Unical ALKON 24 B 60 Datasheet

00332925 - 2nd edition - 02/09
ALKON 24 B 60
ALKON 35 B 60
INSTALLATIONAND
SERVICING MANUAL

Warning: this manual contains instructions to be used exclusively by the installer and/or a
competent person in accordance with the current laws in force.
The end user MUST not make any alterations to the boiler.
Failure to follow the instructions indicated in this manual, which is supplied with the boiler,
could cause injury to persons, animals or damage to property. UNICAL shall not be held
liable for any injury and/or damage.
CONTENTS
1GENERALINFORMATION ................................................................................................................................................................................... 3
1.1 Symbols used in this manual ....................................................................................................................................................................... 3
1.2 Correct use of the appliance ....................................................................................................................................................................... 3
1.3 Water treatment ............................................................................................................................................................................................ 3
1.4 Information to be handed over to the user .................................................................................................................................................. 3
1.5 Safety warnings ............................................................................................................................................................................................ 4
1.6 Data badge .................................................................................................................................................................................................... 5
1.7 General warnings ......................................................................................................................................................................................... 6
2TECHNICAL FEATURESAND DIMENSIONS ..................................................................................................................................................... 7
2.1 Technical features ........................................................................................................................................................................................ 7
2.2 Dimensions ................................................................................................................................................................................................... 8
2.3 Main components ......................................................................................................................................................................................... 9
2.4 Boiler water circuit ...................................................................................................................................................................................... 10
2.5 Performance data according to the Standard UNI 10348 ....................................................................................................................... 11
2.6 General features ......................................................................................................................................................................................... 12
3INSTRUCTIONS FOR THE INSTALLER ............................................................................................................................................................ 12
3.1 General warnings ...................................................................................................................................................................................... 12
3.2 Standard codes for installation ................................................................................................................................................................. 13
3.3 Packaging .................................................................................................................................................................................................. 13
3.4 Boiler location ............................................................................................................................................................................................ 14
3.5 Boiler installation ........................................................................................................................................................................................ 15
3.6 Gas connection ......................................................................................................................................................................................... 15
3.7 Central heating connections ..................................................................................................................................................................... 16
3.8 DHW connections ..................................................................................................................................................................................... 17
3.9 Condensate drain ...................................................................................................................................................................................... 18
3.10 Flue outlet installation................................................................................................................................................................................ 19
3.11 Electrical connections ............................................................................................................................................................................... 26
General warnings ...................................................................................................................................................................................... 26
Connection to mains supply 230V ............................................................................................................................................................ 26
Outdoor sensor connection ..................................................................................................................................................................... 27
ON-OFF digital room controller connection ............................................................................................................................................ 28
Modulating RT/OT room controller connection ....................................................................................................................................... 28
Layout of the electrical connection for zone control systems ............................................................................................................... 29
3.12 Wiring diagrams ........................................................................................................................................................................................ 30
3.13 Filling the system .............................................................................................................................................................................. 31
3.14 Initial lighting .............................................................................................................................................................................................. 32
3.15 Burner pressure adjustment .................................................................................................................................................................... 33
3.16 Variation of output range ........................................................................................................................................................................... 36
4SERVICINGSCHEDULE .................................................................................................................................................................................... 37
Instructions for inspecting and servicing the appliance .................................................................................................................................. 37
5FAULT CODES ................................................................................................................................................................................................... 38
5.1 Fault codes ................................................................................................................................................................................................ 38
6CE CERTIFICATE ............................................................................................................................................................................................... 40

3
General information
1.1 - SYMBOLS USED IN THIS MANUAL
When reading this manual particular care has to be given to the parts marked with the followings symbols:
NOTE!
Suggestions for the user
WARNING!
Indicates a potentially dangerous situation
for the product and the environment
DANGER!
Indicates serious danger for your
personal safety and for your life
1.2 - A CORRECT USE OF THE APPLIANCE
The ALKON PLUS appliance has been designed utilizing today’s heating technology and in compliance with
the current safety regulations.
However, following an improper use, dangers could arise for the safety and life of the user or of other
people, or damage could be caused to the appliance or other objects.
The appliance is designed to be used in pumped hot water central heating systems and for the production
of domestic hot water.
Any other use of this appliance will be considered improper.
UNICAL declines any responsibility for any damages or injuries caused by an improper use; in this case the
risk is completely at the user’s responsibility.
In order to use the appliance according to the foreseen scopes it is necessary to carefully follow the
instructions indicated in this manual.
• The hardness of the mains water supply conditions the frequency with which the DHW heat exchanger is
cleaned.
• In hard water areas where the main water can exceed 15°f total hardness, a scale reducing device is
recommended. The choice of this device has to be made taking into consideration the water’s characteristics.
• In order to improve the resistance to lime scale it is recommended to adjust the domestic hot water tempera-
ture as near as possible to the one you really require.
• We recommend you to check the state of cleanliness of the domestic hot water heat exchanger at the end of
the first year and subsequently, on the basis of the lime scale found, this period can be extended to two years.
1.4 - INFORMATION TO BE HANDED OVER TO THE USER
1GENERAL INFORMATION
The user has to be instructed on the use and operation of his heating system, in particular:
• Hand over these instructions to the end user, together with any other literature regarding this appliance placed
inside the envelope contained in the packaging. The user has to keep these documents in a safe place in
order to always have them at hand for future reference.
• Inform the user on the importance of air vents and of the flue outlet system, stressing the fact that is absolutely
forbidden to make any alterations to the boiler.
• Inform the user how to check the system’s water pressure as well as informing him how to restore the correct
pressure.
• Explain the function of time and temperature controls, thermostats, heating controls and radiators, to ensure
the greatest possible fuel economy.
• Remind the user that, in order to comply to the standards in force, it is necessary to inspect and service the
boiler according to the current codes of practice and according to the schedule indicated in this manual by the
manufacturer.
• If the appliance is sold or transferred to another owner or if the present user moves home and leaves the
appliance installed, ensure yourself that the manual always follows the appliance so that it can be consulted
by the new owner and/or installer.
Failure to follow the instructions indicated in this guide, which is supplied with the boiler, could cause injury
to persons, animals or damage to property. The manufacturer shall not be held liable for any such injury and/
or damage.
1.3 - WATER TREATMENT

4
General information
1.5 - SAFETY WARNINGS
WARNING!
The installation, adjustment, and servicing of this appliance must be carried out by a competent person and
installed in accordance with the current standards and regulations. Failure to correctly install this applian-
ce could cause injury to persons, animals or damage to property. The manufacturer shall not be held liable
for any injury and/or damage.
DANGER!
Servicing or repairs of the appliance must be carried out by competent qualified service technicians;
UNICAL recommends drawing up a service contract. Bad or irregular servicing could compromise the
safe operation of the appliance, and could cause injury to persons, animals or damage to property for
which UNICAL shall not be held liable.
Alterations to parts connected to the appliance
Do not carry out any alterations to the following parts:
- the boiler
- to the gas, air, water supply pipes and electrical supply
- to the flue pipe, safety relief valve and its drainage pipe
- to the constructive components which influence the appliance’s safe operation
WARNING!
When tightening or loosening the screw pipe connections, use only adequate fork spanners.
The improper use and/or the use of inadequate equipment can cause damages (for example water or gas
leakages).
WARNING!
Indications for appliances operating with propane gas
Ensure yourself that before installing the appliance the gas tank has been purged.
For a correct purging of the tank contact the liquid gas supplier or a competent person who has been legally
authorized.
If the tank has not been purged correctly problems could occur during ignition.
If this occurs contact the liquid gas tank’s supplier.
Smell of gas
If you smell gas follow these safety indications:
- Do not turn on or off electrical switches
- Do not smoke
- Do not use the telephone
- Close the mains gas tap
- Open all windows and doors where the gas leakage has occurred
- Contact the gas society or a company specialized in installing and servicing heating systems
Explosive and easily inflammable substances
Do not use or leave explosive or easily inflammable material (as for example: petrol, paint, paper) in the room
where the appliance has been installed.

5
General information
LEGEND:
1 = YearofCEcertification issue
2=Boiler type
3=Boiler model
4=Number of stars (Directive 92/42/CEE)
5=(S.N°) Serial number
6=P.I.N. code
7=Approved fluing configurations
8=(N0x) N0x class
A = Central Heating circuit features
9=(Pn) Nominal output
10 = (Pcond) Condensing nominal output
11 = (Qmax) Nominal heat input
12 = (Adjusted Qn)Adjusted for nominal Heat input
13 = (PMS) Max. pressure C.H. system
14 = (T max) Max. C.H. temperature
B = Domestic Hot Water circuit features
15 = (Qnw) Nominal heat input in D.H.W. mode (if different from Qn)
16 = (D) Specific D.H.W. flow rate according to EN 625 - EN 13203-1
17 = (R factor) N° taps based on the quantity of water declared EN
13203-1
18 = (F factor) N°stars based on the quality of water declared
EN 13203-1
19 = (PMW) Max. pressure D.H.W. system
20 = (T max) Max. temperature D.H.W system
C = Electrical features
21 = Electrical power supply
22 = Consumption
23 = Protection grade
D = Countries of destination
24 = Direct and indirect country of destination
25 = Gasfamily
26 = Supply pressure
E = Factory setting
27 = Adjusted for gas type X
28 = Space for national brands
1.6 DATA BADGE
CEMarking
- TheCEmarkingdocumentsthattheboilerssatisfy:
- TheessentialrequirementsoftheDirectiveregardinggasappliances(Directive
90/396/CEE)
- TheessentialrequirementsoftheDirectiveregardingelectromagneticcompatibility
(Directive89/336/CEE)
- TheessentialrequirementsoftheEfficiencyDirective(Directive92/42/CEE)
- TheessentialrequirementsofthelowvoltageDirective(Directive73/23/CEE)
®
1
2
3
5
7 8
6
4
9
11
13
10
12
14
15
17
19
16
18
20
28
A
B
21 22
23
24 25 26
27
C D
E

6
General information
1.7 - GENERAL WARNINGS
This instruction manual is an integral and indispensable part
of the product and must be retained by the user.
Please read carefully the instructions contained in this ma-
nual as they provide important indications regarding the safe
installation, use and servicing of this appliance.
Keep this manual in a safe place for future reference.
The installation and servicing must be carried out in accor-
dance with the regulations in force according to the manufac-
turer’s instructions and by legally competent authorized per-
sons.
By a competent person, we imply a person who has a specific
technical qualification in the field of components for central
heating systems designed for domestic use, domestic hot water
production and servicing. The person must have the qualifica-
tions foreseen by the current laws in force.
Bad or irregular servicing could compromise the safe opera-
tion of the appliance, and could cause injury to persons, ani-
mals or damage to property. The manufacturer shall not be
held liable for any such injury and/or damage.
Before carrying out any cleaning or servicing switch off the
electrical supply to the boiler by means of the ON/OFF switch
and/or by means of the appropriate shutdown devices.
Do not obstruct the inlet/outlet terminals.
In the event of failure and/or faulty functioning of the applian-
ce, switch off the boiler. Do not attempt to make any repairs:
contact qualified technicians.
Any repairs must be carried out solely by Unical authorized
technicians and using only original spare parts. Non-obser-
vance of the above requirement may jeopardize the safety of
the appliance.
To guarantee the efficiency and correct functioning of the ap-
pliance it is indispensable to have the boiler serviced annual-
ly by a qualified person.
If the boiler remains unused for long periods, ensure that any
dangerous parts are rendered innocuous.
If the appliance is sold or transferred to another owner or if the
present user moves home and leaves the appliance instal-
led, ensure yourself that the manual always follows the ap-
pliance so that it can be consulted by the new owner and/or
installer.
Only original accessories must be used for all appliances
supplied with optional extras or kits (including electrical ones).
This appliance must be used only for the purposes for which
it has been expressively designed. Any other use shall be
considered incorrect and therefore dangerous

7
Technical features and dimensions
2.1 -TECHNICAL FEATURES
The ALKON 24/35 B 60 boilers are thermal gas fired units
with an atmospheric fully pre-mixed burner and electronic
ignition, for (*) HEATING AND D.H.W. PRODUCTION by 60
liter storage tank in stainless steel AISI 316 L.
ATTENTION: These boilers are fit to the production of water
for the human consumption.
These boilers have an output of 24 kW and are designed for
use on the 2nd family gas category II2H3P, and can therefore
operate with natural gas or LPG, in compliance to the regula-
tions indicated by UNICAL.
They are room sealed appliances, because the air neces-
sary for combustion is taken from outside the room in which
the appliance is installed.
The air inlet and combustion products outlet duct can be car-
ried out using concentric or twin pipe flue outlet systems.
These systems offer numerous advantages, amongst whi-
ch:
- The possibility of installation in rooms with reduced spa-
ce and with no ventilation required.
- A wide variety of fluing options available giving excellent
siting flexibility for all types of applications.
The ALKON 24/35 B 60 boilers are supplied complete with all
the safety and control devices in accordance with all the cur-
rent regulations. Their technical and functional features com-
ply with the regulations prescribed by the law No. 1083 dated
06/12/1971, concerning safety and use of combustible gas
and with the requirements prescribed in the law No. 10 dated
09/01/1991 and any subsequent amendments – Gas Direc-
tive 90/396 CEE – Efficiency Directive 92/42 CEE – Electro-
magnetic Compatibility Directive 89/336 CEE – Low Voltage
Directive 73/23 CEE.
Direttiva compatibilità elettromagnetica 89/336 CEE - Diretti-
va bassa tensione 73/23 CEE.
The boilers of the ALKON 24/35 B 60 range have obtained a
4 star category for efficiency, according to the Directive 92/42
CEE
DESCRIPTION OF COMPONENTSAND FEATURES
2TECHNICAL FEATURES AND
DIMENSIONS
• Aluminium heat exchanger/condenser;
• 60 litre inox storage tank
•Control and management microprocessor;
• CH expansion vessel
• CH low water safety pressure switch;
•Automatic air vent;
•Safety limit thermostat;
• Filling system cock;
• Automatic air vent valves;
• Flow temperature NTC sensor;
• Return temperature NTC sensor;
• Thermoidrometer
•Condensate drain siphon;
• Control panel with electrical protection IP X4D;
• By-pass on heating circuit
• Flame modulation in function of the absorbed power;
•CH temperature adjustment between 30°C – 85°C;
•DHW temperature adjustment between 35°C - 65°C
• Electronic frost protection mode
• Steel wall mounting template for system pipework con-
nections
• Outdoor NTC sensor (optional);
• Modulating roomstat (optional)

8
General information
VIEW FROM ABOVE
VIEW FROM BELOW
257
41
342
372
311
468
481
99
323
248
138
323
177
207
275
66,5
M
R
G
C
F
Rc
V
sb
393
453
Vsr
372
275
214
242 358
468
481
ALKON 35 B 60
ALKON 24 B 60
323
248
138
M
G
R
Rc
V
sb
CF
323
177
207
275
66,5
393
453
184
Vsr
2.2 - DIMENSIONS
G Gas inlet – ¾”
C DHW outlet – ½”
F Cold water inlet - ½”
M C.H system flow – ¾”
R C.H. system return – ¾”
Rc Filling system cock
Vsb Safety valve, storage tank 7 bar
Vsr Safety valve, heating circuit 3 bar
VIEW FROM ABOVE
VIEW FROM BELOW
855
884
600
855
884
600

9
Technical features and dimensions
1 Pump
2 Sifone
3 Gas valve
4 CH flow sensor
5 Combustion chambre
6 Flue outlet pipe
7 Automatic air vent
8 Storage tank
9 Expansion vessel
10 Filling system cock
1 Pump
2 Gas Valve
3 CH low water safety pressure switch
4 CH flow sensor
5 Combustion chambre/Fan
6 Flue outlet pipe
7 Automatic air vent
8 Storage tank
9 Expansion vessel
10 Filling system cock
ALKON 35 B 60
ALKON 24 B 60
1
2
3
4
5
6
7
8
9
10
1
2
8
9
10
7
6
5
4
3
2.3 - MAIN COMPONENTS

10
General information
2.4 - BOILER WATER CIRCUITS
1 By-pass
2 Heating Expansion Vessel
3 Diverter valve
4 Pump
5Air vent valve
6 Return temperature sensor
7 Aluminium heat exchanger/condenser
8 Ignition and flame detection electrode
9 Fan
10 Premix
11 High limit thermostat
12 Safety thermostat
13 Inox storage tank
14 Expansion Vessel DHW
15 Flow restrictor
16 Storage tank safety valve
17 Filling system cocK
18 Gas valve
R
4
2
1
3
6
10
9
8
7
11 12
13 14
16
17
15
5
18
GAS
M C F

11
Technical features and dimensions
l/min
bar
bar
l
°C
°C
l
bar
l
bar
bar
l
l/min.
l/min.
l/min.
l/min.
l/min.
l/min.
l/min.
l
°C
V-Hz
A (F)
W
IP
kg
24 B 60
II2H3P
2,90
0,5
3
2,4
80
30
7,5
1
139,3
0,5
6,0
60
15,52
12
6,92
7,78
8,89
10,37
12,45
132,69
35-65
230/50
4
152
X4D
64
ALKON 35 B 60
II2H3P
3,58
0,5
3
3
80
30
7,5
1
172,4
0,5
6,0
60
19,3
15
9,84
11,07
12,65
14,76
17,71
165,43
35-65
230/50
4
163
X4D
67
2.5 -PERFORMANCE DATA ACCORDING TO STANDARD UNI 10348
Forinformationregardingtheadjustmentof:INJECTORS-BURNERPRESSURES–DIAPHRAGMS–OUTPUTS–GASCONSUMPTIONSpleaserefertotheparagraphBURNERADJUSTMENT.
Nominal heat output
Minimal heat output
Nominal output 80/60
Minimum output 80/60
Efficiency at full load 80/60
Efficiency at min load 80/60
Number of stars (according to CEE 92/42)
Nominal output IN CONDENSING MODE 50/30
Minimum output IN CONDENSING MODE 50/30
Efficiency at full load IN COND. MODE
Efficiency at min load IN CONDENSING MODE
Combustion efficiency at full load (100%)
Combustion efficiency at reduced load
Stand-by losses (max)
Flue losses with burner off
(*) Flue gas temperature tf-ta (max)
Flue gas mass flow rate (max)
Air excess l
Condensate production max
(**) CO2 (min.-max)
COat0% of O2 (min - max)
N0x (value according to EN ....A3)
N0x class
Flue losses with burner in operation (max)
Appliance’s family gas category
Min. water flow rate in CH circuit (Dt 35°C)
Min. pressure in CH circuit
Max. pressure in CH circuit
Water content in primary circuit
Max operating temp. in CH mode
Min operating temp. in CH mode
Total volume CH expansion vessel
Total pre-loading expansion vessel
Max water content CH circuit (calculated for a max temp. of 90°C)
Min. DHW inlet pressure
Max DHW inlet pressure
Storage tank capacity
DHW specific flow rate (Dt 30°C)
DHW flow restrictor
DHW production in continuous operation with Dt 45 K
DHW production in continuous operation with Dt 40 K
DHW production in continuous operation with Dt 35 K
DHW production in continuous operation with Dt 30 K
DHW production in continuous operation with Dt 25 K
DHW available at a temp. of 45°C in the first 10 mins of draw-off
with storage tank water at 60°C and cold water at 10°C (*)
DHW adjustable temperature
Electrical supply /power consumption
Fuse rating
Maximum absorbed power
Electrical protection
Net weight
(*) mixed water
2.6 - GENERAL FEATURES
Technical data registered with the appliance operating with natural gas (G20)
kW
kW
kW
kW
%
%
n.
kW
kW
%
%
%
%
%
%
%
g/s
%
kg/h
%
mg/kWh
mg/kWh
%
mg/kWh
ALKON 24 B 60
23,8
4,3
22,8
4,0
95,85
101,02
4
24,1
4,62
101,10
106,01
97,02
98,19
0,63
0,47
61,6
10,43
20,57
4,04
-
26,72 - 146,94
57,62
5
2,79
35 B 60
34,5
5,5
33,2
5,0
96,31
93,89
4
34,6
5,79
100,42
105,24
97,19
98,34
0,75
0,44
56,2
15,68
25,53
5,55
-
21,15 - 118,53
34,83
5
2,93
(*) Room Temperature = 20°C
(**) See table ‘’INJECTOR- PRESSURES’’

12
Instructions for the installer
3INSTRUCTIONS FOR THE
INSTALLER
WARNING!
This boiler has to be destined for the use for
which it has been expressively designed for.
Any other use shall be considered improper
and therefore dangerous.
This boiler is designed to heat water at a tem-
perature inferior to boiling point at an atmo-
spheric pressure.
WARNING!
These appliances are exclusively designed
to be installed inside adequate sitings.
Therefore these appliances must not be in-
stalled and operated outdoors. An outdoor
installation could cause malfunctioning and
could be dangerous. For external installa-
tions, it is recommended to use appliances
which are specifically designed and predi-
sposed for this purpose.
Before installing the boiler the following points
have to be carried out by a competent engine-
er:
a) The whole system should be thoroughly flu-
shed in order to remove any residual dirt or
grime which could compromise correct boi-
ler operation.
b) Check that the boiler has been preset for
operating with the gas type available.
This is verifiable via the indication on the
packaging and on the data badge;
c) Check that the chimney/flue pipe has an
adequate draught, does not have any con-
strictions, and that no other appliance’s flue
outlets have been fitted, unless the chim-
ney is serving more than one heating ap-
pliance, according to the specific standar-
ds and regulations in force. The connec-
tion between the boiler and chimney/flue
outlet can be made only after this verifica-
tion has been carried out.
WARNING!
In rooms where aggressive vapours or dust
is present the appliance must operate inde-
pendently from the air present in the boiler’s
location room!
WARNING!
The appliance must be installed by a quali-
fied engineer, who complies to the techni-
cal-professional requirements according to
the law 46/90 and whom, under his own re-
sponsibility, guarantees the compliance of
the standards according to the latest regu-
lations.
WARNING!
Theappliance must be installed only on a ver-
tical flat wall, made of non combustible ma-
terial.
The appliance must be positioned so that at
least the minimum operational and servicing
clearances are provided.
NOTE:
The boiler must be connected to a heating sy-
stem which is compatible to its performance
and output.
3.1 - GENERAL WARNINGS

13
Instructions for the installer
PACKAGING DIMENSIONS A B C
ALKON 24/35 B 60 675 989 575
C
A
B
3.3 - PACKAGING
The ALKON range of boilers are supplied fully assembled in a
strong cardboard box.
After having unpacked the boiler check that it
is intact and undamaged.
Keep the packaging material (cardboard box,
plastic bags, polyester protection etc.) out of
the reach of children as they can be dange-
rous.
UNICAL refuses all liability for injury to persons,
animals or damage to property deriving from
not having respected the above mentioned re-
commendations.
In the packaging, in addition to the boiler, you can also find
the following contents:
- Service logbook
- User’s instruction guide
- This installation and servicing manual
- Warranty
- Nr. 2 spare parts request coupons
- Nr. 2 wall plugs for fixing the boiler to the wall
- Pipe kit
- Wall mounting template
- Condensate drain siphon
3.2 - STANDARD CODES FOR INSTALLA-
TION
The appliance must be installed in compliance to the instruc-
tions contained in this manual.
The installation must be carried out by a competent qualified
engineer, whom will assume the responsibility of complying
to all the local and/or national regulations published in the
official publications, as well as all the applicable codes of
practice.
Before installing the appliance please contact the gas supply
company.
The installation must be carried in accordance to the codes of
practice, the regulations and the requirements hereby indica-
ted, which constitute an indicative list, but not a complete one,
as these continue to undergo developments.
National installation regulations:
Gas plants for domestic use fed by network distribution
Standard UNI-CIG 7129
Gas plants for domestic use not fed by network distribution
Standard UNI-CIG 7131
Law dated 5.03.90 n°46
D.P.R. 447/91
D.M. n° 37 del 22/01/2008
Legge del 9.01.91 n°10
D.P.R. 412/93
Other applicable statutory requirements:
Law 1083/71 (ref. Standard UNI for the design, installation
and maintenance).
D.M 1.12.1975
D.M. 174 - 6 Aprile 2004
UNI 11071: Gas fired heating boilers - Specific
requirements for condensing boilers
Moreover, the boiler must be installed in accordance to all the
regulations regarding the boiler room, and comply to the bu-
ilding regulations and the prescriptions regarding central he-
ating plants in force in the country the boiler is installed.
The appliance must be installed, commissioned and serviced
according to the regulations in force. This is also valid for the
hydraulic system, the flue outlet system and the boiler loca-
tion room.

14
Instructions for the installer
ALKON 24/35 B 60 WALL MOUNTING TEMPLATE
3.4 - BOILER LOCATION
When selecting the position for the installation of the boiler
please comply to the following safety requirements:
- Fit the appliance in rooms protected from frost;
- In rooms where aggressive vapours or dust are present,
the appliance must be able to operate independently from
the air of the location room;
- Do not use or leave explosive or easily inflammable mate-
rial (as for example: petrol, paint, paper) in the room whe-
re the appliance has been installed.
- The appliance must be installed exclusively on a vertical
and solid wall, capable of adequately supporting the wei-
ght of the boiler;
- The wall must not be made of inflammable material;
- Leave a clearance of 100 mm on each side of the boiler to
facilitate subsequent servicing;
Every appliance is supplied with a steel “Wall mounting tem-
plate” which, once fixed on to the wall chosen for the installa-
tion by means of the screw anchors supplied together with the
boiler, permits:
- Supporting the boiler;
- Marking the exact point for positioning the system pipework
connections:
• Gas supply
• Cold water feed
• Hot water outlet
• CH flow
• CH return
M= CH system flow ¾”
C= Hot water outlet ½”
G= Gas supply ¾”
F= Cold water supply ½”
156
S-C
237
S-R
ALKON 24 B 60 ALKON 35 B 60
R= CH system return ¾”
S-C = Condensate drain outlet Ø 32
S-R = CH safety relief valve drainage point
CM
199 190
90
FRG
600
140,568 68 117 59 147,5
290
50
780
884
65
58
120120
CM
199 190
90
FRG
600
140,5
68 68 117 59 147,5
290
50
780
884
65
43
120120

15
Instructions for the installer
Note:
The appliances are equipped with expan-
sion vessels. Before installing the applian-
ce check that the vessel’s capacity is suf-
ficient;ifthis is notthecase, provisionmust
be made to fit an additional expansion
vessel.
3.5 - BOILER INSTALLATION
Before connecting the boiler to the heating system the fol-
lowing requirements must be carried out by competent and
qualified engineers:
a) The system is flushed out with a suitable product in order
to eliminate any metallic tooling or welding residues and
oil and grime which could reach the boiler and affect the
proper running of the boiler;
b) Check that the boiler has been preset for operating with
the gas type available.
This is verifiable via the indication on the packaging and
on the data badge;
c) Check that the chimney/flue pipe has an adequate drau-
ght, does not have any constrictions, and that no other
appliance’s flue outlets have been fitted, unless the chim-
ney is serving more than one heating appliance, accor-
ding to the specific standards and regulations in force.
The connection between the boiler and chimney/flue out-
let can be made only after this verification has been car-
ried out.
As a safety measure against gas leaks, Unical
recommends installing a surveillance and pro-
tective system composed of a gas leakage
detector combined with an on-off selenoid
valve fitted on the gas supply line.
The gas supply pipe must have a section which is identical or
greater then the one used on the boiler and must assure a
correct gas pressure.
It is however important to comply with the “General installa-
tion standards” indicated in the standards UNI 7129, UNI 7131
and UNI 1137-1.
Before commissioning an internal gas distribution system and
therefore before connecting it to the gas meter, the complete
installation must be tested for gas soundness.
If any part of the system is concealed from view the gas soun-
dness test must be carried out before covering the pipes.
Before connecting the pipework the system must be tested
with air or inert gas at a pressure of at least 100mbar.
Before commissioning the boiler ensure that the following
operations are carried out:
- Open the gas meter cock and vent the air contained in the
piping and subsequently proceed to vent device by devi-
ce.
- Check, with the gas cock turned off, that there are no gas
leaks. During the 2nd quarter of the hour from the start of
the test, no pressure drop should be detected by the pres-
sure gauge. Any gas leaks must be found by using only
water soap solutions, or an equivalent product, and elimi-
nated.
Never look for gas leaks using a naked flame.
For fitting the boiler:
- Place the steel mounting template on to the wall.
- Determine the position of the holes for fixing the support
bracket.
- Drill the holes and fix the support bracket using the screw
anchors supplied with the boiler.
- Engage the boiler on to the support bracket.
- Mark the positions of the gas, cold water supply, hot water
outlet, CH flow and return, pressure relief valve and/or
condensate drain.
DANGER!
The gas connection must be carried out only
by a qualified engineer who will have to res-
pect and comply to the regulations in force
and to the requirements indicated by the lo-
cal gas supplier. An incorrect installation
could cause injury to persons, animals or
damage to property. The manufacturer shall
not be held liable for any injury and/or dama-
ge.
Before installing the boiler it is recommen-
ded to thoroughly clean all the fuel feed pi-
pework in order to remove any eventual resi-
dual grime which could compromise the boi-
lers correct functioning.
If you smell gas:
a) Do not turn on or off electrical switches,
use the telephone or any other object
which can provoke sparks;
b) Open all doors and windows in order to
allow fresh air to enter and purify the
room;
c) Close all gas cocks
d) Contact a service engineer, qualified in-
staller or the gas supply company.
3.6 - GAS CONNECTION

16
Instructions for the installer
0
1
2
3
4
5
6
0,2
1,2
2,2
3,2
4,2
5,2
6,2
0,4
1,4
2,4
3,4
4,4
5,4
0,6
1,6
2,6
3,6
4,6
5,6
0,8
1,8
2,8
3,8
4,8
5,8
0 50 100 150 200 250 300 350 400 450 500 550 600 650 700 800 850 900 950 1000 1050 1100 1150 1200 1250 1300 1350 1400 1450 1500
By-pass Open
By-pass Closed
D
e
liv
e
ry h
e
a
d
H
(m)
Flow rate Q (l/h)
GRAPH:FLOWRATE/AVAILABLEHEAD (ALKON 35 B60)
100 200 300 400 500 600 700 800 900 1000 1100 1200 1300 1400 1500
0
1
2
3
4
5
6
0,2
1,2
2,2
3,2
4,2
5,2
0,4
1,4
2,4
3,4
4,4
5,4
0,6
1,6
2,6
3,6
4,6
5,6
0,8
1,8
2,8
3,8
4,8
5,8
01600 1700
By-pass Open
By-pass Closed
Delivery he
a
d
H
(m)
Flow rate Q (l/h)
GRAPH:FLOWRATE/AVAILABLE HEAD(ALKON24B60)
When determining the size of the CH circuit pipes it is essen-
tial to bear in mind the pressure losses induced by the radia-
tors, any eventual thermostatic radiator valves, lockshield
valves and by the system’s layout.
The routing of the piping has to be laid down taking all the
necessary precautions in order to avoid air locks and to faci-
litate the continuous purging of the system.
Ensure yourself that the system’s piping is
not used as earth clamps for the electrical
ortelephonicsystem. They are absolutely un-
suitable for this use. In a short time this could
cause serious damage to the piping, boiler
and radiators.
Pressure relief valve drain pipe
In correspondence to the heating pressure relief valve, provi-
sion should be made to install a discharge pipe with a funnel
and a siphon which lead to an adequate drainage. The drai-
nage has to be controllable by sight.
WARNING!
If this precaution is not taken it could lead to
injury to persons, animals or damage to pro-
perty. The manufacturer shall not be held lia-
ble for any such injury and/or damage
3.7 - CENTRAL HEATING CONNECTIONS
WARNING!
Before installing the boiler we recommend
that the system is flushed out with a suitable
product in order to eliminate any metallic to-
oling or welding residues, oil and grime whi-
ch could reach the boiler and affect the pro-
per running of the boiler.
Do not use any solvents for flushing out the
system as they could damage the system
and/or its components.
Non-observance of these instructions could
cause injury to persons, animals or damage
to property. The manufacturer shall not be
held liable for any such injury and/or dama-
ge.
The CH flow and return circuits have to be connected to the
boiler via the respective connections ¾” M and R as indica-
ted on page 16

17
Instructions for the installer
DUA 24 B 60 DOMESTIC HOT WATER PRODUCTION
65
60
55
50
45
40
35
30
060 120 180 240 300 360 420 480 540 6000
TEMPE
R
AT U
R
E (°C)
TIME (sec)
DUA 35 B 60DOMESTIC HOT WATER PRODUCTION
DRAW-OFF
12 l/min
The routing of the piping has to be laid down taking all the
necessary precautions in order to avoid air locks and to faci-
litate the continuous purging of the system.
Ensure yourself that the system’s piping is not used as
earth clamps for the electrical or telephonic system. They
are absolutely unsuitable for this use. In a short time this
could cause serious damage to the piping, boiler and ra-
diators.
Pressure relief valve drain pipe
In correspondence to the heating pressure re-
lief valve, provision should be made to install
a discharge pipe with a funnel and a siphon
which lead to an adequate drainage. The drai-
nage has to be controllable by sight.
WARNING!
If this precaution is not taken it could lead to
injury to persons, animals or damage to pro-
perty. The manufacturer shall not be held lia-
ble for any such injury and/or damage
3.8 - CENTRAL HEATING CONNECTIONS
WARNING!
Before installing the boiler we recommend
that the system is flushed out with a suitable
product in order to eliminate any metallic to-
oling or welding residues, oil and grime whi-
ch could reach the boiler and affect the pro-
per running of the boiler.
Do not use any solvents for flushing out the
system as they could damage the system
and/or its components.
Non-observance of these instructions could
cause injury to persons, animals or damage
to property. The manufacturer shall not be
held liable for any such injury and/or dama-
ge.
The CH flow and return circuits have to be connected to the
boiler via the respective connections ¾” M and R as indica-
ted on page 16
When determining the size of the CH circuit pipes it is essen-
tial to bear in mind the pressure losses induced by the radia-
tors, any eventual thermostatic radiator valves, lockshield
valves and by the system’s layout.
COLD WATER INLET 9°C
COLD WATER INLET 9°C
65
60
55
50
45
40
35
30
0
70
60 120 180 240 300 360 420 480 540 6000
TEMPE
R
A
TU
R
E (°
C
)
TIME (sec)
75
80
DRAW-OFF
15 l/min

18
Instructions for the installer
3.9 - CONDENSATE DRAIN
During the combustion process the boiler produces condensa-
te which, through the “A” pipe, flows into the siphon.
The condensate which forms inside the boiler has to be routed
into an adequate drain by means of the pipe “B”.
DANGER!
Before commissioning the appliance fill the
siphon and check the correct drainage of the
condensate.
If the appliance is used with the condensate
drain siphon empty there could be danger of
intoxication resulting from the escape of flue
gasses.
The connection between the appliance and the
sewage system must be carried out in com-
pliance with the specific reference standards, and in particular:
- prevent the end user utilizing the condensate produced;
- a siphon must be fitted (supplied with the boiler)
- there must be no bottlenecks;
- it must be installed so as to avoid freezing of the liquid
when the boiler is operating and prevent the eventual pres-
surization of the sewage system;
- consent the correct downflow of the appliance’s liquid di-
scharges;
- it must be made with one of the following materials which
are resistant to condensate:
• Grès, according to the Standards DIN 1230-1 and 6, EN
295-1 or 2 or 3
• Glass (boron silicate)
• Polyvinyl chloride (PVC) , according to DIN V 19534-1
and 2, and DIN 19538
• Polyethylene (PE) DH type, according to DIN 19535-1
and 2 and DIN 19537-1 and 2
• Polypropylene (PP) and copolymer styrene (ABS) ac-
cording to DIN V 19561
• Polyesterific resin (GF-UP), according to DIN 19565-1
• Stainless steel
Condensate outlet, pipe to
connect to the sewage
system
Make the plastic pipe living
in the rear side of the boiler
"S-C" ref. page 14.
A
B
B
A
ALKON 35 B 60ALKON 24 B 60
Condensate inlet
coming from the
flue outlet
Condensate inlet
coming from the
boiler
Condensate inlet
coming from the
boiler

19
Instructions for the installer
3.10- FLUE OUTLET INSTALLATION
The flue system must be installed in accordance with the local
and national Standards (refer to Standard UNI-CIG 7129, point
4 and UNI-CIG point 5)
WerecommendusingonlyoriginalUNICALflue
outlet systems.
Damages caused by installation errors and for
non-observance of the instructions given by
the same manufacturer will invalidate all the
supplier’s contractual or extra contractual re-
sponsibilities.
If the boiler has to be replaced ALWAYS replace the flue
outlet system.
The boiler has been approved for the following flue configu-
rations:
Type C13
Boiler designed for connection to horizontal inlet and outlet
terminals, which admit fresh air to the burner and discharge
the products of combustion to the outside through concentric
or twin ducts.
The minimum distance between the inlet air duct and the flue
outlet duct must be of 250 mm and both terminals must be
positioned within a 500 mm square section.
aa
aa
aa
aa
aa
aa
aa
aa
aa
aa
aa
aa
aa
aa
aa
aa
aa
aa
aa
aa
Type C33
Boiler designed for connection to vertical inlet and outlet ter-
minals, which admit fresh air to the burner and discharge the
products of combustion to the outside through concentric or
twin ducts.
The minimum distance between the air inlet duct and the flue
gas outlet duct must be of 250 mm and moreover both termi-
nals must be positioned within a 500 mm square area.
Type C43
Boiler designed for connection to collective flue systems in-
cluding two ducts, one for the air inlet and the other for the
discharge of products of combustion through concentric or
twin ducts.
Type C53
Boiler with separate air inlet and products outlet. These ducts
can discharge into areas with different pressure.
The two terminals must not be fitted on to two opposite
walls.
Type C83
Boiler designed for connection to a terminal for the intake of
combustion air and to an individual or collective chimney for
the discharge of the products of combustion.
The chimney must comply to the current regulations.
Type B23
Boiler designed to be connected to an open flue which will
terminate vertically through the roof. The combustion air is
withdrawn directly from the room where the boiler is installed.
WARNING: for this type of connection the room must comply
with the same installation regulations valid for open chimney
boilers.
The chimney must comply to the current regulations.
Type C63
Boiler designed for connection to a combustion air inlet and
flue products discharge system approved and sold separa-
tely.

20
Instructions for the installer
Type C13
The minimum allowable length of the horizontal concentric
pipes is of 0,75 metres.
The maximum allowable length of the horizontal concentric
pipes is of 3,5 metres. For each elbow added the maximum
length permitted has to be reduced by 1 metre.
pendenza 3%
SMOKES EVACUATION DUCTS Ø 80 MM, WITH AIR SUCTION IN THE INSTALLATION ROOM -
INSTALLATION TYPE B23
The maximum length of the evacuation ducts is of 30
meters.
For this type of installation the chimney has
tobe independent and serve just thisboiler.
FLUE OUTLETS WITH CONCENTRIC DUCTS Ø 60/100 mm
Important: the outlet/inlet flue has to
have a minimum inclination of 3%
towards the top in the outlet direction,
so as to enable the collection of any
condensate formed in the boiler.
Tipo C33
The maximum allowable length of the vertical concentric pi-
pes is of 5 metres flue terminal included (Ø 80/125); for each
elbow added the maximum length permitted has to be redu-
ced by 1 metre.
KIT5800C
KIT5810C
KIT5800C
KIT5740C
00360674
KIT5820C
00361334
372
SmokeAccessories Ø 80 mm for type B23
- 00361435Kit DUCTSPLITTER+
- 00361446AIR SUCTINGNOZZLE
Ø80with grate
257 (24 kW)
242 (35 kW)