Astra B-25E User manual

HEATING BOILER
Astra B-25E
ASTRA MACHINERY PLANT AB • ANNO 1929
CONTACT INFORMATION OF THE FACTORY:
MACHINERY PLANT“ASTRA”AB
ULONŲ G. 33, LT62161 ALYTUS, LITHUANIA
TEL.: [phone]
FAX: [phone]
EMAIL: INFOASTRA.LT
WWW.ASTRAGAS.LT
INSTALLATION AND OPERATION MANUAL

TABLE OF CONTENTS
1. SAFETY REQUIREMENTS..................................................................................................... 3
2. TECHNICAL DESCRIPTION................................................................................................... 4
• General View of the Boiler ................................................................................................................................ 4
• Technical Data of the Boiler .............................................................................................................................. 5
• Ceramic Elements of the Boiler ......................................................................................................................... 6
• Turbulence Plates ............................................................................................................................................. 6
3. INTENDED USE.................................................................................................................. 7
4. TRANSPORTATION, STORAGE, UNPACKING ........................................................................... 7
5. INSTALLATION.................................................................................................................. 7
• Accumulation Tank ........................................................................................................................................... 7
• Description of the Emergency Cooling System Diagram.................................................................................... 8
• Description of the House Heating System Scheme............................................................................................ 8
• Requirements for Connection of the Boiler to the Heating System.................................................................. 10
• Circuit Diagram of the Boiler........................................................................................................................... 10
• Connection of the Circulation Pump.................................................................................................................11
• Removing the Rooftop Cover of the Boiler .......................................................................................................11
• Controlling the Temperature of Water Returning to the Boiler........................................................................ 12
• Heating Output, Water Temperature and Water Flow Relationship................................................................. 12
• Installation of the Boiler Room ....................................................................................................................... 13
• Requirements for the Chimney ....................................................................................................................... 13
6. FUEL ............................................................................................................................. 14
7. OPERATION .................................................................................................................... 15
• Front Control Panel......................................................................................................................................... 15
• Rear Control Panel .......................................................................................................................................... 16
• Controller KR–5.............................................................................................................................................. 16
• Verication of the Controller Program Version................................................................................................ 18
• Indication of Temperature of a DHW Boiler, Smoke Temperature and Rotations of a Ventilator....................... 18
• Programming of the KR–5 Controller ............................................................................................................. 19
• Preparation for Firing ..................................................................................................................................... 20
• Kindling Procedure of the Boiler ..................................................................................................................... 20
• Fire Bed .......................................................................................................................................................... 21
• Regulation of the Boiler Temperature............................................................................................................. 21
• Addition of Fuel.............................................................................................................................................. 21
• Combustion Control........................................................................................................................................ 22
• Regulation of Primary and Secondary Air Supply............................................................................................ 22
• Description of the Smoke Temperature Sensor Function................................................................................. 22
• Cleaning the Boiler ......................................................................................................................................... 23
• Emergency Shut Down of the Boiler ............................................................................................................... 24
8. POSSIBLE FAULTS ........................................................................................................... 24
• Error Indication............................................................................................................................................... 24
• Erasing the Error Indication ............................................................................................................................ 25
9. WARRANTY AND ITS VALIDITY TERMS................................................................................ 25
10. ACCEPTANCE CERTIFICATE............................................................................................... 26
BOILER INSTALLATION PROTOCOL......................................................................................... 27
WARRANTY AND POST-WARRANTY REPAIR CARD.................................................................... 27
DECLARATION OF CONFORMITY............................................................................................ 28

3
INSTALLATION AND OPERATION MANUAL
1. SAFETY REQUIREMENTS
1.1. The room where the boiler is to be installed should be ventilated.
1.2. Free inow of air into the room should be ensured.
1.3. The boiler ue connection with the chimney should be tight. Do not heat up the boiler with leaking ue connections!
1.4. The boiler should be installed in a closed heating system with a closed (membranous) expansion vessel, the volume
of which should be no less than 10% of the total volume of the heating system (including the boiler) (the volume of the
expansion vessel can be calculated according to the standard EN 12828 annex D).
1.5. A safety valve for no more than 2 bar response pressure should be tted onto the boiler in the heating system for the
boiler Astra B-25E (please see Chapter 5, “Requirements for connection of the boiler to the heating system”).
1.6. Remove the accumulated soot and resin from the boiler ues, as instructed in this manual.
1.7. The room where the boiler is installed should have re-extinguishing tools: re extinguishers, sand box, shovel and
other tools.
1.8. Do not place ammable materials on or near the boiler.
1.9. Connect the boiler to the electric system only via a three-pole plug plugged into an adequate three-pole socket with
earthing. Protect connection cable from damages.
1.10. Observe operation of temperature control devices and gauge readings when operating the boiler. In case of faulty
operation of the boiler, stop operation and remove the fault.
1.11. Kindle the boiler and put the rewood into the boiler only as indicated in Chapter 7 of this manual.
1.12. Keep children away from the boiler! The boiler can be serviced only by adults.
1.13. Before kindling the boiler, check if the heating system is lled with water and deaerated.
1.14. The operating pressure in the heating system should not exceed the following:
• 2 bar – for boiler Astra B-25E.
1.15. The electrical connections are factory tested and the following parameters were conrmed:
• integrity of the protective circuit – electrical resistance of the protective circuit does not exceed 0.1;
• resistance of the electrical insulation – at least 1.0 M;
• resistance of electrical insulation was checked at 50 Hz, 1 000 V voltage.
1.16. Check the boiler emission values after the rst installation. Adjust air supply shutters if required.
1.17. Before rst using of the boiler, learn verbal instructions of exploitation from a competent person.

4
HEATING BOILER: Astra B-25E
2. TECHNICAL DESCRIPTION
• GENERAL VIEW OF THE BOILER
Fig. 1 General view of the boiler
A – front view; B – Rear view; C – top view; D - section.
1. Front control panel; 2. Fuel chamber door; 3. Primary air regulation shutter; 4. Secondary air regulation shutter; 5. Combustion chamber door;
6. Adjustable support legs; 7. Handle of the upper ue damper; 8. Smoke temperature sensor; 9. Water drain nipple; 10. Return water pipe; 11.
Connections of the cooling serpentine; 12. Flow water pipe; 13. Rear control panel; 14. Flue; 15. Exhaust fan with the protective shield; 16. Flue
cleaning cap; 17. Sensor immersion pocket ½” of the safety temperature limiter 95°C valve; 18. Rooftop cover; 19. Water temperature sensor;
20. Safety ventilator shutdown 95°C thermostat sensor; 21. Upper combustion chamber opening to the ue; 22. Primary air inlet openings; 23.
Ceramic burner; 24. Secondary air inlet openings; 25. Segments of the ceramic basket; 26. Opening to the ue; 27. Peephole of the combustion
process.
Astra B boiler model B L H h k D d N S
Astra B-25E 648 1038 1157 942 145 150 G1 1/2“ 414 227
BA
CD
H
h
S
N
d
k
B
L
D
1
2
7
5
6
14
15
138 12 11
9
10
19
20
21
22
24
25
26
23
16
3
4
17
18
d
27

5
INSTALLATION AND OPERATION MANUAL
• TECHNICAL DATA OF THE BOILER
Name of indicator Indicator value
Astra B-25E
Nominal heat output, kW ring with wood logs 25
ring with wooden briquettes 28
Class according to EN303-5 3
Class of protection against electric impact 1
Eciency rate,% 85
Power of emergency cooling system, kW 15
Water volume in the boiler, l 70
Setting range of the temperature regulator, °C 65-90
Minimal required draught, mbar 0.19
Exhaust ow, kg/s 0.018
Working pressure of water in the system, bar, max. 2.0
Testing pressure of the boiler, bar 3.0
Water side resistance, mbar t=10°C 9,5
t=20°C 2,8
Max. allowable water temperature in the boiler, °C 108
Max. allowable operating water temperature in the boiler, °C 90
Water temperature of safety heat exchanger, °C 10±5
Electric characteristics:
voltage, V / frequency, Hz 220/50
average consumed power at the rated heating output, W 31.9
average consumed power in the stand by mode, W 0.4
Level of electric protection of the boiler IP30
Dimensions:
height, mm 1200
width, mm 648
depth, mm 1038
Noice level according to EN 15036-1, db 28
Weight of boiler, kg, 320
Threaded connection diameter 11/2"
Volume of fuel chamber, l 105
Combustion period at the rated heating output, h 4..12
Dimensions of the loading aperture, mm 350x285
Flue gas duct diameter, mm 150
Length of wood pieces, mm 500
Average temperature of the ue gases at the nominal heat output, °C 150
The boiler operates at under pressure in ue gas outlet.

6
HEATING BOILER: Astra B-25E
• TURBULENCE PLATES
Turbulence plates – a technology invented and patented by “Astra” engineers (Patent No., 6004, Ministry of SPB), used for
capturing more heat from the hot exhaust smoke. It forces the exhaust smoke to hold, become turbulent and thus transfer
moreheatto theadjacentheatexchanger. Thecoreof thedeviceconsists ofthe turbulenceplates, positionedatan angle in the
rectangular-shaped ue channel of the boiler. The inspection aperture 1 is installed on the top part of the ue channel (Fig. 3),
covered with a screw-on cover with a gasket. This aperture is used
for cleaning the ue channel and placing/removing the turbulence
plates. The turbulence plates 2, shown in Fig. 3, maintain their
position in the ue due to their force of gravity alone. They are
inserted into the ue channel or removed using a poker 3, which
is provided with the boiler. Poker 3 (Fig. 3) is bent at an angle of
approximately 80° to the handle, so that the hooked plate does
not slide o. In order to be able to hook the turbulence plate 2 with
a poker, a hole has been made in its upper part for hooking with
a poker. The plate rests upon the heat exchanger 4 of the boiler
ue on four supports: two bottom and two upper supports. When
inserting the plate 2 with a poker 3 into the ue channel, rst the
lower position is found, and after slightly loosening the poker, yet
without removing it from the hole, the plate is allowed to descent
onto the opposite side of the heat exchanger due to the force of
gravity until it touches the wall of the heat exchanger with its
upper supports. Then the tool can be removed and the next plate
can be installed in a similar way.
Turbulence plates decrease the temperature of the exhaust
smoke. The boiler can be operated without the plates, but then
greater losses of heat through the chimney will occur.
The turbulence plates shall be removed from the
boiler while keeping the sharper edge up!
• CERAMIC ELEMENTS OF THE BOILER
Four types of ceramic elements are present in the boiler: the ceramic burner 1 and the segments of the ceramic basket 2, 3
and 4 (Fig. 2). All the segments of the basket must be pushed to the rear wall of the boiler chamber until they halt. If needed,
the ceramic burner 1 can be removed. For this purpose, use a screwdriver to remove the sealing rope from between the
ceramic burner and the frame of the boiler, then this ceramic insert can be removed.
Fig.2 Ceramic inserts and their positions
1. Ceramic burner; 2, 3 and 4. Segments of the ceramic basket.
Ceramic element Boiler type
B-25E
1. Burner
K-30.00.007 1
2. Segments of the ceramic basket
B25E001 2
B25E003 1
B25E002 1
1
2
2
3
4
Fig. 3 Turbulence plate technology
1. Inspection aperture; 2. Turbulence plates; 3. Poker; 4. Heat
exchanger of the boiler ue.
2
3
1
2
4

7
INSTALLATION AND OPERATION MANUAL
3. INTENDED USE
The heating boiler is designed for the heating of residential and public buildings, manufacturing shops and other
buildings where a closed heating system has been installed. Control and regulation devices are installed in the boiler, which
automatically maintain the set water temperature, ensure economically ecient usage of the boiler and safe operation.
Boilers of this type are designed to burn wood, partially generating gases. Gas is extricated (generated) from the burning
rewood in the upper combustion chamber of the boiler and burned in the lower chamber. The intensity of gas generation
and combustion is regulated by the frequency and duration of air inow into the combustion chambers.
Advantages of the boiler are the following:
• gas generating combustion ensures eective burning of wood and a high eciency coecient since the burning process
takes place at a high temperature of 900°C;
• the combustion period of one fuel load is long due to the large volume of the fuel chamber;
• complete fuel combustion ensures cost-ecient fuel usage;
• the turbulence plates installed in the ue of the boiler enhance heat exchange in the boiler and reduce the temperature
of the smoke in the chimney;
• it is sucient to remove the ashes 1-2 times per week.
4. TRANSPORTATION, STORAGE, UNPACKING
The heating boiler is to be transported and packaged in accordance with the documentation of the manufacturer, protected
from precipitation and dust. It can be transported only in vertical position, fastened to avoid sliding and falling. If the boiler
is transported in other than vertical position, decorative surfaces may be damaged, cladding battered, control and regulation
equipmentbroken,built-inceramic inserts mayfalldownandsplinter.Theheatingboilershouldbecarefullyloaded, unloaded
and transported, without any signicant impact.
The boiler should also be stored in a vertical position. It is not allowed to put one boiler on top of another, as a packaging
frame is not designed for this purpose. The boiler should be stored in a closed room protected from precipitation. The air
humidity of the room should not exceed 80%, in order to avoid condensate forming on the surfaces of the boiler. Storage
temperature may vary from -40°C to +60°C.
If the boiler was transported or stored in minus temperatures, then before it is kindled, it should be kept in plus temperature
for no less than 2 hours.
After the heating boiler is delivered to the site, take o the packing frame and polyethylene lm, unscrew boiler bolts and,
fastening to the packaging base, remove the boiler from the packaging base.
Open the doors of the boiler and check if all elements listed in a delivery kit are included.
The delivery kit consists of the following: boiler - 1 pc.; poker - 1 pc.; scraper - 1 pc.; ventilator - 1 pc.; operation manual - 1
pc.; support legs - 4 pcs; plug of a circulation pump - 1 pc.
Check if painted surfaces have not been damaged during transportation, if the components are not bent and if control and
regulation equipment is intact. In case you notice any inadequacies, present your claims to the vendor company.
5. INSTALLATION
• ACCUMULATION TANK
These solid fuel boilers are intended to be fully loaded during the operation; the most ecient mode of their exploitation is

8
HEATING BOILER: Astra B-25E
at the nominal or maximum heat output. It is mandatory to install an accumulation tank of sucient size in their proximity,
which could accumulate the excessive heat. If the boiler is operated without the accumulation tank, its lifetime can be
shortened because, in such a case, a relatively low temperature of the outowing water is maintained in the boiler (65-70°C).
Therefore, the temperature of the water returning to the boiler from the heating system is as low as 55-60°C. More water
vapour condenses in the boiler at such operating temperatures, more tar accumulates on the internal walls of the boiler and
metal corrosion intensies. When operating the boiler with an accumulation tank, it is possible and advisable to maintain
constantly maximum temperature of outowing and returning water, respectively 85°C and 72°C, then condensation of water
vapour and metal corrosion will be signicantly lower. Recommended capacity of the accumulation tank is approximately 50
litres per 1 kW of nominal power of boiler:
Boiler model Astra B-25E
Required volume of the accumulation tank, litres 1200
The boiler is to be operated only with an emergency cooling system installed!
• DESCRIPTION OF THE EMERGENCY COOLING SYSTEM DIAGRAM
A thermostatic safety temperature limiter 95°C valve (Fig. 4) protects the boiler form the overheating. If the water
temperature in the boiler exceeds 95°C, the valve automatically opens the ow of cold water from the public water supply
network through the cooling serpentine, where it absorbs the excessive heat
energy and ows out into the sewage. The sensor of the valve with the external
thread ½” is screwed onto the socket on the rear wall of the boiler.
Technical data of the thermostatic safety valve are the following: Opening
temperature - 95°C; Maximum operating temperature- 110°C; Operating
pressure - 10 bar; Bulb of the sensor - L=142 mm, external thread ½“.
The emergency cooling system protecting the boiler from
overheating cannot be used for heating domestic water.
• DESCRIPTION OF THE HOUSE HEATING SYSTEM SCHEME
The house heating system with an accumulation tank could be divided
functionally into two circles: heat production and heat consumption. Both
circles operate independently and interact in the accumulation tank. The
heat production circle consists of a boiler, Laddomat 21 thermostatic mixing
unit with a circulation pump installed in it, expansion vessel, ttings and
accumulation tank. The intended use of this circle is to charge the accumulation
tank only. To charge the tank, the boiler could operate on its maximum heat
output and outowing water temperature 87°C. That mode of boiler operation
is optimal for the boiler and combustion process itself.
The heat consumption circle uses the heat accumulated in the tank. The circle
consists of a room thermostat or a programmed control processor, room or/
and outside temperature sensors, 3-way servo drive, mixing valve, underoor
heating system, radiators, piping, ttings. The programmed processor controls
a 3-way mixing valve, which allows more or less heat (45-60°C) into the radiators, according to demand. This way of heat
consumption allows the heating of the house as long as the tank stores heat independently from the boiler.
Fig. 4 Connection diagram of the
emergency cooling system
1. To sewage; 2. Thermostatic safety temperature
limiter 95°C valve; 3. Filter; 4. Water from public
water supply, pressure 2-6 bar, temperature
10±5 °C; 5. Sensor of the thermostatic safety
temperature limiter 95°C valve.
4 3 2
5
1

9
INSTALLATION AND OPERATION MANUAL
Fig. 5 Principle scheme of the house heating system including heat accumulation
Laddomat 21 Thermostatic Mixing Valve
Pump Control
Flow Control Valve
Heating Boiler
Flow Control Valve
Air Outlet Water Heating
Domestic Water Recirculation
Pump Control Thermostatic Switch
Membrane Expansion Vessel
Thermostatic Mixing Valve
Domestic Water Preparation
From Water Supply
Hot Water
Air Outlet
Other Notations:
Automatic Water Addition Valve
Accumulation Tank
Thermometer
3-Way Servo Drive Mixing Valve
Return Overflow Valve
Filter
Heating System Supply
Heating System Return
Automatic Air Outlet
Return ValveValvePressure Relief
Valve Pump
Thermometer - Manometer Manometer
With Valve
Water Supply
Programmable Heating System Processor
Min 65oC!
Heat production Heat consumption

10
HEATING BOILER: Astra B-25E
• REQUIREMENTS FOR CONNECTION OF THE BOILER TO THE HEATING SYSTEM
The following requirements should be fullled when installing the boiler:
• The boiler should be installed in a closed heating system with a closed membranous expansion vessel, the volume of
which should be no less than 10% of the total volume of the system. A closed heating system is a kind of system with no free
access to atmospheric air, which actuates corrosion. Due to this, drainage of water from the system without an important
reason is undesirable, e. g. in summer. It is also necessary to ensure watertightness of the system in order to need fewer rells
with fresh water containing free oxygen. The quantity of the additional water let in should not exceed 5% of the system
water volume per year;
• The boiler is connected to the heating system through connection pipes 12 – water supplied to the heating system and
10 – water returning from the heating system (Fig. 1);
• Internal threads G 1½” of pipes 10 and 12 ;
• There is a nipple 9 for water lling or draining from the boiler (Fig. 1);
• Internal thread G ½” of the nipple 9;
• A pressure relief valve is to be installed in the heating system as close to the boiler as possible at a location easy to reach
by hand;
• pressure relief valves and control devices must conform to the following technical characteristics:
Instrument Technical characteristics Type of boiler
Pressure relief valve Connection diam. does not exceed ½”, set opening pressure 2 bar Astra B-25E,
Thermometer-manometer Range of temperature 0-120°C, pressure 0 – 4.0 bar All boilers
There must be no ball valves installed between the boiler and the pressure relief valve.
• Water from the pressure relief valve should be conducted via an otake pipe. It should be conducted in a way that will
allow the water passing through the pressure relief valve to ow safely, avoiding exposure of people and electrical parts of
the boiler. The diameter of the otake pipe should be no less than the diameter of the otake opening connection nipple of
the safety valve. The total length of the otake pipe should not exceed 2 m. No more than 2 elbow joints at angles of 90° are
to be used when installing this duct. No ball, mixing or other valves are to be installed in the water otake pipe. This otake
pipe is to be installed in a way that will make the ow of the passing water visible. If part of the pipe installed is hidden, e.
g., in a sewerage pipe, then such a pipe should have a special funnel enabling visual observation of the otake ow of water.
Operation of the pressure relief valve is to be checked at least once a month. The valve is opened
for a short period of time, by turning its head, to reveal a small amount of the otake water. If this is not
done periodically, the parts of the valve can stick together due to high temperature and fail to open, when
required. In case the safety valve fails to open in an emergency situation, serious damage to the boiler and
the heating system can occur as well as hazard to the health and life of people.
In order to guarantee natural water circulation of water in the boiler, the pipework between the boiler
and the mixing valve in the line boiler–mixing valve–boiler is to be of the same diameter and correspond to
the diameter of the connection pipes of the boiler.
• CIRCUIT DIAGRAM OF THE BOILER
• An electric installation with earthing, in accordance with the electric safety regulations in force, is to be installed when
connecting the electric part of the boiler.

11
INSTALLATION AND OPERATION MANUAL
Protect the isolation of the mains cable against damage.
• CONNECTION OF THE CIRCULATION PUMP
In order to insure a continuous ow of water, a circulation pump is to be installed in the system, on the return water pipe
behind the mixing valve. The electronic controller of the boiler controls the pump. The circulation pump is connected to the
socket on the rear control panel indicated with symbol .
• REMOVING THE ROOFTOP COVER OF THE BOILER
Before detaching the rooftop panel of the boiler, unplug it from the electrical supply. The cover is removed in the following
sequence (Fig. 7): 1) unscrew two fastening bolts, 2) lift the backside part of the cover, 3) push the cover forward and then
lift it up.
Fig. 6 Circuit diagram of the boiler
S1 - power supply switch; S2 – ventilator switch; SK – emergency ventilator shutdown 95°C thermostat; C-Capacitor; F - fuse; M - ventilator;
J - Socket of a circulation pump of the heating system; KR – electronic controller; U1,2 - water temperature sensors; U3- smoke temperature
sensor; U4- DHW boiler temperature sensor.
1 2
N
3
L
4
L1
5
L1
6
L14
7 8 9
N
10
L3
11
N
12
L4
L1 N L2 L3 L4
M
P
NL
P
N
LP N L
X4 X2
X1
P
L N
L2
L14
L1
L
U1U4U2
KR-5
S1 S2
SK
F
220 V
2
N
L
2A
2B
3
1
2
X3
1
1A
1B
3
12
1
C
J
U3
X5

12
HEATING BOILER: Astra B-25E
• CONTROLLING THE TEMPERATURE OF WATER RETURNING TO THE BOILER
It is absolutely necessary to maintain the
temperatureofthewaterreturningfromthe
heating system to the boiler at a constant
level, no less than 65°C, as this will prolong
the lifetime of the boiler and will make the
combustion process more eective. This is
because when a constant high temperature
of water returning to the boiler is
maintained, there arises signicantly less
water vapour condensation inside the
boiler. The heavy water condensation is
harmful to the boiler, because deposits of
tar, pitch and soot accumulate on the walls
of the heat exchanger, causing intense
metal corrosion. Moreover, the resulting
layer of soot impedes eective heat transfer
and the eciency of the boiler falls.
In order to maintain the temperature, we recommend installing the small circulation circle together with a Swedish-made
thermoregulation device, “Laddomat 21-60”. Make sure that the “Laddomat” is supplied with the 78°C or 72°C thermostat
cartridge. The mentioned temperature is the one at which the valve of the device opens completely. However, the actual
temperature of the water returning from the system and getting into the boiler after mixing, is 5-6°C lower. The higher the
temperature of the return water is, the better it is for the boiler. Thermoregulation devices of other manufacturers could be
used for maintaining the temperature of the returning water as well.
• HEATING OUTPUT, WATER TEMPERATURE AND WATER FLOW RELATIONSHIP
The heating output supplied to a heating system depends directly upon the dierence of ow and return water
temperatures t and the intensity of the water ow circulating through the boiler. The boiler will fail to reach the desired
temperature of the ow water if the returning water temperature is too cold or the circulation pump is too powerful. This
will happen because the boiler will be forced
to produce a larger heating output than it has
been designed for. The most eective boiler
operation occurs when the dierence between
the ow and return water temperatures is 12-
14°C. If the boiler is forced to operate with a
20°C or even greater temperature dierence,
it will work ineectively, consume too much
of fuel, and the combustion period of one fuel
loadwillconsequently shorten.Ifthe previously
mentioned dierence of temperatures is kept
less than 10°C, the fuel in the boiler will again burn ineciently and fume because of a lack of air supply. If you know the
water ow intensity near your boiler, in the above presented table you can check, what the dierence of ow and return
temperatures your boiler is capable to maintain, when operating at the nominal heating output.
Dierence
of water
temperatures
t, °C
Heating output, kW
18 25 32 40
Water ow, l/min
11 24 33 43 53
12 22 31 39 49
13 20 28 36 45
14 19 26 33 42
15 18 24 31 39
16 16 23 29 37
17 16 22 28 34
18 15 20 26 33
Fig. 7 Removing the rooftop cover of the boiler
1. Unscrew bolts; 2. Lift the backside of the cover; 3. Push the cover forward , then raise.
3
1
2

13
INSTALLATION AND OPERATION MANUAL
Do not forget to keep the returning water temperature as high as possible, at least 65°C or even higher!
It is necessary to assure that a thermometer is installed on the returning water pipe. The place of installation
should be as near the return pipe of the boiler as possible. A mixing valve changes water temperature- that
is why it should not be installed between the boiler and the return water temperature thermometer. The
immersion pocket of the thermometer must be tight.
• INSTALLATION OF THE BOILER ROOM
The boiler room should be ventilated. The required air inow necessary for combustion should be also ensured. For this
purpose, boiler room doors should have ventilation grating or there should be a sucient gap between the doors and the
oor. If there is no possibility to supply air in from another rooms or the house is very tight, it will be necessary to install an
opening in the exterior wall. The cross-section area of the opening should be at least 0.001 m2/kW.
Place the boiler as close to the ue as possible on a hard concrete levelled basement. Leave at least 600 mm gap between
the backside casing of the boiler and the room wall for boiler servicing and cleaning. The smallest distance between a lateral
casing of the boiler and a building structure is 400 mm. If the building structure is made of ammable materials, this distance
should be doubled. A freely approachable space of at least 800 mm should be then left from the opposite side of the boiler
to ensure access to the backside of the boiler, for its servicing and cleaning. The oor under the boiler, within the distance
of 50 cm in front of it and within the distance of 30 cm around the boiler should be made of inammable materials. Screw
supporting legs onto the base of the boiler and level the boiler with screw nuts using a level; then connect the heating system
circulation pump to the boiler.
The smoke exhaust pipe of the boiler should be connected to the chimney through a metal duct. The internal diameter of
the metal connecting duct should be at least the same as the external diameter of the smoke exhaust pipe of the boiler. To
improve the draught, the connecting duct between the boiler and the chimney should be installed at an inclination towards
the boiler. All junctions should be carefully tightened using a heat-resistant material and insulated using thermal insulation.
If temperature, emissions or draught measuring points are to be installed on the exhaust pipe they must be self locking and
tight.
If an additional damper is installed between the boiler and the chimney for the draught control
purpose, the damper should not close more than 2/3 of the cross-section area of the opening in its fully closed
position.
• REQUIREMENTS FOR THE CHIMNEY
It is recommended to insert acid-resistant stainless steel liner, if the chimney is made from masonry. It improves draught
of the chimney and protects the masonry from destruction due to the impact of condensate. Internal diameter of the liner
should be no less than the external diameter of the smoke exhaust pipe of the boiler. The chimney liner can be round or
oval. It is not recommended to use rectangular-shaped liner as, due to the temperature uctuations, its walls deform, gaps
appear at the element junction points, through which the condensate falls on the walls of the bricks chimney. Additional air
is sucked in, which reduces draught of the chimney. Draught for each boiler model should correspond to the referred value of
draught in the table “Technical data”. The liner should be factory made. Minimum permissible height of the chimney should
be at least 6 m. The top of the chimney should be above the ridge at least by 0.5m. If the chimney is further from the ridge
than 1m, the angle horizon- the ridge- the cap of the chimney should consist 10° or less degrees. Draught of the chimney
can also be negatively aected by various obstructions near the building: trees, hills, other buildings. Fig. 8 presents the
recommended minimal angles between the chimney, nearby objects and the horizon. Angles larger than those indicated will

14
HEATING BOILER: Astra B-25E
Fig. 8 Positioning of a chimney in respect to vicinity objects
cause reduction of draught of the chimney.
This boiler is ecient. As a result, smoke getting into the ue is rather cold - the average temperature of it is 150° C. Low
temperature of smoke raises a possibility of the condensate falling onto the walls of the ue. Deposits of combustion products
residues for the same reason can grow up in the ue faster. To avoid draught impairment in the chimney, make sure that:
• stainless steel liner or ceramic insert, preferably well-insulated thermally, is installed in the chimney;
• the condensate
drain pot is installed at
the bottom part of the
chimney;
• when suspecting
too fast deterioration
ofthechimneydraught
during the boiler
exploitation, raise the
temperature of smoke
by taking out 1-3
turbulence plates from
the boiler ue channel.
The eciency of the
boiler will decrease
but the situation of the
chimney draught will
improve.
The connection of other devices to the chimney to which the boiler is connected is prohibited.
The chimney should be cleaned at least once a year!
6. FUEL
The boiler is red only by wood logs and wood briquettes. It is possible to re it with fuel peat briquettes, however the
operation of the boiler becomes less comfortable for the user as it is necessary to remove the ashes of these highly ash-
producing briquettes after each loading. The ceramic elements of the lower chamber can be damaged if they are removed
every day when cleaning, thus their lifetime will be shorter. Therefore, we recommend usage of fuel peat briquettes only in
rare, exceptional cases.
It is recommended to re dry rewood with a moisture content of 12-20 %. The drier the rewood, the larger its caloric
capacity.
When the moisture content of the rewood is 20%, the heat potential of 1 kg is approximately 4 kWh; when the moisture
content is 50%, its heat potential is reduced by half.
The length of the rewood should be at least 5cm shorter than the length of the boiler combustion chamber.
Type of boiler Astra B-25E
Length of rewood, mm 500

15
INSTALLATION AND OPERATION MANUAL
The recommended thickness of the wood logs is 100-150mm. Thicker pieces of rewood should be split at least once. Up to
15% of the fuel load can consist of ne wooden splinters and sawdust. However, they must be loaded in such a way so as not
to block the opening of the ceramic burner 23 (Fig. 1) connecting the upper and lower chambers of the boiler.
Do not re freshly prepared and excessively damp pieces of rewood. The operation of the boiler
becomes inecient, deposits of resin emerge on its inside walls as well as excessive condensate. Corrosion of
the boiler takes place several times faster when ring it with freshly prepared wood or wood that has been
dried outside for several months only!
Recommendations for rewood preparation:
• put split wood in a properly-ventilated place – if possible, in a sunlit place;
• rewood should be well sheltered from rain and snow;
• pieces of split wood should be stacked with sucient gaps between them so that the freely-circulating air can blow away
the moisture evaporated from the pieces of rewood;
• there should be sucient space above the heap of rewood below the roof and sucient ventilation to remove the moist
air;
• it is not advisable to store freshly-cut rewood in a basement since the rewood needs sun and free air movement to dry.
Dry wood can be stored in the basement where sucient ventilation is guaranteed;
• it is recommended to dry the split rewood outdoors under the above-mentioned conditions. Depending on the type of
wood, soft wood (alder, asp, r, poplar) must be dried for at least 8 months, and hard wood (oak, ash, birch) for at least 20
months.
Firing the boiler with coal, rubber or plastics is prohibited. However, loading wood briquettes into the
boiler together with their plastic packaging bags is allowed.
7. OPERATION
• FRONT CONTROL PANEL
The front control panel has an electronic boiler regulator 1, a green button for switching voltage to the boiler on/o 2 and
a red button for switching on the ventilator 3. The ventilator button possesses two operational positions:
- START - turns on the ventilator and launches the controller program;
MINUTE MAX mode temporarily, for a 1 minute switches on the exhaust fan for a MAXIMUM capacity in order to avoid
Fig. 9 Front control panel
1. Electronic boiler regulator; 2. Green button for switching the voltage of the boiler on and o; 3. Red button for switching on the ventilator.
PAUSE
START
START
1 2 3

16
HEATING BOILER: Astra B-25E
smoke penetration into a room. Meanwhile a running boiler program
is being stopped for the same period. After 1 minute elapses, the
rotational speed of the fan returns to the former level and the boiler
program continues from an interruption point. The MINUTE MAX
mode duration can be prolonged by means of service programing.
• REAR CONTROL PANEL
The following safety devices are installed in the rear control panel:
thermal fuse1,electricfuse 2 andsocketforconnectionofacirculation
pump3(Fig.10).Thepurposeofthethermalfuse,otherwisecalledthe
maximum boiler temperature emergency thermostat, is to switch o the boiler ventilator if water temperature in the boiler
exceeds the maximum permissible 94°C due to unforeseen reasons. The temperature sensor of the thermostat is installed in
a dedicated sleeve 20 (Fig. 1). The burning intensity decreases when the ventilator is switched o and the water temperature
decreases. When the emergency thermostat trips, the lamp of the ventilator switch 3 on the front panel switches o (Fig. 9)
and the lighting indicator bulb 4 “Firing o” on the electronic regulator lights up (Fig. 11). In this case, it is necessary to nd
out the causes of tripping and to remove them. After the boiler cools down, the emergency thermostat can be returned to its
normal operating mode. For this purpose, unscrew its cover and depress the red button.
The maximum boiler temperature emergency thermostat has passed factory test. During testing, tripping
temperature of the thermostat is set to 94°C with a special test rig.
The cause of overheating of the boiler and tripping of the emergency thermostat must be found and
removed. If this is not done, the risk of serious damage to boiler equipment as well as hazard to human health
and life remains. If the user cannot locate and remove the cause of tripping of the emergency thermostat, a
professional servicing company must be consulted!
The electric fuse is designated to protect the elements of the electric circuit in case the current in the mains exceeds 2 A. If
the fuse is damaged, the boiler will not switch on and its indicator lamps will not light. In this case, remove and replace the
fuse.
The rear control panel of the boiler is grounded.
• CONTROLLER KR5
The controller KR–5 is designed for commanding a
solid fuel boiler. It controls:
1. Ventilator of the boiler.
2. Central heating (CH) pump.
3. Additional device, for example, a domestic
hot water (DHW) pump.
The ventilator is commanded in accordance with
the PID regulation law. The controller adjusts the
rotation speed of the ventilator using the impulse
method, thus intensifying or slowing down the burning process. The speed of the ventilator is dened in proportion to the
actual temperature deviation from the set temperature, the duration of the deviation and the speed of temperature change
of the boiler. The controller reacts to the water temperature in the boiler and smoke temperature in the ue. A NTC–type
Fig. 11 Front panel of regulator KR-5
1 - digital temperature indicator; 2 - temperature setting buttons; 3 - lamp
“Firing on”, 4 - lamp “Firing o”, 5 - lamp “Pump on”, 6 - lamp “Ventilator on”,
7 - lamp “Programmable channel on”, 8 - Button 8 is a multipurpose service
programming button.
PAUSE
START
START
1 2
7
3 4 5 6 8
FUSE
! 95°C 220 V
FUSE
FUSE
1 2
Fig. 10 Rear control panel
1. Thermal fuse ; 2. Electric fuse. 3. Socket for connection of
a circulation pump.
3

17
INSTALLATION AND OPERATION MANUAL
sensor for measuring water temperature is installed in the special immersion pocket 19 (Fig. 1), the outer side of which is
submerged in water inside the boiler. A PT–type sensor for measuring smoke temperature is installed in the special sleeve 8
(Fig. 1), which is located in the ue gases duct of the boiler.
The digital temperature indicator 1 (Fig. 11) indicates both the measured and the set temperature of water in the boiler.
The setpoint temperature is adjusted using the buttons 2. After a short press of or , the digital indicator 1 starts
showing the setpoint temperature of the boiler water. In order to change it, the appropriate button must be pressed:
for increasing and for decreasing the temperature. When several seconds pass after the last press of the button, the
setpoint temperature is saved and the indicator returns to showing the measured temperature of the boiler water. When
it indicates the setpoint temperature, a dot lights up beside the readout . When the indicator indicates the real
measured temperature, the dot does not appear . The controller allows adjustment of the temperature within the
range of 65–90°C.
Lamp 3 “Firing on” indicates the active status of the boiler. This lamp lights up when the ventilator is switched on using the
button 3 (Fig. 9) on the front control panel and regulation of the ventilator speed starts. The ventilator can be in operation
mode only when the signal lamp 3 (Fig. 11) lights. When the button 3 (Fig. 9) of the ventilator is pressed to the “PAUSE”
position, the symbol blinks on the screen, and the ventilator switches to the fuel loading mode. To exit this mode,
press the button 3 (Fig. 9) to “START” position or do nothing and wait for 5 minutes. Duration of the fuel loading mode could
be programmed in the range of 1–5 minutes (see “Programming of the controller KR–5”).
If during the "MINUTE MAX" mode the ventilator remains idle, the controller should be reprogrammed to operate with
other type of ventilator. This could be done before or after a burning cycle of the boiler:
1. Turn o the boiler with the green switch 2 (Fig. 9) to the position OFF.
2. Press the red switch 3 of a fan (Fig. 9) to the position MINUTE MAX and keep it pressed.
3. While pressing the red switch, turn on the boiler with the green switch 2 (Fig. 9) to the position ON.
4. The symbol starts blinking on a display. This symbol indicates the type of the fan: pressurizing.
5. Press the knob and check if the symbol appears on the display. This symbol indicates the type of the
fan: exhaust.
6. Wait for 5 seconds while the symbol stops blinking on the display. Now the newly set type "exhaust" is saved.
Lamp 4 lights up when the boiler turns to the mode “Firing o”. This boiler operation mode is established if during operation
the temperature of ue gases drops below 75°C and does not rise for some time, for example, 20 minutes. Both values– the
“Firing o” temperature of ue gases and the delay period– could be programmed in the 50–99 °C and 1–30 min ranges
respectively (see “Programming of the controller KR–5”).
Lamp 5 “Pump on” lights up when the controller switches on the central heating (CH) pump. The CH pump can be
turned on in two ways: 1) at once, together with the electrical supply of the boiler, 2) when the boiler water exceeds some
temperature, for example 60°C. The turn on temperature in the second case can be programmed in the range of 55–73
°C (see “Programming of the controller KR–5”). The CH pump becomes always switched o, when the ring in the boiler

18
HEATING BOILER: Astra B-25E
nears the end and the “Firing o” mode conditions are
fullled: the smoke temperature decreases to less than
the programmed value (75 °C) and lasts on that level for
the set period (20 min). Then, pump indicator lamp 5
switches o as well.
Lamp 6 “Ventilator on” lights up when the boiler
ventilator is operating. The more frequently it blinks,
the higher the rotational speed of the ventilator is,
since its blinking frequency corresponds to the impulse
frequency of the power supply to the ventilator. If this
lamp is lighting constantly, it means that the ventilator
is operating at 100% of its capacity. The ventilator
becomes always switched o, when the ring in the
boiler nears the end and the “Firing o” mode conditions
are fullled: the smoke temperature decreases to less
than the programmed value (75 °C) and lasts on that
level for the set period (20 min).
Lamp 7 lights up when the output channel of the
additional device is activated and works (see “Programming of the controller KR–5”).
Button 8 (P) is multipurpose, and is used for some support functions and service programming.
The boiler controller is connected to the boiler circuit in accordance with the scheme shown in Fig. 12. The ventilator of the
boiler gets power supply from L2 only if the emergency thermostat has not tripped. The impulse commutator regulating
the ventilator connects periodically L2 to L3. When the boiler switches to status “Firing o”, L3 does not supply power to
the ventilator and lamp 4 (Fig. 11) lights up. To quit the mode “Firing o”, the ventilator switch 3 (Fig. 9) should be pressed
to “START” position or the power supply button 2 (Fig. 9) should get turned o and later – on. The CH pump control relay
connects L4 to N. The relay of the additional device channel connects P to L1. The power of the operating ventilator ranges
between 20÷100 VA. The maximum allowed power of the CH circulation pump connected to the regulator is 250 VA. The
maximum allowed power of the additional device channel is 250 VA.
• VERIFICATION OF THE CONTROLLER PROGRAM VERSION
Switch o the electrical supply of the boiler with button 2 (Fig. 9). Press and hold the button “P” on the controller panel.
While pressing, simultaneously turn on the electrical supply of the boiler with button 2 (Fig. 9). A number of the program
version will light up on the screen shortly, later the controller will return to a normal operating mode. The number of the
version consists of 6 digits being exposed in sets of 3 digits one after the other. For example, if “151” and “118” are shown
subsequently, then the program version is “151118”.
• INDICATION OF TEMPERATURE OF A DHW BOILER, SMOKE TEMPERATURE AND ROTATIONS OF A
VENTILATOR
When in a normal operation mode, shortly (up to 3 sec) press the button “P”. The symbol ” will appear on a
screen.Scrollwith and buttonstoexhibitthenext indications: (rotations of the ventilator),
X-2 X-3 X-5 X-4 X-1
U2 U3 U4
1 2 3 L1 N L2 L3 L4 P
KR-5
Rear panel of the regulator
Fig. 12 Regulator connection diagram
L1, N – power supply to the regulator; L2- power supply from front control
panel to the ventilator; L3 – voltage to the ventilator; L4 – voltage to the
pump; P – voltage to the programmable channel; U2 – water temperature
sensor; U3 - smoke temperature sensor; U4 – DHW boiler temperature sensor;
1, 2, 3 - fan control.

19
INSTALLATION AND OPERATION MANUAL
(temperature of smoke), (the DHW boiler temperature). Press once again the button “P” shortly to see the desired
indication. For example, if the indication will light shortly and after it, value will be shown on the screen,
then it means that the smoke temperature is 129 °C. When the ventilator parameter has been chosen, the symbol
lights on the screen and, for example, value . This means that the ventilator works at 79% of its capacity. If the DHW
boiler indication has been chosen, the symbol lights alternately with the temperature readout . Press the
button “P” to quit the indications mode. Then the water temperature of the boiler will appear on the screen.
• PROGRAMMING OF THE KR5 CONTROLLER
The controller operates in accordance with set parameters which can be changed. Below is presented a list of parameters
and their short description:
P00 – type of a central heating (CH) pump control (“1” – turned on constantly, “0” – turned on at a set temperature).
Factory setting: “0”;
P01 –turn on temperature of the CH pump (45..72 °C). Factory setting: 60 °C;
P04 – additional device turn on temperature (0..300 °C). Factory setting: 2 °C. Important: if the additional device is a
charging pump of a domestic hot water (DHW) boiler, then the turn on temperature is dependent from turn o temperature
and is entered as a dierence (hysteresis) from it. For example, if the turn on temperature needs to be 62 °C, and turn o
temperature– 65 °C, then the value of P04 parameter must be 3;
P05 – additional device turn o temperature (0..300 °C). Factory setting: 2 °C. If the DHW pump is controlled, then this
parameter represents turn o temperature of this pump;
P07 – time period measured in minutes and intended for fuel addition into the running boiler. During the period,
the controller pauses the ongoing ring program, and at the end of the period, returns to the previous operation point
automatically. Factory setting: 5 minutes, range of setting: 1–5.
P10 – temperature of smoke designated as “Firing o” mode start temperature (50..99 °C). Factory setting: 75 °C;
P11 – optimal temperature of smoke. The temperature helps the controller to guide a combustion process towards it (from
„P10“+10 °C to 200 °C). Factory setting: 130 °C;
P16 – output control mode of an additional device: “0”–related with water temperature of the boiler input, “1” – related
with smoke temperature input; “2”– turns on while fuel addition mode is active (P07); “3”– the DHW pump control mode.
The turn o temperature of the DHW pump is set with parameter P05, and the turn on temperature dierence – with P04.
For the DHW pump to be turned on, the next conditions must be fullled:
• the boiler is in the “Firing on” mode;
• the measured water temperature in the DHW boiler is lower than turn o temperature (P05);
• the water temperature in the boiler must be at least 5 °C degrees higher than in the DHW boiler.
If one of the above mentioned prerequisites ceases to exist, the DHW pump is turned o. The pump is turned o either
when the set turn o temperature (P05) of the DHW boiler is achieved. After water in the DHW boiler cools down below
the calculated turn on temperature (P04), the pump is turned on again. If during a period of charging of the DHW boiler
temperature of water in the wood boiler starts falling, then the DHW pump is switched o when the dierence between the
DHW boiler and the wood boiler temperatures diminishes to 3 °C. Factory setting of the parameter P16: “0”;

20
HEATING BOILER: Astra B-25E
P17 – “strict” control mode. “Strict” means that the ventilator is switched o completely when the measured water
temperature in the boiler reaches the set water temperature plus 5 °C. The ventilator is turned on again when the measured
water temperature drops to the set temperature. Alternative to “strict” control means that the ventilator continues working
at the lowest output after reaching the set water temperature and is stopped only in emergency cases. “0”– “strict” control
is turned o, “1”– turned on. Factory setting: “1”.
To enter a programming mode, press the button “P” and hold it for 3 seconds. symbol appears on the screen. To
reach another parameter, scroll with and buttons. To enter the particular parameter submenu, press “P”. To
change a value of the parameter appearing on the screen, press the button “P” and hold it for 3 seconds until the parameter
value starts blinking. Change the value with and buttons. Save the new value by pressing the button “P”. To
quit the parameter changing mode, press and buttons simultaneously or simply wait 30 seconds without
pressing any buttons.
• PREPARATION FOR FIRING
Before kindling the boiler, inspect a position of the ceramic basket in the lower boiler chamber- all segments of the ceramic
basket must be pushed forward until they touch the rear wall of the chamber (Fig. 2).
Fill the heating system with water. The lling pressure should be 0.2 bar bigger than the hydrostatic pressure, yet it must
not exceed the operating pressure of the boiler. After lling the system with water, perform a visual check of the tightness of
the entire system. Perform it before kindling the boiler, then again after kindling and reaching the nominal operating mode.
Check if the heating system is properly deaerated.
• KINDLING PROCEDURE OF THE BOILER
Before kindling the boiler, check whether all requirements indicated in the section 1 are executed.
2 stages kindling. Open the upper damper to a ue by pulling the handle 7 (Fig. 1) towards yourself. Close the lower boiler
door 5 (Fig. 1) if it stays ajar. Open the upper boiler door 2 (Fig. 1) and put rst layer of smaller or medium-sized pieces of wood
onto the ceramic insert 23 (Fig. 1), lengthwise or perpendicularly. Load a bunch of wood chips and paper over them. Then,
put normal-sized wood pieces on top of a pile so that the paper sheets stay accessible for kindling. Switch on voltage using
the button 2 (Fig. 9). Set the required outowing boiler water temperature using the temperature setting buttons 2 (Fig. 11);
we recommend a temperature of at least 75°C or – even better –a higher temperature. Then, press shortly the ventilator
button 3 (Fig. 9) into the „START“ position and see the ventilator starting. Set the kindling material on re and wait, until it
ames up. Then, close the upper damper to the ue by pushing the handle 7 (Fig. 1). If aming up develops successfully close
the fuel chamber door 2 (Fig. 1). After approximately 15 minutes elapse, press shortly the ventilator button 3 (Fig. 9) into the
„MINUTE MAX“ position, open the upper damper to the ue 7 (Fig. 1), slowly open the fuel chamber door 2 (Fig. 1). MINUTE
MAX mode sets the ventilator on its MAXimal speed for a 1 MINUTE. This regime of operation is intended for the highest
smoke exhaustion during the fuel chamber loading. Now you can ll the fuel chamber with a desired quantity of fuel. Then,
close the fuel chamber door 2 (Fig. 1), close the upper damper to the ue 7 (Fig. 1) and press shortly the ventilator button 3
(Fig. 9) into the „START“ position.
After 1 minute passes away, a controller of the boiler exits the MINUTE MAX mode automatically and
returns the rotational speed of the ventilator to the former level. If required MINUTE MAX mode duration could
be extended by means of service programing.