ALFA TERM 20 Guide

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STOVE FOR FLOOR HEATING
ALFA TERM -20
INSTRUCTIONS FOR INSTALLATION, ADJUSTMENT AND USE

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0. TECHNICAL DATA
HEATING POWER WITH GRATE IN LOWER POSITION:
Rated heating power (wood/coal)
22,9 kW / 22,8 kW
Heating power of stove emission (wood/coal)
8,7 kW / 8,1 kW
Thermal power of delivered water (wood/coal)
14,2 kW / 14,7 kW
HEATING POWER WITH GRATE IN UPPER POSITION:
Rated heating power (wood/coal)
16 kW / 20kW
Heating power of stove emission (wood/coal)
6 kW / 8 kW
Thermal power of delivered water (wood/coal)
10 kW / 12 kW
REQUIRED FLUE DRAFT
16Pa
DIAMETER OF FLUE EXTENSION
150 mm
HEIGHT FROM FLOOR TO AXIS OF FLUE EXTENSION
690 mm
STOVE DIMENSIONS:
Width
900 mm
Height
850 mm
Depth
600 mm
OVEN DIMENSIONS:
Width
460 mm
Height
260 mm
Depth
440 mm
FIREBOX DIMENSIONS:
Width
265 mm
Height (min./max.)
264/452 mm
Depth
414 mm
OPENING OF FIREBOX DOOR (width/height)
175/200 mm
CONNECTIONS OF DISCHARGE AND RETURN LINE
R1RS
CONNECTIONS OF THERMO VALVE AND SAFETY VALVE
R1/2RU
CONNECTIONS OF COOLING PIPES
R1/2RS
BOILER VOLUME
14 (l)
HEATING VOLUME WITH GRATE IN LOWER POSITION:
280-380m3(total)
Heating volume of stove emission
100 -135 m
3
Heating volume of hot water (radiators)
180-230 m
3
HEATING VOLUME WITH GRATE IN UPPER POSITION:
190-250m3(total)
Heating volume of stove emission
70-95 m3
Heating volume of hot water (radiators)
120-155m3
MAXIMAL OPERATING PRESSURE
1,9 bar
MAXIMAL OPERATING TEMPERATURE
90 C
WEIGHT (gross/net)
200/170 kg
FLUE GAS TEMPERATURE (wood/coal)
268 / 272 ºC
CONTENT OF CO (13% O2)
0,96 / 0,68 %
ENERGY EFFICIENCY
74 / 77 %
Note:
The heating power is shown for stoking dry beech wood with lower heating power Hd=4255W/kg and brown
coal Hd=4926W/kg.

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DEAR BUYERS!
Thank You for the trust you showed us buying our stove for floor heating. We assure You that You have
chosen a quality and economic product that is a result of many years of experience of this factory in the
production of stoves and furnaces for floor heating.
We hope that we fully met Your requirements in terms of design, as well as in terms of the surface of living
area that you can heat.
Please carefully read these instructions before connecting the stove and adhere to every advice provided
herein.
1. PURPOSE
The continually burning stove for floor heating with solid fuel is used for:
-cooking,
-baking,
-heating apartments, individual houses and offices,
-production of hot sanitary water.
It is mostly installed as a stove for floor heating, and it can also be installed for central heating.
2. APPEARANCE AND STRUCTURE OF A STOVE WITH A FLOOR HEATING BOILER (fig.1)
1. Stove cover
2. Cooking panel (hob)
3. Cooking panel extension
4. Butterfly knob for opening and closing
5. Oven door (oven)
6. Oven thermometer
7. Firebox door
8. Secondary air regulator knob
9. Ashtray door
10. Thermostat knob (combustion regulator)
11. Rod for shaking ash
12. Ashtray (ash box)
13. Ember holder
3. SAFETY AND RELIABILITY IN STOVE OPERATION
The stove for floor heating is constructed so that it enables maximum safety during operation.
Safety during stove operation is provided in three ways:
- combustion regulator (thermostat) (fig. 1 pos.10), located in the ashtray door, which automatically closes the
air intake in the stove firebox when the set water temperature in the boiler is reached,
-Thermal valve (thermal fuse) (Fig. 7, Item 13 and Fig. 7a) when installed in the heating system serves as a
thermal fuse if the stove becomes overheated,
- safety valve (Fig. 7 and 8, Item 5) which MUST be installed on an R1/2" connection (Fig. 4, Item 4.)
NOTE:
Thermal valve and safety valve are not delivered with stove, while the thermostat is installed on the
stove's ash pan door.
4. STOVE PLACEMENT (INSTALLING)
- The stove may be installed in the kitchen part or at some other convenient spot.
- An inflammable pad should be put under the stove.
- If the pad is flammable (wood, plastic), place a tin plate that should protrude from the lateral sides with 10cm
and 50cm from the front side.
- The furniture and objects located in front of or close to the stove must not be from flammable material. If they
are from flammable material, then the minimal distance from the stove must be 20cm.
14. Draving for wood
15. Cover for cleaning
16. Manometer
17. Thermometer
18. Hob cover
19. Thermostat flap
20. Flue extension
21. Cover of opening for cleaning
22. Handrail
23. Grate carrier
24. Additional cover
25. Rod bracke

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1
2
18
7
16
17
13
11
25
12
3
4
5
6
15
14
19
20
21
22
7
8
16
17
10
11
9
23
24
9
Figure 1

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- If a cupboard is installed above the stove, the minimum distance between the stove hob and the cupboard
should be at least 70cm.
- Flammable materials (for example wallpapers, frames, doors etc.) from the flue should be at a distance of at
least 20cm. This distance may be reduced if thermal insulation is placed on the flue pipe and the temperature
of the surrounding objects does not exceed 80°C.
- The stove should be installed in horizontal position or slightly elevated from the back side (3-4mm).
5. FLUE INSTALLING
Review the unpacked stove and become familiar with the parts of the stove and the accessories, and
especially pay attention to the following:
- The special channels of the firebox door, the ashtray, the cover for cleaning and the hob frame should have
pigtails with no asbestos that seal well and do not allow uncontrolled air intake.
- The combustion regulator (thermostat) with regulation knob (fig.1 pos.10) should properly open and close the
regulator flap (fig.1 pos.19).
- The ember holder (fig.1 pos.13) should be properly placed in its bearing and should be easily open.
The flue connection (plug), that is delivered together with the stove and is placed in the drawer for wood,
should be set and screwed on the openings of the plug carrier (hob) or on the opening on the lateral side. The
existing cap must be previously removed and the same screws for connecting plugs should be used.
WARNING:
If Your flue is not the best or it is with suspicious quality, we recommend that You install a flue connection on
the plug carrier (from the top), and not on the side.
The flue reaches its rated power if the flue draft is 20Pa. We recommend the following flue sizes with which
this draft is obtained:
Stove
Denotement
Rated heating power
(kW)
Flue height (m)
6
7
8
9
10
ALFA TERM 20
Brown coal
wood
Dimensions of light surface (mm.)
22,8
22,9
145x200
145x145
145x145
145x145
145x145
- Proper flue and meeting other requirements set out in the material that follows are a prerequisite for flawless
functioning of the stove.
- The flue connection should be installed with uplifting.
- Horizontal flue pipe pieces longer then 0,5m should have an uplifting of 10towards the flue.
- The flue extension, flue pipes and the flue must not be narrowed.
- All connections as well as the flue must be well sealed, with no soot and grime in flue pipes.
- The flue should be protected from cold (it should be heat insulated). This especially applies for flues made of
sheet metal and flues built on external walls.
- Flue pipes that do not have thermal insulation and do not stand vertically, must not be longer then 1,25m.
Check of the draft strength is performed by using candles (fig. 2).
slight draft good draft very strong draft
Figure 2
The flue is functioning well if it satisfies the following conditions (fig. 3):
- It protrudes above the roof top (ridge) at least 0,5m.
- It is higher than the neighboring house that is close to the flue, a tree or some other barrier.
- It is in the internal walls of the house or it is well insulated if it is in the external walls.
- The extension should be closely connected to the flue if it is being extended.
- The flue pipe should not be inserted deeply in the flue opening as this reduces the space for smoke output.
- All other unnecessary openings as well as the door for cleaning should be well closed (sealed) so that so
called “false” air would not be created.

6
cm
Figure 3
6. INSTALLING STOVE IN WATER HEATING SYSTEM
Installing of the stove should be performed by a qualified person according to the appropriate project.
The stove is intended for floor and central heating.
It can be installed in closed and open heating system. Adhere to the regulations JUS M.E7.201 and JUS
M.E7.202. Diagrams of closed and open system are shown on fig.7 and fig.8.

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The back of the boiler and connections are shown in Fig. 4 where:
Figure 4
- Item 1 is an R1" connection with an outer thread for the flow pipe,
- Item 2 is an R 1" connection with an outer thread for the return pipe,
- Item 3 is an R1/2" connection with an inner thread for installation of the thermal valve safety pipe,
- Item 4 is an R1/2" connection with an inner thread for safety valve installation.
6.1 DISCHARGE AND RETURN LINE (fig.4 pos.1 and 2 and fig.7 and fig.8 pos.3 and 10)
The outlets of the discharge and return water of the boiler are 1" and they must not be reduced, that is,
narrowed up to the first bifurcations. Use steel pipe 1" or copper pipe with external diameter F28mm. (or bigger
diameter).
When performing the installation, strictly pay attention to the pipe slopes which should be 0,5% (5mm. per
meter of pipe) and to the system venting (boiler, pipes, radiators).
On the discharge line you may set thermal-manometer although thermometer and manometer are mounted on
the front side.
Set a “by-pass” on the return line with a pump, expansion vessel and valve for filling and draining the system.
When mounting the pump, pay attention to the pump direction.
Warning:
Make a "by-pass" only if there are conditions for so called gravitational heating.
. 6.2 THERMAL VALVE WITH BUILT-IN THERMAL PROTECTION AND ADDITIONAL ELEMENTS FOR
CONNECTION
To install thermal valve it is necessary to purchase and install:
1. Thermal valve with built-in thermal protection type 544, 1/2", product Caleffi (Fig. 7a) and Fig. 7, Item 13.
2. Slope pressure regulator with manometer 1/2", the same or similar as shown in Fig. 7b and Fig. 7, Item 19.
3. Filter for cold water at the input of the water supply to the thermal valve, Fig. 7, Item 20
4. Filter for hot - boiling water intake of the boiler and water outlet of thermal valve, Fig. 7, Item 21.
Note:
These components are not included with product for central heating you bought!
Installation of thermal valve with built-in thermal protection (Fig. 7, Item 13 and Fig. 7a) with additional
elements ensuring safe operation, such as pressure regulator (Fig. 7, Item 19 and Fig. 7b). Water filter on the
boiler intake (Fig. 7, item 20) and water filter on the boiler outlet in closed central heating system is
MANDATORY. This specially refers to a closed system, when the radiators are submerged and where in case
of termination of the pump operation for any reason, the water temperature in the boiler rapidly increases and
overheating occurs very quickly.
In the open central heating system, installation of thermal fuse is not mandatory.
6.2.1 THERMAL VALVE WITH BUILT-IN THERMAL PROTECTION (Fig. 7, Item 13 and Fig. 7a)
Thermal fuse is installed near the stove, depending on the available space. It can be installed in any position.
You should take into account the direction of cold water intake and hot water outlet from the boiler which is
clearly marked on the valve body.
The thermal fuse probe (Fig. 7, Item 22) is best to place in the thermal valve connection (Fig. 7, Item 18). It can
be placed on the discharge - distribution pipe (Fig. 7, Item 3) but at a distance from the boiler of 500 mm the
most or at the highest point of the boiler before the exhaust pipes.
Seal it with hemp or other sealing material by tightening.
Fig. 7 shows the thermal valve installation diagram.

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The device is of one piece with the thermal valve and valve for filling.
Valve opening temperature is 100°C (+0°C/-5°C).
The fluid recommended in the installation is water and glucose antifreeze of 30%.
Note:
At reaction, and valve operation, during fluid cooling in an overheated boiler part of the new fluid is injected into
the boiler, but the part is also ejected from the boiler. It will be poured down the drain. If the antifreeze is in the
installation you must keep in mind that a certain percentage will go out and pour down the drain!
We recommend the thermal valve Caleffi type 544, 1/2" as shown in Figure 7a.
6.2.2 SLOPE PRESSURE REGULATOR 1/2" WITH MANOMETER (Fig. 7, Item 19 and Fig. 7b)
When installing the thermal valve it is required to mount the slope pressure regulator as shown in Fig. 7, Item
19. The pressure that is maintained by pressure regulator must be set at a higher pressure than the pressure
that is in the heating system. If you do not have a higher water pressure of at least 0.8 bar compared to the
pressure in the heating system thermal valve will not work or cannot inject cold water into the boiler that needs
to be cooled.
Pressure regulator should be set to 2.8 to 3 bars.
You should take into account the direction of placing the slope pressure regulator
6.2.3 WATER FILTER OF THE BOILER INTAKE (Fig. 7, Item 20)
In front of the slope pressure regulator on water intake from water supply line it is necessary to install a filter
that will clean the water from solid objects, primarily of sand, which can damage the tap seal or seals of the
thermal valve and the slope pressure regulator.
This filter does not need to be resistant to high water temperatures due to cold water that flows through.
6.2.4 WATER FILTER OF THE BOILER OUTLET (Fig. 7, Item 21)
It is required to install the filter on the boiler outlet which will clean the hot - boiling water from dirt and solid
objects that can damage the tap seals, or seals of the thermal valve.
This filter must be resistant to water temperatures up to 150°C.
NOTES:
- After the completion of thermal valve activation, checking the pressure in the installation and filling the system
with cold water is mandatory.
- In cases where antifreeze is used, after filling the installation with water it is required to check percentage
content of antifreeze in a mixture of water and antifreeze!
- To avoid elimination of the antifreeze agent solution from the installation, it is best to have backup battery
supply of the pump with an inverter.
6.3 SAFETY VALVE (fig. 7 and 8 pos. 5 and fig. 4 pos. 6 )
On the back side of the boiler under the hob, a connection R1/2" is welded (fig.4 pos.6) in which you are
OBLIGED to set a safety valve. The safety valve should be between 2,5 to 3 bar. It can be installed directly on
the terminal or at a distance from the stove of 1m the most, provided that there is no block valve between the
boiler and the safety valve.
In an open heating system, the safety valve is not put normally, but we advise that you put it as one more type
of insurance of the boiler and the system (due to unforeseen circumstances).
WARNING:
If the safety valve is not set as previously explained, the guarantee ceases.
6.4 THERMOMETER AND MANOMETER (fig. 1 pos. 16 and 17 and fig. 5)
On the stove itself, on the additional cover (fig.1 pos.24) between the firebox door and the ashtray door,
thermometer and manometer are mounted (fig.1 pos.16 and pos.17, and fig.5) so they do not have to be
placed on the installation.
The thermometer pos. 17 shows the temperature of water in the boiler (operating temperature) in °C.
The manometer pos. 16 shows the water pressure in the boiler, that is, in the system, in bars.

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Figure 5 Figure 6
7. PRACTICAL INSTRUCTIONS AND ADVICE FOR HEATING SYSTEM USE
- We recommend that you choose a closed system due to the risk of corrosion in an open heating system.
- All connections must be well sealed and fastened.
- Before commissioning, the complete installation should be examined with water with pressure of 2,4 bar.
- It is desirable that water is drained out from the system at least once because of the grime located in the
system.
- For an installation in which only a stove “alfa term 20” is connected, we recommend expansion vessel from
18 (l) but not less than 12(l) which would be placed on returning water, as close as possible to the boiler, and
no block valve should be set between the boiler and the expansion vessel.
INSTALLATION DIAGRAM OF STOVE WITH CLOSED CENTRAL HEATING SYSTEM
ALFA TERM 20
Figure 7

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1. Hot water boiler
2. Flue pipe connection
3. Distribution pipe
4. Closed expansion vessel
5. Safety valve
6. Radiator valve
7. Radiator
8. Air vent valve
9. Circulation pump
10. Return pipe
11. Charge and discharge cock
12. Regulation valve
13. Thermal fuse
14. Connection line for water supply system
15. Hot water discharge
16. Manometer
17. Connection for safety valve
18. Connection for thermal valve
19. Pressure regulator
20. Water filter at the input of the boiler
21. Water filter at the output of the boiler
22. Thermal fuse probe
23. Thermal fuse capillary pipe
Figure 7a Figure 7b
INSTALLATION DIAGRAM OF OPEN SYSTEM OF STOVE FOR FLOOR HEATING ALFA TERM 20
10
9
68
1
3
16
711
212 515
4
14
13
Figure 8
1. Hot water boiler
2. Flue extension
3. Distribution line
4. Open expansional vessel
5. Safety valve
6. Radiator valve
7. Radiator
8. Air vent
9. Circulation pump
10. Return line
11. Filling and emptying tap
12. Safey valve connection
13. Thermo valve connection
14. Vent pipe
15. Hot water outlet
16. Manometer

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- It is desirable to insert a pump R1" for more speed whose flow capacity is always appropriate for the current
need of the system. Directly in front and behind the pump, install shut-off valves so that displacement of the
pump could be performed for repairs, changes etc., without releasing water.
- Mount a tap for the filling and draining the system at the lowest system point.
- Before commissioning the system should be filled with water as follows:
a) If the system is open, fill the system through the tap for filling and draining until water starts to leak
from the overflow pipe of the expansion vessel,
b) If the system is closed, the system pressure (working pressure) should be 11,5 bar.
In both cases, fill the system slowly so that air can come out through the air releasing valves. If the valves do
not open themselves, they should be manually open until water starts to leak, than close them.
- The water from the heating system should not be drained in summer neither since it protects the internal
side of the system from spreading oxidation (corrosion).
- If you don’t use the boiler for a longer period in winter, and there is not antifreeze asset in the system, it is
best to drain the water from the system. At the same time open the valves on the radiators, the combined
valves and the other shut-off elements in the system.
- Fire must not be kindled if the water in the boiler is frozen, neither if there is not enough water in the boiler.
8. COMMISSIONING AND STOKING
Before stoking, the entire system for floor (central) heating should be filled with water, well vented and the
stove should be properly connected to the flue as explained in the previous paragraphs.
WARNING:
The stove must not be used without water. It must be connected to an installation on which
consumers (radiators) are connected with a minimum power of 8 kW.
When the system is cold, the flap of the power regulator (combustion regulator, thermostat) located in the
ashtray door (fig.1 pos.10 and pos.19) should be open. Pull ahead the butterfly knob for opening and closing
(fig. 1 pos.4 and fig. 16). That way the butterfly knob is open and kindling is enabled. Later when the stove is
inflamed, we adjust the regulator flap on the appropriate position that depends on the pulling power of the flue
and the desired power, and the butterfly knob should be pushed back. Then the butterfly knob is closed and
full use of the combustion is enabled, thus better heating, cooking and baking. During this, the door of the
firebox and the ashtray (fig. 1 pos. 7 and pos. 9) must be closed if we want regulated combustion. The
butterfly knob for kindling is open only during the kindling of the stove (10 to 15 minutes).
The firebox and ashtray doors can be open and closed manually, as well as with the bent wrench as shown
on figure 6.
We stoke the stove as all permanently burning stoves on solid fuels. When the grade is in lower position, we
perform kindling through the open door of the ashtray and the ember holder (fig.9 and fig.10). We open the
ember holder (fig.1 pos.13 and fig.9) by raising and pulling. When the grate is in upper position through the
open door of the firebox (fig.11) on the grate we put paper, small pieces of chopped wood and kindle. When
everything is burning well, we can fill the stove with wood or coal if the grate is in upper position. If the grate is
in lower position, do not put at once all the needed heating material for full firebox, but divide it on two or
three parts and put it in the firebox at intervals of 10-15 minutes on flaming heating material. The stove filled
in this manner burns from 1 to 6 hours, depending on the intensity of combustion in the stove and the
adjusted power regulator (thermostat).
Figure 9 Figure10 Figure 11

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The firebox can be filled from the upper side as well (fig.12). The cover is lifted by using a wrench and
firewood is put. It is not recommended to put some organic waste in the stove (plastic bags, bones etc.)
because in this case tar collects on the walls of the flue channel and this can cause a fire.
After every filling it is recommended that the stove burns with maximum power for at least half an hour since
in the beginning all volatile compounds in the fuel burn, which are actually the main causes for condensate
creation in the stove.
Insert the coal when there is good (strong) ember in the firebox, two to three times at intervals of 15 minutes.
Figure 12
9. GRATE USE IN UPPER AND LOWER POSITION
For cooking, baking and frying in the transit period, the upper grate position is used (fig.11) so that the flame
could directly reach the hob thus saving the costs for cooking, baking and heating.
The stove is delivered with a grate in lower position. In order to move the grate from the lower to the upper
position, it is necessary to do the following:
- Remove the hob from the stove and open the door of the firebox and the ashtray.
- The grate should be pushed completely back with a rod for shaking the grate and then through an opening
of the ashtray door and the space for ash and the front part of the grate should be lifted by hand and should
be pulled out from its bearing (position). After this, the carrier of the grate is lifted and pulled out.
- The placement of the grate in upper position is performed in reverse order. The grate carrier is placed on
the grate holders (pieces 4) welded in the boiler firebox in front and on the back side (pieces 2+2) (fig.1
pos.23). In the grate carrier bearing insert the grate under an angle (aslant) so that the back part of the grate
enters first and then put down the front part of the grate. Move the grate forward and backward so that it lies
well in the grate carrier bearing. Put the hob in the carrier bearing of the hob frame.
- Placement of the grate in lower position (fig.9 and 10) is performed in the same manner as the upper
position, provided that in the end the front part of the grate is lifted a little and through the rectangular opening
of the rod carrier (fig.1 post.25) the rod for shaking the grate should be inserted. The grate is slowly put down
so that the grate notch falls in the opening of the rod for shaking the grate.
Warning:
- In the lower grate position, the heating of water is better, larger number of radiators can be heated and
bigger surface of living space, but cooking is more difficult.
- In the upper grate position, the heating of water is weaker, small number of radiators can be heated and
small surface of living space, but cooking is much easier.
- In both grate positions baking is the same (it is not impeded).
10. AUTOMATIC REGULATION
The stove power is adjusted with a thermostat (power regulator, combustion regulator) located in the ashtray
door and which automatically adjusts the lapse of the regulator flap depending on the adjustment of the
regulating knob (fig.1 pos.10 and pos.19) and the height of water temperature in the stove heater. The
regulation knob has many positions written on the knob and this is shown in table 1 as follows:
Table 1
Position of regulator knob
0
3
4
5
7
9
Water temperature in the stove (C)
Closed regulator
30
40
50
70
90
The cover (flap) for air in the power regulator system completely regulates the air intake for combustion it he
remaining openings are closed.
11. SECUNDARY AIR REGULATOR
A secondary air regulator is placed in the firebox door (fig.1 pos.8 and fig.13). It is used for regulating the
subsequent ignition and combustion of unburned gases. Its opening and closing is performed manually
through a knob positioned on the firebox door.

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Leave the secondary air regulator open when the grate is in lower position while stove usage. Close the
secondary air regulator when the grate is in upper position.
12. COOKING, BAKING AND FRYING
The stove is mainly used for heating during the heating season. For this purpose the grate is placed in lower
position. For quicker baking, cooking and frying use dry wood for stoking.
The butterfly knob for stoking must be closed, and the power regulator must be open. After baking, cooking
and frying is completed, put the power regulator on the green position.
When baking, the water temperature should be increased to at least 60C, if necessary by closing some
radiators while baking, and adjust the stove temperature according to the food that is baked.
13. HEATING MATERIAL
The heating material can be kept in the heating material drawer (fig.14). The drawer moves on rails. If we
want to take out the drawer from the stove we must lift it up so that it would fall out from the rails.
Use heating material that is shown in the table 2 which will ensure that the boiler has rated thermal power of a
flue draft of 20 mbar (20Pa).
Do not burn coal dust, sawdust and waste that releases smoke intensively!
Figure 13 Figure 14 Figure 15
Table 2
Heating material
Heating power (kJ/kg.)
Brown coal
15000 –19000
Dry beech firewood
15300
WARNING:
In order to get rated heating power and as higher rate of usage, we recommend that you use dry
beech wood cut with a length of L=33cm as a heating material.
14. CLEANING AND MAINTENACE
Before every filling with fuel, the stove grate must be cleaned with a spade by opening the ember holders or
through the open door of the firebox. The ash from the ashtray should be removed at least once a day and
larger residues (slag) should be removed by opening the door of the ashtray and the ember holder. The clean
heating surfaces guarantee economic operation of the stove. Cleaning of the stove once a month is
recommended, and if necessary more frequently as well.
Do not clean enameled surfaces of the stove and the stove frame with a wire brush and wire sponge since
the enamel and the protection may be damaged, instead, use a damp cloth and cleaning assets and fine
detergents. Clean the oven after every use while it is still warm. Leave the oven door open after cleaning for
couple of minutes so that unpleasant odor would not be sensed during the next warming up.
Temporarily clean the stove hob with fine sandpaper and in case of longer brakes it should be greased with
oil that does not contain acids (vegetable oil). Remove burnt things from the hob by using a palette knife or a
knife and eventually treat it with graphite or ash from the ash box or with oil.
It is forbidden to artificially cool the stove with unnatural draft and soaking the firebox with water so that it gets
cold.

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15. STOVE STORAGE
After finishing the stoking season, the stove should be cleaned from ash and smoke. Water should be
released only in case when some repair of the installation should be performed. If the installation is not used
in the heating season, pour a certain quantity of some antifreeze liquid or release the water from the
installation as a protection from freezing.
16. FAULTS
Table 3
RB
Faults
Possible cause
Elimination
1
Water pressure in
installation is slowly
decreasing
The installation does not seal
Check the sealing of welded
connections, threaded fasteners,
nuts etc.
2
Cold radiators on the
highest installation point
and a sound is heard
Air in the installation and low
pressure in the installation
Increase pressure in the installation
and release air from the installation
and from radiators
3
The radiators do not
heat along the entire
length
Air in radiators
Release air from radiators through
the vent valve
4
The safety valve drains
water from the
installation, and the
pressure is less than 3
(2,5) bar
Safety valve failure
Replace safety valve
5
The pressure in the
installation is more than
3 (2,5) bar and the
safety valve does not
drain water from the
installation
Safety valve failure
Replace safety valve
6
Sudden water
temperate increase in
the installation
Air in the installation
Perform radiator venting
Closed valves towards radiators
Open all valves in the heating
system and provide normal water
circulation in the installation
Circulation pump failure
The circulation pump should be
repaired or replace it thereby
allowing operation of the heating
system
Electrical power loss
You should open all valves that
reduced the heating system. This
mostly refers to the “by-pass”
valve.
Stop or reduce stoking with strong
control so that the water
temperature in the system would
not exceed 90C until electricity
arrives.
7
Sudden pressure
increase in the
installation while water
temperature increase
Decreased pressure in the
expansion vessel or completely
empty. Remove the cover or the
vessel valve cap and release some
air through the valve. If the
membrane is destroyed, water
shall leak from the valve, and if it is
only half-empty, only air will come
out
If water is leaking from the valve,
replace the expansion vessel.
If only air comes out from the
valve, remove the installation
vessel and pump it. The pressure
in the vessel must be equal to or
greater than height difference of
the highest and lowest installation
point. Example:
For height difference of 5m. the
pressure is Pmin.0,5 bar.

15
Air in the installation
Perform venting of the installation
8
The circulation pump
does not switch on or
blow a fuse
No power on the electrical
connection. Loose connectors.
Check and tighten the screws at
the connection spots. Check and if
necessary, replace the fuses,
eliminate the malfunction of the
motor or installation connection
Capacitor failure
Replace the capacitor
Rotor blockage
Before the start of each heating,
examine the easy rotor turning. Hot
water deposition may lead to rotor
blockage. Turn around the motor
shaft with a wrench until free
turning of the rotor is enabled.
The pump is blocked due to
sediment
Disassemble and clean the pump.
9
The thermometer or
manometer does not
show the amount of
temperature or water
pressure in the
installation
Thermometer or manometer
failure
Replace the thermometer or
manometer
10
Noise (sounds) from the
eating system
Defective pump. Great clearance
between the rotor shaft and
bushings
Reduce pump speed. Replace the
pump envelopes or the entire pump
The pump is functioning at too
high speed
Select low speed.
Air in installation
Release air from the heating
system
Loose knobs or some screw on
the stove
Tighten knobs and screws
11
Sounds in the pump
The pressure at the pump suction
part is to low
Increase system pressure or check
the expansion vessel.
12
The stove overheats,
loud noise (cracking) is
heard in the boiler of the
stove.
Electricity outage has occurred,
the circulation pump does not
work and the boiler of the stove
overheats. There is a danger of
boiler rupture.
To avoid this occurrence, it is best
to have backup battery power
supply of the circulation pump with
an inverter.
Installation of a thermal exhaust
valve (Fig. 7, pos. 13) is required
as additional security against stove
overheating.
If you do not have backup supply of
the circulation pump or a thermal
exhaust valve installed, then you
should open the bypass valve
connected in parallel with the
circulation pump on the pipeline
system and remove embers from
the stove.
13
Cooling thermal fuse is
activated (thermo valve)
because
water temperature
increased over 95C due
to:
- loss of electricity
This is proper and do not touch
anything. When the system is cold,
thermal valve will be closed.
After that, check the pressure in
the installation and fill the system to
the required.

16
- open ashtray door and no
regulated combustion
Close the ashtray door and through
the knob on the cover of the
ashtray door and thermostat,
reduce the water temperature in
the system.
- the grate is in lower position and
small number of radiators are
switched on
Transfer the grate to upper position
or switch on some other radiator.
Keep the ashtray door closed.
14
Water condensate in
the boiler
Damp heating material
Change heating material
Too low temperature of returning
water from the heating system
Insert combined valve or switch off
some radiator from the heating
system
15
Outlet water
temperature is not
appropriate (low)
Non-calorific heating material
Change heating material
Heating system is oversized
(a large number of radiators)
Switch of some radiators
Little heating material is inserted in
the firebox
Increase the quantity of heating
material in the firebox
16
Fire does not burn
regularly
Weak flue draft
Make a new flue or repair the old
one
Flue pipe connections do not seal.
The doors on the stove and the flue
do not seal. The flue draws “false
air”.
Seal all connecting spots so that
“false air” would not occur
17
There is not enough
heat in baking, cooking
The thermostat is set to a lower
temperature
Increase water temperature
through a thermostat or shortly
open the ashtray door
18
There is too much heat
in baking, cooking
The thermostat is set to a high
temperature
Reduce water temperature through
the thermostat or stoke moderately
19
The boiler-stove
releases smoke during
initial startup
Combustion and heating of the
stove and flue
It is normal for the stove to release
some smoke during initial startup,
and this stops after some time.
20
The boiler-stove
releases smoke during
regular use
Uncleaned flue, flue pipes and
stove
Clean the internal part of the flue,
the flue pipe and stove.
Damp heating materials of the
heating materials you use
intensively release smoke
Change heating material. Use dry
hating material and heating
material that does not release
smoke
Overloaded firebox
Fill the firebox slowly, gradually, in
a couple of times
Bad flue
Repair or make a new flue
21
The grate is stuck when
cleaning is performed
Some spike is stuck, slag or
something else on the grate
Clean the grate of undesirable
objects
17. TIME OF GUARANTEED SERVICING
This implies the period during which we guarantee the service, accessories and space parts, starting from the
day of purchase of the device.
The time of guaranteed servicing is in accordance with the valid legal regulations.
In case of change of the model and the design of the device, the term for change of parts that have modified
design is within the legal term.
After this term we provide the modified parts in the new designs.

17
17.1 CONDITIONS OF THE GUARANTEE
The guarantee of the product is valid within the legally defined term.
The guarantee is not valid for the glass, the glass-ceramic panel and the physical damages that have
occurred after purchase.
THE MANUFACTURER RETAINS ALL THE RIGHTS TO MAKE CHANGES.
The device will properly function within the guaranteed term only if it is used in accordance with these
guidelines for connection and application.
The guarantee cases to apply if it is determined that:
-the connection or the repair of the product was performed by an unauthorized person, that is, if unoriginal
parts have been embedded,
- if the device has not been properly used in accordance with these guidelines,
- if some mechanical damaging of the device occurred during usage,
- if the repairs of defects were performed by an unauthorized person,
- if the device has been used for commercial purposes,
- if the damage has occurred during transportation after the device was sold,
- if the defects occurred due to improper mounting, improper maintenance or mechanical damaging by the
buyer,
- if the defect occurred after too strong or insufficient power, as well due to force major.
We can repair the defects of Your device also outside the guaranteed period, with original spare parts for
which we also provide a guarantee under the same conditions.
This guarantee does not exclude or affect the rights of the customer in regard to the conformity of the goods
pursuant to the legal regulations. If the delivered product does not conform to the agreement, the customer
has the right to ask the seller to repair that lack of conformity without any reimbursement, by repair or change
of the product in accordance with the valid legal regulations.
CONTENT:
2. APPEARANCE AND STRUCTURE OF A STOVE WITH A FLOOR HEATING BOILER (fig.1)................3
3. SAFETY AND RELIABILITY IN STOVE OPERATION...............................................................................3
4. STOVE PLACEMENT (INSTALLING)........................................................................................................3
5. FLUE INSTALLING.....................................................................................................................................5
6. INSTALLING STOVE IN WATER HEATING SYSTEM..............................................................................6
6.1 DISCHARGE AND RETURN LINE (fig.4 pos.1 and 2 and fig.7 and fig.8 pos.3 and 10).....................7
. 6.2 THERMAL VALVE WITH BUILT-IN THERMAL PROTECTION AND ADDITIONAL ELEMENTS
FOR CONNECTION...................................................................................................................................7
6.2.1 THERMAL VALVE WITH BUILT-IN THERMAL PROTECTION (Fig. 7, Item 13 and Fig. 7a).........7
6.3 SAFETY VALVE (fig. 7 and 8 pos. 5 and fig. 4 pos. 6 )......................................................................8
6.4 THERMOMETER AND MANOMETER (fig. 1 pos. 16 and 17 and fig. 5).............................................8
7. PRACTICAL INSTRUCTIONS AND ADVICE FOR HEATING SYSTEM USE ..........................................9
8. COMMISSIONING AND STOKING..........................................................................................................11
9. GRATE USE IN UPPER AND LOWER POSITION..................................................................................12
10. AUTOMATIC REGULATION..................................................................................................................12
11. SECUNDARY AIR REGULATOR...........................................................................................................12
12. COOKING, BAKING AND FRYING........................................................................................................13
13. HEATING MATERIAL.............................................................................................................................13
14. CLEANING AND MAINTENACE............................................................................................................13
15. STOVE STORAGE.................................................................................................................................14
16. FAULTS..................................................................................................................................................14

18
Overall dimensions of stove ALFA TERM 20
300
309 712
781
797
806
64
152
268.5
64 235
1"
1"
1/2"RU
1/2"RU
1/2"RS
1/2"RS
880
850
100
500
1448
900
Ø146
Ø142
690
132
65
600
197
24.5
35
35
107