Wood-fired and coal-fired Viadrus Hercules U22 reviews

Home & Gg; Solid fuel boilers & Gg;

Viadrus long-burning solid fuel heating boilers first appeared on the market in 1920 and even then proved to be reliable, powerful and easy-to-use equipment. Now the Czech company Viadrus is one of the most famous manufacturers of fuel equipment in the world. ISO 9001 (1993) and ISO 14001 (1997) certifications ensure that all cast iron products are made from high quality materials using sustainable manufacturing technologies.

Viadrus solid fuel boilers are economical and easy-to-use and maintain devices. They are equally successfully used for heating residential and industrial buildings, shops, holiday homes, schools and greenhouses.

Compared to other brands, Viadrus solid fuel boilers have additional advantages:

High efficiency and design reliability.
Durable cast iron heat exchanger and long service life of all other parts.
Increased volume of the combustion chamber, which allows the simultaneous use of a large amount of fuel (coal, brown coal, firewood, diesel, peat, gas, pellets, etc.). It is worth noting that among the firewood, the best are oak, which emit more heat than other species, and birch firewood, which also has a very high calorific value.
The possibility of converting a solid fuel device to burn another type of fuel (from firewood to gas or diesel and vice versa).
The efficiency of devices of the brand when burning coal and coke is 80%, and when burning wood 75-78%.

Viadrus takes its products extremely seriously, working in different countries only through reliable trusted dealers. Each heating device is supplied not only with quality certificates and a long-term warranty, but also with detailed instructions (in the language of the recipient's country), which contains all the technical characteristics of the device and the procedure for its maintenance.

Fig. 1 The company logo is a quality mark on all Viadrus devices

The difference between Viadrus boilers

Modern solid fuel boilers Viadrus are popular heating devices. Their installation does not require the consent of certain services. As in the case of other solid fuel units, in order to install a boiler of this brand, you will need to equip a boiler room and a fuel storage room.

The main advantages of Czech boilers are as follows:

High efficiency.
Very easy maintenance.
Long service life.

To ensure stable operation of the device for many years, it is required to clean the combustion chamber from ash and soot twice a week and carry out full maintenance at the beginning and end of the heating season.

Principle of operation

The Viadrus solid fuel boiler uses wood, coke or coal as fuel. The model range includes pellet boilers with automatic fuel supply. This type of heating unit is the most convenient, therefore it does not require much attention from the owner.

Any type of fuel is loaded into the firebox, then the lid is hermetically closed. This minimizes heat loss and improves the efficiency of the equipment.

The principle of operation of the Viadrus boiler

Experts recommend using coke with a grain size of 40-60 mm as fuel, while the manufacturer guarantees efficient operation on the following types of fuel:

Walnut 1. Fuel (coke or anthracite) with a fraction of up to 40 mm.
Walnut 2. The size of non-caking coal fractions is up to 50 mm.

Detailed information about the types of coal and its characteristics can be found here.

Please note that if the chimney draft is good (that is, at least 20 Pa), then lump coal with a grain size of up to 80 mm can be used.

Almost all models also take firewood as fuel. It is important to use only dry logs with a maximum moisture content of 20%. If this figure is higher, then it is quite possible that the efficiency of the boiler will decrease. It is possible to use firewood with a diameter of up to 100 mm, the length is chosen based on the dimensions of the combustion chamber.

According to the instructions, the use of the following type of fuel is not prohibited:

chips;
sawdust;
pellet granules.

If you decide to pour chips or sawdust in order to melt the device, then it is advised to put firewood on the bottom of the chamber. Thus, you will exclude the falling of small particles into the ash chamber.

When operating automatic pellet boilers, fuel is poured into a special bunker, from where it is supplied autonomously to the combustion chamber.

Operating conditions

Owners of Viadrus solid fuel boilers note the ease of operation of the device. But still, before starting the equipment, you need to read the instructions.

Before starting the Czech boiler:

Take readings from the thermomanometer and make sure that there is enough fluid in the system.
Opens the valves that are installed on the system pipes.
Check the cleanliness of the smoke channels, grate and ash chamber. If there is soot, you need to remove everything.
Place the firewood on the wire rack.
Open the flap and close the loading doors.
Fuel is ignited through the fire door.
Close the firebox door and open the muffler to allow air to flow.
The main fuel is poured onto the burnt wood, and it is distributed evenly.
When the flame turns dark red, use a key to open the dampers on the loading doors.
When the fire turns yellow, the flaps on the doors close.
After the coolant reaches the required temperature, the volume of incoming air is reduced. Using a muffler, the air supply is regulated for the boiler to operate in the specified mode.
If necessary, fuel is still reported. The time between approaches to the heating unit for filling fuel depends on the type of fuel and the strength of combustion.

Solid fuel boiler Viadrus Hercules U22 characteristics

If we talk about the Viadrus Hercules boilers, then they can also burn wood chips, cardboard, container board, shavings and briquettes. It will not work to burn sawdust in these boilers, the quickly forming crust prevents the sawdust from burning, because there is no forced pressurization for burning fine wood fuel.

The Viadrus Hercules D modification differs from the Viadrus Hercules C in that the D has a large firebox and a large loading door, which allows storing rather large logs. Accordingly, modification D is intended for wood burning, and modification C is intended for coke and coal.

Another interesting point is related to the design of the flue gas removal. This boiler is very undemanding to draft, some owners manage to operate their heat generator with a chimney 4 meters high, although the minimum boiler height recommended by the manufacturer is from 6 meters.

And one more thing, the Viadrus Hercules U22 boiler can be used in a heating system with natural circulation of the coolant.

It is believed that this boiler can be easily converted to gas or diesel fuel, it is only necessary to install the appropriate burner. However, it is worth considering how much you need such a replacement. And is it not worth hanging a separate gas wall holder, and leaving Viadrus as a backup boiler in the heating system in case the gas is cut off in the main.

Different modes of operation

In order for the solid fuel boiler to switch to night mode, I do the following:

Clean the grate.
They fill the fuel and wait for it to warm up.
Turn the smoke flap and reduce the boiler output.

In the morning, they open the flap and the holes on the doors, after which they shove the grate through the open ash doors. After the end of the work, the doors are closed.

The ash chamber needs to be cleaned two to three times a week; thermal protective gloves are required for work.

Solid fuel boiler Viadrus U22 С / D

Viadrus U22 c / d boiler

Viadrus U22 С / D is a heating boiler capable of operating on various types of solid fuels, including coal, logs, fuel briquettes, pellet pellets. The difference between modifications C and D is only that the model with the D index is characterized by a wider door of the loading chamber, and this makes it possible to load thicker firewood into the boiler when kindling.

The basis of the design is a sectional cast iron heat exchanger. In addition to the front and rear sections, solid fuel boilers of different sizes have several internal sections. Accordingly, the more sections there are, the more powerful the model. The range includes nine standard sizes for the C series and seven for the D series.

The heat exchanger sections connected to each other form a single volume filled with liquid. The inner space is reserved for the kindling and ash chamber. The rear section has a chimney outlet, in the upper part there is a supply circuit branch pipe, in the lower part - a return circuit. The front section has doors for the loading chamber and ash pan. The size of the heating unit affects the structure of the internal sections.

For more convenient regulation of the chimney damper opening, the knob is installed on the front panel. There are also two channels of air supply to the boiler. The first is a flap on the ash chamber door. The force of its opening, as well as the volume of air that is supplied to the combustion chamber from under the grate, is adjusted either by an automatic draft regulator, or manually by means of a screw. On the door of the loading chamber, there is also an opening for air supply directly to the combustion chamber of the heating unit. The force of its opening is regulated by the owner.

To monitor the temperature and pressure of the fluid in the system, there is a thermomanometer on the top cover of a Czech solid fuel boiler. Its sensor is immersed in the rear section, and the device itself is brought into the control box.

The body of the Viadrus solid fuel boiler has a special type of thermal insulation, which reduces heat losses and, thus, increases the performance of heating equipment. The casing is coated over the insulation with wear-resistant and heat-resistant paint.

Review the table to understand the main specifications of the Viadrus U22 C.

Viadrus U22 C Specifications
Number of sections	2	3	4	5	6	7	8	9	10
Power (coal), kW	11,7	17,7	23,3	29,1	34,9	40,7	46,5	52,3	58,1
Heated area, m2	120	180	230	290	350	410	460	520	580
Fuel consumption, kg / h	1,9	2,9	3,8	4,7	5,7	6,6	7,5	8,5	9,4
Efficiency%	75-80
Chimney diameter, mm	156							176
Cost, rub.	49 200	52 000	55 900	60 150	64 550	71 800	76 250	81 200	89 850

As well as the parameters of the Viadrus U22 D.

Viadrus U22 C Specifications
Number of sections	4	5	6	7	8	9	10
Heated area, m2	220	270	330	380	440	490	530
Fuel consumption, kg / h	6,4	8,0	9,6	11,2	12,8	14,4	15,7
Efficiency%	75

Solid fuel boilers

There are manual loading and automated models in this category. There is a pyrolysis boiler, universal models that can work on wood or coal, there are only coal or only wood. To reduce heat loss, the body is insulated with a layer of mineral wool. A steel casing painted according to a special technology is installed on top of the thermal insulation.

Wood-burning boiler Viadrus Lignator (Viadrus Lingator)

Solid fuel wood-fired boiler using afterburner technology. Like all Viadrus boilers, the capacity increases with an increase in the number of sections. It can only be used in closed-type systems with a pump for forced circulation of the coolant. For safe operation, the equipment is equipped with protection against overheating of water in the system.

The principle of operation of the wood-burning boiler Viadrus Lignator

The wood-fired Viadrus Lignator boiler is equipped with a cast iron heat exchanger, which ensures long-term operation. The grate water cooling system is also used, which prolongs the service life without repair.

Boiler solid fuel cast iron Viadrus Lignator. Characteristics. (Click to enlarge)

To ensure normal operation and high productivity, dry wood should be used - no more than 20% moisture. The dimensions of the firewood depend on the selected power of the unit (the building is sectional and the firebox increases with the number of sections), but the diameter of the thickest log should not exceed 10 cm.

Viadrus Hefaistos P1

The pyrolysis (gas generating) boiler with a steel furnace Hefaistos is designed for burning firewood. The minimum boiler power is 30 kW. It is possible to re-hang the doors for more convenient fuel loading. Read about the features of the pyrolysis boilers here.

Pyrolysis (gas generating) boiler Viadrus Hefaistos P1

The wood-burning boiler Viadrus Hephaestus has two control options:

With the help of electronics. Installed on units of 3-5 sections. In this case, the letter "E" is added to the marking. This control option makes it possible to set the priority for DHW operation mode.
Thermostats. This type of control is installed on boilers from 6-7 sections. Thermostats control smoke output, operating temperature, water temperature in the heating system. Marked with the letter "T". The boilers of this modification are non-volatile.

Automation (in modification "E") needs to install a stabilizer that protects against power surges, an inverter is also desirable, giving a correct sine wave with a fixed frequency. If you install an on-line type UPS (uninterruptible power supply), you can get a stable voltage and an almost ideal shape, plus additionally provide some heating operation time during a power outage. Read more about UPS power supplies here.

Hefaistos steel furnace pyrolysis boiler Characteristics. (click to enlarge)

For normal operation of the Viadrus Hefaistos wood-fired boiler, certain conditions must be met: the wood must have a moisture content of no more than 20%, the return temperature must not be lower than 60 ° C. If your system is long enough and the water has time to cool down to lower temperatures, it is necessary to mix hot water from the supply into the return pipe before entering the boiler, raising the temperature to the required value.

Universal boiler Viadrus Hercules 22 D / C

Universal boiler Viadrus 22 D / C

Viadrus Hercules can work on solid fuels - coal (C), wood and briquettes (D). It works on the principle of direct combustion, but the special shape of the furnace allows maximum use of the energy of the fuel: secondary air is supplied to the upper furnace for afterburning the gases formed during fuel combustion. The boiler is considered multi-fuel:

A gas or oil burner can be installed.
A pellet burner can be installed.

To install the burners, a special door with a hole for the burner unit and the burner itself are required; additional parts for the heat exchanger are also needed. The advantage of this equipment can be considered low requirements for smoke draft.

The boiler output depends on the number of installed sections (from 2 to 10). The unit has a sufficiently high efficiency for this type of device: 75-80% on coal, 75% on wood. Rather stringent requirements are imposed on firewood and coal: it must be dry, no more than 20% moisture. It is permissible to use wood with 25% humidity, but then the efficiency drops (insignificantly, but noticeably). Briquettes can be used as fuel, which greatly increases efficiency (due to the greater calorific value of such fuel) and facilitates maintenance - the ash briquettes give several times less, therefore the equipment requires less cleaning. Read about fuel briquettes here.

The boilers of this line can be used both in closed-type systems with a circulation pump, and in open or closed gravity systems. For more economical heating, liquid heat accumulators can be used. When installing the boiler in a closed system with a circulation pump, protection of the equipment against overheating is required.For this, either a cooling coil with a thermostatic valve (equipment not included) or a safety shut-off device (optional) can be used.

To regulate the outlet of combustion products, there is a smoke damper, the position of which is adjusted by a knob with a draft, located near the loading hatches. The primary air flow is regulated by an opening in the ash chamber door. Manual control by means of a screw, or by a draft regulator. For afterburning, secondary air is supplied through an opening in the loading door. To change its size and thus adjust the intensity of combustion, you need a special tool that comes with the delivery. It is impossible to do this with your hands because of the high temperature to which the door is heated.

Modifications of this boiler have some design features depending on the main type of fuel. Viadrus Herkules U 22 C boiler - main fuel is coal. Its counterpart Herkules U 22 D (the main fuel is wood) has a wider door for more comfortable fuel loading. In all other respects, the design and technical parameters are the same. The technical characteristics of both modifications are shown in the table.

Combined boiler Viadrus Hercules 22 D / C (click to enlarge)

When installing, do not forget that if the mass of the boiler (with water, chimney and full fuel load) exceeds 700 kg, it needs a separate incoherent foundation, which is 20-30 cm larger than the boiler in all directions. The depth of the foundation depends on the type of soil, but is usually done to the same depth as the foundation of the building.

Wood-fired boilers "Viadrus". Structure (to enlarge the picture, click)

Viadrus Hercules U 24

The solid fuel boiler Hercules U24 can burn coke, coal and brown coal, firewood and briquettes. But a boiler was developed for burning brown coal, on which it gives the best performance. Fuel moisture requirements: any coal - no more than 15%, wood - no more than 20%.

Solid fuel boiler Hercules U24

The increase in capacity occurs with the traditional Viadrus increase in the number of sections. Powerful modifications (from 8 sections and more) have additional traction control, which is located at the rear.

Boilers can operate in open and closed systems. When installed in closed systems, equipment is required to prevent overheating of the coolant (not included in the general package, but ordered separately).

Combined boiler Viadrus Hercules U 24 (click to enlarge the table)

Viadrus Hercules U 26

This unit can be fired with coal, coke and lump wood. The principle of direct combustion is used. One tab of coal and coke burns for 4 hours, firewood - 2 hours. The boiler can be used in systems with or without pumps. In closed systems, it is necessary to install protective equipment against overheating: a cooling circuit and a two-way valve, which, at a water temperature in the heating circuit above 95 ° C, connects an additional cooling loop (this equipment is not included in the basic package).

Overheating protection system for solid fuel boilers

If the system has a volume of more than 300 liters, then for more economical heating it is better to install a liquid heat accumulator.

Owner reviews

To fully understand what the unit of this brand is, you need to read the reviews on the Viadrus solid fuel boiler. For example, the Viadrus U22 D boiler. Users confirm that with careful treatment and correct operation, the device works stably and in accordance with the specified technical characteristics. The temperature is kept according to the specified error of 2-3 ° C. A single bookmark of firewood is enough for 1.5-2 hours. After a good warming up of the boiler and the entire system, the user closes the damper and the fuel smolders. Thus, the logs burn twice as long, however, immediately after kindling, the owners do not recommend using this mode: only on a high-quality heated system.People note the high reliability of Viadrus U22 D, the doors open and close easily, and the system works as it should.

Feedback from the owner of the Viadrus boiler The furnace at the Viadrus boiler turned out to be small and completely inconvenient. Firewood 20-25 cm enters there. If you heat with coal, then it also enters in small volumes. Well, and accordingly, the whole thing quickly burns out and you need to often put it on. In winter, our temperature reaches - 40 or more, and we have to constantly be near the boiler. So no pluses can fully compensate for this. Yang

Some owners of Czech boilers, model U22 4D, note the effective operation of the draft regulator in the device, but at the same time complain about problems with soot accumulation due to the use of raw logs, and sometimes the formation of soot in the chimney.

As a rule, the reviews on the Viadrus solid fuel boiler are positive. If there are drawbacks, then they are wrongly used or initially the wrong choice of the device in terms of technical characteristics. In the event of any breakdown and a valid warranty, the user can apply for a free repair to the company's specialists. Therefore, Viadrus boilers can be safely called reliable.

Wood and coal boiler Viadrus Hercules U22 pros and cons

There are three main advantages of the Viadrus Hercules boiler:

Firstly, it is a good heat exchanger made of high-quality cast iron, which allows us to speak about the overall durability of the boiler.
Secondly, this is a very reasonable price for boilers from a European manufacturer. For example, the Viadrus Hercules U22 D-4 boiler (four sections, power 23 kW, firewood fuel) costs from 36,000 to 42,000 rubles from different dealers. If you guess the time and get under the dealer's shares, then you can buy a boiler even cheaper.
Thirdly, the Viadrus Hercules U22 boiler has a fairly accurate regulation of the combustion process, whether on wood or coal. That is, you can be sure that your system does not boil, that the boiler automation will be able to extinguish the flame in the firebox in time.

There are not many disadvantages to the Viadrus Hercules J22 boiler.

Firstly, the rather strange recommended chimney diameters for models are 156, 175 mm. Non-standard pipes or adapters increase the cost of installing the boiler and chimney.
Secondly, models up to 5 sections, inclusive, have a very small firebox depth. That is, only D-6 (power 33/35 kW) can have a log length of 45 cm. This is a standard length that is sawn in Russia and sold at any corner from trucks.

And for models with 4 and 5 sections, the length of the log is ridiculous 27 and 35 cm. That is, a boiler that heats a house of 200-300 sq.m. you need to drown with such ridiculous chumps, sawing standard firewood.