TOP 9 best long-burning solid fuel boilers with a water circuit: rating 2021-2022, technical characteristics and distinctive features of the devices

A long-burning heating boiler is designed to heat residential premises for a long time without adding fuel, as well as to obtain hot water for the needs of residents.

Most of these devices are capable of operating on a single addition of solid fuel for about 12 hours.

Some models can maintain heat for up to several days.

The choice of such equipment is huge; it is important to be able to distinguish an efficient high-quality boiler from less functional devices.

Distinctive features

A long-burning double-circuit boiler operating on solid fuel is a modernized version of classic heating equipment.

It, among other things, also has a heat exchanger built into it, providing the home with a full-fledged hot water supply.

The design of the two-circuit model includes the following elements:

1. Housing - can be made of sheet steel or cast iron. The thickness of the metal ranges from 4 to 6 mm.
2. Fire chamber . Usually made from the same material as the body of the device.
3. Grate type grate . It is located inside the combustion chamber; the material is cast iron. Enriches the fuel with the oxygen necessary to support combustion.
4. Ash pan . Accumulates solid waste generated during combustion.
5. Chimney - removes combustion products outside the room.
6. "Water Shirt" . Most often it is built into the boiler body and filled with water, which receives heat from the walls, after which it enters the heating system.
7. Additional heat exchanger coil - distinguishes double-circuit models from single-circuit ones. It is built into the water jacket of heating equipment to provide hot water supply to the house.

The main disadvantage of this design is the low degree of productivity . Therefore, models made of cast iron are more popular because they take longer to cool down.

Kiturami KF-35

at a price of 108,060 rub.

Koreans are famous for their passion for computerizing any equipment.
One of the latest models of the KF-35 solid fuel boiler from Kiturami is no exception. This is a double-circuit boiler with a closed combustion chamber and a cast iron heat exchanger with three combustion stages, due to which the efficiency of the installation can reach 91.5%. The model has a combustion chamber for 40 kg of fuel and is more adapted for working with wood (maximum length - 500 mm), but any other solid fuel can be used. Fine-tuning and automatic regulation of air flow ensures energy and fuel savings for boiler operation. Among the advantages of the equipment is a well-thought-out system for removing pyrogenetic water, which allows you to use even very wet firewood. Main technical characteristics of Kiturami KF-35

Watch a video review of Kiturami KF-35 and other solid fuel boilers of this brand:

Types of devices

According to the method of fuel combustion, long-burning boilers with a double circuit can be divided into:

• Pyrolysis . Equipped with two combustion chambers. In one of them, the process of smoldering and the release of gas for pyrolysis occurs, in the other, the resulting gas is mixed with oxygen and burned. Equipment of this type is characterized by high environmental friendliness - a minimal amount of harmful substances is released into the atmosphere. The combustion process produces little soot. If the boiler is equipped with automation, power adjustment will be possible.
• With upper combustion chamber . Such boilers are very easy to maintain. The amount of automation required for their stable operation is minimal; it is possible to operate in autonomous mode without electricity. There are also disadvantages - a lot of ash is generated during operation, there is a list of requirements for fuel types. For example, small wood chips or sawdust are not suitable for kindling.
• Pellet . To kindle such equipment, special pellets or compressed fuel briquettes are used. Such boilers are environmentally friendly, economical and efficient, and have a long service life. One of the main disadvantages is the high price of the boiler and the special conditions that will have to be maintained for fuel storage. The room should be dry; high air humidity will contribute to the deterioration of pellets.

A little more about power

It is important!
Both a lack of power and its excess - all this negatively affects the efficiency of the heating system. If in the first case it simply won’t be possible to heat the premises, then in the second there will be pointless expenses. This also applies to overpayment for the boiler itself (more powerful, more expensive), and its operation: if the unit operates at partial power, this is associated with the formation of condensate and, as a result, a reduction in the service life of the boiler. In an effort to solve this problem, the user will consume more fuel than is actually needed to heat the premises. If you find it difficult to choose equipment, we strongly recommend paying an engineer who will carry out all the calculations for your home. Summary table of solid fuel boiler models

Advantages and disadvantages

Advantages:

• high level of environmental safety;
• increased heat transfer capabilities, which account for up to 90 percent of the generated thermal energy;
• the equipment is easy to install and maintain;
• for kindling, you can use various types of solid fuel, including inexpensive ones;
• the device can be used for both heating and hot water supply;
• compact dimensions of the boiler;
• there is no need for constant and frequent loading of raw materials to maintain combustion;
• the equipment can operate autonomously without the constant presence of a person.

Flaws:

• raw materials used for kindling in long-burning boilers must meet certain quality and humidity requirements;
• it is important to strictly follow safety rules at any stage of work, be it transportation and storage of fuel, its combustion, disposal of boiler waste;
• a significant level of labor costs when loading raw materials in non-automated boilers;
• high cost of such a unit in comparison with conventional boilers;
• automated equipment depends on constant access to the power grid;
• To store kindling materials you need to have sufficient free space.

Bosch Solid 2000 B SFU 20

at a price of 60,500 rubles.

Steel coal boiler Bosch Solid 2000 B SFU 20 with a power of up to 20 kW from a well-known manufacturer of household appliances.
Fuel loading is vertical through a receiver with an extended inlet. The furnace of the unit has been improved: in addition to regulating the air supply, the design includes turbulators that ensure prolonged contact of hot air with the walls of the heat exchanger. The design is designed in such a way as to ensure an efficiency of 76%, minimal attention to the operation of the unit, and ease of maintenance. On average, two full loads of fuel per day are required in winter. Ash is easily removed and weekly maintenance takes up to half an hour. The grate bars are cast iron, movable. The unit is universal and can be used in both forced and gravity heating systems. The kit includes a thermomechanical draft regulator and a thermomanometer. It is possible to combine the operation of this model with Bosch gas boilers. Main technical characteristics of Bosch Solid 2000 B SFU 20

Watch a video review of a model from the same line, but with less power - Bosch Solid 2000 B SFU 12:

How to choose and what to pay attention to?

The most important indicators when choosing long-burning solid fuel boilers with a built-in water circuit are:

1. Availability of necessary fuel.
2. The power level of the device depends on the area of ​​the heated premises and the required temperature conditions of the coolant.
3. The type of draft created inside the combustion chamber. Can be forced or natural. This parameter affects the possibility of placement in a particular room and the level of boiler performance.
4. Efficiency. It will depend on the type of fuel used, design features and additional equipment used (presence or absence of exhaust hood, automation of fuel supply, etc.).
5. The material of the heat exchanger - usually cast iron or steel - affects the reliability of the device and the characteristics of heating equipment.
6. The type of location of the water jacket is important in order to correctly determine the installation location of the boiler from the point of view of fire safety rules.
7. The weight of the unit is an important factor in determining the base where the boiler will be located. It must be strong enough and not subject to deformation.
8. The method of loading fuel and the dimensions of the combustion chamber are important for determining the cycle of use of the unit and the possibility of setting up its automated maintenance.
9. The design features of the ash pit and its accessibility will affect the ease of performing maintenance and maintenance work on the boiler.
10. Cost level - depends on a combination of the factors listed above and the reputation of the equipment manufacturer's brand.

Criterias of choice

Modern boilers differ in many ways, and when choosing, you should start from several basic criteria. Despite their heavy weight and large dimensions, such installations continue to be in demand. This is primarily due to their availability.

Fuel type

When purchasing a unit, you need to choose what type of fuel it will operate on. Modern devices operate on ordinary wood, peat, various types of coal, and so on.

The choice of a certain type of raw material affects heat transfer, operating time from one load and operating comfort. If wood is used, then preference should be given to deciduous and soft-leaved species.

Fuel should be stored in a ventilated area. For this purpose, a separate closed place is allocated, where precipitation does not fall. Some types of wood do not burn well, while others may not even be laid dry. Each breed has its own calorific value.

Recently, installations operating on briquettes - pressed waste wood or peat - have been in great demand. These are environmentally friendly resources that do not produce a spark during a fire. Briquettes should also be stored in a place protected from precipitation.

Advantages of pellet boilers:

• environmental friendliness;
• no waste remains;
• availability;
• high thermal conductivity.

Pellets are pressed material of plant origin. Their characteristics are similar to coal, which is not so common now, as it releases sediment and sulfur during combustion. For its storage, certain conditions should also be provided: protection from rain and snow, humidity not more than 75%.

Weight

Steel products are inferior in weight to cast iron by about 17%. This means their cost will be lower. Plus, they are easier to install. Cast iron models are more durable and reliable, but their installation often requires a special foundation. Steel analogues withstand temperature better, but if they start to rust, they cannot be repaired.

When choosing a material, you should proceed from the climate zone in which the equipment will be operated. If the temperature does not “jump”, then it is better to give preference to a cast iron product.

Power

Power is the key parameter by which the unit is selected.

There are 2 simple formulas:

1. 1 kW of power is needed to heat 10 m2 of room area, provided that the ceiling is no higher than 3 meters. Thus, in order to heat a house measuring 200 m2, the installation power must be at least 20 kW.
2. Not only the volume of the room is taken into account, but also the quality of thermal insulation. To express its degree, it is recommended to use simple coefficients. If the house is poorly insulated or has large window openings, the coefficient will be 60. When installing high-quality thermal insulation, it will be 40. The formula is not complicated. As an example, let's take a room without insulation with an area of ​​200 m2 with a ceiling height of 2.5 m. The calculation looks like this: 200 × 2.5 × 60 = 30,000 W (36 kW).

The second formula is more accurate, since it takes into account energy savings.

Loading chamber volume

Once the required power of the equipment is known, you should decide on the dimensions of the boiler, namely the volume of the firebox. This determines how quickly the unit will heat the room.

To determine the useful volume, you should make 1 load of fuel and understand what heating power is obtained during its combustion. The reloading interval is also taken into account. The material from which the firebox is made also plays a certain role. In steel models the ratio will be as follows - from 1.6 to 2.6 l/kW, in cast iron - from 1.1 to 1.4 l/kW.

Efficiency

This is an indicator of effectiveness.

It all depends on the type of boiler:

• standard - up to 76%;
• universal - up to 82%;
• pyrolysis - up to 85%;
• pellet - up to 95%.

As can be seen from the list, pellet equipment will have the best efficiency. However, given this feature, you need to understand that fuel burns differently. Wood can be burned longer than pellets, which means there will be more heat, albeit with less intensity.

Models whose efficiency is higher ultimately leave less ash, which means they are easier to clean.

Popular manufacturing companies

Heating equipment is always in high demand, which is why the majority of technically developed world countries are engaged in the production of such units.

Among the foreign manufacturers, the following brands are best known::

• Stropuva - produces long-burning boilers operating on solid fuel, chimneys and water heating systems, as well as shut-off and control valves (Lithuania).
• Buderus is a German specialist in the field of heating technology.
• WATTEK is a Czech company dealing with a wide range of issues - design, production, installation and maintenance of heating equipment.
• ACV is a Belgian manufacturer of heating and hot water equipment for domestic and industrial use.
• Wirbel is a company from Austria that produces various types of heating boilers, both solid fuel and electric.

Among Russian companies producing long-burning boilers, the following manufacturers are popular among users:

• NMK , full name - Novosibirsk Metalworking Company, is engaged in the production of various products, including solid fuel boilers of the Magnum series.
• ZOTA . The production is located in Krasnoyarsk and produces equipment for plumbing, heating units, including various types of boilers.
• TK TeploGarant LLC is a company from Kostroma that produces boilers for domestic and industrial use and various components for them.

Stropuva S20U

at a price of RUB 117,760.

The original design of the Stropuva S20U model, originally from Lithuania, ensures that one load of fuel burns for up to 120 hours.
Unlike most solid fuel boilers, here the fuel burns from top to bottom, and not vice versa. There is layer-by-layer combustion of coal, pellets, briquettes or firewood with air supplied to the combustion area. This approach, in addition to a long laying interval, guarantees economical fuel consumption and an efficiency of 85%. If you plan to work only with wood, then the product will be completely energy independent. To burn coal, it is necessary to use a fan for forced air injection; accordingly, such a modification requires a connection to the network. It works best when using high-calorie coal. Up to 116 kg of such fuel is placed in the combustion chamber, while firewood is about 54 kg. The manufacturer especially emphasizes the need to install the product by specialists, because independent installation does not always take into account all the nuances and, as a result, the coolant boils and other unpleasant consequences. Main technical characteristics of Stropuva S20U

Watch video review of Stropuva S20U:

The best long-burning solid fuel boilers with a water circuit

Stropuva Mini S8 8 kW

Heating boiler running on solid fuel. capable of heating residential or industrial premises with an area of ​​up to 80 m2 .

It is efficient and fully prepared for intensive operating conditions, including year-round use. A separate advantage is independence from electricity. The boiler can work with different types of solid fuel - coal, firewood, pellets.

Differs in compact sizes . Fuel loading is simplified by the vertical position of the firebox door. The ash pit is designed so that cleaning can be done only a couple of times a month.

The special combustion technology used in this model allows for long-lasting combustion of fuel with high efficiency.

One load of raw materials will provide you with warmth for at least a day. The burning time of pellets is up to 48 hours, depending on external conditions and fuel quality.

Characteristics:

• power - 8 kW;
• heated area - up to 80m2;
• purpose - heating;
• boiler volume - 40l;
• combustion chamber type - open;
• weight - 145kg;
• dimensions - 55.5*136.5x55.5 cm.

Advantages:

• high efficiency - up to 90%;
• safety;
• reliable design;
• built-in thermometer.

Flaws:

• significant weight;
• The door is difficult to clean due to the rough coating.

ZOTA Topol-22VK 22 kW

In this model, the configuration of the heat exchanger has been successfully changed and water-filled grates are used . The device body is reliably thermally insulated.

It has 2 combustion chambers, making both horizontal and vertical loading of fuel possible. The cell doors are securely locked.

The boiler combines a relatively budget cost with high device efficiency.

There is a separate door that allows you to remove ash even while the device is operating. One load of fuel will provide you with heat for 10-12 hours.

Additionally, you can install an external control panel to block the heating element and automate the combustion process.

Characteristics:

• power - 22 kW;
• Efficiency - 70%;
• non-volatile;
• heated area - up to 200m2;
• purpose - heating;
• weight - 128kg;
• dimensions - 90.5*47*87 cm.

Advantages:

• can heat a large area;
• easy to manage and maintain;
• vertical and horizontal loading.

Flaws:

• low efficiency.

ZOTA Topol-16VK 16 kW

Another representative of the line of boilers with a water-filled grate, which guarantees an increase in the heat transfer of the device.

Its pipe has a triangular shape, which eliminates blockages and increases service life. The boiler can consume pellets, wood or coal as fuel.

The boiler is convenient to operate, thanks to the large size of the firebox and two ways of loading fuel - it is convenient to load coal from above, and firewood - into the fire door.

The low cost is favorably combined with the efficiency of space heating.

Characteristics:

• power - 16 kW;
• Efficiency - 70%;
• heated area - up to 160m2;
• purpose - heating;
• weight - 108kg;
• dimensions - 80.5*44*87 cm.

Advantages:

• affordable price in its segment;
• efficiency;
• ease of use and cleaning.

Flaws:

• low efficiency.

ZOTA Topol-32VK 32 kW

The boiler, operating on various types of solid fuel, has a high level of performance, which allows you to make the heating system of your home high-quality and stable..

The equipment is considered very practical since it can be converted to natural gas consumption.

The equipment body has good thermal insulation, allowing it to be installed in any convenient place.

The efficiency of the device is quite high, given the low price among analogues . A single load of fuel allows you to maintain heat in the heating system for up to 12 hours.

Characteristics:

• power - 32 kW;
• Efficiency - 70%;
• non-volatile;
• heated area - up to 320m2;
• purpose - heating;
• weight - 143kg;
• dimensions - 87*44*100.5 cm.

Advantages:

• versatility;
• ease of management and cleaning;
• precise temperature control.

Flaws:

• No.

Stropuva S30 30 kW

Solid fuel heating boiler for installation in residential and commercial premises . Cost-effective, ready for seasonal or year-round use.

Does not depend on electricity, can operate on different types of solid fuel, and has high efficiency.

It is compact and does not require separate space for installation, and has an environmental safety certificate . The burning time for wood is up to 30 hours, for pellets – up to 2 days. No power required.

Characteristics:

• power - 30 kW;
• Efficiency - 85%;
• heated area - up to 300m2;
• purpose - heating;
• weight - 143kg;
• dimensions - 87*44*100.5 cm.

Advantages:

• high efficiency;
• safety;
• quality and long service life.

Flaws:

• high price.

Stropuva S40 40 kW

Long-burning solid fuel boiler with one circuit for heating rooms up to 400 m2. The fuel can be firewood or wood briquettes .

It has an open combustion chamber and is installed on the floor.

Characteristics:

• power - 40 kW;
• Efficiency - 85%;
• heated area - up to 400m2;
• purpose - heating;
• weight - 143kg;
• dimensions - 87*44*100.5 cm.

Advantages:

• reliability;
• attractive design;
• ease of maintenance.

Flaws:

• high price.

TEPLOV Universal TA-40 40 kW

Long-burning water heating and heating boiler, can heat residential and industrial premises and provide them with hot water.

Suitable fuels are briquettes, wood and coal.

You can choose an automated or non-volatile device option.

In the first case, you will receive reliable protection against overheating, freezing of liquid in the system, and the ability to adjust the temperature level for day and night mode.

Characteristics:

• power - 40 kW;
• Efficiency - 82%;
• heated area - up to 400m2;
• purpose - heating and hot water supply;
• weight - 390kg;
• dimensions - 147*48*77 cm.

Advantages:

• fuel versatility;
• heating and hot water;
• possibility of automation.

Flaws:

• large dimensions and significant weight of the installation.

SAS UWT 14 14 kW

The solid fuel boiler is made of steel and insulated with mineral wool to reduce heat loss . Can be installed as part of closed or open systems.

Equipped with an automatic control system.

It is possible to connect a hot water boiler.

The preferred fuel is coal, but wood burning is also possible.

Characteristics:

• power - 14 kW;
• Efficiency - 83.5%;
• heated area - up to 120m2;
• purpose - heating;
• weight - 310kg;
• dimensions - 54*141*101 cm.

Advantages:

• process automation;
• high level of efficiency;
• reliability and high build quality.

Flaws:

• high price.

TRAYAN TPG-15 15 kW

The boiler is equipped with one circuit and is intended for use as part of a central heating system with forced or natural circulation.

It is possible to connect a DHW boiler.

The unit differs from analogues in its low price while maintaining high performance.

The fuel can be firewood, peat or fuel briquettes.

Characteristics:

• power - 15 kW;
• Efficiency - 82%;
• heated area - up to 130m2;
• purpose - heating;
• weight - 270kg;
• dimensions - 72*73*160 cm.

Recommendations for use

When installing a boiler, attention should first of all be paid to the quality of the chimney. Stainless steel pipes with a diameter of 120 to 200 mm (depending on the model) are best suited for it. The ideal option would be a finished pipe with thermal insulation - a sandwich. Pipes with thick walls are not recommended. They take longer to warm up, and soot remains on the walls. It is necessary to clean the chimney once every 2 months.

When the boiler is turned on for the first time, an unpleasant odor may appear. Don't worry - this is normal, as special oil is applied to the metal during production. The first combustion should begin in a ventilated room, and the boiler should be turned on at maximum power. The duration of its operation in this mode is 1 hour.

The fuel is placed in the chamber in a loose layer so that there is an air gap between the firewood. This will allow them to ignite better. To control the combustion process in the ash chamber, the damper opens and closes.

Cleaning the boiler is allowed only after it has completely cooled down. During cleaning, it is recommended to leave some of the ash on the grate, which will serve as natural thermal insulation. This will extend the life of the element. To clean the boiler itself, use a wire brush or scraper. The smoke damper must be open at this time.

Depending on what fuel is used, a certain amount of soot is formed during boiler operation. Coniferous wood produces more waste. Sometimes condensation may form in the chimney: this depends on the level of thermal insulation and the moisture content of the fuel. To reduce the soot layer, it is recommended to use aspen firewood.

Principle of operation

Long-burning solid fuel devices burn wood from top to bottom. The reservoir is filled completely. For ignition, small wood chips are used, for which a small space is left at the door. At this stage, air enters the chamber.

Construction of a solid fuel boiler.

When fuel is occupied, oxygen access is minimized. The firewood begins to smolder. The top layer burns first, and then the bottom. During thermal decomposition, the fuel releases large amounts of gases. They have a high energy potential and go into an afterburning chamber, where they burn out completely. If you analyze the operating principle of a long-burning solid fuel boiler, you can correct the shortcomings that arise.

As a result, heat is released. The fuel itself is processed into fine ash.