Italtherm CITY GLASS 20 FR manual 

CITY CLASS
use
installation
adjustment
maintenance
Handbook
instruction
ENG
20 FR
25 FR
30 FR
35 FR
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
Commands related to Domesc Hot Water � � � 9
Typical use � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � 9
Preliminary operaons � � � � � � � � � � � � � � � � � � � � � � � 9
Boiler acvaon � � � � � � � � � � � � � � � � � � � � � � � � � � � 10
Temperature adjustment � � � � � � � � � � � � � � � � � � � � 10
An-Legionella funcon � � � � � � � � � � � � � � � � � � 10
Incidental malfunconing � � � � � � � � � � � � � � � � 11
The burner doesn’t turn on � � � � � � � � � � � � � � � � � � 11
Shortage of domesc hot water producon � � � � 11
Boiler inacvity � � � � � � � � � � � � � � � � � � � � � � � � � 11
Safety shut o � � � � � � � � � � � � � � � � � � � � � � � � � � � � � 11
Stand-by mode with an-frost & an-locking
funcon � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � 12
“Ambient An-Frost” Funcon � � � � � � � � � � � � � � � 13
 
Law and regulaon prescripons for the
installer � � � � � � � � � � � � � � � � � � � � � � � � � � � � � 13
Dimensions and connecons � � � � � � � � � � � � � � 14
Pump capacity diagram � � � � � � � � � � � � � � � � � � 14
Warnings for the installaon of oponal kits
or special systems � � � � � � � � � � � � � � � � � � � � � 15
Floor heang system � � � � � � � � � � � � � � � � � � � � � � � 15
Specicaons for intake air � � � � � � � � � � � � � � � 15
Domesc water supply characteriscs � � � � � � 16
Protecon against freezing � � � � � � � � � � � � � � � 16
Outdoor installaon in a parally protected
place � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � 16
Posioning and fastening � � � � � � � � � � � � � � � � � 17
Hydraulic system (DHW and heang) � � � � � � � 18
Advices and suggesons to avoid vibraons and
noises in the system � � � � � � � � � � � � � � � � � � � � � � 18
Cleaning and preservaon of the systems � � � � � � 18
Heang system � � � � � � � � � � � � � � � � � � � � � � � � � � � � 18
Piping between the boiler and the storage unit � 19
Heang system lling and pressuring � � � � � � � 19
DHW storage tank lling � � � � � � � � � � � � � � � � � � 19
Gas connecon � � � � � � � � � � � � � � � � � � � � � � � � � 20
Electrical connecons of the boiler � � � � � � � � � 20
Electrical connecon between the boiler and
the storage unit � � � � � � � � � � � � � � � � � � � � � � � 21
Flue systems � � � � � � � � � � � � � � � � � � � � � � � � � � � 22
General indicaons � � � � � � � � � � � � � � � � � � � � � � � � � 22
Reducer for short systems � � � � � � � � � � � � � � � � � � � 22
Flue system types � � � � � � � � � � � � � � � � � � � � � � � � � � 23
 
First starng up � � � � � � � � � � � � � � � � � � � � � � � � � 24
Access to the inside of the boiler � � � � � � � � � � 25
Inlet gas check � � � � � � � � � � � � � � � � � � � � � � � � � � 26
Max and Min pressure adjustment � � � � � � � � � 26
PCB parameters sengs (technician menu) � � 27
Main boiler parameters (PC) � � � � � � � � � � � � � � � � � 27
Combuson test � � � � � � � � � � � � � � � � � � � � � � � � 29
So ignion � � � � � � � � � � � � � � � � � � � � � � � � � � � � 30
Accessing the main board � � � � � � � � � � � � � � � � 30
Gas conversion � � � � � � � � � � � � � � � � � � � � � � � � � 31
Draining the heang system � � � � � � � � � � � � � � 32
Pump sengs � � � � � � � � � � � � � � � � � � � � � � � � � � 32
Alarms - boiler block � � � � � � � � � � � � � � � � � � � � � 32
Warnings for servicing � � � � � � � � � � � � � � � � � � � 36
Technical data � � � � � � � � � � � � � � � � � � � � � � � � � � 38
Boiler internal components - 20 FR - 25 FR -
30 FR � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � 42
Boiler internal components - 35 FR � � � � � � � � � 43
Electrical diagram � � � � � � � � � � � � � � � � � � � � � � � 44
Hydraulic diagram � � � � � � � � � � � � � � � � � � � � � � � 45
 
Outdoor Sensor Kit � � � � � � � � � � � � � � � � � � � � � � 46
Installaon and seng � � � � � � � � � � � � � � � � � � � � � � 46
Outdoor Sensor kit and Remote Control � � � � � � � 46
Remote Control Kit � � � � � � � � � � � � � � � � � � � � � � 47

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

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;

    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 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 22). 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.
fDo not obstruct the air intake or ue outlet terminals, even momentarily or parally.

Green Heating Technology

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 cy-
clically switches its working
mode. The current mode is
displayed by the wring
(boiler in stand-by) or by the
symbols:
+ = Winter;
= Summer (DHW only);
= heang only.
00357 00

To set the CH system temperature. If the Outdoor Sensor Kit was installed, see also "Out-
door Sensor Kit" on page 46.

To set the DHW temperature in the storage tank.
 Press to reset the boiler in case of breakdown�
See further details in "Alarms - boiler block" on page 32.
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 heat the water in the storage tank.
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 �

Green Heating Technology
8
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 27).
Three digit display under the symbol
Normally, it displays the temperature of the hot water in the storage. 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 32); 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 32 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 32 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 46.
Commands on the lower side
1System pressure gauge
2GAS cock
Commands outside the boiler
Externally the boiler, suitably posioned in the building
(generally by the installer or by the electrician), some
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 32).
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-
00332_00
2
1

Green Heating Technology 9
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 47
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.
a device must be foreseen, by the installer, to ll and pressurize
the system. Basically it is a faucet or valve, possibly near the boiler, connected to the fresh water
source. If, however, the plant is to be lled with heat exchanger uid (eg an-freeze soluon) instead
of water, it must be equipped with a hose plug or other ng suitable for supply, under pressure, the
system with such liquid (see also "Heang system lling and pressuring" on page 19).

By the point of view of the domesc hot water, the boiler is designed to be implemented in a system
with a domesc hot water storage tank, usually combined with a solar system, that on its turn is nor-
mally equipped with suitable commands and indicators to manage the hot water sent to the users.
Only when a storage temperature probe, connected directly to the boiler, is present, the seng of the
DHW temperature, by means of the knob , determinates the temperature to which the water in the
storage is heated*. If no temperature adjustment devices, downstream the storage, are installed, the
knob adjusts the temperature of the water to the user. Otherwise, this seng will aect only the
maximum available temperature* and on the "duraon" of the availability of hot water. (* in absence of
heat input from external systems, e.g. solar). More complex systems can manage directly both the storage tem-
perature (by forcing the boiler to heat the storage, if required) and the temperature to the user. See the
or ask for informaon to the installer or to the designer�
Also gas consumpon
depends on the set temperature, aside from the quality of the storage thermal insulaon.
Remark: Because of the thermal dissipaon along the pipings, it could be necessary a certain me
before the temperature of the water out of the faucet gets stabilized.
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, use
the system lling device up to restore, on the gauge, the pressure �
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.

Green Heating Technology

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;
• pressing a third me to set the boiler in Heang Only mode, i.e. for making the boiler working for
CH only, leaving the DHW producon OFF. Heang Only mode is recognizable by the presence of
only symbol on the display;
• at each press of the buon , the boiler cyclically switches from to Summer , to Win-
ter + and to Heang Only mode �
fOn Winter mode + or Heang Only mode , when room thermostat demands for heang,
the burner res up and thanks to the water ow the heang gets transferred to the heaters of the
building.
fOn Winter mode + , in case of contemporary demand of heang from both DHW storage 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 46.
fthe knob sets the temperature of the water in the DHW storage
(the value, during the adjustment, is shown on the display under the symbol ). See also "Com-
mands related to Domesc Hot Water" on page 9 about the DHW temperature.

With regular periodicity the boiler, in Summer or Winter mode, automacally provides for the heang
of the water in the storage, so as to destroy eventual bacteria (expecially Legionella spp.) which form in
quiet warm water.
Remark: the An-Legionella funcon is not acve when the boiler is set in or in Heang
only mode.

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 32;
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 10);
fcall a qualied technician to check gas valve regulaon;
fcall a qualied technician to check, and eventually clean, the coil of the DHW storage.
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 of the DHW storage.

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, included the primary circuit of the storage unit and the relevant coil, 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

Green Heating Technology

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
DHW storage.
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
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 32.
We recommend that you completely empty the hot and cold sanitary water system, including
the sanitary circuit and the DHW storage. The an-frost funcon does not protect the sanitary
circuit outside the boiler.

Green Heating Technology 
“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 NOT to leave the boiler in mode but in
a mode that allows the heang, e.g. Heang Only mode (that saves from useless heang of
the DHW storage, although keeping its an-freeze funcon acve), or in Winter + 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, including the DHW storage, 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
RMMBGRB GRRBMBM
2
400 300
7279
10
7070 65 65 65 657070 65 65 65 65 120
23÷43 23÷43
700
TA / L
00382 01
185
207 193
1
Legend:
 Flue outlet
2 Air intake for coaxial system
M System ow (¾”)
MB Flow to storage coil (¾”)
G Gas: connecon on the boiler ¾”;
on the wall, using the oponal
original ng kit ½”
RB Return from storage coil (¾”)
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 17
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 32.
0
1
2
3
4
5
6
7
0200 400 1000 1200600 800 1400
0
1
2
3
4
5
6
7
0200 400 1000 1200600800 1400
00381
A 00
pressure (m H2O)
pressure (m H2O)
water ow (l/h)water ow (l/h)
speed 3 - 2 of the pump


The graph is referred
to the capacity available
to the system.
DHW storage coil
CH system

Green Heating Technology 
0
1
2
3
4
5
6
7
0200 400 1000 1200600 800 1400
0
1
2
3
4
5
6
7
0200 400 1000 1200600800 1400
00381
B 00
pressure (m H2O)
pressure (m H2O)
water ow (l/h)water ow (l/h)
speed 3 - 2 of the pump

The graph is referred
to the capacity available
to the system.
DHW storage coil
CH system
0
1
2
3
4
5
6
7
0200 400 1000 1200600 800 1400
0
1
2
3
4
5
6
7
0200 400 1000 1200600800 1400
00381
C 00
pressure (m H2O)
pressure (m H2O)
water ow (l/h)water ow (l/h)
speed 3 - 2 of the pump

The graph is referred
to the capacity available
to the system.
DHW storage coil
CH 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 to foresee the air
intake from outdoor, choosing the type C installaon.

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.
In case of higher pressure     upstream the
boiler�
If the water hard-
ness 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 (included the primary circuit of the storage
unit and the relevant coil) 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 gly-
col 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.
 


This type of forced draught boiler can be installed
outdoor, but only in parally protected places.
The boiler minimum and maximum working tem-
peratures are menoned in the paragraph "Tech-
nical data" on page 38 and on the boiler data
plate�
The materials used for the boiler installaon, in-
cluding the devices and/or the materials used for
thermal insulaon, should be so to maintain their
 within the temperature range indi-
cated 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.
00004 00

Green Heating Technology 

Remark: A re-usable metal jig ( D in the gure) can be ordered sepa-
rately, 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 14 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, storage
coil ow and return, 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 14. The upper edge of boiler’s body, used
as a reference in the paragraph "Flue system types" on page 23, is represented by the doed line
C in the gure.
If the Storage Unit is not installed in the same moment
of the boiler, remember to close the and
Return from Storage connecons, to allow the lling and
pressurizaon of the heang system.
•model 35 FR only: pull upwards and remove the plasc
blocks that hold the sides of the expansion vessel�
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.
00359 00
Heang
Flow (3/4”)
Flow to
storage coil
(3/4”)
Gas (1/2”)
Return from
storage coil
(3/4”)
Heang
Return (3/4”)
Electrical
Power Supply
Room
Thermostat
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
00335 00

Green Heating Technology

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

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 
Piping between the boiler and the storage unit
Link the connecon on the boiler idened by MB (ow to storage) to the MB connecon of the Storage
Unit, and the RB (return from storage) connecon of the boiler to the RB connecon of the Storage Unit.
 
Warning: If a recirculaon pump is installed, install a check valve.

Once all system connecons have been carried out, pro-
ceed 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, incorpo-
rated in the boiler circulator, is unscrewed: if not, un-
screw it and leave it unscrewed, even aerwards, for
normal operaon;
fLocate the system lling device, foreseen externally to
the boiler, and proceed depending on its type:
• lling from aqueduct: open it and let water ow in
the system
• lling with an-freeze soluon: pump in the soluon and pressurize the system.
fCheck the correct funconing of automac venng devices, eventually installed on the heang sys-
tem and/or on the storage coil circuit;
fClose the radiators venng devices as soon as water or an-freeze soluon ows out of them;
fIf the storage coil or the relevant circuit were equipped with manual venng valves, use them to
purge the residual air from them;
fMake sure, by reading the pressure gauge, that the pressure reaches the opmal value of 
;
fClose the lling device and bleed each radiator again;
fRepeat the venng and pressurizaon operaons unl the air is completely purged from the system.

fFill the DHW storage tank (on storage unit):
• open one of the hot water taps in the DHW system;
• gradually open the hand valve installed on the cold water inlet of the storage unit;
• when only water ows out of the tap, close it.
00337_00
3
4
1

Green Heating Technology
20

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.
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.