has other disadvantages.

The useful volume is taken away from the loading chamber by the block of heaters, which significantly affects the burning time from one load.
The operation of the device directly depends on the stability of the power supply.
The cost of combi boilers is much higher compared to classic options solid fuel boilers.
The efficiency during operation of the heating elements drops by 2-5% due to the air flow that passes through the cooled firebox. The reason for this is the constant draft in the chimney, it forces the air out of the rooms to leave through the chimney and thereby cools the water jacket of the heater.

Do not forget one more important detail. As in the case of a classic solid fuel boiler, a combined heating boiler of the wood and electricity type must be connected to the water heating through a three-way valve, as shown in the diagram below. A small circulation circuit is necessary to protect the furnace from the negative effects of condensate during kindling.

In order to prevent the walls of the combustion chamber from being covered with condensate when the temperature drops, the solid fuel boiler must be connected according to the standard scheme with a three-way valve:

In the event that the power of the heating elements is not enough to heat the coolant to a temperature of + 55 ° C or more, then condensate will never appear in the furnace of the combined boiler during ignition, and the unit with a three-way mixing valve will not be needed. But as practice shows, a small circulation circuit, nevertheless, is necessary, at least in the event of a power outage or a breakdown of one of the heating elements.

How to choose a boiler "firewood electricity"?

Manufacturers offer combined heating boilers that run on both wood and electricity, which differ in performance, power and equipment. When buying this equipment, you need to pay attention to the following points:

Power - given parameter depends on what type of fuel is used. It is necessary to determine in advance the main type of fuel for the purchased device.
The dimensions of the combustion chamber - its volume will show how often it will be necessary to load fuel.
Silence - installation special valve will ensure quiet operation of the unit.
Number of circuits - some models heat water only with the help of heating elements.
The most economical models are those in which the coil is mounted in the combustion chamber.
Heat exchanger. It is made from both steel and cast iron. Cast iron ones are not so susceptible to corrosion, they give off heat longer, although they heat up longer, they also have a rather serious weight, and with sudden temperature changes they can crack. Steel has less resistance to corrosion and oxidation, but they are lighter and more resistant to temperature extremes.
Grids. The material of manufacture can be very different. They can be both cast iron and ceramics. Cast iron has a higher heat resistance and is suitable for the combustion of any solid fuel. Honeycomb cast iron grate with ceramic coating is suitable for bulk materials, the combustion of which consumes more oxygen.
The weight and dimensions of the unit. Due to the large dimensions, it may be necessary to reinforce the surface area where the unit will be installed with a concrete screed.

When choosing a boiler for heating a house, you need to correctly calculate the power of the device based on the parameters of the area of \u200b\u200bthe room. This will indicate how much fuel consumption will be required. If the area of the house does not exceed 80 m2, then you do not need to buy a boiler whose capacity is designed to heat a house with an area of 400 m2. This may lead to overspending of budgetary funds for the purchase of the unit, and for its subsequent operation.

A combined wood and electricity boiler is perhaps one of the most good decisions for heating a summer house or a private house small area. In a cottage that has 2-3 floors, heating elements will only save the system from freezing. Combined boilers help out in the event that it is not possible to use a constant and reliable source of energy. In addition, these boilers will save you quite a lot of money if you use more expensive fuel as a fallback.

For the installation of such a boiler, it is better to use the services of a specialist who works in this profile. He will advise the most suitable device model for you and without unnecessary problems it will be installed based on the requirements of safety rules and technology requirements.

From year to year modern systems autonomous heating are becoming more and more popular among owners of suburban real estate. For one reason or another, traditional gas heating units are rejected by the owners of private houses (mainly due to the high cost and inaccessibility of gas) and they are being replaced by universal combined boilers.

These are surprisingly reliable, functional and productive devices, thanks to which you can provide heating for a house or any other property.

Combined heating boilers: electricity and wood as the main fuel

At present, wood-fired and electric heating boilers are in the greatest demand among combined equipment. A feature of this technique, as you can already see from the name, is the simultaneous operation of both solid fuel (wood, woodworking waste) and electricity. Such versatility is provided due to the unique thoughtful and rather practical design of the equipment.

By and large, heating boilers for wood and electricity differ from traditional solid fuel boilers only in an additionally built-in heating element (installed in the heat exchanger tank). It should be noted that such heating equipment also uses an automation system that allows you to change the boiler power, operating modes, and also provide switching between fuel types.

Heating technology: accessories and functionality extensions

A variety of combined heating boilers, gas, firewood and electricity are often equipped with special sensors and other systems, due to which the performance of the equipment is significantly increased. Such sensors allow equipment to automatically turn on electric heating elements, thereby ensuring the continuity of heating.

Such versatility is especially effective in cases where the power of the equipment in the combustion mode of firewood or other solid fuels is not enough.

Any heating boiler on electricity and wood is also good because it copes well with low-power operating modes. The instruction for such a technique assumes that even with irregular operation of the boiler, it will be able to effectively maintain a constant minimum temperature indoors, excluding the possibility of freezing of the liquid in the heating system.

Design features of boilers

Any heating boiler for wood and electricity, as a rule, has a rather simple, but at the same time well-thought-out design. Often, a firebox is installed at the bottom of the unit, where any solid fuel is loaded, whether it be firewood, coal or peat.

The heat released during the combustion of the fuel heats the heat exchanger with the liquid, which subsequently enters the heating system.

Heat source: firewood - electricity in the house

If you switch the heat source to the mode of operation on electricity, then the coolant in the system will be heated by heating elements. Yes, and with low-power operation, it is electricity that allows you to automatically maintain a constant minimum temperature of the coolant.

Installation and operating conditions of combined boilers

Unlike traditional heating units, boilers using a combination of several types of energy require special conditions installation and maintenance. It is especially important to consider these requirements for the installation process if the work is done by hand.

To begin with, it is necessary to indicate the fact that a special separate room must be allocated for such heating units in a private house. Also, it is necessary to provide a concrete cushion for the unit, equip the chimney and ventilation system. On our website you can see photos and videos of installed boilers in various houses.

Advice. If you are not sure about own forces- trust the implementation of all installation work qualified professionals. Real masters will perform the entire range of work in the shortest possible time, ensuring their high quality and compliance with requirements and standards. In addition, you will have a guarantee for the work performed.

Advantages of solid fuel and electricity boilers

If we compare the combined equipment for heating country houses with traditional gas or simple solid fuel boilers, then their advantages become simply obvious:

Availability and low price of fuel. Due to the possibility of working on solid fuel, it is possible to ensure the combustion of almost any waste from the woodworking industry, the cost of which is simply a penny;
Versatility. Due to the presence of TEN heaters in the design, it is possible to receive heat from the boiler even when there is no possibility of using firewood;
Profitability. Wood and electricity are the most affordable types of fuel in our time, and therefore you can save a lot on installing a combined boiler and heating your home. Savings are especially relevant in the light of the regular rise in gas prices;
Ecological cleanliness and absence of harmful emissions from the heating system;
Availability of automation systems and special programmers. Such equipment makes it possible for the heating equipment to work in automatic mode in the absence of owners in the house;

High quality heating. Woodworking industry products, like electricity, emit a lot of heat, and therefore the heat carrier will be heated as quickly and efficiently as possible. In addition, there are no significant energy losses, as the combined equipment has a well-thought-out design;
Duration of trouble-free operation.

Conclusion

Combined heating systems are a great choice for any private home. Fuel availability, reliability, versatility and high performance favorably allocate units from the total number of heating boilers presented on the domestic market.

If there is no gas in the house, then this is not a problem - you can heat it with firewood bought or chopped in the forest. In addition, solid fuel boilers can operate on other types of solid fuels. Also on sale are combined units connected to the mains. Heating boilers for a private house on wood and electricity are more convenient to operate than their traditional counterparts. Let's take a look at what kind of equipment it is, how it works and what its advantages are.

Features of boilers for wood and electricity

A traditional solid fuel boiler is a wood-burning stove with a built-in heat exchanger that provides the heating system with a hot coolant. Firewood is placed in its firebox, burning merrily and generating thermal energy absorbed by the coil. And in order for the house to always be warm, it is necessary to throw all new logs into the firebox - even at night. That is, instead of sleeping, you will have to get up and stomp to the insatiable unit.

Wood-fired heating boilers cause inconvenience even during the day. The logs in them burn out very quickly. If you do not follow the level of the flame, the heating will cool down, the house will become noticeably cooler. This problem resolved in the following ways:

Purchase of pyrolysis units and models with large fireboxes;
Purchase of pellet boilers automatic feeding fuel;
Installation of a boiler that runs on wood and electricity.

The last option is the cheapest. Pyrolysis units are complex and expensive, the same drawbacks are inherent in pellet samples. But boilers and stoves on wood and electricity have an affordable price.

An electric wood-burning boiler is a conventional solid fuel appliance that runs on wood. But as soon as the firewood in its interior runs out, and the temperature of the coolant drops below a predetermined level, the heating element (or several heating elements at once) is turned on. It maintains the temperature in the circuit, preventing it from cooling down quickly.

Heating elements are responsible precisely for maintaining the temperature, they are not able to warm houses only due to their power. They also allow a gradual cooling of the coolant, but they are enough for several hours.

Temperature control can be built-in or external - some models are equipped with built-in thermostats.

Solid fuel combined boilers are equipped with one or two heating elements of limited power. The power source for them is single-phase and three-phase networks(usually single-phase).

Advantages and disadvantages of wood-fired boilers and electricity

Boilers for heating on wood and electricity are characterized by the following advantages:

Availability of support temperature regime- prevents too rapid cooling of the coolant;
Balanced cost - equipment is distinguished by its low cost, which will be discussed in our review;
No additional maintenance is required, as required by combined devices with liquid and gas burners.

By installing a heating boiler on wood and electricity in your house, you will not jump up at night to lay a portion of firewood.

Not without traditional disadvantages - this is high power consumption and the need for hardy electrical wiring.

Popular Models

Let's see how to choose a combined wood-electricity heating boiler for home heating. The main parameter here is the power of the device. Usually 10 sq. m. heated area requires 1 kW of thermal energy. Also, do not forget about 15-20% of the reserve in case of cold winters.

Heating elements in wood and electricity boilers can be optional or built-in. In the first case, they will have to be purchased separately, and in the second they are supplied in the original configuration. It would be nice if there was already a thermostat on board to maintain the temperature - then you do not have to buy it separately. You should also evaluate the power of the heating element used, since samples with a power of 8-9 kW and above operate from three-phase networks.

Before us is a typical boiler on wood and electricity for heating a large house - up to 200 square meters. m. It is non-volatile, but comes with a pre-installed block of heating elements, the power of which is 9 kW. The model is single-circuit, designed for traditional floor installation. The combustion chamber is open, it burns briquetted fuel, coal, firewood and other types of solid fuel.

If you are going to buy this boiler, you will make a bargain. After all, it can work not only on wood and electricity, but also on gas - for this, a connected gas-burner. The cost of this model in online stores varies between 22-28 thousand rubles.

Electro wood stoves for a house with water heating are in demand among those who are tired of freezing when the fire is attenuated in the furnace. Using the ZOTA Poplar M20 model, you will have at your disposal a powerful heating device from a well-known brand. Its power is 20 kW, efficiency - 75%, control - mechanical. It is possible to work from electricity, but for this you will have to buy a block of heating elements for it. The boiler is omnivorous, it burns wood, coal and anthracite. Estimated cost for Russian market is about 36,000 rubles.

The GEFEST company produces not only gas and electric stoves known throughout Russia, but also heating boilers for a private house using wood and electricity. A typical example of this is the above model. It is made in a simple rectangular case, devoid of any hint of design. The power of the sample is 25 kW, the heated area is up to 250 square meters. m. The efficiency is up to 82%, this is a fairly high figure.

Despite the apparent simplicity, the GEFEST VPR KSTGV-25 boiler on wood and electricity is not at all as simple as it seems. The thing is that it is a double-circuit - it gives heat and hot water. The capacity of the DHW circuit is 8.5 l / min at a temperature change of 35 degrees. The primary heat exchanger is made of steel, the secondary heat exchanger is made of copper. As soon as you get tired of spending firewood and electricity, the device can be switched to gas by purchasing a burner for it.

Who knows how to do good boilers that work equally well on wood and electricity, so these are Siberian manufacturers. The presented model has a power of up to 12 kW and can heat an area of up to 100 square meters. m, consuming up to 3.2 kg of fuel per hour. As soon as the firewood in the firebox comes to an end, the electric heater will turn on - it will maintain the temperature in the heating circuit and will not let it cool down until the next fuel load.

The boiler for wood and electricity Sibenergoterm Prometheus 12M-5 12 kW works not only on wood, but also on other types of fuel - coal and coal briquettes. Moreover, coal acts as a fuel recommended for this model. Separately, the high efficiency of the model, which is 84 kW, pleases. It also includes an air vent and safety valve. Heating elements for operation from the mains are purchased separately.

This boiler, which can work on electricity and wood, is combined, because a gas burner is also connected to it. The power of the device is 16 kW, which is enough to heat houses up to 160 square meters. m. The fuel for this model is traditional firewood, coal and wood briquettes, as well as coal.. The block of heating elements is already pre-installed, you do not need to purchase anything additionally. The device is one of the most affordable, its average cost is about 24 thousand rubles. For this money, consumers receive almost omnivorous equipment.

Some half a century ago, the concept of " heating system” meant only one type of heater - a wood-burning stove with a rough - heat exchanger.

Today, there are many modern units, compact and safe, capable of extracting heat from other energy sources - gas, diesel fuel, electricity.

They have found wide application in the private sector and are used to heat houses, cottages and even individual apartments in high-rise buildings.

Installation of a double-circuit gas boiler modern modification in a three-room apartment and connecting it to autonomous system heating will entail a significant reduction in utility bills.

In country houses automated heating equipment can simplify the process of heating a building, eliminating the need to control the degree of combustion of wood / coal and maintain a flame in the furnace furnace.

Natural gas is considered the cheapest energy source., but not all areas, especially summer cottages, are gasified. And the only alternative to solid fuel in such settlements is electricity, so there are widespread electric boilers heating.

But unfortunately, in our conditions, the power supply of objects of the third category, which include summer cottages and residential villages, cannot be called stable. According to the current legislation, the power supply organization has the right to turn off the supply of electricity to these facilities for three days without warning.

And if there was any large-scale accident that requires more time to restore the network, then the organization responsible for the power supply is obliged to notify the residents about the planned dates.

In any case, in winter time even a three-day shutdown can be fraught with a country or residential building - freezing and destruction of water-bearing communications are possible, moisture condensation on internal surfaces, building structures, which leads to the rapid growth of mold fungi and the violation of decorative finishes.

How to be in this situation? The best solution would be to install a combined boiler in the heating system that operates on both solid fuel and electricity.

Scheme and principle of operation of the combined boiler "electricity - firewood"

Design

Structurally, boilers "electricity - firewood" resemble conventional solid fuel units, equipped with a heat exchange tank.

The main difference from the latter is the presence of one or more tubular electric heaters built into the tank and a more complex automatic system management.

The combined boiler can be operated both in separate modes (only solid fuel or only electricity), and in a joint one.

For example, you heat country house firewood during the day. At night, the temperature drops and the electric heater turns on automatically, maintaining the set parameters.

Combination boiler structure

The design of heating equipment of the "electricity - firewood" class assumes the presence of the following mandatory elements:

Frame. Manufactured from sheet steel coated on the outside with heat-resistant paint.
Firebox for solid fuel. It is located at the bottom of the unit, under the tank.
Smoke pipe. It is usually located at the top of the back of the device.
Ash blower. It is separated from the furnace by means of a grate.
There are four doors on the front surface of the boiler: furnace, blower, air and shurovochnaya.
Also mandatory elements of combined boilers are protective, adjusting and instrumentation: pressure gauge, gate lock, regulator, ground bolt, heat limiter, temperature sensor, a drain pipe, pressure relief valve and others.

Specifications

To the main technical specifications combined boilers "electricity - firewood" include:

thermal power of the unit when operating on solid fuel and from the mains;
consumed electric power;
mass and dimensions devices.

Choice of combined heating boiler

The choice of a hybrid boiler is primarily affected by performance. The higher it is, the larger the area the heating system can heat. Today, there are two main approaches to calculating the required performance of heating equipment:

Average. According to this calculation, it is assumed that with a room height not exceeding 2500 centimeters, to create normal temperature about one kilowatt of performance is required for every ten square meters of heated area. Yes, for a small country house area of 80 sq.m. you will need an 8 kW apparatus, and for a larger country cottage with an area of 250 sq. m. it will be necessary to install equipment with a capacity of 25 kW.
Based on heat loss. It is generally accepted that the level of heat loss in houses without additional thermal insulation (for example, monolithic concrete) is 120-200 watts per meter square square, in old houses with thermal insulation - about 90-120, and in modern thermal houses with vacuum three-layer double-glazed windows, the loss value is 60-90 watts per square meter.

The required power of heating equipment is calculated based on their formula:

Boiler power = heat loss x area / 1000.

It turns out that for the same country house, made according to modern technologies, it is necessary to install a heating unit with a capacity of 4.8-7.2 kW, and erected without thermal insulation - 9.6-16 kW.

Advantages of combi boilers "electricity - firewood"

Consider the advantages of such boilers on the example of products from the Teplodar company. You can get acquainted with the assortment and detailed characteristics on the official website.

The main advantage of such heating equipment is the ability to produce heat from various energy sources - electrical energy and solid fuels.

Moreover, most modern modifications of these units are able to function equally effectively on various types solid fuels - granulated pellets, coal, peat, briquettes, firewood and others.

This is what causes the rapidly growing popularity of such heating equipment.

Hybrid units are especially convenient in country houses, in which people do not live permanently, but, say, visit every weekend.

For these purposes, during the absence of residents on a boiler powered by electricity, the minimum mode is set to maintain the temperature in the rooms of the order of + 5 ... + 10 degrees, and upon arrival, the owners turn on the heating at full power, throw firewood into the furnace and the country house warms up quickly.

After reaching comfortable temperature you can turn off the heating element, using only firewood for heating, or set it to the “support” mode, in which the firebox takes on the main load of heat generation, while the electric heater is connected only if you suddenly forgot to add fuel.

This function is carried out automatically, there is no need to constantly be on duty near the combi boiler.

What to pay attention to?

When buying a combi boiler "electricity - firewood", you should pay attention to the following factors:

the possibility of connecting a water heating circuit and its type;
heat exchanger material. Cast iron is the most corrosion-resistant, but in the case of frequent temperature changes, it may crack. Steel, on the other hand, has greater ductility, but is subject to corrosion processes. Therefore, in the case of constant operation of the unit in winter, the first modification should be preferred. The second is more suitable for giving with a periodic visit. When using a steel heat exchanger, it is desirable to use liquids as a coolant that have anti-corrosion properties and are unable to freeze at low temperatures;
safety valve. This element today is a mandatory element that ensures the safety of operation. heating system. If the safe pressure threshold is exceeded, this valve automatically releases part of the superheated coolant into the prepared container;
ceteris paribus, preference should be given to designs with a larger solid fuel chamber. Its size directly affects the required frequency of laying firewood;
grate material. Cast iron is considered the best, since it is able to “work” normally with all types of solid fuels: firewood, coal, peat, pellets and others;
also need to take into account overall dimensions of the boiler, its weight to predict in advance the possibility of installation in the selected location.

Which combi boiler to choose?

Today in Russia, due to the ever-growing demand for hybrid boiler equipment, a lot of new foreign-made products appear, and the production of its own thermal products is being established.

On Russian manufacturer would like to draw Special attention. Our domestic hybrid units are mainly produced on imported equipment and the quality of the final product is no worse than that of imported analogues with the same technical characteristics.

For example, the Russian combined unit manufactured by Evans is adapted for burning any type of solid fuel, it works equally well on coal, pellets, and wet wood. The efficiency of the boiler is average - up to 75 percent.

Of the main advantages - small size and weight. But the price for it is three times less than that of the Finnish analogue produced by the Jäspi Group. These are one of the few hybrid devices that have found a mass consumer in Russia.

This is explained, first of all, by the similarity of climatic conditions, that is, Finnish thermal equipment works well in the harsh Russian winter.

In addition, the manufacturer of boiler equipment has been on the heat engineering market for more than a dozen years, therefore it uses verified manufacturing technologies.

Video. TO combined boiler TEHNI-X KOT-15-U-P-premium:

Combined heating: installation and installation requirements

Combined type boilers due to the use various types fuels require compliance with larger parameters during installation than products operating on a single energy carrier. So, for the safe operation of units of the "electricity - firewood" type, the following conditions must be observed.

Requirements for the premises

First, the room must be finished with non-combustible materials that are unable to spread fire.
Secondly, it is forbidden to install any non-hermetic electrical equipment (IP below 44) in wet rooms - showers, bathrooms.
Thirdly, the room must be equipped with high-quality supply and exhaust ventilation, preferably forced. This will ensure the flow of outdoor air, oxygenated, which, in turn, will contribute to the complete combustion of fuel.
And fourthly, before installing heavy heating equipment, the mass of which is several centners, it is necessary to consider strengthening the floor surface.

Chimney Requirements

Since from time to time the heater has to be operated on solid fuel, a chimney must be installed.

The main condition for a high-quality chimney pipe is the absence of holes, slots, holes in it, hermetic connection all joints and the presence of good draft, which is ensured by installing the chimney in such a way that its upper part protrudes above the roof level by a distance of at least half a meter.

The chimney must also be properly insulated., in order to exclude the occurrence of condensate, which can lead to the formation of ice plugs inside the pipe.

Electrical Requirements

The electrical network for connecting the heating elements of the combined boiler must correspond to the configuration and power thermal equipment:

With a power consumption of up to three or four kilowatts, single-phase heaters are usually used, and if this indicator exceeds the 5-kilowatt mark, the units are equipped with three-phase heating elements.
The cross section of the electrical wiring must correspond to the maximum current consumption of the device.
Similarly, automatic protection of boiler equipment is selected: by current - in accordance with the cross section of the supply wiring. That is, the nearest higher standard value from the nomenclature of automatic protection is selected than maximum power boiler, but less than the electrical wiring can withstand.
It is also recommended to connect the unit through a differential relay (residual current device) that operates at a leakage current value of 30 milliamps.
First you need to do a thorough cleaning. heating circuit special tool or mount a new system.
Install ball valves on incoming and outgoing pipes.
Install the chimney in accordance with the rules for safe operation.
Connect the chimney to the boiler nozzle, carefully treat with a heat-resistant sealant.
Connect the heating system to the unit.
We check the presence of traction and the tightness of closing all the doors in the boiler.
We mount a shield with automatic protection near the unit, connect it to the mains.
With a flexible three- or five-wire cable, we connect the terminals of the boiler box to the machines. Don't forget to connect the ground wire.
In the case of a single-phase version, the device can be equipped with a Euro plug and connected to a three-pole socket.

On the video you can see how the Retra 3M solid fuel boiler is connected to electricity:

Combination boilers: installation step by step

Prices

The cost of combined heating equipment starts at $300. But these are the most low-power and unreliable boilers of Russian and Ukrainian production. Domestic units costing from $ 700 are considered optimal in terms of price / quality ratio.

For example, this is a modification of AOTVK-0-14-3, capable of effectively heating a building with an area of up to 110 square meters. The power of the boiler is 14 kW when using solid fuel and 3 kW when powered from the mains. The cost of a more powerful and larger boiler from the same manufacturer (22 and 6 kW, respectively) can reach $ 1000.

Imported units from European manufacturers are much more expensive.

Installation cost

The cost of installation and connection of combined heating boilers depends on many factors:

dimensions and weight of equipment;
binding difficulties - stop valves, pump, expansion tank and other elements of the system;
the need to prepare the foundation;
the complexity of arranging the chimney.

The minimum cost of all operations for the installation and connection of hybrid heating equipment is 4,500 rubles.

Summing up this article, it is necessary to highlight the main advantages and disadvantages of combined boilers of the "electricity - firewood" type.

Advantages:

the ability to burn any type of solid fuel;
the possibility of simultaneous operation of the combustion chamber and heating elements;
independence from the availability of electricity;
the ability to maintain a minimum temperature to avoid freezing at home in the absence of the owners.

Flaws:

Of the shortcomings, only one can be distinguished - a small volume of the furnace compartment, which will require frequent laying of solid fuel in the absence of power supply. Otherwise, hybrid heating units have absorbed all the advantages of gas and solid fuel boilers.