AIC NESTA CHROME 24 Manual

EN
installation
and maintenance
manual
FOR THE INSTALLER AND THE USER
24·32·38·45 kW
WALL — HUNG CONDENSING BOILER
F-111280 • 02
NESTA CHROME

G-2 F-111280_EN • 02
Table of ConTenTs
General InformatIon ................................G-4
Liabilities of the Manufacturer, the Installer
and the End user ..............................................G-4
About this Manual ............................................G-5
Safety Instructions ...........................................G-6
Package Contents ...........................................G-7
Boiler Marking ..................................................G-7
Product descrIPtIon ...............................G-8
NESTA CHROME 24-32-38-45 ........................G-8
General Description..........................................G-8
Frost Protection .......................................................G-8
Safety Devices .........................................................G-8
Optional equipment .................................................G-8
Control Panel and Main Functions.................G-10
Symbols and Messages on the Control Panel ...G-11
technIcal sPecIfIcatIons ........................G-12
Dimensions and Clearances...........................G-12
Performance and
Eciency Data ...............................................G-14
ErP Data .........................................................G-14
Combustion Data ...........................................G-15
Electrical Data ................................................G-15
Gas Data ........................................................G-16
Gas categories ...............................................G-16
Hydraulic Data................................................G-17
Pressure Drop Curve ......................................G-17
Flow Rate .......................................................G-17
InstructIons for the user......................G-18
Safety Instructions for the User......................G-18
Periodic checks .............................................U-19
Starting the Appliance....................................U-20
Stopping the Appliance..................................U-20
What to Do if... ...............................................U-20
Operating the Controller - End User Level .....U-21
Basic Settings ................................................U-24
Safety Instructions for the Installation............U-27
Handling the Product .....................................U-28
Unpacking the Product ..................................U-28
Installing and Preparing the Boiler .................U-28
Installing the Wall Bracket ..............................U-28
Installing and Removing the Condensate Trap ... U-29
Removing and Installing the Front Panel........U-30
Requirements for the Hydraulic Connections ..... U-31
Water Quality Requirements to Prevent
Scaling and Corrosion....................................U-32
Typical Hydraulic Connections - Heating Circuit.U-33
Hydraulic Connections - Cascaded boilers,
with External Domestic Hot Water Tank and
Plate Heat Exchanger.....................................U-34
Hydraulic Connections - Cascaded boilers,
with External Domestic Hot Water Tank and
Low Loss Header ...........................................U-35
Safety Instructions for the Gas Connection ...U-36
Conversion to Propane...................................U-37
Adjustment of Fan Speeds.............................U-38
Combustion Adjustment after Gas Conversion .. U-39
Safety Instructions for the Chimney Connections.U-41
General Instructions for the Installation of
AIC-approved Chimney Components............U-42
Chimney Connection......................................U-43
AIC-Approved Chimney Components............U-46
Engineering the Chimney System ..................U-48
Accessories ....................................................U-48
Calculation of the Chimney Length ................U-48
Equivalent Length of Chimney Components .......... U-48
Maximum Chimney Length (terminals incl.)............. U-48
Safety Instructions for the Electrical
Connections ...................................................U-49
Cables ............................................................U-49
Routing the Cables.........................................U-49
Wiring Diagram...............................................U-50
Accessing the High and Low Voltage Terminal
Strips and Electronic Board ...........................U-52
commIssIonInG .......................................u-53
Safety Instructions Before Start-up................U-53
Filling the System ...........................................U-53
Start-up and Commissioning .........................U-54
Combustion Adjustments (G20/G25/G31) .....U-55
Combustion Adjustments (G20Y20)...............U-55
Commissioning Wizard...................................U-56
Accessing the Commissioning Wizard.................... U-56
General Structure of the Commissioning Wizard .... U-57
maIntenance..........................................u-60
Safety Instructions for Maintenance ..............U-60
Maintenance Requirements ...........................U-61
Shutting Down for Maintenance.....................U-62
Draining the Boiler..........................................U-62
Restarting after Maintenance .........................U-62
Removing and Installing the Ignition and
Ionisation Electrodes......................................U-63
Removing and Installing the Fan and Air-Gas
Mixer Assembly..............................................U-64
Removing and Installing the Burner ...............U-66
Checking and Cleaning the Combustion
Chamber.........................................................U-68
Checking the Flue Pressure Switch operation...U-68
addItIonal InformatIon for the Installer.u-69
Optional Accessories .....................................U-69
Extension Modules................................................. U-69
Web Server Module ............................................... U-69
Cascade module.................................................... U-69
Hydraulic kits ......................................................... U-69
Boilers in a Cascade System .........................U-70
Weather Compensation Curve .......................U-72
Boiler Settings for the Installer .......................U-73
Access Levels........................................................ U-73
Selecting the User Level & Accessing the Complete
Parameter List ....................................................... U-73
Menus and Settings ............................................... U-73
Quick access to functions for the Installer.....U-74
Structure of Menus for the Installer................U-75
Error Codes and Solutions .............................U-78
Performing Reset ...........................................U-83
Troubleshooting..............................................U-84
Maintenance Messages .................................U-85
Installation Checklist ......................................U-86
Combustion Parameters - Log Sheet.............U-89
Water Parameters - Log Sheet.......................U-90
declaratIon of conformIty ....................u-91

G-3
F-111280_EN • 02
Index of IllustratIons
Fig. 1. Data Plate - Typical..............................................G-7
Fig. 2. Boiler Components .............................................G-9
Fig. 3. Control Panel..................................................... G-10
Fig. 4. Typical Display................................................... G-11
Fig. 5. Single Boiler Clearances.................................. G-12
Fig. 6. Clearances for Cascaded Boilers................... G-12
Fig. 7. Hydraulic pressure drop - N 24 to N 45 WH........... G-17
Fig. 8. Wall bracket Installation ....................................U-28
Fig. 9. Condensate Trap Installation............................U-29
Fig. 10. Removing/Installing the Access Panels..........U-30
Fig. 11. Typical Heating System ....................................U-33
Fig. 12. Cascaded Boilers, with External Domestic
Hot Water Tank and Plate Heat Exchanger....U-34
Fig. 13. Cascaded Boilers, with External Domestic
Hot Water Tank and Low Loss Header...........U-35
FIG. 14. NESTA CHROME Gas Valve............................U-36
Fig. 15. Gas Conversion - Orice Replacement..........U-37
Fig. 16. Fan Speed Adjustment - Typical Screen........U-38
Fig. 17. Combustion Adjustment - Control Panel .......U-39
Fig. 18. Combustion Adjustment on Gas Valve ..........U-40
Fig. 19. Routing the Electrical Cables N 24 WH to
N 45 WH .............................................................U-49
Fig. 20. Accessing the Terminal Strip and Electronic
Board...................................................................U-52
Fig. 21. Filling the System - Typical ...............................U-53
Fig. 22. Combustion Adjustment on Gas Valve ..........U-55
Fig. 23. Draining the Boiler - Typical..............................U-62
Fig. 24. Removing and Installing the Electrodes .........U-63
Fig. 25. Removing and Installing the Fan and
Air-Gas Mixer Assembly ...................................U-65
Fig. 26. Removing and Installing the Burner ................U-67
Fig. 27. Cleaning the Combustion Chamber...............U-68
Fig. 28. Testing the Flue Pressure Switch.....................U-68
Fig. 29. Extension Module..............................................U-69
Fig. 30. Cascade Module ...............................................U-69
Fig. 31. Web Server Module...........................................U-69
Fig. 32. Principles of Cascade .......................................U-70
Fig. 33. Cascading Module............................................U-70
Fig. 34. Cascade System with Plate Heat Exchanger /
Low Loss Header .............................................U-71
Fig. 35. Heating Curve Slope.........................................U-72
Appliance Naming
In the documentation, products of the Nesta Chrome range can be designated indierently using a full
name or abbreviated name:
“Nesta Chrome 24 (N 24 WH)” Nesta Chrome 24 or N 24 WH
“Nesta Chrome 32 (N 32 WH)” Nesta Chrome 32 or N 32 WH
“Nesta Chrome 38 (N 38 WH)” Nesta Chrome 38 or N 38 WH
“Nesta Chrome 45 (N 45 WH)” Nesta Chrome 45 or N 45 WH

Manufacturer
Our products are manufactured in compliance
with the requirements of the applicable Europe-
an Directives and standards, and are therefore
delivered with all the required documentation
and markings.
The quality of our products is essential to
us, and we aim therefore at improving them
continually. To this end, we reserve the right
to change the technical characteristics and
features of our products without prior notice.
Please check for the latest revision of the man-
ual on our website (www.myaic.eu).
The manufacturer shall not be held liable for
any malfunction of the product resulting from:
îThe failure to comply with the safety
and installation instructions provided
herein,
îThe failure to comply with the safety
and operation instructions and recom-
mendations provided herein,
îThe failure to have the appliance main-
tained regularly,
îA modi cation of the appliance that is
not approved by the manufacturer,
îThe use the product for any other pur-
pose than its intended use,
îThe use of components and accesso-
ries that are not approved by the man-
ufacturer.
Installer
The installer is responsible for the correct in-
stallation, conversion (as required) and com-
missioning of the appliance according to:
îThe instructions and recommendations
provided herein
îThe applicable regulations and standards
The installer shall provide the end-user with:
îAny relevant explanation about the op-
eration of the appliance and the heat-
ing system as well as the safety devices
that are provided,
îAny instruction regarding periodic
checks to be performed and possible
anomaly to be reported
îAll the documentation delivered with
the appliance and installed accessories.
The installer shall also inform the end-user of
the necessity to have the appliance checked
and maintained regularly by a quali ed profes-
sional.
End-user
To ensure the best performances and safety of
the appliance, the end-user shall:
îMake sure that the appliance is in-
stalled, converted (as required), com-
missioned and adjusted by a quali ed
professional,
îMake sure that the appliance is checked
and maintained regularly by a quali ed
professional,
îComply with all the instructions and rec-
ommendations provided in the appliance
documentation,
îMake sure to receive from the installer
all the necessary explanations related
to the operation of the appliance and
the safety devices,
îMake sure to receive from the installer
all the appliance and accessories doc-
umentation,
îKeep all the appliance documentation
in a safe place for future use.
The end-user shall use the product for its in-
tended use.
îShould the installer or the end user not comply with the instructions and require-
ments stated in this manual, the warranty will be void.
îFor more information on the warranty terms and conditions, please connect to
our website: www.myaic.eu.
i
G-4 F-111280_EN • 02
Liabilities of the Manufacturer, the Installer
and the End user
General InformatIon

This documentation is part of the product. It will be handed over to the end-user who will keep it,
with all the other applicable documents, in a safe place and readily available for use.
Before installing, operating or maintaining the appliance, please carefully read this manual and all
the applicable documents provided with the components and accessories. They contain essen-
tial safety information.
Symbols in this Manual Symbols on the Appliance
Symbols on the Packaging
Indicates an essential instruction
which, if not followed, can result
in a hazardous situation that can
cause serious damage to equip-
ment and/or injuries or death.
Indicates an important instruction
which, if not followed, could re-
sult in a hazardous situation that
could cause damage to equip-
ment and/or injuries.
Indicates an essential instruction
in relation with the presence of
electrical power and a danger of
electrical shock.
The appliance must be started/
stopped using the ON/OFF switch
installed on the appliance.
ON OFF
The electrical supply to the appli-
ance must be activated/deactivated
through the external circuit breaker
or the power supply cable must be
connected/disconnected.
The gas supply to the appliance must
be provided/shut down through the
external gas tap.
The water circuit of the appliance
must be full of water/empty.
The front and top access panel(s) of the
appliance must be removed/installed.
This side up
Keep dry
Fragile
Do not stack
The appliance must have cooled down.
Indicates important information.
i
Gas connection.
Ground / Earth.
Heating circuit supply connection.
Heating circuit return connection.
Heating circuit connection.
High Voltage - danger of electric shock.
Gas connection.
G-5
F-111280_EN • 02
General InformatIon
About this Manual
For an explanation of the symbols on the control
panel, please see “Symbols and Messages on
the Control Panel” on page G-11.
The prexes used in the page number-
ing indicate the following:
G- : General information
U- : Pages intended for the end user
I- : Pages intended exclusively for the
qualied professional (e.g. installer)
i

IF YOU SMELL GAS:
DO NOT:
îUse an open  ame
îSmoke
îUse electrical devices (phones,
doorbell, etc.) or switches
DO:
îClose the gas supply
îOpen all doors and windows to
ventilate the room
îInform the neighbours of the danger
by knocking at the doors.
îGet out of the building
îCall the gas company
îThis product is intended as a heat
generator for heating systems.
îThis appliance must be installed ac-
cording to the applicable local regula-
tions and standards.
îThis appliance can be used by chil-
dren who are at least 8 years old and
by persons with reduced physical,
sensory or mental capabilities or lack
of experience and knowledge, provid-
ed that they are under supervision or
have been given instructions concern-
ing the use of the appliance in a safe
way and that they understand the haz-
ards involved.
îCleaning and user maintenance shall
not be performed by children without
supervision. Children shall not play
with the appliance.
îAny modi cation to the appliance and
its components is strictly forbidden
without the prior written consent of the
manufacturer.
îIf components need to be replaced,
only genuine factory parts or compo-
nents approved by the manufacturer
must be used.
îWhen working on the appli-
ance and the system, make
sure to use the appropriate
tools to avoid damaging the
pipes and components.
îIf works need to be performed close to
the appliance (e.g. in the boiler room
or close to the air inlets), make sure
to shut down the appliance to prevent
dust from entering and accumulating
in the appliance.
îThe appliance contains a frost-protec-
tion feature that will protect the appli-
ance against frost, provided that the
appliance remains in operation and the
radiator valves are open.
îWhen unpacking the appli-
ance, check the integrity and
condition of the packaging
and that all the components
and accessories described
in the packing list are pres-
ent. Contact your supplier in
case of problem.
îWhen discarding the packaging, do not
contaminate the environment. Dispose of
it according to the applicable local regu-
lations on recycling.
i
G-6 F-111280_EN • 02
General InformatIon
Safety Instructions

Fig. 1. Data Plate - Typical
Nesta Chrome
Wall-Hung condensing Boiler | Wiszący kocioł kondensacyjny | Caldera mural de condensación | Caldaia murale
a condensazione | Wandcondensatieketel | Stenski kondenzacijski kotel | Wand-Brennwertkessel | Chaudière murale
à condensation | Caldeira mural de condensação | Настенный конденсационный котел | Zidni kondenzacijski kotao |
Λέβητας συμπύκνωσης τοίχου |Стенен газов кондензен котел | Cazan cu condensare suspendat
G20/G25 G31
Qmin
kW
Qn
kW
Pmin (80/60°C) kW
Pn (80/60°C)
kW
Pmin (50/30°C)
kW
Pn (50/30°C)
kW
Model
PIN
Serial No.
Date
MM.YYYY
AIC Europe No.
AIC Europe B.V.
Graafschap Hornelaan 163A
NL-6001 AC Weert
The Netherlands 1015 YY
G20 – 20 mbar
Adjusted | Skorygowana | Configurado | Regolato | Afgesteld op | Prilagojen | Eingestellt für | Réglé pour | Configurado |
Скорректировано | Podešen | Προσαρμοσμένη | Коригирано | Ajustat
Range
rated
EXAMPLE
G-7
F-111280_EN • 02
General InformatIon
Package Contents
îA NESTA CHROME boiler
îAn Installation and Maintenance manual
îA bracket and hardware for wall installation
îA condensate trap (syphon), to be installed
îA gas conversion kit
Refer to “Unpacking the Product” on page U-28
for the complete unpacking and installation in-
structions.
Boiler Marking
The data plate is located at the bottom of the boiler.
In addition, the S/N and appliance type are also
available on a sticker placed inside the front face
ap to make the information easily available if tech-
nical support is needed.
Symbol Description
Electrical data
PMS maximum operating
pressure
Tmax maximum primary
temperature
Vwater content
PMS maximum operating
pressure (DHW circuit)
Tmax maximum DHW
temperature
Vwater content
Chimney types
NOx class
The use of symbols on the data plate depends on the type of product.
i
Symbol Description
Qmin Minimum heat input
Qn Nominal heat input
Pmin (80/60°C) Minimum heat output (80/60°C)
Pn (80/60°C) Nominal heat output (80/60°C)
Pmin (50/30°C) Minimum heat output (50/30°C)
Pn (50/30°C) Nominal heat output (50/30°C)
CE sign for the compliance of the
device with CE directives
Note about handling waste
electronic equipment

G-8 F-111280_EN • 02
NESTA CHROME 24-32-38-45
General Description
This wall-hung series of NESTA CHROME boilers
consists of compact, low-emission condensing
appliances with a pre-mix burner, a stainless steel
heat exchanger and a lightweight casing.
The fully radial burner ensures a high modulation ra-
tio, combustion stability and very low NOx emissions.
The unique and proven “re-tube” heat exchanger
oers a large heat exchange surface to optimise
energy and heating eciency.
The NESTA CHROME series is designed for heat-
ing systems and can be used for Domestic Hot
Water production (provided that the system con-
tains an optional external tank).
The appliances are built for natural gas but can be
converted to operate with liqueed gas (propane),
by changing the gas valve orice and performing
additional setup. The gas conversion process must
take place before commissioning and comply with
applicable local regulations and standards.
NESTA CHROME boilers are able to control 3
heating circuits with mixing functions, through 3
optional extension modules. Each extension mod-
ule requires a power supply and a bus connection.
Refer to “Optional Accessories” on page U-69
for more information.
The appliance is not provided with a built-in cir-
culating pump. Therefore, the system must be
equipped with at least one pump for standard sys-
tem set up.
NESTA CHROME boilers can be connected in a
cascade conguration, which means that the boil-
ers are connected to the same water circuit and
electronic controller, with one boiler operating as
the “Principal”, and the others as “subsequent”).
Refer to “Boilers in a Cascade System” on page
U-70 for more information on cascade system
possibilities.
Frost Protection
The NESTA CHROME boilers have a built-in an-
ti-frost protection. The pump and the burner are
started as required when the return water temper-
ature drops below 5°C (as measured by the boiler
internal sensor installed on the return circuit).
Product descrIPtIon
The pump and/or burner will turn o when the re-
turn temperature reaches the required setpoint.
The anti-frost protection function only protects the
boiler, not the entire system.
Safety Devices
The NESTA CHROME boilers are equipped with a
series of sensors and switches that provide safety
for your appliance and heating system, such as:
îWater circuit temperature sensors (supply, re-
turn, system, etc.)
îGas pressure switch
îFlue pressure switch
îWater pressure sensor
îFlue temperature sensor
îAlarm contacts
The NESTA CHROME boilers are not provided with
the following mandatory safety equipment that the
installer must place in the system:
îExpansion tank, suitable for the system size
îSafety group, composed of a safety valve (pres-
sure rating adapted to the system), an automat-
ic relief valve and a manometer
îAir relief valve(s), at the high point(s) of the system
Optional equipment
Some optional equipment can be used with the
NESTA CHROME boilers. Please contact your AIC
representative for more information and a list of
available equipment.
To lengthen the life of your boiler and heating sys-
tem, in addition to the recommended water char-
acteristics described in “Water Quality Require-
ments to Prevent Scaling and Corrosion” on
page U-32, the following equipment can be in-
stalled in the heating circuit:
îWater lter / dirt separator
îAir separator
îLow loss header
îPlate heat exchanger
See “Requirements for the Hydraulic Connec-
tions” on page U-31 for more information on this
equipment.

1
2
3
4
12
11
10
9
13
14
15
17
16
18
5
6
7
8
11
10
20
19
G-9
F-111280_EN • 02
Product descriPtion
1. Concentric chimney connection (Ø 80/125 mm)
2. Gas valve, with throttle and oset screws for combustion
adjustment
3. Stainless steel “re tube” heat exchanger
4. Gas pipe
5. Flue exhaust pipe with temperature sensor
6. Stainless steel condens dish
7. Flue pressure switch
8. Heating return with temperature sensor
9. Electronic junction box (incl. boiler management unit - not
shown)
10. Control panel with LCD display
11. On-O switch
12. Condensate trap
13. Heating supply pipe
14. Ionisation electrode
15. Flame sight glass
16. Air vent
17. Ignition transformer
18. Burner assembly, with fan and air-gas mixer
19. Gas pressure switch
20. Air inlet to air-gas mixer
KEY
Fig. 2. Boiler Components

Fig. 3. Control Panel
12
3
30.12.2019 14:42
Flow temp 35°C
Return temp 32°C
Outside temp 18°C
DHW temp 55°C
System Automac
G-10 F-111280_EN • 02
Product descriPtion
Control Panel and Main Functions
1. LCD Display - The display illuminates whenever the
rotary selector is rotated or depressed, and remains
on for 8 minutes. For a detail of the symbols and
messages displayed on the screen, see “Symbols
and Messages on the Control Panel” on page
G-11.
2. Removable panel - To access the USB connector
and Reset button located underneath (showed in
light grey on the picture, for information).
3. Rotary selector - It can be used in 3 dierent ways:
îTurning the selector to the left or to the right
allows to scroll through the menus (icons/func-
tions) or increase/decrease a value after select-
ing a function.
When entering a menu/sub-menu, the slow
rotation of the selector to the right (clock-
wise) allows to scroll through the menu,
down to the last function. Turning the selec-
tor to the left (counter-clockwise) allows to
scroll up to the rst function of the menu.
îDepressing the selector (short push) allows to
select a function/value and validate a choice.
îDepressing the selector for more than 3 sec.
when an error is displayed on the screen, takes
you back to the Home screen. Doing the same
in Expert menus brings back to the Expert view
start page.
For more information on the operation and menus of the
controller, see ”Basic Settings” on page U-24.
i
KEY

G-11
F-111280_EN • 02
Product descriPtion
Fig. 4. Typical Display
30.12.2019 14:42
Flow temp 35°C
Return temp 32°C
Outside temp 18°C
DHW temp 55°C
System Automac
2
1
3
4
5
Symbols and Messages on the Control
Panel
The control panel display is divided into several
zones (See Fig. 4):
îa vertical menu bar (1) on the left side of the
screen, comprising a series of icons to access
various menus. When one of the icon is select-
ed and active, it displays against a black back-
ground (2). When one icon is selected and ac-
tivated by pressing the selector, the menu bar
disappears and gives way to the work area.
îa horizontal status bar (3) at the top of the
screen. It permanently displays the time and,
according to the situation, specic icons (Alarm,
Maintenance, Event, Manual adjustment, User
level and Producer in operation). See a detail of
the symbols below.
îa work area (4), comprising menu and func-
tion-specic information as well as operating
mode. It also displays a back arrow (5), allow-
ing to exit the work area and go back to the
vertical menu bar.
Service/settings. Gives access to setting op-
tions on device or system, allows to operate
special operations (e.g. for maintenance work)
and allows to log in, in expert view (access to
additional pages for the Installer only).
Diagnostics (Expert only). Analyze and test
info on the system.
Adjust/repair (Expert only). Allows to adjust
the parameters in the ‘Complete parameter
list’, and to access the commissioning wizard.
Symbols appearing in the horizontal status bar:
Alarm. Indicates an error in the system.
Maintenance/Special operations. It indi-
cates the presence of a maintenance mes-
sage or special operation feedback.
Manual mode. Indicates that the operating
modes on the topic pages are set to manual.
User type. This symbol with number 1, 2 or
3 indicates the access level:
1 - End user/commissioning
2 - Heating engineer/installer
3 - OEM
Producer. This symbol indicates the main
producer (e.g. oil/gas boiler, heat pump) that
is currently switched on.
Symbols and indications In the work area:
abc Selected item (text or icon)
abc Activated item (text or icon)
Back To go back to higher level in the menu
To return to the vertical menu bar icons
Symbols used in the manual to illustrate the oper-
ation of the selector:
turn the selector to the left or to the right
depress shortly the rotary selector
depress the rotary selector for more than
3 seconds.
Symbols of the vertical menu bar (some of them
will appear only if the circuit is enabled):
Home. Gives access to the System status
and change it from automatic to off.
Temperature. Gives access to the heating
functions and setpoints.
Ventilation. Not used.
Domestic Hot Water. Gives access to the
DHW-related functions.
Information. Gives access to messages
(history, errors, etc.), system information and
consumption information.

Min. 400 mm
Min. 400 mm
Min. 40 mm Min. 40 mm
Fig. 5. Single Boiler Clearances Fig. 6. Clearances for Cascaded Boilers
40 mm 40 mm
G-12 F-111280_EN • 02
technIcal sPecIfIcatIons
Dimensions and Clearances
Clearances Min. Recommended
top mm 400 1,000
bottom mm 400 700
front mm 700 1,000
sides mm 40*
* In a cascade conguration, boilers can be installed side-by-
side with a 40 mm clearance between them.
Wall bracket
location
445 mm
95 mm 110 mm
400 mm
600 mm
980 mm
880 mm

G-13
F-111280_EN • 02
Technical SpecificaTionS
N 24 WH N 32 WH N 38 WH N 45 WH
dry weight kg 53 64
connections (Ø)
supply/return ( ) [M] in. 3/4 1
gas ( ) [M] in. 3/4
chimney mm 80/125
N 24 WH N 32 WH N 38 WH N 45 WH
Amm 47
Bmm 145
Cmm 257
Dmm 329
Emm 179
Fmm 286
Gmm 288
A
B
C
D
E
F
G

G-14 F-111280_EN • 02
Technical SpecificaTionS
Performance and
Eciency Data
N 24 WH
(min. - max.)*
N 32 WH
(min. - max.)*
N 38 WH
(min. - max.)*
N 45 WH
(min. - max.)*
heat input (net) G20/G25/G31 kW 3,2 - 24,0 3,2 - 32,0 4,5 - 38,0 4,5 - 45,0
G20Y20 3,0 - 22,7 3,0 - 30,3 4,3 - 36,0 4,3 - 42,6
heat output at 80/60°C G20/G25/G31 kW 3,1 - 23,3 3,1 - 31,1 4,4 - 37,0 4,4 - 43,8
heat output at 50/30°C G20/G25/G31 kW 3,4 - 25,4 3,4 - 33,8 4,8 - 40,2 4,8 - 47,5
heating eciency 80/60°C G20/G25/G31 %97,0 97,0 97,3 97,3
heating eciency 50/30°C G20/G25/G31 %105,9 105,7 105,7 105,6
useful eciency at 30%
(return at 30°C) %108,4 108,4 107,7 107,7
seasonal eciency %93 93 93 93
* “min. - max.” stands for “@Min output” and “@Max output”
boiler type and model N 24 WH N 32 WH N 38 WH N 45 WH
condensing boiler Y/N YYYY
low temp boiler Y/N YYYY
combination heater Y/N NNNN
useful heat output
at 30% of rated heat
output (P1)kW 7,8 10,4 12,3 14,5
at rated output and high-
temp regime (P4)kW 23,3 31,1 37,0 43,8
useful eciency
at 30% of rated heat output (η1)%97,6 97,6 97,0 97,0
at rated output and high-
temp regime (η4)%87,3 87,3 87,6 87,6
auxiliary electricity consumption
at full load (elmax) kW 0,0675 0,0675 0,09 0,09
at part load (elmin) kW 0,016 0,016 0,0455 0,0455
in standby mode (PSB)kW 0,0028 0,0028 0,0033 0,0033
standby heat loss (Pstby)kW 0,05 0,05 0,055 0,055
annual energy consumption for
space heating kWh 11 428 14 760 18 018 20 950
sound power level indoors LWA dB 57 58 60 61
seasonal space heating energy
eciency class A
ErP Data

G-15
F-111280_EN • 02
Technical SpecificaTionS
Electrical Data N 24 WH N 32 WH N 38 WH N 45 WH
supply voltage / frequency / current V / Hz / A 230 / 50 / 6
protection class IP X4D
Combustion Data N 24 WH
(min. - max.)*
N 32 WH
(min. - max.)*
N 38 WH
(min. - max.)*
N 45 WH
(min. - max.)*
chimney type(s) B23, B23P, C13(x), C33(x), C43(x), C53(x), C63(x), C83(x), C93(x)
ue gas temperature at 80/60°C °C 60-67 60-67 60-67 60-67
ue gas temperature at 50/30°C °C 30-51 30-51 30-51 30-51
overheat ue gas temperature °C 110
max. ue gas pressure
(incl. max wind condition) Pa 160 210
Max. chimney length (80/125) m15 15
mass ow rate of ue gases g/s 1,47 - 10,33 1,47 - 13,98 2,1 - 16,64 2,1 - 19,7
max. condensate volume kg/h 2,9 3,9 4,6 5,5
CO emissions mg/kWh 25 31 43 57
CO2contents (G20) %8,7-9,3±0,2 8,7-9,1±0,1 8,6-9,1±0,2 8,6-9,1±0,2
CO2contents (G25) %8,7-9,3±0,2 8,7-9,3±0,2 8,5-9,1±0,2 8,5-9,1±0,2
CO2contents (G31) %10,3-10,9±0,2 10,3-10,9±0,2 10,4-10,9±0,2 10,4-10,9±0,2
O2contents
(G20/G20Y20) %5,4-4,3±0,3 5,4-4,6±0,15 5,5-4,6±0,3 5,5-4,6±0,3
O2contents (G25) %5,1-4,0±0,3 5,1-4,0±0,3 5,5-4,4±0,3 5,5-4,4±0,3
O2contents (G31) %5,2-4,3±0,25 5,2-4,3±0,25 5,0-4,3±0,3 5,0-4,3±0,3
NOx level (weighted) mg/kWh 35,1 35,1 37,6 37,6
NOx class 6
Fan speeds
G20/
G20Y20/
G25/G31
rpm Refer to “Adjustment of Fan Speeds” on page U-38.
Ignition fan
speed
G20/
G20Y20/
G25/G31
rpm 3300 2700
* “min. - max.” stands for “@Min output” and “@Max output”

G-16 F-111280_EN • 02
Technical SpecificaTionS
Gas categories Gas type Pressure (mbar) Country of destination
I2E(S,R) G20 20 BE
I2H G20 20 AT, CH, CZ, DK, EE, ES, FI, GB, GR, HR, HU,
IE, IT, LT, LV, NO, PT, RO, SE, SI, SK, TR
I2E G20 20 DE, PL, RO
I2ELL* G25 20 DE
I2EK* G20/G25.3 25 NL
I3P G31 30/37/50 AT, BE, CH, CZ, ES, FR, GB, GR, HR, HU, IE,
IT, LT, NL, PL, PT, SL, SK, RO, TR
II2E3P G20/G31 20/37 PL
II2EK3P* G20/G25.3/G31 20/25/37 NL
II2L3P G25/G31
20/25/37 FR
25/30 RO
II2H3P G20/G31
20/30 CZ, FI, RO
20/37 CH, CZ, GR, HR, IT, LT, SI, SK, TR
20/50 AT, CH, CZ, SK
II2Er3P G20/G25/G31 20/25/37/50 FR
Gas Data N 24 WH
(min. - max.)**
N 32 WH
(min. - max.)**
N 38 WH
(min. - max.)**
N 45 WH
(min. - max.)**
gas type(s) G20 - G20Y20 - G25 - G25.3 - G31
gas categories*** I2E(S,R), I2H, I2E, I2ELL, I2EK, I3P, II2E3P, II2EK3P, II2L3P, II2H3P, II2Er3P
gas
pressure
G20/G20Y20
(20 mbar) mbar 17-25
G25 (25 mbar) mbar 20-30
G25.3 (25 mbar) mbar 18-33
G31 (30/37/50 mbar) mbar 25-35 / 25-45 / 42,5-57,5
gas ow rate (G20)* m3/h 0,34 - 2,54 0,34 - 3,37 0,47 - 4,01 0,47 - 4,75
gas ow rate (G25)* m3/h 0,38 - 2,87 0,38 - 3,84 0,54 - 4,54 0,54 - 5,37
gas ow rate (G31)* m3/h 0,13 - 0,96 0,13 - 1,29 0,18 - 1,53 0,18 - 1,81
* 15°C, 1013.25 mbar, dry gas
** “min. - max.” stands for “@Min output” and “@Max output”
*** Gas categories I2E and I2H can operate with G20Y20 gas type
Appliances operating with gas categories I2E and I2H can also operate with G20Y20 gas type
(G20 natural gas + 20% Hydrogen). Please check your applicable local regulations for compli-
ance before any installation.
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G-17
F-111280_EN • 02
Technical SpecificaTionS
Hydraulic Data N 24 WH N 32 WH N 38 WH N 45 WH
water content l8,0 8,0 11,5 11,6
pressure drop at ∆T = 20k mbar < 40 mbar
minimum operating pressure bar 0,6
maximum operating pressure bar 6
maximum boiler temperature °C 85
Pressure Drop Curve
Flow Rate N 24 WH N 32 WH N 38 WH N 45 WH
minimum water ow rate
at ∆T = 20k l/min 17 23 27 32
Fig. 7. Hydraulic pressure drop - N 24 WH to N 45 WH
0
20
40
60
80
100
120
140
160
180
200
0 0,5 1 1,5 2 2,5 3 3,5 4 4,5 5
---------- rabmniporderusserP>
----------> Flow in cubic mtrs/hour
Pressure drop 24-32
Pressure drop 38-45

îThis appliance can be used by chil-
dren who are at least 8 years old and
by persons with reduced physical,
sensory or mental capabilities or lack
of experience and knowledge, pro-
vided that they are under supervision
or have been given instructions con-
cerning the use of the appliance in a
safe way and that they understand
the hazards involved.
îCleaning and user maintenance shall
not be performed by children without
supervision. Children shall not play
with the appliance.
îFor safety reasons, we recommend
that smoke and carbon monoxide
detectors are installed in the living ar-
eas of your building according to the
applicable local regulations.
îIf smoke is present, shut down the
appliance, ventilate the room and exit
the building. Then call your installer
to investigate and solve the problem.
îDo not store any  ammable, corrosive or
explosive products near the appliance.
îDo not modify or deactivate any compo-
nent, nor any safety device in the system.
îDo not operate the appliance when
the casing is open.
IF YOU SMELL GAS:
DO NOT:
îUse an open  ame
îSmoke
îUse electrical devices (phones,
doorbells, etc.) or switches
DO:
îClose the gas supply
îOpen all doors and windows to ven-
tilate the room
îInform your neighbours of the dan-
ger by knocking at the doors.
îGet out of the building
îCall your installer or gas company
îDo not modify or block the
condensate outlet(s).
îDo not open any sealed part
or component. Failure to
comply with this instruction
can result in damages and/
or injuries.
îThe sight glass can be very hot when
the appliance is in operation. Do not
touch the sight glass or its immediate
surroundings.
îMake sure that the appliance and the
heating system are prevented from
freezing.
îIn case of water leakage, disconnect
the appliance from the power supply
and gas source, turn o the water sup-
ply and call a quali ed professional.
îDo not modify any part of
the electrical system or ac-
cess internal components.
îDo not touch the appliance with any
wet body parts when the appliance is
supplied with electrical power.
G-18 F-111280_EN • 02
InstructIons for the user
Safety Instructions for the User

When cleaning the appliance
cabinet panels, do not use sol-
vents or aggressive/abrasive
cleaning agents. Wipe the sur-
faces using a soft clean cloth,
water and soap.
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îIf works need to be per-
formed close to the appli-
ance (e.g. in the boiler room
or close to the air inlets),
make sure that the appli-
ance is shut down to pre-
vent the ingress and accu-
mulation of dust.
îIn case of abnormal noises in the sys-
tem or the appliance, please notify a
quali ed professional.
îAny setting of the appliance by the
end-user using the installer-speci c
functions, that would cause the ap-
pliance to malfunction, could result in
damages to the equipment. Only the
end-user settings described in this
manual are available to the end-user.
îIf a condensate neutralisation sys-
tem is installed, have it checked and
cleaned at least once a year.
Disposal of the Product at the End of
Service Life
At the end of service life, the product
should not be disposed of as solid
urban waste, but should be handed
over to a di erentiated waste collec-
tion centre.
îCheck regularly that the wa-
ter pressure of the system is
at least 0,8 bar when cold. If
not, top up the system with
water as instructed by the
installer at appliance instal-
lation or call your installer.
îIf a topping up of the system is required
to maintain the minimum recommend-
ed water pressure, always turn the ap-
pliance o and only add small quanti-
ties of water at a time. If a large amount
of cold water is added in a hot appli-
ance, the appliance can be damaged
permanently.
îIf the system needs to be topped up
regularly, there may be a leak in the
system. In that case, call your installer.
îCheck regularly that there is no water
below the appliance. If there is, call
your installer
îCheck regularly that there is no error
code displayed on the control panel
screen. Call your installer as required.
U-19
F-111280_EN • 02
InstructIons for the user
Periodic checks

U-20 F-111280_EN • 02
InstructIons for the user
What to Do if... Cause Action
Boiler does not start No power supply
1. Check that the power button is in ON position (illumi-
nated).
2. Make sure the power supply is connected to the
mains.
3. Check the external power supply box (circuit break-
er) and reset it as required.
Error code 133 displayed Time out for ame ignition
1. Open controller removable panel and depress Reset
button. Refer to “Control Panel and Main Func-
tions” on page G-10
2. If the fault appears several times, call your installer.
Error code 111 displayed Temperature limit switch
open
Check that radiator valves are open/that there is ow
across the boiler.
Error code 105 displayed
Maintenance message
Select the Information icon ( ) for details. Refer to
“Symbols and Messages on the Control Panel” on
page G-11.
Maintenance icon ( )
Error code 118 displayed Low water pressure Rell the heating system.
Starting the Appliance
The rst start-up of the boiler after its
installation must be performed by a
qualied professional, according to the
procedure in “Start-up and Commis-
sioning” on page U-54.
Conditions:
Procedure:
1. Make sure that the power supply cable is
connected to the boiler.
2. Press the On/O switch located on the right
side of the control panel.
When in the ON position, the switch
remains illuminated.
3. Select the heating mode as required.
4. Activate the DHW mode as required.
Follow-on tasks:
Check the pressure of the circuit in operation. It
should be between 1.2 and 6 bar (with pump on).
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Stopping the Appliance
Conditions:
None
Procedure:
1. Press the On/O switch located on the right
side of the control panel.
When in the OFF position, the switch
internal light comes out.
2. To completely cut the power supply to the
boiler, either disconnect the power supply
cable from the boiler, or use the external cir-
cuit breaker.
Follow-on tasks:
None
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To remove an error code from the display temporarily and go back to the Home screen, de-
press the rotary selector for more than 3 seconds.
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