Flexiheat CITY BOX 25 K User manual

Green Heating Technology
CITY BOX
use
installation
adjustment
maintenance
Handbook
instruction
ENG
25 k
35 k
CLASS
CLASS CF
SLIM SOLAR
CITY OPEN
CITY BOX
CLASS C NOx
TOP

Green Heating Technology
2
Table of Content
Safety warnings 3
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
User guide 7
Boiler controls � � � � � � � � � � � � � � � � � � � � � � � � � � � � � 7
Remote control � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � 7
Commands outside the boiler � � � � � � � � � � � � � � � � 7
Service Control Panel � � � � � � � � � � � � � � � � � � � � � � � 8
Typical use � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � 8
Preliminary operaons � � � � � � � � � � � � � � � � � � � � � � � � � � 8
Boiler use � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � 8
Incidental malfunconing � � � � � � � � � � � � � � � � � � � 8
The burner doesn’t turn on � � � � � � � � � � � � � � � � � � � � � � 9
Shortage of domesc hot water producon � � � � � � � � 9
Boiler inacvity � � � � � � � � � � � � � � � � � � � � � � � � � � � � 9
Safety shut o � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � 9
OFF mode with an-frost & an-locking funcon � � � 10
Installaon 11
Law and regulaon prescripons for the
installer � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � 11
Specicaons for intake air � � � � � � � � � � � � � � � � � 11
Domesc water supply characteriscs � � � � � � � � 11
Warnings for the installaon of oponal kits or
special systems � � � � � � � � � � � � � � � � � � � � � � � � � 12
Floor heang system � � � � � � � � � � � � � � � � � � � � � � � � � � 12
Pump capacity diagram � � � � � � � � � � � � � � � � � � � � 12
Dimensions and connecons � � � � � � � � � � � � � � � � 13
Protecon against freezing � � � � � � � � � � � � � � � � � 14
Outdoor installaon in a parally protected
place � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � 14
Installaon of the thermal unit into the ush-
mounted box � � � � � � � � � � � � � � � � � � � � � � � � � � � 15
Hydraulic system (DHW and heang) � � � � � � � � � 16
Advices and suggesons to avoid vibraons and
noises in the system � � � � � � � � � � � � � � � � � � � � � � � � � 16
Cleaning and preservaon of the systems � � � � � � � � � 16
Heang system � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � 16
Electric an-freeze heaters � � � � � � � � � � � � � � � � � � � � � 16
Condense drain � � � � � � � � � � � � � � � � � � � � � � � � � � � 17
Heang system lling and pressuring � � � � � � � � � 17
Gas connecon � � � � � � � � � � � � � � � � � � � � � � � � � � � 18
Electrical connecons � � � � � � � � � � � � � � � � � � � � � � 19
Remote Control installaon and connecon � � � 20
Flue systems � � � � � � � � � � � � � � � � � � � � � � � � � � � � � 21
Intake/outlet ange � � � � � � � � � � � � � � � � � � � � � � � � � � � 21
General indicaons � � � � � � � � � � � � � � � � � � � � � � � � � � � � 21
Sizing C63 systems � � � � � � � � � � � � � � � � � � � � � � � � � � � � 22
Examples of installaon of intake and outlet ducts � � 23
Sizing the ue system � � � � � � � � � � � � � � � � � � � � � � � � � � 24
Flue system length � � � � � � � � � � � � � � � � � � � � � � � � � � � � 24
How to use the tables � � � � � � � � � � � � � � � � � � � � � � 24
System length tables � � � � � � � � � � � � � � � � � � � � � � � 25
Allowed ue types � � � � � � � � � � � � � � � � � � � � � � � � � � � � 26
Adjustment and Maintenance 27
First starng up � � � � � � � � � � � � � � � � � � � � � � � � � � � 27
Maintenance operaons � � � � � � � � � � � � � � � � � � � 28
Access to the inside of the boiler � � � � � � � � � � � � 29
Venng the primary exchanger � � � � � � � � � � � � � � 30
Combuson group cleaning and check � � � � � � � � 30
PCB parameters sengs (technician menu) � � � � 32
Main boiler parameters (PC) � � � � � � � � � � � � � � � � � � � � 32
Combuson test � � � � � � � � � � � � � � � � � � � � � � � � � � 36
Power adjustment tables � � � � � � � � � � � � � � � � � � � 37
Max heang power adjustment � � � � � � � � � � � � � 37
Combuson calibraon � � � � � � � � � � � � � � � � � � � � 38
Accessing the main board � � � � � � � � � � � � � � � � � � 39
Main board replacement � � � � � � � � � � � � � � � � � � � 39
Board conguraon codes � � � � � � � � � � � � � � � � � � � � � � 39
Gas conversion � � � � � � � � � � � � � � � � � � � � � � � � � � � 40
Draining the heang system � � � � � � � � � � � � � � � � 41
Pump sengs � � � � � � � � � � � � � � � � � � � � � � � � � � � � 41
Alarms - boiler block � � � � � � � � � � � � � � � � � � � � � � � 41
Warnings for servicing � � � � � � � � � � � � � � � � � � � � � 48
ErP Data - EU 813/2013 � � � � � � � � � � � � � � � � � � � � 49
Product che - EU 811/2013 � � � � � � � � � � � � � � � � 49
Technical data � � � � � � � � � � � � � � � � � � � � � � � � � � � � 50
Boiler internal components � � � � � � � � � � � � � � � � � 52
Electrical diagram � � � � � � � � � � � � � � � � � � � � � � � � � 53
Hydraulic diagram � � � � � � � � � � � � � � � � � � � � � � � � � 54
Addendum 55
Outdoor Sensor Kit � � � � � � � � � � � � � � � � � � � � � � � � 55
Installaon and seng � � � � � � � � � � � � � � � � � � � � � � � � � 55
The Service Control Panel � � � � � � � � � � � � � � � � � � 55
Boiler and Remote Control acvaon � � � � � � � � � � � � � 57
Temperature adjustment (manual working modes) � 58
Modulang circulang pump - details � � � � � � � � 59
Status indicator � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � 59
Circulang pump rotor unlocking � � � � � � � � � � � � � � � � 59
Appliance disposal � � � � � � � � � � � � � � � � � � � � � � � � 60

Green Heating Technology 3
Safety warnings
This instrucons manual is an essenal and complementary part of the product and it is supplied
together 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.
fThe installaon must be carried out by a qualied technician, in accordance with manufacturer
instruc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 O2 mix can be explosive.
fA qualied technician 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 operaons that the user can do 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) must not be le within children easy reach, as
they are potenally dangerous.
fBefore any cleaning or servicing operaon, 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�
fIf the appliance should be denively dismissed, remove or cut o any potenal dangerous item.
Dispose of it according to the regulaons in force (page 60).
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 must be used for its clearly recommended ulizaon only. Any other ulizaon must
be considered dangerous and incorrect.
fIt is strictly forbidden to use the appliance for dierent purposes than the specied ones.
fThis appliance must be installed exclusively to wall�

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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 laws and norms in force in the territory where the installaon takes place prevail on the indicaons
contained in this handbook, that are inconsistent with them.
All the references to norms and naonal laws 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 comply with naonal and/or local regulaon about WORK SAFETY of Personnel in
charge of installaon.
Always proceed with cauon when handling the boiler and carrying out installaon/maintenance
work as metal parts may cause injuries such as cuts and abrasions. Wear personal protecon
devices (especially gloves) while doing the above menoned operaons
Installaon, use and maintenance
Always comply with naonal and/or local regulaon about BOILER INSTALLATION.

Green Heating Technology 5
User warnings
Important
In case of gas smell:
1 - do not press electrical switches, use the telephone or other objects that can provoke
sparks;
2 - open immediately the windows and the doors in order to cleanse the room air;
3 - close the gas supply taps;
4 - call a qualied technician.
Do not obstruct the venlaon openings 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
requirements 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).
This boiler is designed and prepared to be supplied with Natural Gas G20 (Methane). It can be
set, just by means of electronic sengs, but always by a qualied technician, to operate with
Commercial Propane G31 or Air/Propane G230. It must never be used with butane gas G30
(that can be present, pure or mixed with Propane G31, in the portable gas boles for cookers).
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 ue intake/outlet system that must be ecient and made according to the laws in
force (see examples in paragraph “Flue systems" on page 21). 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 9 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 contact with them can cause dangerous scalds. It is then forbidden to let children or
inexperienced people be close to the boiler, during its operaon.

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fDo not expose the wall hung gas boiler to water or other liquids sprinklings, or to vapours directly
coming from gas cookers/hobs�
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 supervision
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.
fOnly for those models that draw directly from the installaon room (type B appliances installed
indoor): the installaon of aspirators, replaces or similar appliances in the room where the type B
appliance 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
carried out by qualied technicians, 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
booklet (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
decide 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 7
User guide
Boiler controls
Remote control
All user controls of the boiler are located in the Remote
Control, which is supplied with its own instrucon manual.
For the descripon of all controls and for the boiler
management operaons that are not included in this booklet,
refer to the instrucon manual of the Remote Control.
Therefore, when removing the Remote Control from
its box, take care to keep the relevant instrucons for
use. Aach them to this instrucon booklet.
The original Remote Control is much more than just a
chronothermostat:
•it opmises the boiler operaon, interfacing with the
relevant electronics;
• it features a built-in weekly climac programmer, easy
to set and to use, but extremely complete:
◦ for example, it determines the boiler power according to the dierence between set and
measured temperature
◦ for this and other reasons, it should be formally considered as an “advanced thermoregulaon
system”
•it responds to all boiler controls and provides the Technician with diagnosc informaon and
further funcons;
• easy to install, it is connected in place of the Ambient Thermostat;
• it is powered from the boiler through the data link, with extra-low voltage, therefore it is electri-
cally safe and it doesn’t need baeries or addional power supply connecons.
Commands outside the boiler
Gas cock: it is located on the boiler inlet gas pipe, usually in close proximity to it. The posion of this
device must be known and accessible to the User since it must be used when the gas to the boiler
must be removed or supplied.
Omnipolar switch: conveniently posioned in the property (usually by the installer or by the person in
charge of installing the electrical system), there is the power supply omnipolar switch. The posion
of this device must be known and accessible to the User since it has to be used when it is necessary
to cut o the power supply to the boiler.
The regulaons in force require the presence of these two important devices for safety reasons and
describe their characteriscs.
CONTROLLO REMOTO
MANUALE DI
ISTRUZIONI

Green Heating Technology
8
Service Control Panel
The electric box that contains the electronic control unit (pos. 13 on page 52) is complete with
standard controls. It cannot be accessed from the outside, but it is a useful control panel that can be
used by the Technician in the following cases:
•maintenance with access to funconal parameters or procedures reserved to the Technician;
•acvaon of temporary emergency of the boiler basic funcons, in case of connecon problems
or malfunconing of the Remote Control;
•enabling of the Remote Control to control the boiler (see page 56).
for details, see the appendix “The Service Control Panel" on page 55.
Typical use
Preliminary operaons
fBe sure the gas cock is opened.
the heang system should already be lled during the installaon phase at the proper pressure of 1°Bar
in a cold state. The pressure value cannot be directly read (the pressure gauge is inside the boiler), but
should it be insucient, when the boiler is electrically powered, the system that automacally restores
the pressure will be acvated, with signal E18 or E19 or E21 on the Remote Control�
Note: addional informaon on these alarms are available in paragraph “Alarms - boiler block" on
page 41. For details on the inial manual lling of the system, performed by the Technician,
see “Heang system lling and pressuring" on page 17.
The system pressure raises with the temperature: a too
high inial cold-system pressure could lead to water
drain from the 3 Bar safety valve aer the system
heang-up.
Boiler use
All the informaon on boiler use for the User is described in the
instrucon booklet of the Remote Control, where the boiler is
referred to as “UC”.
Incidental malfunconing
Avoid performing personally any intervenon that are job of the technician, for example the
ones on the electrical circuits, on hydraulic system or on the gas system, and whatever other
operaon that's not menoned in this "User Guide" secon and expressly allowed to the User.
Always address yourselves to qualied personnel.
Boilers must be always equipped with original accessories only.
ITALTHERM S.p.A. is not responsible for damages caused by the incorrect, wrong or
unreasonable use of not original materials.
CONTROLLO REMOTO
MANUALE DI
ISTRUZIONI

Green Heating Technology 9
The burner doesn’t turn on
fCheck whether the Remote Control uses an alarm code; in this case, depending on the code, try to
restore the operaon as described in paragraph “Alarms - boiler block" on page 41.
fIf the Remote Control display is completely o, the Remote Control connecon may be insucient,
but rst make sure that the power supply omnipolar switch of the boiler is not turned o or that
there are no other power supply interrupons.
fCheck that the value of the set ambient temperature is not higher than the current one, in this case
it is not necessary to turn on the burner. If you sll want to turn on the burner, it will be necessary to
set, on the Remote Control, an ambient temperature higher than the current one (see the instrucon
booklet of the Remote Control).
Shortage of domesc hot water producon
fCheck that the set temperature value of domesc water is not too low, in this case adjust it (see the
instrucon manual of the Remote Control).
fHave the boiler internal water lters checked by a technician.
fHave the boiler adjustments and correct programming checked.
fHave the domesc water exchanger checked and, if necessary, have it cleaned.
Remark: where the water hardness value is too high, it is suggested the installaon of a soening
device, in order to prevent the limestone precipitaon; this operaon avoids a frequent cleaning
of the coil�
Boiler inacvity
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 SAFETY SHUT OFF state disconnecng all the
supplies, or to leave it on OFF mode (but electrically supplied) in order to let the An Frost Funcon
work. When there is the possibility of freezing it is convenient to chose between the advantages and the
disadvantages 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.
• Let the condense collector syphon be emped unscrewing its inferior cap.
• completely empty the hot and cold sanitary water system, including the sanitary circuit and the
boiler’s sanitary exchanger.

Green Heating Technology
10
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 switching on the boiler again, have the circulang pump checked by a technician to make
sure it is not blocked due to inacvity (for the technician: proceed as described in paragraph
“Circulang pump rotor unlocking" on page 59).
OFF mode with an-frost & an-locking funcon
When boiler is le to OFF for the inacvity period, it will be protected from freezing through funconsset
in the control equipment and devices specically intended for this type of boiler (designed for outdoor
installaon):
fwhen the ambient temperature detected by the Remote Control is near 0°C, the heang system is
acvated;
The "Room An-Freeze" funcon does not ensure protecon of the domesc water circuit
outside the boiler, in parcular of the areas not reached by the heang system. It is therefore
necessary to have the parts of the domesc hot and cold water system emped, since they may
be likely to freeze.
fwhen the temperature detected by domesc hot water probe is near 0°C, the domesc water
operang mode is acvated (without hot water withdrawal);
fthere are electric an-freeze heaters under the funnel of the condensate, on the system lling device
and on the domesc water inlet and outlet hoses, since these parts are not covered by the an-
freeze acon of the two previous funcons. They are automacally controlled only when required
because of low ambient temperatures.
Moreover,in this status, boiler periodically acvates main internal components to avoid the rare blocking
cases caused by inacvity in presence of water and limescale. This happens also when boiler is locked-
out (alarm signal on the remote control display), but only if 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 OFF mode by means of the Remote Control;
• system pressure must be correct (1÷1.5 bar in a cold state, minimum 0.5 bar) or the cold water
supply should be available on boiler's input, to allow the automac lling
In case of gas supply failure, or if the boiler locks for other reasons (alarm warning on Remote Control
display) 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
system, following the producer’s instrucons.
We recommend to ask directly the installer/technician about the type of anfreeze product
put in the heang system during installaon.
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 41.

Green Heating Technology 11
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.
Installaon
Law and regulaon prescripons for the installer
Always comply with naonal and/or local regulaon about BOILER INSTALLATION.
Always comply with naonal and/or local regulaon about WORK SAFETY of Personnel in
charge of installaon.
Characteriscs of the room: 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�
Permanent venlaon of the installaon room is mandatory and extremely important 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.
Presence of other appliances: 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).
Instrucng the user: 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.
Specicaons for intake air
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 to foresee the air
intake from outdoor, choosing the type C installaon.
Domesc water supply characteriscs
The cold water inlet pressure must be lower than 6 Bar. Besides, for an opmal boiler funconing,
water pressure should be more than 1 Bar. 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 it is indispensable to install a PRESSURE REDUCER upstream the
boiler�
The cleaning frequency of the DHW heat exchanger depends on the water supply hardness. If the
water hardness is more than 25° fr it’s required to install a soener to bring the hardness below that
value.

Green Heating Technology
12
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.
The condensing burner/exchanger assembly requires parcular characteriscs for the heang
system liquid, more restricve than the ones of the inlet domesc water. See the "Heang"
secon of the table “Technical data" on page 50.
Warnings for the installaon of oponal kits or special systems
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
proximity of the boiler, otherwise frequent and unjused boiler locks, caused by its triggering,
are possible�
Pump capacity diagram
0
1
2
3
4
5
6
0 200 400 1000 1200 1400600 800
00331A
01
MAX
pressure (m H2O)
water ow (l/h)
City Box 25 K
See also “Pump sengs"
on page 41. The curves
MAX shown in these graphs
refer to the head available
to system at factory seng
(see par. 35 on page 35)
and are net of the load loss
of the circuits inside the
boiler. The area represents
the working range with pump
in modulang mode (see
par. 33 on page 34)
0
1
2
3
4
5
6
0 200 400 1000 1200 1400600 800
00331C
01
MAX
pressure (m H2O)
water ow (l/h)
City Box 35 K

Green Heating Technology 13
Dimensions and connecons
The boiler is ush-mounted, using exclusively the ush-mounted box and the original connecon kit.
30 120 65
38
15
11
168
79
45
124
187
62 63
65 65 65 70
55
P
00404 00
CRL
IS
FS
US
MCGFR
SS
SC
Flue system - precut holes
of the ush-mounted unit
1 Coaxial system (air intake + ue outlet)
2 Flue outlet, split-pipe or B22
3 Air intake, split-pipe
Hydraulic and electric connecons on the
ush-mounted box lower side
legend (le to right):
IS Hot water inlet to Solar Kit (from solar
system) (½”) (D)
L Electrical power supply wiring
CR Remote Control wiring
FS Cold water inlet to Solar Kit (½”) (B)
US DHW outlet from Solar Kit (½”) (B)
M System ow (¾”)
C DHW outlet from the boiler (½”) (A)
G Gas (½”)
F Cold water inlet to the boiler (½”) (A)
SS Safety valve drain (¾”)
R System return (¾”)
SC Condensate drain
(A) Use if you will NOT install the oponal
Solar Kit with connecons
(B) Use, in place of connecons C and F, only
if you want to install the oponal Solar Kit
with connecons (see the note below the
drawing)
(D) Use if you want to install the oponal
Solar Kit with connecons
30 120 65
38
15
11
168
79
45
124
187
62 63
65 65 65 70
55
P
00404 00
CRL
IS
FS
US
MCGFR
SS
SC
Remark: if the installaon of the Solar Kit is foreseen for the future, we recommend to preset the connecon IS coming from
the place of installaon of the Solar System. Besides, we recommend to preset the cold and hot water connecons in the
posions FS and US in place of C and F and to connect the boiler to them by means of 1/2” exible hoses (commercially
available).

Green Heating Technology
14
Protecon against freezing
Boiler is protected from freezing through funcons set in the control equipment that heat the con-
cerned parts when temperatures go below the minimum values predened in the factory.
The temperatures of the heang circuit inside the boiler (primary circuit) and of the domesc water
circuit are detected by the same probes that control their operaons. Rooms, and consequently the
heang system outside the boiler and radiators, are controlled through the ambient temperature probe
integrated into the Remote Control�
An-freeze heang is obtained by turning on the burner and the circulator (both in heang and do-
mesc water use) and/or by acvang electric an-freeze heaters properly applied on boiler internal
hydraulic circuits, in parcular in the secons of the domesc water circuit that cannot be heated by
the primary circuit.
In case of gas supply interrupon or boiler shut-down, boiler cannot be switched on. In this case, the
circulator is acvated and the an-freeze heang is carried out only by electric heaters.
If some part(s) of the system external to the boiler could be subject to freezing risk, it is advisable
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 will not be held responsible for consequent damages.
Instruct the User about the anfreeze funcon of the boiler and about the anfreeze product
added in the heang system.
Outdoor installaon in a parally protected place
This type of forced draught condensing boiler has been designed to be installed outdoor in parally
protected places�
The boiler minimum and maximum working temperatures are menoned in the paragraph “Technical
data" on page 50 and on the boiler data plate.
The materials used for the boiler installaon,
including the devices and/or the materials used
for thermal insulaon, should be so to maintain
their funconality within the temperature range
indicated on the data plate�
If the place where the boiler is located
is converted from outdoor to indoor (e.g.
veranda) it will be necessary to verify
the compliance of the new conguraon
with the laws and rules in force, and to
make the modicaons required.
00103 00

Green Heating Technology 15
Flush-mounted box posioning and fastening
Gas
P
00101 B 00
1. Depending on the depth of the wall, create a recess or an opening of the same dimensions as the
ush-mounted box and a space under it, so that connecons can be carried out. See measures in
paragraph “Dimensions and connecons" on page 13. Bend the 4 clamps P, which are on the
ush-mounted box sides, outwards;
2. insert the ush-mounted box in its seat
and carry out the various connecons:
electric, gas, water, ue;
3. close the ush-mounted box with the
front panel, which can be then painted
with the same colour as the building;
The box must be completely ush-mounted into the wall, so that the front panel is ush with
the wall external surface and does not project from it.
Installaon of the thermal unit into the ush-mounted box
1. Install the diaphragms, if any, on the upper surface of the gas-ght housing (see “Flue systems" on
page 21) and the connecons necessary for the ue system;
2. Preset the hoses for the connecon to the boiler on the hydrau-
lic pipes at the boom of the ush-mounted box (see paragraph
“Dimensions and connecons" on page 13);
3. Remove the plasc caps placed to close the hydraulic connec-
ons and the condense outlet hose of the boiler;
4. install the thermal unit inside the ush-mounted box by hanging
the slots 2 on the xing hooks 1;
5. then connect the thermal unit to the hoses and ghten these
laer correctly.
The boiler hoses are designed to house swivel connecons,
interposing a gasket UNTIL SNUG, of suitable size and mate-
rial, which oer a reliable ghtness even without excessive
clamping forces. Hemp, Teon tape and other similar materi-
als are not suitable for this use.
00104 00
1
2

Green Heating Technology
16
Hydraulic system (DHW and heang)
Make sure that the hydraulic and heang systems ducts are not used as earth connecons of
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 components,
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 therefore
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,
reported also in laws on energy saving�
Thoroughly wash the heang system with water, before connecng the boiler. This will
eliminate 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
components (pump etc.).
fIn case of old or very dirty systems, to wash them use specic, proven eciency products, 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 cannot be held responsible for any
damage arising from that situaon.
Electric an-freeze heaters
Remember to hook the two spare electric
heaters to the pipings for cold water inlet F
and hot water outlet C�
00172_00

Green Heating Technology 17
Condense drain
Insert the exible pipe of condense outlet inside the outlet funnel (or other inspectable connecon
device) properly installed for this purpose, or in the outlet funnel of the safety valve, in case of the
above menoned outlet is able to receive the acid liquids of the condense as foreseen by the norms in
force in maer of condensing boilers.
Requirements for the condense drain system:
◦ It must be made in a way that doesn't allow the condense freezing or other blockages, and it
must not allow modicaons or obstrucons
◦ before the rst starng up of the appliance, ensure that the condense can be correctly drained
◦ if the intended use of the building unit foresaw the installaon of a condensate neutralizaon
system, make sure that you have the relevant instrucons for use, cleaning and maintenance
Heang system lling and pressuring
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:
During this operaon, the boiler should not be electrically supplied.
If the boiler is supplied, an automac system lling cycle will start. If the system is empty, this
operaon will be incorrectly performed and it will cause, uselessly, many boiler blocks.
fRemove the front panel of the ush-mounted unit (ref. “Access to the inside of the boiler" on
page 29) to access all the devices involved in the operaon;
fOpen the radiators venng devices;
fCheck that the plug of the automac air vent, incorporated 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 solu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 by using a suitable at screwdriver;
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 1, that the pressure reaches the opmal value of 1.0 bar
(max 1.5 bar);
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� 12
00394 01

Green Heating Technology
18
Gas connecon
Due to various installaon possibilies, the gas cock 3 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.
While connecng the gas inlet of the boiler to the gas supply piping, it is MANDATORY to
insert a PLAIN GASKET, whose dimensions and material must be adequate. Connecon is NOT
suitable for hemp, teon strip or similar materials. Because of the type of ng, the use of
those materials does not make the suitable seal with consequent gas leaks!
This boiler is designed and prepared to be supplied with Natural Gas G20 (Methane). It can be
set, just by means of electronic sengs, but always by a qualied technician, to operate with
Commercial Propane G31 or Air/Propane G230.
It must never be used with Butane gas G30 (that can be present, pure or mixed with Propane
G31, in the portable gas boles for cookers) therefore, if the boiler is prepared for operaon
with commercial Propane G31, we recommend to inform the supplier of the fuel, for example,
by applying a suitable warning on the gas tank or in its immediate vicinity, so that it is visible
to the employee when it is being relled.
Using Propane gas G31, it is absolutely necessary to install a pressure reducer upstream the
boiler. Failure to do this, the gas valve of the boiler will get damaged. The inlet gas pressure
must be compliant with the one specied in “Technical data" on page 50.
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.
fVerify what follows:
• cleaning of all system gas pipes in order to avoid the presence of work residuals that could
compromise 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 mandatory
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).

Green Heating Technology 19
Electrical connecons
The link of the Remote Control works with a safety extra low voltage (SELV); connect it to the
supplied Remote Control only, as the boiler can't work without it. On NO account must any
electrical voltage be applied to these terminals�
To avoid malfuncons due to electrical noise, the Remote Control connecons, as well as all
low-voltage connecons, should be kept separated from power supply cables, e.g. by enclosing
it into separate raceways�
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; - Neutral N=blue) -
otherwise the boiler may not work - and the earth connecon (yellow-green cable).
Place upstream the boiler a bipolar switch 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
mandatory the earth connecon in accordance with the rules actually in force. 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 earthing
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�p�A� 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.
It is absolutely necessary to connect the ush-
mounted unit to the earth connecon of the boiler,
using the suitable cable supplied. The connecon
must be carried out as shown in the gure on the
side�
1 Earth cable (already connected to the boiler)
2 Flush-mounted box earth connecon
3 Boiler (thermal unit) earth connecon
4 Flush-mounted box earth connecon screw
5 Toothed spring washer
6 Earth cable terminal eyelet
00108_00
2
3
4
2
5
6
145
6
1
2

Green Heating Technology
20
Remote Control installaon and connecon
Extract the Remote Control from its package. Keep the relevant user instrucon booklet and
annex it to this Manual.
To avoid malfuncons due to electrical noise, the
Remote Control connecons should comply with the
following requirements:
• use 2x0.75 mm² (min. 0.5 mm²) shielded cable
• max length 50m
• possibly use a dedicated electrical conduit
• keep separated from power supply cables
Nor the Remote Control neither the relevant cable coming from the boiler must not, for any
reason, be connected to the 230Vac supply mains.
Make sure that boiler is not electrically powered, especially during the connecon.
IMPORTANT! For the Remote Control to be correctly detected by the boiler electronics, it is
essenal to set the laer to Summer / Remote Control mode using the service Control panel
inside the boiler, as described in paragraph “Boiler and Remote Control acvaon" on page 57.
Otherwise the Remote Control will not work.
fInstall and connect the Remote Control as described in the relevant Instrucon Booklet;
ffor the connecon from the boiler side, see the CR component in “Electrical diagram" on page 53.
Please remember that the connecon is NOT polarised.
CONTROLLO REMOTO
MANUALE DI
ISTRUZIONI