Italtherm CITY CLASS 24 C manual 

CITY CLASS
use
installation
adjustment
maintenance
Handbook
instruction
ENG
24 C
28 C
Green Heating Technology

Green Heating Technology
2
Table of Content
 
Safety warnings symbols legend � � � � � � � � � � � � 4
References to Laws and Norms � � � � � � � � � � � � � 4
Personnel in charge of installaon � � � � � � � � � � � � � 4
Installaon, use and maintenance � � � � � � � � � � � � � 4
User warnings � � � � � � � � � � � � � � � � � � � � � � � � � � � 5
Important � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � 5
First starng up and Use � � � � � � � � � � � � � � � � � � � � � 5
Installaon, rst starng up, maintenance and
servicing � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � 6
Appliance booklet or central plant booklet � � � � � � 6
Combuson checking � � � � � � � � � � � � � � � � � � � � � � � � 6
Boiler operaon and servicing � � � � � � � � � � � � � � � � � 6
 
The front control panel � � � � � � � � � � � � � � � � � � � � 7
Commands on the lower side � � � � � � � � � � � � � � 8
Commands outside the boiler � � � � � � � � � � � � � � 8
Typical use � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � 9
Preliminary operaons � � � � � � � � � � � � � � � � � � � � � � � 9
Boiler acvaon � � � � � � � � � � � � � � � � � � � � � � � � � � � � 9
Temperature adjustment � � � � � � � � � � � � � � � � � � � � � 9
Incidental malfunconing � � � � � � � � � � � � � � � � 10
The burner doesn’t turn on � � � � � � � � � � � � � � � � � � 10
Shortage of domesc hot water producon � � � � 10
Boiler inacvity � � � � � � � � � � � � � � � � � � � � � � � � � 11
Safety shut o � � � � � � � � � � � � � � � � � � � � � � � � � � � � � 11
Stand-by mode with an-frost & an-locking
funcon � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � 11
“Ambient An-Frost” Funcon � � � � � � � � � � � � � � � 12
 
Law and regulaon prescripons for the
installer � � � � � � � � � � � � � � � � � � � � � � � � � � � � � 12
Dimensions and connecons � � � � � � � � � � � � � � 13
Pump capacity diagram � � � � � � � � � � � � � � � � � � 13
Warnings for the installaon of oponal kits
or special systems � � � � � � � � � � � � � � � � � � � � � 14
Floor heang system � � � � � � � � � � � � � � � � � � � � � � � 14
Specicaons for intake air � � � � � � � � � � � � � � � 14
Domesc water supply characteriscs � � � � � � 15
Protecon against freezing � � � � � � � � � � � � � � � 15
Posioning and fastening � � � � � � � � � � � � � � � � � 16
Hydraulic system (DHW and heang) � � � � � � � 17
Advices and suggesons to avoid vibraons and
noises in the system � � � � � � � � � � � � � � � � � � � � � � 17
Cleaning and preservaon of the systems � � � � � � 17
Heang system � � � � � � � � � � � � � � � � � � � � � � � � � � � � 17
Heang system lling and pressuring � � � � � � � 18
Gas connecon � � � � � � � � � � � � � � � � � � � � � � � � � 18
Electrical connecons � � � � � � � � � � � � � � � � � � � � 19
Chimney connecons � � � � � � � � � � � � � � � � � � � � 20
 
First starng up � � � � � � � � � � � � � � � � � � � � � � � � � 21
Access to the inside of the boiler � � � � � � � � � � 22
Inlet gas check � � � � � � � � � � � � � � � � � � � � � � � � � � 22
Max and Min pressure adjustment � � � � � � � � � 23
PCB parameters sengs (technician menu) � � 24
Main boiler parameters (PC) � � � � � � � � � � � � � � � � � 24
Combuson test � � � � � � � � � � � � � � � � � � � � � � � � 26
So ignion � � � � � � � � � � � � � � � � � � � � � � � � � � � � 26
Accessing the main board � � � � � � � � � � � � � � � � 27
Gas conversion � � � � � � � � � � � � � � � � � � � � � � � � � 27
Draining the heang system � � � � � � � � � � � � � � 28
Pump sengs � � � � � � � � � � � � � � � � � � � � � � � � � � 28
Alarms - boiler block � � � � � � � � � � � � � � � � � � � � � 28
Warnings for servicing � � � � � � � � � � � � � � � � � � � 32
Technical data � � � � � � � � � � � � � � � � � � � � � � � � � � 33
Boiler internal components � � � � � � � � � � � � � � � 35
Electrical diagram � � � � � � � � � � � � � � � � � � � � � � � 36
Hydraulic diagram � � � � � � � � � � � � � � � � � � � � � � � 37
 
Outdoor Sensor Kit � � � � � � � � � � � � � � � � � � � � � � 38
Installaon and seng � � � � � � � � � � � � � � � � � � � � � � 38
Outdoor Sensor kit and Remote Control � � � � � � � 38
Remote Control Kit � � � � � � � � � � � � � � � � � � � � � � 39

Green Heating Technology 
Safety warnings
This instrucons manual is an essenal and complementary part of the product and it is supplied to-
gether with the boiler�
Carefully read the manual, achieving all important informaon for a safe installaon, use and
servicing�
fCarefully keep the manual, together with the documentaon of all the accessories of the boiler and
of the system, for any further consultaon you may need.
f must be carried out by a qualied technician, in accordance with manufacturer in-
strucons and with the relevant requirements of the current issue.
fCarbon monoxide (CO) danger: the CO is a no-smelling and no-colour gas. When a forced draught
boiler with air intake from the room (appliance type B2) is installed, permanent venlaon of the
installaon room is mandatory and extremely important. Venlaon must be made and sized in
compliance with Laws and Rules in force. Whatever manumission, closing or neutralizaon of the
permanent venlaon could lead to very serious consequences to people in the rooms, as intoxica-
on by CO, permanent damage and death. Besides, the CO and O2mix can be explosive�
fA  is a person with a specic technical competence in the eld of the heang
appliances for domesc use and domesc hot water producon, in compliance with Laws and Rules
in force�
fThe  are only and exclusively the ones contained in the "USER GUIDE"
secon.
fThe manufacturer has no contractual and extra-contractual responsibility for any damage arising
from wrong installaon, wrong use and non-observance of current laws and instrucons given by
the manufacturer himself.
fImportant: this gas boiler is used to heat the water at a temperature lower than the boiling one, at
atmospheric pressure; it must be connected to an heang system and/or to a domesc hot water
system, in accordance with its features and power.
fPacking items (cartons, nails, plasc bags and so on) , as
they are potenally dangerous.
f, disconnect the boiler from the mains electrical supply by
means of the main electrical switch and stop the gas supply by means of the suitable cock.
fIn case of fault and/or bad operaon of the appliance, disconnect it immediately and do not try to
repair it by yourselves.
fBoiler servicing and repair must be carried out exclusively by qualied technicians, which will use
original spare parts. Strictly observe the above requirement, avoiding any risk of compromising the
appliance safety�
f, remove or cut o any potenal dangerous item.
fWhen transferring the appliance (e.g. leaving it installed aer a removal or a sale of the building),
make always sure that the instrucons manual is close to the boiler for the future use of new owners
and/or installers.
fThis appliance . Any other ulizaon must
be considered dangerous and incorrect.
fIt is strictly forbidden to use the appliance  than the specied ones.
fThis appliance must be installed exclusively to wall�

Green Heating Technology
4
Safety warnings symbols legend
Generic safety
warning
Electrical danger
(fulguraon)
Physical danger
(personal damage)
Thermal danger
(burns)
General warning or advice to avoid material damage
or to achieve improvements
References to Laws and Norms
All references to laws and laws contained in this handbook, as well as all installaon, maintenance and
use prescripons and the relevant pictures, are relevant to European and/or Italian regulaon.
-

All the   menoned in this handbook are indicave as
laws and norms are subject to issues and integraons by the authories in charge. Also comply
to eventual local norms and laws (not menoned in this handbook) in force in the territory
where the installaon takes place.
Personnel in charge of installaon
            

Always proceed with cauon when handling the boiler and carrying out installaon/mainte-
nance work as metal parts may cause injuries such as cuts and abrasions. Wear personal protec-
 (especially gloves) while doing the above menoned operaons
Installaon, use and maintenance


Green Heating Technology 5
User warnings
Important
In case of gas smell:
              
sparks;
2 - open immediately the windows and the doors in order to cleanse the room air;
close the gas supply taps;
4 - 
    of the gas boiler room, in order to avoid possible
dangerous situaons as the creaon of poisonous or explosive mixtures.
First starng up and Use
The rst starng up and the maintenance of the boiler must be performed by a professionally
qualied sta (for example the installer or the Service Centres authorized by ITALTHERM)
The laer will check that:
fthe label technical data of the gas boiler correspond to those of the gas available;
fthe main burner regulaon is compable with the gas boiler output;
fthe chimney works correctly, expelling the combuson products;
fthe air supply and the combuson products evacuaon work correctly, in accordance with the re-
quirements in force;
fthe condions for a correct venlaon are guaranteed, also when the gas boiler is located inside a
closed space (with suitable caracteriscs).

�
The User must not touch sealed items nor break the seals. Only specialized technicians and the
ocial technical service can break the seals of sealed items.
The boiler is ed with safety devices that block operaon the case of problems with the boiler
or related systems. These devices must never be disabled: if a device intervenes frequently,
have a qualied technician located the cause, even in systems to which the boiler is connected,
and in the Flue Products Outlet System that must be ecient and made according to the laws
in force (see examples in paragraph "Chimney connecons" on page 20). Besides, the air sup-
ply and room venlaon system must be ecient and made according to the laws in force. If a
boiler component has failed, you must only use original replacement parts
When the boiler is o for a long period see the Paragraph "Boiler inacvity" on page 11 for
the necessary precauons about the electrical supply, the gas supply and the protecon against
freezing.
Do not touch the heated surfaces of the boiler, as the doors, the ue, the chimney pipe, etc.,
also aer the boiler operaon because, for a certain me, these surfaces are overheated. Any
 It is then forbidden to let children or inexperi-
enced people be close to the boiler, during its operaon.
fDo not expose the wall hung gas boiler to water or other liquids sprinklings, or to vapours directly
coming from gas cookers/hobs.

Green Heating Technology
6
fDo not obstruct the air intake or ue outlet terminals, even momentarily or parally.
fDo not put any object on the gas boiler and don't leave any ammable liquid or solid materials, (e.g.
paper, clothes, plasc, polystyrene) in its proximity.
fThis appliance is not intended for use by persons (including children) with reduced physical, sensory
or mental capabilies, or lack of experience and knowledge, unless they have been given supervi-
sion or instrucon concerning use of the appliance by a person responsible for their safety. Children
should be supervised to ensure that they do not play with the appliance.
fIf the gas boiler is going to be denively unused, call a qualied technician to carry out all required
operaons, checking in parcular disconnecon of gas, water and electrical supplies.
f (type B appliances installed in-
door): the installaon of aspirators, replaces or similar appliances in the room where the type B ap-
pliance is installed (and in adjacent rooms in case of indirect venlaon) is prohibited except in cases
foreseen by rules in force and anyway the installaon must be made in compliance with all specic
safety measures menoned in the rules and laws in force, even in case of modicaons or addions.
Installaon, rst starng up, maintenance and servicing
All operaons for installaon, rst starng up, maintenance, servicing and gas conversion must be car-
, in accordance with the Norms and Laws in force.
Maintenance operaons must be carried out in compliance with the manufacturer prescripons, and in
compliance with the laws and rules presently in force for what is not menoned in this handbook; we
advice to perform them at least once a year to maintain the boiler’s performance.
Appliance booklet or central plant booklet
All appliances must have an appliance booklet (for outputs less or equal 35 kW) or a central plant book-
let (for outputs more than 35 kW). All maintenance and servicing operaons and combuson checks
must be wrien on the booklet, together with the name of the person responsible for servicing.
Combuson checking
Combuson checking consists of a control of the boiler eciency. Boilers that, aer the checking, will
have eciency rates lower than the ones required and not changeable with suitable adjustments (that
must be performed by qualied technicians), must be replaced.
Boiler operaon and servicing
The user (owner or tenant of the at where the boiler is installed) or the administrator of the block of
ats (in case of a central heang system) are responsible for the appliance operaon and servicing; they
can both transfer the responsibility of the servicing and eventually of the operaon to another person,
which must be a qualied technician as indicated by the Laws. Even if the user or the administrator de-
cide to assume personally this responsibility, ordinary servicing of the warm air heater and combuson
checks must be anyway carried out by a qualied technician

Green Heating Technology 
User guide
The front control panel


At every press, the boiler
switches its mode from
to summer or winter mode.
00357 00

To set the CH system tempera-
ture. If the Outdoor Sensor Kit
was installed, see also "Out-
door Sensor Kit" on page 38.

To set the DHW temperature.
 Press to reset the boiler in case of breakdown�
See further details in "Alarms - boiler block" on page 28.
Display - symbols enabled in this model and their descripon

If ashing, it means that the boiler is funconing in CH mode. See also the remark in the
descrion of symbol 
Burner ON
It indicates the presence of the ame in the burner.

If ashing, it means that the boiler is funconing to produce hot water.
If both and symbols ash at the same me, a Technician-reserved funcon
has been acvated. In this case, turn immediately the boiler o - and then turn it
on again - by means of the buon �
Two digit display under the symbol
Normally, it displays the CH ow temperature, i.e the temperature of the liquid on boiler's
outlet that is sent to the CH system.
During the CH temperature seng (by rotang the knob ), it shows the
temperature value changing; in case of  ; during the -
served to the Technician) it displays the chosen parameter ID number (see "PCB param-
eters sengs (technician menu)" on page 24).

Green Heating Technology

Three digit display under the symbol
Normally, it displays the temperature of the hot water on boiler's outlet. When the boiler
is in stand-by mode, it displays 
During the DHW temperature seng (by rotang the knob ), it shows the temperature
value changing; in case of alarm it displays the ID number of the alarm (see "Alarms -
boiler block" on page 28); during the      it displays
the value of the chosen parameter�
 It appears when the boiler is locked or anyway is present an error that the user could man-
age. See "Alarms - boiler block" on page 28 to idenfy the problem and the relevant
acons to be carried out.
 It appears when the boiler has detected an error (mainly a fault) that has to be managed
by the Technician. The User can anyway see "Alarms - boiler block" on page 28 to get
informaon about and the eventual acons to be carried out.
It informs that the outdoor probe (accessories) is installed.
Note: In this case the CH system temperature is automacally set and so the use of the
knob is dierent from the standard way: for deeper detailsrely on kit instrucon
and see "Outdoor Sensor Kit" on page 38.
Commands on the lower side
1System pressure gauge
2System lling and pressure restoring cock
3GAS cock
Commands outside the boiler
Externally the boiler, suitably posioned in the build-
ing (generally by the installer or by the electrician), two
devices that the user should access to, are present. The
presence and the characteriscs of these devices are pre-
scribed by the regulaon in force.
Two-pole switch: it is located usually close to the boiler and it's for electrically insulang the boiler
itself from the domesc mains power supply network. It is useful to disconnect the boiler from the
electrical supply, e.g. during inacvity periods (see "Safety shut o" on page 11) or in some cases
of alarm (see "Alarms - boiler block" on page 28).
Room thermostat: it commands electrically the boiler to acvate or deacvate the heang system, in
order to keep the room temperature (detected by a sensor) within a value set by the user, Regula-
on in force prescribe its posioning, the temperature limits within the user can adjust it and the
periods of heang.
Remark: an oponal, original Remote Control kit is available (see "Remote Control Kit" on page 39
for informaon) or a cung-edge chronotermostat kit featuring weekly programming of various
temperature levels and other special funcons. Also wireless and GSM controlled versions are
available.
00315_00
2
3
1

Green Heating Technology 9
Typical use
Preliminary operaons
fBe sure the gas cock is opened�
fBe sure the boiler is electrically powered and set in: only has to be displayed on the screen�
fMake sure, by the gauge that the -
. When the pressure , the boiler stops working. In this case, open
the system lling cock 2 up to obtain, on the gauge, �
The system pressure raises with the temperature: a too high inial cold-system pressure could
lead to  aer the system heang-up.
Boiler acvaon
fPress the buon :
• once to set the boiler in summer mode only (DHW only). Summer mode is recognizable by the
only symbol presence on the display and not by the symbol presence ;
•pressing twice to set the boiler in winter mode for making the boiler working both for CH and
DHW. Winter mode is recognizable by the both symbols presence and on the display;
• at each press of the buon , the boiler cyclically switches from to summer and to
winter + mode�
fOpening a DHW tap, the burner res up, and later then DHW is available.
fOn winter mode + , when room thermostat demands for heang, the burner res up and
thanks to the water ow the heang get transferred . In case of contemporary demand of both DHW
and CH, the DHW demand has the priority ll the demand nish. Usually, as DHW does not last for
long, this priority does not aect the CH eciency in the system.
Temperature adjustment
Note: correct adjustment leads to creang the condions for energy saving.
Note: if a Low Temperature Kit or an Outdoor Probe Kit are installed, refer to the relevant documen-
taon for what concerns the heang system temperature adjustment.
Note: don't make confusion between the heang system temperature here described, with the
temperature of the room set on the Room Thermostat.
fby using the knob , the seng of the heang system temperature
is made (the value, during the adjustment, is shown on the display under the symbol ). Generally,
in the deep cold season and/or with poor building thermal insulaon (or if you noce that the burner
stays on for a long me, but the room temperature rises too slowly) prefer higher sengs. On the
contrary, if you noce that the room temperature exceeds too much, for thermal inera, the value
set on the room temperature, it's appropriate to decrease the system temperature. When the op-
onal Outdoor Temperature Probe Kit is installed, the system temperature is automacally man-
aged and the use of the knob is dierent: for details, see also "Outdoor Sensor Kit" on page 38.
fthe knob sets the temperature of the hot water produced by
the boiler (the value, during the adjustment, is shown on the display under the symbol ). On this
type of boiler, we suggest to set it in such a way to have a comfortable hot water temperature by draw-
ing only hot water or eventually by mixing it with a lile cold water. Avoid maximum values if not strictly
needed, that will force to mix the hot water with bigger quanes of cold water. Consider that, because
of the dispersions along the pipings, a certain me is needed to have a stable water temperature on the
cock outlet, therefore the best temperature evaluaon is achieved during a bath or a shower.

Green Heating Technology


 



 
 

The burner doesn’t turn on
fif the room thermostat (or programmable room thermostat, or similar) is installed, check that it is
really requiring the room heang;
fbe sure the boiler is set on winter + or summer mode (not in). The reference symbols
must be shown on the display (see "The front control panel" on page 7);
fin case the display shows or , or in case the boiler seems to be working in an
inappropriate way, see "Alarms - boiler block" on page 28;
fcheck on the gauge that the boiler pressure is correct (1÷1.5 Bar in a cold state) or at least not below
�
Shortage of domesc hot water producon
fcheck the DHW temperature is not set on a too low value: if so, adjust it (see "Temperature adjust-
ment" on page 9);
fcall a qualied technician to check gas valve regulaon;
fcall a qualied technician to check, and eventually clean, the DHW exchanger.
Remark: where the water hardness value is too high, it is suggested the installaon of a soen-
ing device, in order to prevent the limestone precipitaon; this operaon avoids a frequent
cleaning of the coil�

Green Heating Technology 

The eects of the periods of inacvity can be relevant in parcular situaons such as in ats used only
for some months per year, most of all in cold places.
The user will have to decide to put the boiler in the  disconnecng all the sup-
plies, or to �
When there is the possibility of freezing it is convenient to chose between the advantages and the dis-
advantages of the SAFETY SHUT OFF and of the Stand By/An Freezing Way.
Safety shut o
fTurn o the general switch on the Electrical Supply Line of the Boiler;
fClose the Gas Tap;
When it is expected that the temperature is going to decrease under 0°C, call a technician to do
the following:
• Fill the system with an an-freezing soluon (unless the system was already lled with said solu-
on) otherwise it must be completely emped. Noce that if it had been necessary to restore
the pressure (because of possible loss) in an heang system already lled with an An freezing
soluon, the concentraon of the soluon could have decreased and it could not guarantee the
An freezing Protecon.
• completely empty the hot and cold sanitary water system, including the sanitary circuit and the
boiler’s sanitary exchanger.
Remark: the boiler is equipped with a system which protects the main components from the excep-
onal cases of mechanical lock, due to the inacvity in presence of water and scale. The an-
locking funcon can’t work in Safety shut o mode, because of the lack of electrical supply.
Before re-igning the boiler, have a technician check that the pump is not blocked due to inac-
vity (for the technician: unscrew the plug in the centre of the cap to access the rotor sha and
turn it with a screwdriver or other suitable tool).
Stand-by mode with an-frost & an-locking funcon
When the boiler is le in mode during a period of inacvity, it will be protected against freezing by
several funcons provided in the electronic controller, which heat the parts involved when the tempera-
ture falls below factory set values.
The an-frost heang is accomplished by turning on the burner and pump.
In addion, when the boiler is in stand-by, it periodically acvates the main internal components to
avoid rare cases of blockage due to inacvity in the presence of water and lime. This can also occur
when the boiler is locked (red lamp on) provided that the system pressure is correct.
In order for these systems to be acve:
• the boiler must be receiving gas and electricity;
• boiler must be le on mode ( shown on the display);
• system pressure must be correct (1÷1.5 bar in a cold state, minimum 0.5 bar)
In case of gas supply failure, or if the boiler locks for other reasons (the display shows

Green Heating Technology

or ) the burner won’t turn on. Nevertheless, any me it is possible, the pump will work,
making the water circulate in the system and reducing in this way the possibility of freezing.
ATTENTION: the an-frost protecons cannot intervene in the absence of electricity. If you an-
cipate this possibility, we recommend you add a good brand of an-freeze to the heang sys-
tem, following the producer’s instrucons.
 

When the power comes back on, the boiler will check the temperature measured by the two
probes and, if it suspects freezing veried by a parcular automac control cycle, alarm 39 will
be triggered. For more details, see the relave descripon in the paragraph "Alarms - boiler
block" on page 28.
We recommend that you completely empty the hot and cold sanitary water system, including
the sanitary circuit and the boiler’s sanitary exchanger. The an-frost funcon does not protect
the sanitary circuit outside the boiler.
“Ambient An-Frost” Funcon
Note: if you want to use the “Ambient An-Frost” funcon that is oen available in common room
thermostats or chronothermostats, it is necessary to leave the boiler in Winter + mode
and NOT in mode.
The “Ambient An-Frost” funcon does not protect the sanitary circuit outside the boiler and,
especially, in areas where the heang system doesn’t reach. For this reason, we recommend
that you empty the cold and hot sanitary water from the parts of the system that are at risk of
freezing.



            

as this boiler has an heat output lower than 35 kW (about 30000 Kcal/h),
it is not required to install the appliance in a dedicated room, provided that the room complies with
the regulaon in force and that all installaon rules assuring a safe and regular gas boiler operaon,
are strictly respected�
 when
a boiler with air draught from the installaon room (B… appliance type) is installed. Venlaon
must be made and sized in compliance with Laws and Rules in force.
the presence of other appliances (especially if they interfere with the
boiler draught) can be forbidden by the regulaon in force or can require modicaons (e.g. the
enlargement of the venlaon opening or the making of new ones).
at the end of the installaon, the installer must:
• explain the operaon of the boiler and its safety devices to the user;
• give this user this booklet and the documentaon within his/her competence, duly lled in where
required.

Green Heating Technology 

50
45
L
TA
RMCGF
CF
G R
M G R
C F
M
400 300
7279
10
9
7070 65 65 65 657070 65 65 65 65 120
23÷43 23÷43
700
TA / L
00358 01
200 200
180
S
Legend:
S Flue outlet
M System ow (¾”)
C DHW outlet (½”)
G Gas: connecon on the boiler ¾”;
on the wall, using the oponal
original ng kit ½”
 Fresh water inlet (½”)
R System return (¾”)
Indicave posion for electrical
power supply and room
thermostat wirings
TA Room thermostat wiring
L Electrical power supply wiring
front view -
hydraulic connecons
on the wall
(with oponal ng kit)
see also page 16
upper
view
front view -
hydraulic connecons
on the boiler
le side view -
hydraulic connec-
ons on the boiler

See also "Pump sengs" on page 28.
0
1
2
3
4
5
6
0 200 400 1000 1200600 800 1400 1600
00372
A 01
pressure (m H2O)
water ow (l/h)
mod. 24 C
speed 3 - 2 of the pump
The graph is referred
to the capacity available
to the system.

Green Heating Technology

0
1
2
3
4
5
6
0200 400 1000 1200600 800 1400 1600
00372
B 01
pressure (m H2O)
water ow (l/h)
mod. 28 C
speed 3 - 2 of the pump
The graph is referred
to the capacity available
to the system.

Floor heang system
The safety thermostat(s) that protects the oor against overheang (that could damage the
cladding, the structure or the system itself) must be installed on the ow starng end of the
serpenne embedded in the oor itself. It should not installed on the system ow pipe in prox-
imity of the boiler, otherwise frequent and unjused boiler locks, caused by its triggering, are
possible�

Air must be withdrawn from places free of pollutant (like uorine, chlorine, sulfur, ammonia, alkaline or
similar agents). In the event of installaon of the boiler in atmospheres with not negligible presence of
aggressive chemical substances (e.g. hairdressing salons, laundries) we recommend not to install this
natural draught, open chamber boiler, but a forced draught and sealed chamber boiler instead, with air
inlet from outdoor.

Green Heating Technology 

 Besides, for an opmal boiler funconing, wa-
ter pressure . A lower pressure could make dicult to restore correctly the
pressure the heang system, and reduce the ow of hot water available from the boiler.
In case of higher pressure     upstream the
boiler�
If the wa-
ter hardness is more than 25° fr it’s required to install a soener to bring the hardness below that value.
Besides, the presence of solid residuals or impuries in the water (for example in case of new systems)
could compromise the correct funconing of the boiler. For DHW producon systems, the regulaon in
force prescribes a safety lter to protect the systems.

Thanks to its anfreeze system, inner components could never reach a temperature lower than 5°C. This
system is acvated when the boiler is supplied by the electrical and gas lines, provided that the pressure
in the heang system is correct.
If some part(s) of the system external to the boiler could be subject to freezing risk, it is advis-
able to ll the heang circuit with, instead of water, an anfreeze liquid specic for heang
systems, propylenic glycol based, following the instrucons of its manufacturer. Pay aenon
to the correct product concentraon: adding those substances to the heang water in incorrect
dose could lead to the deformaon of the seals and cause unusual noises during operaon.
ITALTHERM S.r.l. will not be held responsible for consequent damages.
 


Green Heating Technology


Remark: A re-usable metal jig ( D in the gure) can be ordered separately,
so as to facilitate connecons and xing points posioning (when the
original connecon kit is used). If the metal jig and/or the original
connecon kit are not used, refer to the paragraph "Dimensions
and connecons" on page 13 for the posion of the connecons
directly on the boiler.
fLocate the exact posion of the boiler considering the sucient clear-
ances: at least 50 mm from each side, 50 mm from the front and 300 mm
on the boom side
fChoose the fastening/hooking opon among A or B, depending on the
xing devices used or already available if any (open hooks; wallplugs;
“stud” type with nut).
fIf the metal jig is used, hang it on the wall using the same xing devices
and the holes or slots A or B�
fFix up the connecons and all ducts for heang ow and return, cold wa-
ter, hot water, gas and electrical cables, predisposing them in the holes
of the metal jig or, as an alternave, respecng the measures in the paragraph "Dimensions and
connecons" on page 13. The upper edge of boiler’s body, used as a reference in the paragraph
"Chimney connecons" on page 20, is represented by the doed line C in the gure.
fRemove the jig (if used) and hang the boiler to the xing devices, using the chosen holes or slots A
or B�
fplaced to close the hydraulic connecons on the boiler.
fProceed with the hydraulic, gas, electrical and ue connecons following the instrucons and warn-
ings reported in the following paragraphs�
The connecons of the boiler are engineered to t plain couplings with screw ring, interposing
a plain gasket of suitable size and material, that ensure a reliable seal even without excessive
ghtening force. They are NOT suitable for hemp, teon tape or similar materials
32.5
36
18
328
70
45 50
7065656565
9
18
36
335
400
32.5
35 11 14
40 30 15
727
A A
B B
C
D
A
B
C
00321 00
Heang
Flow (3/4”)
Hot Water
Outlet (1/2”)
Gas (1/2”)
Cold Water
Inlet (1/2”)
Heang
Return (3/4”)
Electrical
Power Supply
Room
Thermostat

Green Heating Technology 

Make sure that the hydraulic and heang systems ducts 
the electrical system. They are absolutely NOT SUITABLE for such a use. Besides: they don't
guarantee the earth dispersion; in case of electrical fault they could generate a fulguraon risk;
there could take place galvanic currents in the pipings and consequent corrosion and hydraulic
leaks�
Advices and suggesons to avoid vibraons and noises in the system
fDo not use pipes with reduced diameters;
fDo not use bends with small radius and reducons of important secons.
Cleaning and preservaon of the systems
The eciency, the reliability and the safety of the boilers, as all generic thermal systems and compo-
nents, depend strictly on the features of the water that supply them and on their treatment.
A proper treatment of the water improves the protecon of the systems against corrosions (and there-
fore perforaons, noise, leaks, etc.) and limestone incrustaons that drascally reduce the eciency
of the thermal exchange (consider that 1 mm of limestone incrustaons reduces of 18% the thermal
exchange of the heang element on which it has been formed).
ITALTHERM guarantees its products only if the characteriscs of the water comply with UNI 8065, re-
ported also in laws on energy saving�
Thoroughly wash the heang system with water, before connecng the boiler. This will elimi-
nate residual like welding drops, slag, hemp, masc, mud, rust and other dirt from pipes and
radiators. Otherwise, these substances could enter the boiler and damage the internal compo-
nents (pump etc.).
f, in the
suitable quanty and following the instrucons of its manufacturer.
fIf the water on boiler inlet is harder than 25° fr, it’s required to install a soener to bring the hardness
below that value, as required by the reference regulaon.
fFor oor system and generally all low temperature systems, the water treatment product must have
lming acon (protecon against corrosion and incrustaon) and acon against bacteria and algae.
Heang system
fConnect the safety evacuaon ducts of the boiler to an evacuaon funnel. If safety valves are not
connected to an evacuaon device, their intervenon could ood the room. The manufacturer can-
not be held responsible for any damage arising from that situaon.

Green Heating Technology


Once all system connecons have been carried out,
proceed with system lling. This operaon should be
made with care, respecng the following steps:
fOpen the radiators venng devices;
fCheck that the plug of the automac air vent, incor-
porated in the boiler circulator, is unscrewed: if not,
unscrew it and leave it unscrewed, even aerwards,
for normal operaon;
fIf it's required to ll the system with an-freeze so-
luon, do this operaon, then hermecally close
the connecon or the valve used to put the soluon
in, to allow the pressurizaon.
fGradually open the lling cock 2 ;
fCheck the correct funconing of automac venng devices, eventually installed;
fClose the radiators venng devices as soon as water ows out of them;
fMake sure, by reading the pressure gauge, that the pressure reaches the opmal value of 
;
fClose the water lling cock 2 and bleed each radiator again;
fRepeat the venng and pressurizaon operaons unl the air is completely purged from the system.

Due to various installaon possibilies, the gas cock supplied with the original Connecons Kit has a
simple male Ø ½” connecon, facing the rear of the boiler. The gas pipe 4, upstream the gas cock 3, should
be supplied by the installer.
           


those materials does not make the suitable seal with consequent gas leaks!

�
 
-

The gas connecon, as generally the boiler installaon, must be done by qualied personnel as
prescribed by the regulaon in force, because a faulty gas connecon could lead to re, explosion
and other very serious damages to persons, animals and objects. The manufacturer cannot be
held responsible for any damage arising from that situaon.
00316_00
2
3
4
1

Green Heating Technology 
f
• cleaning of all system gas pipes in order to avoid the presence of work residuals that could com-
promise the correct boiler funconing;
• gas line and ramp conformity with laws and rules currently in force;
• internal and external ghtness of the gas system and connecons;
• supply pipe must have a secon greater than or equal to the boiler one;
• supply gas must correspond to the one for which the boiler has been set: otherwise, it's manda-
tory to ask to qualied personnel to set the boiler for the correct gas type;
• an intercepon valve must be installed upstream the appliance.
fOpen the meter valve and purge the air that is inside the system pipes (including all the appliances).

The link of the room thermostat works with a safety extra low voltage (SELV); connect it to
the voltage free contacts of the room thermostat/chronothermostat. On NO account must any
electrical voltage be applied to these terminals�
All low-voltage wirings (e.g. Room Thermostat or Chronothermostat for trade) must be kept
separate from power supply cables, as to avoid boiler malfunconing due to electrical noise. It
is advisable to use separate tubes for them.
During the connecon of cables from the boiler, make sure that them are not ght and make a
slack that allows the control panel to be fully lted.
The boiler must be connected to a 220÷240V - 50Hz electrical power supply. In any case, the power
supply voltage must be within the range –15% ... +10% from the nominal value (230V); otherwise it
may cause malfuncons or failures. It is necessary to respect the polaries L-N (Live L=brown; - Neu-
tral N=blue) - otherwise the boiler may not work - and the earth connecon (yellow-green cable).
 in compliance with the regulaon currently in force.
The installaon must be made complying the regulaon currently in force and generally with the
standard cra rules.
For the general electrical supply of the appliance the bipolar switch should be used. The use of adaptors,
mulple taps and extensions is not allowed.
If the supply cable must be replaced, use one of the following cable types: H05VVF or H05-VVH2-F. It is
 To replace the cable,
open the control panel cover, unlock its fastening device and disconnect it from the terminals. Install
the new cable proceeding in the reverse way. When connecng the cable to the boiler, it’s mandatory:
• to leave the Earth wire about 2 cm longer than the other (Live and Neutral) wires;
• to lock the cable upstream the terminals by means of the suitable fastening device.
Electrical safety of the appliance is only achieved when it is well connected to an ecient earth-
ing system, executed as indicated by the safety rules actually in force.
A qualied technician must check that the electrical system is in line with the maximum power allowed
by the boiler, indicated on the data plate, with parcular aenon to the cables secon.
ITALTHERM S.r.l. declines any responsibility for damages to persons, animals or things caused by
the faulty or missing connecon of the boiler earthing and by failure to comply with the rules.

Green Heating Technology
20

Carefully follow the prescripons by the Naonal and Local Regulaon in force.
Indicaons to connect the duct to the chimney (except of dierent prescripons by Naonal or Local
Regulaon):
fDon't lean the ue pipe into the chimney, but stop it before the inner surface of the chimney. The
axis of the ue pipe must intersect the axis of the chimney or of the ue duct.
fOn the boiler ue outlet, there must be a vercal ue pipe which length must be at least two mes
the diameter of the pipe itself, measured on the pipe connecon on the boiler.
fAer the vercal length, the pipe must have a minimum upwards slope of 5% and a maximum length
of 2500 mm.
fThe boiler has been tested with a 1 meter chimney length.
fTo calculate the chimney dimensions, refer to the Flue Mass Flow Rate and to the Flue Temperature
data (see "Technical data" on page 33).
Flue duct
or chimney
Combuson
products
test point
min. 1000 mm
max. 2500 mm
Minimum
slope 5%
D
min.
2 x D
NO
NO
YES
00031 00
B11BS
Model Diameter D of the ue pipe
City Class 24 C 130 mm
City Class 28 C 140 mm
The boiler is ed with a safety thermostat for the ue ow detecon, that triggers when the
combuson products reow into the room. This device must never be bypassed or put out of
Combuson products could lead to intoxicaon, permanent damage and death. If the

In case of repeated intervenons of the device (and consequent boiler locks), check that the air
supply / room venlaon system and the Flue Products Outlet System are ecient and made
according to the laws in force�
 
(by momentarily
In case of ue outlet on wall, the posions and the distances prescribed by the regulaon mist be re-
spected�