Viadrus U22 Economy Series Instruction Manual

Heat for your home
since 1888
VIADRUS U22 Economy
Manual for boiler operation and installation
EN_
2015_39
CZ_2015_38
EN_2019_33
5735002060000
2178

Table of content page
1Boiler usage and advantages...................................................................................................................................................................3
2Boiler's technical parameter.....................................................................................................................................................................3
3Description...............................................................................................................................................................................................5
3.1 Boiler structure...................................................................................................................................................................................5
3.2 Regulating and safety elements.........................................................................................................................................................5
3.3 Excessive heat exhausting device .....................................................................................................................................................7
3.4 Heat Removal Device - Accumulating Tanks......................................................................................................................................8
4Positioning and installation.......................................................................................................................................................................9
4.1 Regulations and directives.................................................................................................................................................................9
4.2 Possibilities of placement...................................................................................................................................................................9
5Delivery and assembly...........................................................................................................................................................................11
5.1 Delivery and accessories content.....................................................................................................................................................11
5.2 Mounting procedure.........................................................................................................................................................................11
5.2.1 Boiler drum installation...............................................................................................................................................................11
5.2.1.1 Boiler drum installation - final-cooling loop........................................................................................................................11
5.2.1.2 Boiler drum installation –DBV 1 - 02 two-way safety valve...............................................................................................12
5.2.1.3 Placement of the shaped pieces set, tertiary air nozzle and inclined grate (Fig. No. 16)...................................................12
5.2.2 Mounting of claddings................................................................................................................................................................13
5.2.3 Draught regulator.......................................................................................................................................................................16
5.2.4 Mounting of the cleaning tool.....................................................................................................................................................16
5.2.5 Filling the heating system with water..........................................................................................................................................16
6Commissioning - instructions for contractual service organizations ........................................................................................................17
6.1 Verification activities before commissioning.....................................................................................................................................17
6.2 Commissioning the boiler.................................................................................................................................................................17
7Operating the boiler by user...................................................................................................................................................................17
7.1 Kindling............................................................................................................................................................................................18
7.2 Boiler settings for measuring emissions...........................................................................................................................................19
7.3 Operation.........................................................................................................................................................................................20
8Maintenance ..........................................................................................................................................................................................20
9Use of turbulators...................................................................................................................................................................................20
10 IMPORTANT WARNINGS .....................................................................................................................................................................21
11 Instructions for product liquidation after the lapse of its service life.........................................................................................................21
12 Warranty and responsibility for defects...................................................................................................................................................22
13 Recommended procedure for mounting and putting into operation (Instruction for mounting companies)..............................................22
14 Wrong methods of the connection of the boiler to the chimney...............................................................................................................24
15 Boiler information sheet..........................................................................................................................................................................25
16 Information specified on the name-plate.................................................................................................................................................32
17 Warranty certificate and certificate of quality and completeness for the VIADRUS boiler........................................................................35

3
Dear customer,
We thank you that you have bought a VIADRUS U22 Economy boiler, thus having shown your confidence in VIADRUS brand.
To get you accustom from the very beginning to correct handling with your new boiler, please firstly read this manual for its using, especially
Chapter No. 7. –Boiler servicing by an user, Chapter No. 8 –Maintenance, and Chapter No. 9 –Important warning. Please observe the below
mentioned information, in order to ensure a long-term trouble-free operation to your and our satisfaction.
The VIADRUS U22 Economy boiler is a cast-iron sectional gasifying boiler destined for ecological combustion of lump wood.
Combustion of other substances (for example, plastics) is not allowable.
1 Boiler usage and advantages
The VIADRUS U22 Economy boiler meets the requirements for heating of one-family houses, shops, etc.
The boiler is manufactured as a warm-water boiler with natural and forced circulation of heating water and work overpressure up to 400 kPa (4
bar). Before dispatching, the unit is tested with the testing overpressure of 800 kPa (8 bar).
Advantages of the boiler:
1. High service life of the cast-iron heat-exchanger and all other parts thanks to the quality of the used materials.
2. Long-term proven structure.
3. Sophisticated production technology on the automatic forming lines with permanent and proven quality of the production process (ISO 9001,
ISO 14 001).
4. Combustion efficiency up to 91 %.
5. Low fuel consumption.
6. Simple manipulation and maintenance.
7. Quick warming of the flue channel.
8. Water-tube massive grates
9. Threaded flanges for simple mounting
10. It meets emission class 5 according to ČSN EN 303-5, conditions of „Ecodesign“ and demanding conditions of the German BImSchV Stufe
2 emission norm.
11. Possibility of operation independent on electric energy (without a forced withdrawal of flue gases and without a circulating pump, excepting
systems with a storage tank)
12. Patented system of the combustion chamber ViaBurn ™
2 Boiler's technical parameter
Tab. №. 1 Boiler's sizes and technical parameters
Boiler size - type
16
21
25
30
34
38
41
Combustion chamber volume
dm3
32
39
41
51
63
65
67
Water content
l
40.5
46.5
46.5
52.0
58.0
58.0
58.0
Weight
kg
348
410
410
472
534
534
534
Combustion chamber depth
mm
280
370
370
480
590
590
590
Chimney throat diameter Ø D
mm
156
Boiler sizes: - height x width
mm
1130 x 625
- depth L
mm
890
1000
1000
1110
1220
1220
1220
Feed port sizes
mm
310x236
Maximum operation pressure
kPa
(bar)
400 (4)
Minimum operation water
pressure
kPa
(bar)
50 (0.5)
Testing water overpressure
kPa
(bar)
800 (8)
Hydraulic loss
-
see Fig. No. 1
Minimum input water
temperature
°C
50
Recommended minimum
output water temperature
°C
70
Noise level
dB
< 65
Boiler connections: - heating
water
G 2“ or G 1 ½“ (* the size depends on the used type of the flange)
- return water
G 2“ or G 1 ½“ (* the size depends on the used type of the flange)
Cooling water temperature for
the redundant heat exhaust
device
°C
5 –20
Cooling water overpressure for
the redundant heat exhaust
device
kPa
(bar)
200 –600
(2 - 6)
Tab. №. 2 Technical parameters of VIADRUS U22 Economy, fuel - wood, class A
fuel humidity, max. 20 % calorific value: 14 –18 MJ. kg-1
Boiler size - type
16
21
25
30
34
38
41
Boiler class according to EN 303 –5
-
5
5
5
5
5
5
5
Nominal power
kW
16
21
25
30
34
38
41
Indicative fuel consumption.
kg/h
3.9
5.1
5.9
7.2
8.5
9.4
10.2
Max. fuel weight in the feeding chamber
kg
13
17
19
22
24
26
28
Flue gases temperature at the nominal power
°C
140 - 190
140 - 190
140 - 190
140 - 190
140 - 190
140 - 190
140 - 190
Flue gases mass flow rate at the nominal power
kg/s
0.012
0.014
0.015
0.016
0.018
0.019
0.022
Chimney draught
mbar
0.13
0.16
0.18
0.21
0.25
0.32
0.32
Combustion time
h
min. 2
min. 2
min. 2
min. 2
min. 2
min. 2
min. 2

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Efficiency
%
89.1
89.0
89.0
88.7
91.0
90.4
90.3
Energy efficiency class
A+
A+
A+
A+
A+
A+
A+
Energy efficiency index
116
114
114
114
116
114
114
Season energy efficiency
%
79
78
78
78
79
78
78
Tab. №. 3 Recommended sizes of wood chocks
Chocks diameter
mm
Ø 40 to 120
Chocks length for types of 16, 21, 25, 30
mm
350
Chocks length for types of 34, 38, 41
mm
350 - 500
Fig. №. 1 Hydraulic loss of the boiler drum
* The size depends on the used type of the flange
Boiler size - type
-
16
21
25
30
34
38
41
Length A
mm
890
1000
1000
1110
1220
1220
1220
Length B
mm
620
730
730
840
950
950
950
Fig. №. 2 Main sizes of the VIADRUS U22 Economy boiler
Hydraulic loss - flow rate dependence

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3 Description
3.1 Boiler structure
The main part of the boiler is a cast-iron sectional boiler drum made of grey cast iron according to ČSN EN 1561, EN-GJL-150.
Pressurized parts of the boiler meet requirements for the stiffness according to ČSN EN 303-5.
The boiler drum is compiled from sections with help of pressed boiler inserts with a diameter of 56 mm and is fixed by boiler screws. The
sections create a filling well, combustion chamber and ash-pan, water space and convective part of the boiler. The input and output of heating
water is situated in the rear part of the boiler.
The rear section of the boiler, in its upper part, has a chimney pot and a heating water flange; and its bottom parts - a return water flange.
Stocking and ash-pan doors are fixed to the front section. An inclined grate is placed in the feeding chamber. The entire boiler drum is insulated
with health harmlessness mineral insulation that decreases losses by heat transmission into the environment. The steel cladding of the boiler is
painted with high-quality komaxit spray-type painting.
1. Front section
2. Middle section
3. Single-pass middle section
4. Penultimate section
5. Rear section of the combustion chamber
6. Cladding
7. Stocking door throttle valve
8. Stocking door
9. Ash-pan door
10. Shorting shutter
11. Shorting shutter control
12. Chimney pot
Fig. №. 3 Main parts of the VIADRUS U22 Economy boiler
3.2 Regulating and safety elements
The stocking door throttle valve regulates the supply of the primary combustion air above the fuel. It is controlled with a draught regulator or
manually with help of a throttle valve set screw.
The combined device, thermo-manometer, is designed for the determination of heating water temperature as well as for water pressure in the
heating system. The well of the thermo-manometer sensor is situated in the upper part of the boiler front section.

6
1. Stocking door throttle valve
2. Diagonal fire grate (the size differs depending on the
boiler type)
3. Diagonal fire grate (the size differs depending on the
boiler type)
4. Diagonal fire grate (the size differs depending on the
boiler type)
5. Shorting shutter
6. Cleaning cover of the chimney pot
7. Upper front shaped piece
8. Upper rear shaped piece
9. Tertiary air supply nozzle
10. Left bottom shaped piece with an inlet of secondary air
11. Right bottom shaped piece with an inlet of secondary air
12. Chamber for the inlet of secondary and tertiary air
Fig. №. 4 Assembly of the VIADRUS U22 Economy boiler
After inserting, the upper
part of the fire grate for all
types of the boilers have
to be leaned on the inner
side of the frontal section
under the stocking hole
and in its bottom part - on
the overcasts of the
respective section
see Fig. No. 4

7
3.3 Excessive heat exhausting device
The final-cooling loop or the DBV 1 - 02 two-way safety valve is designed for the exhaust of excessive heat in the case that water
temperature is exceeded over 95 °C. The final-cooling loop is connected to the boiler flanges according to Fig. No. 5; the two-way
safety valve - according to Fig. No. 7).
In the case of boiler overheating (input water temperature is higher than 95 °C), a thermostatic valve will be initiated, and surplus heat is
exhausted through the final-cooling loop.
Fig. №. 5 Hydraulic scheme of final-cooling loop connection
In case that the system is equipped with the DBV 1 - 02 two-way safety valve and the boiler is overheated (output water temperature is higher
than 95 °C), then the two-way safety valve creates a cool water circuit until the temperature decreases under the limit temperature. In this
moment, there will simultaneously closed the discharge cooling device and the input of cool water which is refilled into the system.
Fig. №. 6 DBV 1 - 02 Two-Way Safety Valve
A safety valve with the maximum overpressure of 400 kPa (4 bar), the dimensions of which have to comply to the nominal power of
the boiler, has to be installed in the system. The safety valve must be positioned directly behind the boiler. No shut-off valve can be
placed between the safety valve and the boiler. In case of other questions, please contact our contractual mounting companies and
service organizations.
Technical data of the DBV 1 –02 two-way safety valve (from Regulus Company)
Opening temperature (limit): 100 °C (+0° - 5 °C)
Maximum temperature: 120 °C
Maximum pressure at the boiler side: 400 kPa (4 bar)
Maximum pressure at the water side: 600 kPa (6 bar)
Nominal flow rate at p 100 kPa (1 bar): 1,9 m3/h
Usage
The DBV 1 –02 two-way safety valve is destined for the protection of the central heating against overheating. The discharge and refill valve in
the valve body is controlled by a thermostatic block. When reaching the limit temperature, the discharge and refill valve is simultaneously
opened; it means that cool water flows into the boiler, and at the same time hot water is drained from the boiler. While lowering the temperature
under the limit one, the discharge and refill valve will be closed.
WARNING!!! It does not replace a safety valve
In case of triggering the two-way safety device, when water which does not comply with requirements of ČSN 077401 can be refilled, it
is necessary to prepare water in the system so that it met the requirements of this standard.
1. Heating water output into the system 2“
2. Return water input from the final-cooling loop 1 1/2 “
3. Return water input into the boiler from the system 2“
4. Cooling water output
5. Thermostatic valve TS 130 (STS 20)
6. Heating water output from the boiler 2“
7. Cooling water input
A –cooling water input
B –output into the boiler
C –output into the sewage
D –input from the boiler

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Fig. №. 7 Recommended Wiring Diagram of the DBV 1 - 02 Two-Way Safety Valve
Installation
Only qualified person may perform installation. To ensure correction functionality of the thermostatic two-way safety valve, it is necessary to
follow prescribed conditions for its installation and respect marking of the flow rate directions marked on the valve body. The safety valve is
always mounted into the output pipeline of the boiler or directly on the boiler in a place of its upper part, where heated water leaves the boiler
and is conveyed into the heating system. While installing the valve, it is necessary to check whether the use of the 3/4“ mouthpiece (which can
be either in the pipeline or on the boiler) ensures full submersion of the thermostatic module of the valve. After having mounted into the
mouthpiece, connect the draining pipeline in the place „C“ (Fig. No. 6) in which hot water will outflow from the boiler. In the place „A“ (Fig. No. 6),
connect (according to Fig. No. 7) the cooling water supply line which - after putting the valve into operation - will ensure boiler cooling-down. It is
necessary to install a filter for capturing mechanical impurities on the cooling water supply line. In the place „B“ (Fig. No. 6), connect the pipeline
and - according to Fig. No. 7 - lead it into the return line of the system near the boiler.
Regular Maintenance
Once a year rotate the head of the safety valve to remove possible impurities deposited in it. Clean-up the filter on the cooling water input.
In the case of the use of an opened expansion tank, there is no need in a safety device against overheating.
Each heat source in the opened heating system has to be connected with an opened expansion tank which is situated in the highest point of the
heating system. Expansion tanks have to be dimensioned so that they can cover changes of the water volume which occurred as a result of
heating and cooling.
Opened expansion tanks have to be equipped with non-lockable de-aerating and overflow pipelines. The overflow pipeline has to be proposed
so that it reliably lead away the highest supply rate incoming into the system. It can be achieved by dimensioning of the overflow pipeline by one
DN higher than the feeding pipeline has. The expansion tanks and their connecting pipelines have to be designed and placed in order to reliably
avoid their freezing.
Fig. №. 8 Examples of connection of opened expansion tanks
3.4 Heat Removal Device - Accumulating Tanks
Boilers of VIADRUS U22 Economy series meet conditions of the emission class 5 according to EN-305. They match the requirements of this
class while being operated with the nominal power.
If the nominal power is higher than the immediate request of the facility for heating, it is necessary to exhaust the excessive heat into the
accumulating tank.
If the tank is fully charged, it is necessary to shut down the boiler and heat up with heat from the accumulating tank. After the heat in the tank is
spent, put the boiler into operation again. The accumulating tank enables you to ensure thermal comfort and at the same time a quality
operation of the boiler.
Calculation of the smallest volume of the tank heat-exchanger.
Vsp = 15Tbx QN(1-0,3 x (QH/Qmin))
where:
Vsp accumulation tank volume in l
QNnominal heating power in kW
Tbcombustion time in hours
QHthermal load of buildings in kW
Qmin smallest heating power in kW
Dimensions of the accumulating tank must be determined according to the boiler power and used fuel. It is necessary to consider the highest
calculated volume, whereas the minimal used volume of the accumulating tank has to be 300 l.
The hydraulic scheme of connection of the boilers with the accumulating tanks are available in the project supporting documents of Viadrus,
at http://www.viadrus.cz/projekcni-podklady-76.html.
1. Heat source
2. Expansion tank
3. Safety pipeline
4. Expansion pipeline
5. Overflow pipeline
6. Feeding pipeline
7. Water lever limiter
8. Return pipeline
1. Boiler
2. DBV 1 - 02 Two-Way Safety
Valve
3. Safety valve
4. Pressure control valve
5. Filter
6. Ball-valve
7. Pump
8. Excessive heat removal
9. Discharge valve
I. –Cooling water input
II. –Heating water output
III. –Return water input

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4 Positioning and installation
4.1 Regulations and directives
A solid fuel boiler may be only installed by a company with a valid authorization to perform its installation and maintenance. A project according
to the valid regulations must be prepared for installation. Before installation of the boiler in an old heating system, installation companies have to
perform rinsing (cleaning-up) of the whole system. The heating system has to be filled up with water, which complies with requirements
of ČSN 07 7401, and mainly its hardness mustn't exceed the required parameters.
Tab. №. 4
Recommended values
Hardness
mmol/l
1
Ca2+
mmol/l
0.3
concentration of total Fe + Mn
mg/l
(0,3)*
*) recommended values
WARNING!!! The manufacturer doesn't recommend using of antifreeze mixtures.
In case of the use of non-freezing or anticorrosive additive into heating water, the manufacturer/supplier of the additive has to
guarantee harmlessness of the originated mixture. In case of damage of the boiler or its part as a result of action of the originated
mixture, the manufacturer is not responsible for the occurred damages, and this damage cannot be solved within the warranty.
In case of triggering the two-way safety device, when water which does not comply with requirements of ČSN 077401 can be refilled, it
is necessary to prepare water in the system so that it met the requirements of this standard.
a) for the heating system
ČSN 06 0310 Heat systems in buildings –Design and mounting
ČSN 06 0830 Heat systems in buildings –Securing devices
ČSN 07 7401 Water and steam for heat energetic equipment with steam operation pressure up to 8 MPa
ČSN EN 303-5 Boilers for central heating - Part 5: Solid fuel boilers for central heating, with manual and automatic supply, with
nominal heating power at most of 500 kW –Terminology, requirements, testing and marking.
b) for the chimney
ČSN 73 4201 Design of chimneys and flue gas ducts –Design, fulfillment and connection of fuel consumers
c) regarding to fire-fighting regulations
ČSN 06 1008 Fire safety of heat equipment.
ČSN EN 13501 -1 + A1 Fire classification of building products and building structures –Part 1: Classification according to results of
tests for reaction to fire.
d) for the hot water heating system
ČSN 06 0320 Heat systems in buildings –Preparation of hot water –Development and design
ČSN 06 0830 Heat systems in buildings –Securing devices
ČSN 75 5409 Indoor water distributions
4.2 Possibilities of placement
Boiler placement in dwelling premises (including corridors) is prohibited!
It is necessary to ensure permanent supply of air for combustion and ventilation to the room where the boiler will be installed. Each
solid fuel boiler requires a certain quantity of air for combustion. If it is not ensured by natural infiltration of the facility, it is necessary
to ensure it through a hole from the outdoor environment with a cross section of at least 100 cm2.
Upon installation and usage of the boiler, it is necessary to observe all requirements of ČSN 06 1008.
The boiler in the central heating system has to be connected to a separate venting unit. The chimney with a correct draught is the
basic assumption for a good function of the boiler. It influences both boiler power and its efficiency. It is nut suitable to use flue gas
elbows. The flue gas ducting from the boiler to the venting unit must be as short as possible, preferably without elbows with a slope
from the boiler upwards. The chimney has to have a prescribed draught (depending on the boiler size - see manual). It must be well
tightened and insulated to avoid condensation of water steam and tar.
Fig. №. 9 Connection of the boiler to the chimney.

10
Boiler positioning with regard of fire-fighting regulations:
While installing a boiler of 16, 21, 25, 30 types, we recommend that you to use original cast-iron pedestal (see Fig. No. 11) supplied by the
manufacturer. In case of placement of the boiler without a pedestal, it is necessary to observe conditions specified in Art. 1.
Boiler size - type
-
16
21
25
30
34
38
41
Length L
mm
620
730
730
840
950
950
950
Fig. №. 10 Bedding sizes
Fig. №. 11 Cast-iron pedestal of the
boiler
1. Positioning on the floor made of non-flammable material (Fig. No. 10):
place the boiler on the non-flammable pad exceeding the boiler layout on all sides by 20 mm and just on the depth of the boiler drum;
If the boiler is installed in a cellar we recommend installing it on a bedding at least 50 mm high.
the boiler has to be placed in the center of the pedestal.
2. Safety distance from flammable materials:
when installing and operating the boiler, it is necessary to keep a safety distance of 200 mm from the
materials of combustibility grade of A1, A2, B and C (D);
for lightly combustible materials with the combustibility grade E (F), which quickly burn and burn themselves even after removal of the
ignition source (for example, paper, paste-board, cardboard, asphalt- and tarboard, wood and fiberboards, plastics, floor cloths) the
safety distance is doubled, it means to 400 mm;
the safety distance is to be also doubled in case when the grade of reaction to fire is not proven.
Tab. №. 5 Grade of reaction to fire
Grade of reaction to fire
Examples of building materials and products included in the reaction of fire
(extract from ČSN EN 13501-1+A1)
A1 –incombustible
Granite, sandstone, concrete, bricks, ceramic tiles, mortars, fireproof plasters,...
A2 –hardly combustible
Acumin, izumin, heraklit, lignos, boards and basalt felt, fibreglass boards,...
B–heavily combustible
Beech and oak wood, hobrex boards, plywood, werzalit, umakart, sirkolit,...
C (D) –moderately
combustible
Pinewood, larch, whitewood, chipboard and cork boards, rubber flooring,...
E (F) –lightly combustible
Asphaltboard, fibreboards, cellulose materials, polyurethane, polystyrene, polyethylene, PVC,...
Positioning of a boiler with regard to the necessary handling
space:
basic environment AA5/AB5 according to ČSN 33 2000-1 ed. 2;
in front of boiler there the handling space at least 1000 mm must
be left;
minimum distance between the rear part of boiler and the wall is
400 mm;
at least from one side part, the space for accessing the rear part
of boiler (minimum 400 mm) must be kept.
Placement of fuel:
to ensure correct combustion in the boiler, it is necessary
to use dry fuel. The manufacturer recommend that you stock
fuel in basement premises or at least under a shelter;
it is prohibited to lay fuel behind the boiler or stock it near the
boiler in a distance lower than 400 mm;
it is prohibited to lay fuel between two boilers in the boiler-room;
the manufacturer recommend that you observe distance
between the boiler and fuel at least 1000 mm or place fuel in
other room than the room where the boiler is situated.
Fig. №. 12 Positioning of boilers in a boiler room