ICI Caldaie MONOLITE 320 GT User manual

MONOLITE 120-850 GT_EN Ed. 02 - 10/2018
EN
Low NOx steel condensing boilers
MONOLITE 120-850 GT
INSTALLATION, USE AND MAINTENANCE MANUAL

2
INDEX
SYMBOLS USED IN THE MANUAL
aDANGER
To indicate actions that, if not performed correctly, can result in injury of generic origin or may generate malfunction
or damage to the appliance; therefore require particular caution and adequate preparation.
dIT IS FORBIDDEN
To indicate operations that SHOULD NOT be performed.
mIMPORTANT
To indicate particularly useful information and important.
The illustrations and data presented are not binding. The company reserves the right to make without prior notice any changes it
deems appropriate for continuous improvement and constant updating.
General information
3 Introduction
3 Range
3 Compliance
4 Warnings
4 Prohibitions
5 Hazards
5 Identification
6 Appliance description
7 Structure
9 Dimensions and connections
11 Technical data
12 Control panel (accessory)
12 Burners
Installation
13 Product receipt
14 Handling
14 Installation room
15 System cleaning
15 Hydraulic connections
15 Starting hydraulic circuit
17 Flue exhaust
17 Condensate drain
18 Door opening
19 Door opening inversion (from the right to the left)
20 Door adjustment
22 Insulating casing assembly
23 Burner assembly
24 Electrical connections
25 Water treatment
25 Limestone build-ups
25 Limestone diagram
25 Corrosion on water side
26 System filling and emptying
Use
27 Preliminary checks
27 Commissioning
27 Checks after commissioning
28 Stop periods
28 Short periods of time
28 Long periods of time
28 Decommissioning of old appliances
Maintenance
29 Boiler
29 Burner
30 Any anomalies and remedies
30 Environmental protection and disposal
30 Information for the disposal of electrical and
electronic equipment
Useful information and declarations
31 QR code
32 Declaration of Conformity
Notes

General information 3
1 General information
INTRODUCTION
Dear Customer,
Thank you for having chosen an appliance of the series MONOLITE GT , a high quality and efficiency product, reliable and safe.
We recommend entrusting its maintenance to Professionally Qualied Personnel who, when necessary, uses original spare parts.
This manual contains important information and suggestions that must be observed for easier installation and best possible use
of the appliance.
mIMPORTANT
Failure to observe the instructions in this manual will void the warranty conditions.
RANGE
BOILER BOILER BOILER BOILER
MODEL CODE CODE MODEL CODE CODE
MONOLITE 120 GT 81037120 17010208 MONOLITE 420 GT 81037420 17010207
MONOLITE 140 GT 81037140 17010208 MONOLITE 555 GT 81037555 17010193
MONOLITE 180 GT 81037180 17010205 MONOLITE 700 GT 81037700 17010193
MONOLITE 250 GT 81037250 17010205 MONOLITE 780 GT 81037780 17010194
MONOLITE 320 GT 81037320 17010206 MONOLITE 850 GT 81037850 17010194
COMPLIANCE
MONOLITE GT boilers comply with the following European Directives:
–European Regulation on Gas Equipment GAR 2016/426/EU
–Low Voltage Directive 2014/35/EU
–Electromagnetic Compatibility Directive 2014/30/EU
–Efficiency Directive 92/42/EEC.
Models up to 400kW comply with the Ecodesign of Energy-using Products Directive 2009/125/EC and with the delegated
Regulation (EU) no. 813/2013.
0461

General information4
WARNINGS
mIMPORTANT
–The appliance must be used for the purposes for which it has been expressly designed and any manufacturer’s liability shall
be excluded in case of damage to persons, animals or property due to insufficient maintenance or improper use.
–This manual is an integral part of the Boiler and must be carefully read before installation and commissioning of the
appliance. Moreover, it must be carefully stored for subsequent consultations and must ALWAYS accompany the Boiler
during its entire life-cycle (from Installation to disposal). In case of damage or loss, request a copy from ICI CALDAIE S.p.A.
Technical Assistance Service.
–The appliance is delivered in several separated packages. Upon receipt, check that the supply is intact and undamaged and
promptly contact the ICI CALDAIE S.p.A. if it does not correspond to the order.
–The installation of MONOLITE GT boilers must be performed by a Certified Company which, at the end of the operation,
must provide the owner with the declaration of conformity certifying that the installation has been correctly carried out,
namely in compliance with the Standards and the national and local Laws in force, and with the indications included in the
instruction manuals supplied by ICI CALDAIE S.p.A. .
–The maintenance of the appliance is a legislative obligation. The User must have it carried out by an Authorised Company
or by qualified personnel (maintenance technician) in compliance with the requirements of the local Standards in force.
–Ordinary and extraordinary maintenance must be carried out by qualified personnel in order to promptly detect any
damage to the boiler body under pressure and to the safety and control accessories.
PROHIBITIONS
dIT IS FORBIDDEN
–Operate electrical devices or appliances such as switches, household appliances, etc. if you smell fuel or unburnt materials.
In this case:
- ventilate the room by opening doors and windows
- close the fuel shut-off device
- ask the Technical Assistance Service or qualified personnel to intervene as soon as possible.
–Any technical or cleaning operation carried out before disconnecting the appliance from the power supply mains, by
positioning the system main switch and the control panel main switch to “OFF”.
–Modifying safety or adjustment devices without the Boiler manufacturer’s authorisation and indications.
–Plug or dimensionally reduce the ventilation openings of the installation room. The ventilation openings are essential for
proper combustion.
–Exposing the Boiler to atmospheric agents. It is not designed to operate outdoor and it does not feature automatic anti-
freeze systems.
–Leave flammable substances and containers in the room where the appliance is installed.
–Disperse the packaging material in the environment and leave it within the reach of children as it may be a potential source
of danger. It must be disposed of in accordance with the legislation in force.

General information 5
HAZARDS
aDANGER
–In case of water leakages, disconnect the Boiler from the power supply mains, close the water supply and contact, as soon
as possible, the Technical Assistance Service Authorised by ICI CALDAIE S.p.A. or qualified personnel.
–Sensing the presence of fuel in the thermal power plant, it is appropriate to follow the precautions below to avoid the risk
of explosions and fires:
- do not smoke or cause sparks
- do not turn on lights or electrical devices in general (mobile phones)
- open doors and windows
- close the fuel shut-off valve normally placed outside the thermal power plant
- disconnect the power supply by means of the switch which is usually located outside of the plant room.
–During the normal operation, the appliance has hot parts, such as the channel and the flue gas box, which in case of
accidental contact without appropriate personal protection can cause severe burns.
–An incorrect adjustment of the closing door or an insufficient chimney draught can cause the presence of smoke inside
the heating plant room, leading to fatal intoxications due to carbon monoxide, which is by nature colourless and odourless.
Therefore, make sure that the Boiler is correctly adjusted and installed and that the heating plant room features vents
compliant with the standards in force.
IDENTIFICATION
Each MONOLITE GT Boiler can be identified by means of the technical data plate inside the envelope of the documents supplied
with the Boiler, which includes technical/efficiency informations such as:
–serial number or identification marking
–nominal thermal power in kW
–nominal thermal flow in kW
–types of fuels which can be used
–maximum operating pressure.
–CE marking
mIMPORTANT
The installer of the Boiler MUST apply the technical data plate (1) mandatorily , once the installation is complete, in a
position which is visible and legible with the appliance installed . In case of deterioration or loss, request a duplicate
from ICI CALDAIE S.p.A. Technical Assistance Service providing the Boiler serial number.
1
The appliance is also accompanied by construction certicate attesting the successful result of the hydraulic test.
mIMPORTANT
The installation must be performed in compliance with the local standards by qualied personnel , namely by
personnel with specific technical skills in the field of the heating system components. An incorrect installation may
cause damage to persons or property for which the manufacturer will not be liable.
During commissioning check the effectiveness of all adjustment and control devices in the control panel.
The warranty validity is subject to compliance with the instructions in this manual.

General information6
APPLIANCE DESCRIPTION
The MONOLITE GT appliances by ICI Caldaie S.p.A. are condensing Boilers, made from AISI 316 Ti stainless steel with fire-tube
furnace and vertical exchange surfaces, designed to produce hot water at a maximum temperature of 110°C and also domestic
hot water if combined with a storage heater.
They are equipped with two-stage progressive or premixed modulating gas burner, with cylindrical combustion head and radiation
with low emissions of NOx. The Nominal Efficiency of the MONOLITE GT reaches 108% (REF. NCV) e  (in compliance with
Directive 92/42/EEC).
The control panel suitable for the Boiler can be indifferently installed either on the right side or on the left side of the appliance.
Some of the main characteristics of the Boiler are listed below:
– chassis made of steel vertical profile structure, complete with base
– large-size cylindrical furnace made of TIG welded AISI 316 Ti stainless steel, able to withstand condensate attacks
– vertical primary heat exchanger made of TIG welded anti-acid AISI 316 Ti stainless steel, engaged perpendicularly to the
furnace, made with stainless steel plates printed with particular conic embossed sections, to increase the exchange surface
and facilitate the formation of condensate drops, allowing an appropriate drip drainage. Moreover, the vertical position of the
exchange surfaces facilitates condensate discharge, ensuring an effective self-cleaning function of plates
– welding performed with TIG procedure , a method which does not require any material to be added, and thus ensures that the
main mechanical characteristics of stainless steel are preserved, as well as its capability to resist acid condensate corrosion
– ow ange tting and two system return ttings , to distinguish the Boiler inlet and ensure the minimum possible temperature
at the lowest point, thus getting the most out of condensate benefits, even in the presence of medium-high temperature
return
– smokebox which can collect the produced condensate, which is then drained through a trap to be connected to the
neutraliser (where provided) and thus to the domestic hot water drain line
– very high water content and low thermal load
– ”hot” surfaces insulated with extra-thick glass wool mats, protected by painted steel panels which are easy to disassemble
– front door with reversible opening , made of steel sheet, thermally insulated with ceramic fibre
–radiant premixed modulating burner , which can provide any power output between the min and the max, according to the
instant load request; it allows maximum acoustic comfort and low polluting emissions.

General information 7
STRUCTURE
120 - 140 - 180 models
2
N7
N9
N2
N4
3
4
9
2
1
N3N1
817
N6
N8
5
4
6
4
10
N10
250 - 320 - 420 models
N7
N9
N2
N4
3
4
10
2
1
N3 N1
81
7
N6
N8
5
4
6
4
11
2
N10
9
1 Door hinges
2 Front door
3 Burner support flange
4 Inspection plugs
5 Control panel (accessory)
6 Smokebox
7 Burner
8 Flame inspection window
9 Primary heat exchanger
10 Insulating casing
11 Flue gas drain fitting
N1 Boiler flow fitting
N2 Boiler return fitting at medium temperature
N3 Instruments fitting
N4 System intake/drain fitting
N5 Safety valve(s) fitting
N6 Bulb-holder pockets
N7 Condensate drain fitting
N8 Control pocket
N9 Boiler return fitting at low temperature
N10 Gas fitting

General information8
555 - 700 - 780 - 850 models
3
4
2
1
8 1
7
N6
N7
N9
N2
N4
4
11
10
9
2
N5 N1 N3
N8
N10
5
4
6
1 Door hinges
2 Front door
3 Burner support flange
4 Inspection plugs
5 Control panel (accessory)
6 Smokebox
7 Burner
8 Flame inspection window
9 Primary heat exchanger
10 Insulating casing
11 Flue gas drain fitting
N1 Boiler flow fitting
N2 Boiler return fitting at medium temperature
N3 Instruments fitting
N4 System intake/drain fitting
N5 Safety valve(s) fitting
N6 Bulb-holder pockets
N7 Condensate drain fitting
N8 Control pocket
N9 Boiler return fitting at low temperature
N10 Gas fitting

General information 9
DIMENSIONS AND CONNECTIONS
120 - 140 - 180 models
N7
N4
N1
N6 N8 N3
N9
N2
N10
P2
L2
L1 P1
H1
H
H2
Øc
H12
H6
H10
H9
H8
LP5P4P3
P
Øb
N2
N9
N4
N7
250 - 320 - 420 models
N3 N1
N6
N8
N10
L2
L1
P2
P1
H2
H1
H5
H4
H
L
P5P4P3
L6
N7
N4
N9
N2
N2
N1
N9
N4
N7
Øc
H12
H6
H10
H9
H8
Øb
P

General information10
555 - 700 - 780 - 850 models
P2
P1
H2
P5P4P3
N7
N4
N9
N2
L2
L1
H1
H5
H4
H
L
L6
N2
N1
N9
N4
N7
ØcH12
H6
H10
H9
H8
Øb
P
N6 N5 N1
N3
N8
N10
P7 P8
Dimensions
Description u.m.
MONOLITE GT
120 140 180 250 320 420 555 700 780 850
H mm 1811 1811 1811 2140 2140 2185 2294 2294 2294 2294
H1 mm 1715 1715 1715 1956 1956 1956 2021 2021 2021 2021
H2 mm 1335 1335 1335 1510 1510 1510 1532 1532 1532 1532
H4 mm - - - 1953 1953 1955 2025 2025 2025 2025
H5 mm - - - 2060 2060 2090 2189 2189 2189 2189
H6 mm 241 241 241 358 358 358 310 308 308 308
H8 mm 828 828 828 864 864 864 854 854 854 854
H9 mm 548 548 548 589 589 589 570 570 570 570
H10 mm 423 423 423 549 549 549 525 525 525 525
H12 mm 103 103 103 189 189 189 112 112 112 112
L mm 994 994 994 1104 1104 1104 1188 1188 1188 1188
L1 mm 780 780 780 890 890 890 974 974 974 974
L2 mm 690 690 690 800 800 800 920 920 920 920
L6 mm - - - 150 150 150 200 200 200 200
P mm 1270 1587 1760 1765 2005 2300 2452 2452 2695 2695
P1 mm 851 1106 1106 1041 1281 1536 1560 1560 1810 1810
P2 mm 679 934 934 909 1149 1404 1436 1436 1686 1686
P3 mm 525 595 768 783 783 823 955 955 948 948
P4 mm 350 200 200 195 195 195 520 520 520 520
P5 mm 395 792 792 787 1027 1282 977 977 1227 1227
P7 mm - - - - - - 150 150 150 150
P8 mm - - - - - - 150 150 150 150
Øb mm 150 150 187 205 205 205 225 270 270 270
Øc mm 180 180 180 200 200 200 250 250 250 250
Fittings
Description u.m.
MONOLITE GT
120 140 180 250 320 420 555 700 780 850
N1 DN/in 50 50 50 65 65 80 100 100 100 100
N2 DN/in 50 50 50 65 65 80 100 100 100 100
N1/N2 PN 6666666666
N3 DN/in 1" 1" 1" 1" 1" 1/4” 1" 1" 1" 1"
N4 DN/in 1" 1" 1" 1" 1" 1" 1" 1" 1" 1"
N5 DN/in - - - - - - 1/2” 1/2” 1/2” 1/2”
N6 DN/in 1/2” 1/2” 1/2” 1/2” 1/2” 1/2” 1/2” 1/2” 1/2” 1/2”
N7 DN/in 3/4” 3/4” 3/4” 3/4” 3/4” 3/4” 3/4” 3/4” 3/4” 3/4”
N8 DN/in 1/2” 1/2” 1/2” 1/2” 1/2” 1/2” 1/2” 1/2” 1/2” 1/2”
N9 DN/in 50 50 50 65 65 80 100 100 100 100
N10 DN/in 3/4” 3/4” 1" 1" 1" 1" 1" 1/2 1" 1/2 1" 1/2 1" 1/2

General information 11
TECHNICAL DATA
DESCRIPTION u.m.
MONOLITE GT
120 140 180 250 320 420 555 700 780 850
Type of appliance B23
Fuel
G20
G30 - G31 - - - - -
Effective rated
[1]
kW 109,6 127,9 164,5 228,4 292,4 383,8 507,1 639,6 712,7 776,7
kcal/h 94290 110010 141450 196450 251460 330030 436120 550060 612930 667940
Nominal power
[2]
kW 120 140 180 250 320 420 555 700 780 850
kcal/h 103200 120400 154800 215000 275200 361200 477300 602000 670800 731000
Max. thermal flow rate
kW 111,3 129,9 167 231,9 296,8 389,6 514,8 649,3 723,6 788,5
kcal/h 95730 111690 143600 199440 255290 335060 442760 558440 622260 678110
Min. thermal flow rate
kW 22,26 25,98 33,4 46,38 59,36 77,92 102,96 129,86 144,72 157,7
kcal/h 19144 22343 28724 39887 51050 67011 88546 111680 124459 135622
Efficiency at 100% (ref. P.C.I.)
[1]
% 98,5 98,5 98,5 98,5 98,5 98,5 98,5 98,5 98,5 98,5
100% efficiency (ref. NCV)
[2]
% 107,8 107,8 107,8 107,8 107,8 107,8 107,8 107,8 107,8 107,8
30% efficiency (ref. NCV)
[1]
% 98,5 98,5 98,5 98,5 98,5 98,5 98,5 98,5 98,5 98,5
30% efficiency (ref. NCV)
[2]
% 109 109 109 109 109 109 109 109 109 109
Efficiency of 100% (stars)
[3]
% **** **** **** **** **** - - - - -
Efficiency of 30% (stars)
[3]
% **** **** **** **** **** - - - - -
Max gas flow rate - G20 Stm3/h 11,78 13,74 17,67 24,54 31,41 41,23 54,48 68,71 76,57 83,44
Min gas flow rate - G20 Stm3/h 2,36 2,75 3,53 4,91 6,28 8,25 10,9 13,74 15,31 16,69
Max gas flow rate - G30 kg/h 8,74 10,2 13,11 18,21 23,31 30,6 40,43 51 56,83 61,93
Min gas flow rate - G30 kg/h 1,75 2,04 2,62 3,64 4,66 6,12 8,09 10,2 11,37 12,39
Max gas flow rate - G31 kg/h 8,65 10,09 12,97 18,02 23,06 30,27 40 50,45 56,21 61,26
Min gas flow rate - G31 kg/h 1,73 2,02 2,59 3,6 4,61 6,05 8 10,09 11,24 12,25
Max air flow rate kg/h 180,83 210,97 271,25 376,73 482,22 632,90 836,34 1054,85 1175,40 1280,90
Max flue gas flow rate kg/h 175,52 204,73 263,28 365,65 468,01 614,33 811,75 1023,78 1140,89 1243,26
Min flue gas flow rate kg/h 35,10 40,96 52,66 73,13 93,59 122,86 162,34 204,75 228,18 248,65
Max. fluid flow rate kg/h 10320 12040 15480 21500 27520 36120 47730 60200 67080 73100
Min fluid flow rate kg/h 4128 4816 6192 8600 11008 14448 19092 24080 26832 29240
Pressure drops on exhaust side mbar 1,4 1,4 1,4 2,3 2,9 3,2 3,6 3,9 3,4 4
Chimney residual head mbar 0,2 0,5 0,5 0,5 0,5 0,5 0,5 0,5 0,5 0,5
Noise level dB(A) 62,5 62,5 63 65 66 68 68 68 68 68
Noise level < 40 0 0 0 0 0 0 0 0 0 0
mg/kWh < 40 50 50 50 50 50 50 50 50 50 50
NOx emissions 6666666666
NOx class
[4]
% 1,5 1,5 1,5 1,5 1,5 1,5 1,5 1,5 1,5 1,5
Max chimney heat losses
[2]
% 0,3 0,3 0,3 0,3 0,3 0,3 0,3 0,3 0,3 0,3
Coating heat losses
[2]
% 0,1 0,1 0,1 0,1 0,1 0,1 0,1 0,1 0,1 0,1
Heat losses with burn. Off
[2]
°C 50 50 50 50 50 50 50 50 50 50
CO 2 - G20 % 9,0 9,0 9,0 9,0 9,0 9,0 9,0 9,0 9,0 9,0
CO 2 - G30 %
CO 2 - G31 %
Condense production kg/h 13,96 16,28 20,94 29,08 37,22 48,86 64,56 81,42 90,74 98,88
Fluid pressure drop (ΔT=12K) mbar 18,9 25,7 42,6 28,7 47,1 35,4 25,3 40,2 50,0 59,3
Rated pressure bar 5 5 5 5 5 5 5 5 5 5
Total capacity l 150,0 204,3 204,3 288,0 288,0 347,0 469,0 440,0 506,0 506,0
Total weight Kg 340 430 430 650 711 842 1201 1665 1381 1381
Power supply V ~ Hz 230 ~ 50 230 ~ 50 230 ~ 50 230 ~ 50 230 ~ 50 230 ~ 50 230 ~ 50 230 ~ 50 230 ~ 50 230 ~ 50
Electric protection rating IP 40 40 40 40 40 40 40 40 40 40
Maximum absorbed power W 240 240 360 360 360 750 1150 1150 1150 1150
[1] Average temperature 70°C.
[2] Flow/ret. temperature 50/30°C.
[3] Efficiency Directive 92/42/EEC
[4] Ref. Standard UNI/EN 15502-1; 2015.
G20 (NCV - Hi). 9.45 kW/m3 (15°C, 1013 mbar)
G30 (PCI - Hi). 12.68 kW/kg (15°C, 1013 mbar)
G31 (PCI - Hi). 12.87 kW/kg (15°C, 1013 mbar)

General information12
CONTROL PANEL ACCESSORY
The control panels which can be installed on MONOLITE GT Boilers are mentioned in the table.
They must be ordered separately from the Boiler according to their technical characteristics and to the needs of the system served;
it is recommended to see also the ICI Caldaie S.p.A. CATALOGUE .
For the installation, refer to the manual supplied with the panel.
Description Code
Thermostatic control panel QACC10ELMCE
eterm Boiler control panel QETERM01CE
eterm system control panel QETERM02
eterm Easy manager panel QCTETERM
BURNERS
The burners are supplied together with MONOLITE GT Boilers and are CE marked in accordance with European Directives:
–European Regulation on Gas Equipment GAR 2016/426/EU
–Low Voltage Directive 2014/35/EU
–Electromagnetic Compatibility Directive 2014/30/EU
–Efficiency Directive 92/42/EEC.
Models up to 400kW comply with the Ecodesign of Energy-using Products Directive 2009/125/EC and with the delegated
Regulation (EU) no. 813/2013.
mIMPORTANT
To fit the burners on the MONOLITE GT Boilers refer to the specific chapter “BURNER ASSEMBLY” and to the relevant
manual of the appliance.

Installation 13
2 Installation
PRODUCT RECEIPT
Each phase of the appliance installation must be carried out by Qualied Personnel , wearing appropriate Personal Protective
Equipment (PPE) , in compliance with the national and local Laws in force.
An incorrect installation of the appliance or the failure to use PPE can cause severe damage to persons or property for which the
Manufacturer DECLINES ANY RESPONSIBILITY.
MONOLITE GT Boilers are supplied in six packages, indicated below, positioned on one pallet:
– BOILER BODY (1)
–thermally insulating mineral wool MATS (2) and fastening springs
– SLAT SUPPORT KIT (3)
– SLATS (4)
– CONTROL PANEL (5)
– BURNER (6)
–flow ELBOW (7) and thermoceramic material for burner head
7
5
3
2
4
6
1
mIMPORTANT
Upon receipt of MONOLITE GT Boiler, make sure that the supply is intact and undamaged and promptly contact ICI
CALDAIE S.p.A. if it does not correspond to the order
mIMPORTANT
The instruction manual is an integral part of the appliance and it MUST be carefully read before installing and
commissioning the Gruppo Termico, carefully stored for further consultations and it MUST always accompany il
Gruppo Termico.
mIMPORTANT
PACKAGING: as for packages, ICI CALDAIE S.p.A. complies with the specific recycling systems of each country, ensuring
an optimal reuse of them. All the materials used for the packaging respect the environment and can be recycled, such
as wood, plastic, cardboard.

Installation14
HANDLING
MONOLITE GT Boilers are equipped with fittings for lifting operations and, in any case,they must be carefully moved with
equipment suitable for their dimensions and weights.
aATTENTION
The Personal Protective Equipment required by current legislation must be used.
INSTALLATION ROOM
The room where MONOLITE GT Boilers are to be installed must be exclusively used for them, compliant with the Technical
Standards and the Law in force and equipped with adequately dimensioned vents.
The spaces around the Boiler and towards the ceiling must be suitable for:
–installing the appliance
–reaching the safety devices
–maintenance
–repairing any breakage
–opening the door of the installed burner, considering its opening direction (towards the right or the left).
≥ 2 m
≥ 2 m
≥ 2 m
≥ 2 m
aATTENTION
–Consider the spaces necessary to access the adjustment and safety devices and to perform maintenance in compliance
with the legislation in force in the place of installation.
–If the burner is fed with gas of specific weight greater than that of the air, the electrical parts must be positioned at least
500 mm from the ground.
mIMPORTANT
COMBUSTION AIR: MONOLITE GT Boilers MUST be installed in rooms which are permanently vented with adequately
dimensioned vents, according to the appliance’s thermal power, and which comply with the Technical Standards and
the national and local Laws in force at the place of installation.

Installation 15
SYSTEM CLEANING
Before connecting the Boiler to the system, it is MANDATORY to wash the pipes thoroughly in order to remove any residues which
may compromise the correct operation of the Boiler.
HYDRAULIC CONNECTIONS
The hydraulic circuit must be built by an authorised company or by qualified personnel, in compliance with theTechnical Standards
and the Law in force.
The components shall be charged to the installer that, at the end of the works, must issue a declaration of conformity.
mIMPORTANT
ICI CALDAIE S.p.A. is not liable for any harm to people, animals or property damage caused by errors in the choice of
components or in the construction of the plant.
mIMPORTANT
–Make sure that the hydraulic pressure measured downstream of the pressure regulator on the supply line does not
exceed the operating pressure indicated on the plate del Gruppo Termico.
–Make sure that the drains of the safety valves del Gruppo Termico and of the heater, if any, are connected to a drain
funnel, so that the valves do not flood the room in case of intervention.
–Make sure that the water and heating system pipes are not used as earthing point of the electrical system.
–Once the heating system has been filled, it is recommended to close the supply tap and keep it closed so that any
system losses can be signalled by an hydraulic pressure drop detected on the system manometer.
–For reasons of technical expertise, the system components must be chosen and installed by the installer, that must
operate in accordance with good practice regulations and Laws in force.
STARTING HYDRAULIC CIRCUIT
120 - 140 - 180 models
14
3
2
713
20
19
12
1212
1224
5
2214
16 119108
15
6
25
18
26
21
17
NOTE
If only one return is required, always use the low temperature one.

Installation16
250 - 320 - 420 models
14
3
2
7
13
20
19
12
1212
15 26
1416 22 24 125 11 9 6 10 8
25
18
21
17
555 - 700 - 780 - 850 models
14
3
2
7
13
20
19
12
1212
15
26
1416 22 24 12
58
6
10
9
5
11 23
25
18
21
17
1 Hydraulic backflow preventer
2 Y-shaped filter
3 Flow switch
4 Filling unit
5 Drain funnel with articulated elbow
pipe
6 Pressure gauge
7 Condensate neutraliser (see ICI
catalogue)
8 Pressure transducer
9 Pressure gauge tap
10 Shock-absorbing pipe
11 Safety valve no.1
12 Manual shut-off valve
13 Expansion vessel
14 Level probe glow plug (optional)
15 System flow
16 Fuel shut-off valve probe
17 Water inlet for system refill or top up
18 Medium-temperature return
19 Boiler drain
20 Acid condensate outlet
21 Neutralised condensate outlet
22 Air bleed valve
23 Safety valve no. 2 (only with thermal
power above 580 kW)
24 Fuel shut-off valve
25 Low-temperature return
26 Gas inlet

Installation 17
FLUE EXHAUST
The smoke duct and the connection to the chimney must be built in compliance with the Standards and the Laws in force, with
rigid pipes, suitable for the temperature, resistant to condensate, mechanical stresses and sealed.
mIMPORTANT
The smoke duct must have a diameter equal to or larger than the Boiler fitting.
Ø C
H6
Indicative scheme
Description u.m.
MONOLITE GT
120 140 180 250 320 420 555 700 780 850
H6 mm 241 241 241 358 358 358 308 308 308 308
Ø C mm 180 180 180 200 200 200 250 250 250 250
aDANGER
–the chimney must ensure the draught necessary for the Boiler operation and provided by the Technical Standards in
force, considering a “zero” pressure at the connection with the smoke duct
–unsuitable or badly dimensioned chimneys and smoke ducts can cause problems and adversely affect the combustion
parameters
–non-insulated drain pipes can lead to a potential risk and the tightness of the joints must be ensured with materials
resistant to the temperatures of the drain flue gases (we recommend at least 250°C)
–check that the chimney has an adequate draught and that is free from bottlenecks and waste.
CONDENSATE DRAIN
MONOLITE GT Boilers are equipped with a condensate drain pipe, derived from the appliance and the flue gas drain.
The condensate is acid and MUST be treated, by the installer, in compliance with the national and local Laws in force in the
country of installation.
The condensate acidity can be periodically checked using litmus test paper to determine the pH.
For the choice of the condensate neutraliser, which is system ACCESSORY to be ordered and purchased separately, use the ICI
catalogue.
mIMPORTANT
–The condensate drain pipe must be sealed and have dimensions ≥ than those of the appliance drain pipe and of the trap
and it must not have bottlenecks and reductions.
–It is recommended that it always has a slope ≥ than 3% towards the drain.

Installation18
DOOR OPENING
The door is adjusted in the factory with standard opening to the left (Sx) and hinges on the right (Dx).
120 - 140 - 180 models
For 120 , 140 , 180 models, the door is opened by“pulling”and moving it from the left (LH) to the right (RH).
Before opening the door:
–close the gas line shut-off valves and disconnect the pipes
–loosen the 4 nuts (1) and pull the door, which will slide and move towards the right (RH).
To move it towards the left (LH), operate as described in the following paragraph DOOR OPENING INVERSION.
1
250 - 320 - 420 - 555 - 700 - 780 - 850 models
250 - 320 - 420 - 555 - 700 - 780 models
The door is factory set with a standard opening from the left (LH) to the right (RH).
mIMPORTANT
The hinges of the opening side must have the nut (1) loosened and the conical washer (2) positioned towards the
base of the adjustment tie-rod.
aDANGER
IT IS DANGEROUS TO UNSCREW the ring nuts (3) of the door rotation hinges. Unscrewing them could cause the
detachment of the door, with possible severe damages to persons and property.
Before opening the door:
–close the gas line shut-off valves and disconnect the pipes
–use the lever (4) to unscrew and extract the ring nuts (5) of the two hinges on the opening side of the door and pull it
carefully.
4
35 12
Hinge of rotation
door side
Hinge of opening
door side

Installation 19
mIMPORTANT
To open the door of 420 Boiler WITH INSTALLED BURNER proceed as follows:
–close the gas shut-off valve and disconnect the burner line
–unscrew the hexagonal nut (6) by about 20mm
–move the burner backwards until it stops against the hexagonal nuts
–use the lever (4) to unscrew and extract the ring nuts (5) of the two hinges on the opening side of the door and pull it
carefully.
NOTE
Always keep the two ring nuts well tightened on the side opposite to the opening one.
6
4
5
DOOR OPENING INVERSION (FROM THE RIGHT TO THE LEFT)
To invert the door opening of 120 , 140 and 180 models, proceed as follows:
–leave the 4 nuts (1) which lock the door tightened
–slide the pin (2) out
–move the arm (3) to allow the access to the two screws fastening the support bracket (4) and then remove the two screws
–fasten the support bracket (4) on the Boiler left side using the two screws previously removed, inserting them into the two
relevant seats. Strongly tighten the screws
–connect the arm (3) to the support bracket (4) using the pin (2).
1
3
2
4
Sx
Dx
2
4
3