AIC NESTA 300 Manual

EN
installation
and maintenance
manual
FOR THE INSTALLER AND THE USER
300 kW
FLOOR — STANDING CONDENSING BOILER
A-136280 • A
NESTA

G-2 A-136280_EN ● A
Table of ConTenTs
Index of IllustratIons ..............................G-3
About our Boilers .............................................G-3
Liabilities of the Manufacturer, the Installer and the
End user ...........................................................G-4
About this Manual ............................................G-5
Safety Instructions ...........................................G-6
Boiler Marking ..................................................G-7
Package Contents ...........................................G-7
Product descrIPtIon ...............................G-8
Nesta 300 .........................................................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
Gas Data ........................................................G-16
Electrical Data ................................................G-15
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-21
Basic Settings ................................................U-22
Structure of Menus for the End User .............U-25
Product InstallatIon .............................. I-27
Safety Instructions for the Installation............. I-27
Handling the Product ...................................... I-28
Unpacking the Product ................................... I-28
Installing and Preparing the Boiler .................. I-28
Removing and Installing the Access Panels ... I-29
Requirements for the Hydraulic Connections . I-30
Water Quality Requirements to Prevent Scaling and
Corrosion in a Heating System........................ I-31
Typical Hydraulic Connections - Heating CircuitI-33
Hydraulic Connections - Cascaded boilers, with
External Domestic Hot Water Tank and Plate Heat
Exchanger ....................................................... I-34
Hydraulic Connections - Cascaded boilers, with
External Domestic Hot Water Tank and Low Loss
Header............................................................. I-35
Safety Instructions for the Chimney Connections . I-36
Chimney Connection....................................... I-38
Air Intake Grid Installation in Chimney Systems .. I-39
Engineering the Chimney System ................... I-40
Accessories ..................................................... I-40
Safety Instructions for the Gas Connection .... I-41
Gas Conversion............................................... I-42
Preparing the Boiler for Gas Conversion...................I-43
Adjustment of Fan Speeds.......................................I-44
Combustion Adjustment for Gas Conversion . I-45
Safety Instructions for the Electrical
Connections .................................................... I-47
Connections .................................................... I-47
Accessing the Low Voltage Terminal
Strip and Electronic board............................... I-48
Accessing the High Voltage Terminal Strip ..... I-49
Routing the Cables.......................................... I-49
Wiring Diagram................................................ I-50
commIssIonInG ........................................ I-52
Safety Instructions Before Start-up................. I-52
Filling the System ............................................ I-52
Start-up and Combustion Adjustments .......... I-53
maIntenance........................................... I-54
Safety Instructions for Maintenance ............... I-54
Maintenance Requirements ............................ I-55
Shutting Down for Maintenance...................... I-56
Draining the Boiler........................................... I-56
Restarting after Maintenance .......................... I-56
Cleaning the Condensate Pipe and Trap......... I-57
Removing and Installing the Fan and Air Adapter
Assembly......................................................... I-58
Removing and Installing the Air-Gas Mixer ..... I-60
Removing and Installing the Ignition and Ionization
Electrodes ....................................................... I-62
Removing and Installing the Burner ................ I-63
Checking and Cleaning the Combustion Chamber I-64
Replacing the Gas Valve Filter......................... I-64
Checking the Flue Gas (FPS) and Air (APS) Pres-
sure Switches operation.................................. I-65
addItIonal InformatIon for the Installer.. I-66
Optional Modules ............................................ I-66
Extension Modules & Cable Hub..............................I-66
Web Server Module .................................................I-66
Cascading module...................................................I-66
Boilers in a Cascade System .......................... I-67
Boiler Settings for the Installer ........................ I-70
Access Levels..........................................................I-70
Commissioning Menu ..............................................I-70
Menus and Settings .................................................I-70
Structure of Menus for the Installer................. I-70
Error Codes and Solutions .............................. I-74
Maintenance Messages .................................. I-79
Troubleshooting............................................... I-80
Installation Checklist ....................................... I-82
Combustion Parameters - Log Sheet.............. I-85
Water Parameters - Log Sheet........................ I-86
Gas conversion - Log Sheet............................ I-87
declaratIon of conformIty ..................... I-88

G-3
A-136280_EN ● A
Index of IllustratIons
Fig. 1. Data Plate - Typical..............................................G-7
Fig. 2. Gas Conversion Label - Typical .........................G-7
Fig. 3. Nesta 300 Boiler Components - Front & Rear
Views ...............................................................................G-9
Fig. 4. Control Panel..................................................... G-10
Fig. 5. Typical Display................................................... G-11
Fig. 6. Single Boiler Clearances.................................. G-13
Fig. 7. Clearances for Cascaded Boilers................... G-13
Fig. 8. Boiler transport and Installation .........................I-28
Fig. 9. Removing/Installing the Access Panels............I-29
Fig. 10. Typical Heating System ......................................I-33
Fig. 11. Cascaded Boilers, with External Domestic Hot
Water Tank and Plate Heat Exchanger .............................I-34
Fig. 12. Cascaded Boilers, with External Domestic Hot
Water Tank and Low Loss Header ....................................I-35
Fig. 13. Air intake grid removal from storage .................I-39
Fig. 14. Air intake grid installation ....................................I-39
Fig. 15. Accessing the Gas Valve ....................................I-43
Fig. 16. Gas Valve - Pre-adjustments for Propane.......I-43
Fig. 17. Fan Speed Adjustment - Typical Screen..........I-44
Fig. 18. Combustion Adjustment on Gas Valve ............I-45
Fig. 19. Combustion Adjustment - Control Panel .........I-46
Fig. 20. Accessing the Low Voltage Terminals and Elec-
tronic Board ..........................................................................I-48
Fig. 21. Accessing the High Voltage Terminals..............I-49
Fig. 22. Routing the Electrical Cables .............................I-49
Fig. 23. Filling the System - Typical .................................I-52
Fig. 24. Draining the Boiler - Typical................................I-56
Fig. 25. Cleaning the Condensate Pipe and Trap..........I-57
Fig. 26. Removing and Installing the Fan and Adapter
Assembly ..............................................................................I-59
Fig. 27. Removing and Installing the Air-gas Mixer.......I-61
Fig. 28. Removing and Installing the Electrodes ...........I-62
Fig. 29. Removing and Installing the Burner ..................I-63
Fig. 30. Cleaning the Combustion Chamber.................I-64
Fig. 31. Replacing the Gas Valve Filter ...........................I-64
Fig. 32. Testing the Air Pressure Switch and Flue Pressure
Switch ...............................................................................I-65
Fig. 33. Optional Modules and Cable Hub.....................I-66
Fig. 34. Cascading Module..............................................I-66
Fig. 35. Web Server Module.............................................I-66
Fig. 36. Principles of Cascade .........................................I-67
Fig. 37. Cascading Module..............................................I-67
Fig. 38. Cascade System with Plate Heat Exchanger .I-68
Fig. 39. Cascade System with Low Loss Header........I-69
About our Boilers
Compliance
All our boilers are compliant with the following directives and regulations:
îGAR 2016/426/EU
îBED 92/42/EEC
îLVD 2014/35/EU
îEMC 2014/30/EU
îErP 2009/125/EC
îRoHS 2011/65/EU
Boiler Naming

abbreviated name:
îNesta 300 or N 300 FS

G-4 A-136280_EN ● A
General InformatIon
Liabilities of the Manufacturer, the Installer and the End user
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-5
A-136280_EN ● A
General InformatIon
About this Manual
For an explanation of the symbols on the control
panel, refer to “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
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 an important piece of
information.
i
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-6 A-136280_EN ● A
General InformatIon
Safety Instructions
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

Nesta
Floor-Standing Condensing Boiler | Stojący kocioł kondensacyjny | Caldera de condensación de pie | Caldaia a condensazione
a basamento | Condenserende ketel-vloermodel | Talni kondenzacijski kotel | Standbrennwertkessel | Chaudiére sol á
condensation | Caldeira de Condensação de chão | Напольный конденсационный котел | Podni kondenzacijski kotao |
Επιδαπέδιος Λέβητας Συμπύκνωσης |Подов Кондензен Котел | Cazan in condensatie de sol | Kondenzációs álló gázkazán
Qn
G20/G25 kW
G31 kW
G20Y20
Pn (80/60°C)
G20/G25 kW
G31 kW
G20Y20
Pn (50/30°C)
G20/G25 kW
G31 kW
G20Y20
Model
PIN
Serial No.
Date
MM.YYYY
AIC Europe No.
AIC Europe B.V.
Graafschap Hornelaan 163A
NL-6001 AC Weert
The Netherlands
G20 – 20 mbar
Adjusted | Skorygowana | Configurado | Regolato | Afgesteld op | Prilagojen | Eingestellt für | Réglé pour | Configurado |
Скорректировано | Podešen | Προσαρμοσμένη | Коригирано | Ajustat | Gyári beállítás
1015 YY
kW
kW
kW
EXAMPLE
Fig. 1. Data Plate - Typical
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 indicating the compliance
of the device with CE directives
UKCA sign indicating the compliance
of the device with UK regulations
Note about handling electronic
equipment waste
G-7
A-136280_EN ● A
General InformatIon
Boiler Marking
The data plate is located at the back of the boiler.
The conversion sticker (yellow), is located under
the appliance data plate.
Package Contents
îA Nesta 300 boiler
îAn Installation and Maintenance manual
Refer to “Unpacking the Product” on
page I-28 for the complete unpacking
and installation instructions.
i
Gas conversion label
This appliance was converted on ______________ /______________ /______________
day month year
from gas _________________ (______ mbar) to gas _________________ (______ mbar)
gas type (G20 / G20Y20 / G25 / G25.3 / G31) and its pressure
with kit ________________________________________________________________
fill in with the kit name or number (if required) or cross it out
by ___________________________________________________________________
name and address of the organisation carrying out the conversion procedure and validating its correctness
Please read the Gas Conversion Procedure and follow all safety information, warnings and procedures.
Failure to follow all instructions could cause severe personal injuries, death or property damage!
Place this label UNDER the existing data plate. DO NOT cover up the existing data plate.
Fig. 2. Gas Conversion Label - Typical

G-8 A-136280_EN ● A
Product descriPtion
Product descrIPtIon
Nesta 300
General Description
ompact,
low-emission condensing appliances with a pre-mix
burner and a stainless steel heat exchanger. The
housing of the boiler is made of aluminium.
The fully radial burner ensures a high modulation ratio,
combustion stability and very low NOx emissions.

capacity and a large heat exchange surface to opti-

This boilers are designed for heating systems and can
be used for indirect Domestic Hot Water production
(provided that the system contains an optional exter-
nal tank).
The appliances are built for natural gas (G20) but can
       

gas (propane) or G20Y20 mixture, according to the
procedure provided with the boiler. Gas conversion
must comply with applicable local regulations and
standards.
Nesta boilers are able to control 3 heating circuits with
mixing functions, through 3 optional extension mod-
ules . Each extension module requires a power supply
and a bus connection. Refer to “Optional Modules”
on page I-66 for more information.
These appliances are not provided with a built-in cir-
culating pump. Therefore, the hydraulic system must
be equipped with at least one pump for standard sys-

The Nesta boilers can be connected in a cascade
-
nected to the same water circuit and electronic con-
troller, with one boiler operating as the master, and the
others as “slaves”). Refer to “Boilers in a Cascade
System” on page I-67 for more information on cas-
cade system possibilities.
Frost Protection
The Nesta boilers have a built-in anti-frost protec-
tion. The pump and the burner are started as re-
quired when the return water temperature drops
below 5°C (as measured by the boiler internal sen-
sor installed on the return circuit). The pump and/

reaches the required setpoint. The anti-frost pro-
tection function only protects the boiler, not the en-
tire system.
Safety Devices
The Nesta 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.)
îBurner plate temperature limit switch
îGas pressure switch
îAir pressure switch
îFlue pressure switch
îWater pressure sensor
îFlue temperature sensor
îCondensate level switch
îAlarm contacts
The Nesta boilers are not provided with the follow-
ing 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 automatic
air relief valve and a manometer,
îAir relief valve(s), at the high point(s) of the sys-
tem.
Optional equipment
Some optional equipment can be used with the
Nesta boilers. Please contact your AIC Europe rep-
resentative for more information and a list of availa-
ble 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 in a
Heating System” on page I-31, the following
equipment can be installed in the heating circuit:
î
îDirt separator
îLow loss header
îPlate heat exchanger
îAir separator
See “Requirements for the Hydraulic Connec-
tions” on page I-30 for more information on this
equipment.

G-9
A-136280_EN ● A
Product descriPtion
KEY
Fig. 3. Nesta 300 Boiler Components - Front & Rear Views
1. Fan and burner assembly
2. Air inlet duct
3. Ignition electrode
4. Hoisting ring
5. Water pressure sensor
6. Heat exchanger
7. 
8. Heating return connection, with temperature sensor
9. Condensate vent
10. Condensate level switch
11. Condensate trap
12. Condensate pipe
13. Drain connection
14. Electronic main board and cable hub (for optional module
connection, see “Optional Modules” on page I-66)
15. Electronic junction box
16. Control panel with LCD display
17. Burner plate temperature limit switch
18. Air adapter
19. Gas valve
20. Ionization electrode
21. Manual air vent
22. Heating supply connection, with temperature sensor
23. Flue gas temperature sensor
24. Flue gas connection
25. Condensate drain
26. Rear electrical box (high voltage terminal strip)
27. Gas pipe
28. Gas pressure switch
29. Ignition transformer
30. Air pressure switch
31. Flue pressure switch
1
2
3
4
5
6
7
8
8
9
10
11
12
13
14
15
16
17
30
19
20
21
22
23
31
24
25
26
27
28
29
2
18

0 4 8 12 16 20 24
OK
ESC
11
Fig. 4. Control Panel
G-10 A-136280_EN ● A
Product descriPtion
Control Panel and Main Functions
1. Domestic Hot Water on/o button - Pressing this button ac-
tivates/deactivates of the Domestic Hot Water function ( ).
2. LCD Display - The display illuminates whenever a control
is 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.
3. Heating mode selection button - Pressing this button
activates/deactivates one of the four following heating
mode:
• Automatic mode ( )
• Comfort mode ( )
• Reduced mode ( )
• Protection mode ( )
4. Information display button - Pressing this button dis-
plays more information on the screen (e.g. details of an
error or maintenance code, special mode messages and
INFO lines). It also allows to access the various user lev-
els of the controller menus.
5. Chimney sweep function button - This button allows to

6. Manual operation mode button - The operation de-
-
el). It can also be used to activate the bleeding function
using an air purge installed at all high points of the circuit.
7. Conrmation button - This button allows to access the setting
menus for the end user, and to validate a value or a selection.
8. Rotary selection knob - Turning the knob to the left or to
the right allows to scroll through the menus or increase/
decrease a value.
9. Escape button - To cancel any ongoing operation or go
back to the Home screen.
10. Reset button - To reset an error code displayed on the
screen.
11. Service Socket (BSB) - Not used
For more information on the operation and menus of the
controller, see”Basic Settings” on page U-22.
KEY
1
2
3
4
5
6
7
8
9
10

Fig. 5. Typical Display
1 2
3
4
G-11
A-136280_EN ● A
Product descriPtion
Symbols and Messages on the Control
Panel
The following symbols are present on the control
panel (See Fig. 5):
Domestic Hot Water mode. At activation,
this mode also ensures that the water is
heated up to 65°C once a week to prevent
any development of legionella bacteria in the
DHW circuit. When activated, a black line (1)
is displayed under the symbol.
Automatic mode. This mode operates the
boiler according to a scheduled programme,

() and Reduced ( ) modes. The ECO func-
tion is active (automatic summer/winter
changeover). It also allows the anti-frost and
overheating protections to be active. When
this mode is activated, a black line is dis-
played under the symbol.
Comfort mode. This mode operates the
appliance, up to the temperature setpoint
-
tains it continuously (no scheduler). It also
allows the anti-frost and overheating protec-
tions to be active. The ECO function is NOT
active (automatic summer/winter changeo-
ver). When this mode is activated, a black
line is displayed under the symbol.
Reduced mode. This mode operates the
appliance, up to the temperature setpoint
-
tains it continuously (no scheduler). It also
allows the anti-frost and overheating protec-
tions to be active. When the mode is activat-
ed, a black line is displayed under the sym-
bol.
Protection mode. In this mode, the heating
system is disabled, but the anti-frost and
overheating protections remain active.
Information.
Chimney sweep.
Manual mode.
Reset.
The following symbols are displayed on the screen
(See Fig. 5):
Comfort mode active (3). The time scale (4)
at the bottom of the display indicates the
period during which this mode is active (in
the screen below, the automatic mode, with
scheduler active).
Reduced mode active.
Frost protection active. The appliance will
heat up to the frost-protection setpoint.
Process in progress.
Holiday function active.
12
3Reference to heating circuits.
The burner is in operation.
Maintenance message.
Fault message - An error has occurred and
a fault code and text can be displayed on the
screen by pushing on the Info button.
INFO Information level active (2)
PROG Setting level active - the parameters can be
changed.
ECO Heating system switched o, but ECO
function active.

G-12 A-136280_EN ● A
technIcal sPecIfIcatIons
Dimensions and Clearances
Dimensions & weight N 300 FS
Amm 648
B mm 1524
C mm 793
D mm 721
Emm 681
Fmm 890
Gmm 534
Hmm 471
Imm 167
Jmm 1324
Kmm 1313
Lmm 1098
Mmm 400
Nmm 361
Omm 141
Pmm 334
Qmm 152
Rmm 128
dry weight kg 283
B
A
E
F
C
D
P
Q
R
G
H
I
J
K
L
M
N
O

400
500
500
500
500
500
160
1,000
Fig. 6. Single Boiler Clearances
Fig. 7. Clearances for Cascaded Boilers
G-13
A-136280_EN ● A
Technical SpecificaTionS
Connections N 300 FS
supply/return connections ( ) Ø - [M] in. 2 1/2
safety group connection ( ) Ø - [F] in. 1
gas connection ( ) Ø - [M] in. 1 1/2
Ømm 180
combustion air inlet connection Ømm 125
condensate drain connection Ømm 25
min. cross section area of air inlet mm212 000
Clearances Min. Recommended
top mm 400 800
back mm 500 700
front mm 1000 1 000
sides mm 500*

side with a 160 mm clearance between them. Side clearance

boiler in the chain.
In case of gas conversion, side clearance must be at least 500 mm

G-14 A-136280_EN ● A
Technical SpecificaTionS
ErP Data
 N 300 FS
(min. - max.)*
heat input (net)
G20/G25
kW
31,0 - 280,0
G31 55,0 - 280,0
G20Y20** 31,0 - 280,0
heat output at 80/60°C
G20/G25
kW
30,0 - 272,0
G31 53,3 - 273,8
G20Y20** 30,0 - 272,0
heat output at 50/30°C
G20/G25
kW
33,2 - 300,0
G31 57,9 - 295,1
G20Y20** 33,2 - 300,0
 G20 %96,83 - 97,25
 G20 %107,21 - 107,14
 %108,09
 %93,0
* “min. - max.” stands for “@Min output” and “@Max output”
** up to 20vol.% hydrogen
boiler type and model N 300 FS
condensing boiler Y/N Y
low temp boiler Y/N Y
combination heater Y/N N
useful heat output
at 30% of rated heat output (P1)kW 51,97
at rated output and high-temp regime (P4)kW 272,0
useful eciency
at 30% of rated heat output (η1)%97,39
at rated output and high-temp regime (η4)%87,71
auxiliary electricity consumption
at full load (elmax) kW 0,41
at part load (elmin) kW 0,034
in standby mode (PSB)kW 0,012
standby heat loss (Pstby)kW 0,25
annual energy consumption for space heating GJ 468
sound power level indoors LWA dB 79

G-15
A-136280_EN ● A
Technical SpecificaTionS
Electrical Data N 300 FS
supply voltage / frequency V / Hz 230 / 50
protection class IP X4D
Combustion Data N 300 FS
(min. - max.)*
chimney type(s) B23, B23p, C43, C53, C63, C83
 °C 55,7 - 61,9
 °C 29,7 - 34,6
 °C 97,0

(incl. max wind condition) Pa -25 - 200,0
 g/s 13,0 - 120,0
max. condensate volume kg/h 36,0
CO emissions mg/kWh 66,59
CO2contents**
G20 min output %8,0
max output %8,7
G25 min output %8,1
max output %9,3
G31 min output %10,5
max output %10,5
G20Y20 min output %6,3
max output %7,6
O2contents**
G20 min output %6,7
max output %5,5
G25 min output %6,2
max output %4,0
G31 min output %5,0
max output %5,0
G20Y20 min output %8,9
max output %6,5
NOx level mg/kWh 24,0
NOx class 6
* “min. - max.” stands for “@Min output” and “@Max output”
** Tolerance is +/- 0.3%

G-16 A-136280_EN ● A
Technical SpecificaTionS
Gas Data N 300 FS
(min. - max.)*
gas type(s) G20 - G20Y20 - G25 - G25.1 - G25.3 - G31
gas pressure
G20/G20Y20 (20 mbar) mbar 17 - 25
G25 (25 mbar) mbar 20 - 30
G25.1 (25 mbar) mbar 18 - 33
G25.3 (25 mbar) mbar 20 - 30
G31 (30/37/50 mbar) mbar 25 - 35 / 25 - 45 / 42,5 - 57,5
 m3/h 3,29 - 29,02
 m3/h 3,75 - 33,08
 m3/h 2,25 - 11,51
 m3/h 3,82 - 33,95
* “min. - max.” stands for “@Min output” and “@Max output”
** 15°C, 1013.25 mbar, dry gas
Gas category Gas type Gas pressure Country of destination
I2E(S) G20 20 mbar BE
I2H G20 20 mbar AT, CH, CY, CZ, DK, EE, ES, FI, GB, GR, HR, IE, IT, LT, LV, NO, PT,
RO, SE, SI, SK, TR
I2E G20 20 mbar DE, PL, RO, NL
I2ELL G20/G25 20 mbar DE
I2HS G20/G25,1 25 mbar HU
I2N G20/G25 20/25 mbar BE, DE, DK, ES, FR, GR, NL, PL, PT, SI
I2EK G20/G25,3 25 mbar NL
I3P G31
30 mbar CZ, NL, RO
37 mbar BE, CH, CZ, ES, FR, GB, GR, HR, IE, IT, LT, NL, PL, PT, SI, SK, TR
50 mbar AT, BE, CH, CZ, DE, ES, FR, GB, NL, SK
I2E(R) G20 20 mbar BE
II2E3P G20/G31 20/37 mbar PL
II2E3P G20/G31 20/50 mbar DE
II2E(S)3P G20/G31 20/37/50 mbar BE
II2EK3P G20/G25,3/G31 20/25/37/50 mbar NL
II2H3P G20/G31
20/30 mbar CZ, RO
20/37 mbar CH, CZ, ES, GB, GR, HR, IE, IT, LT, PT, SI, SK, TR
20/50 mbar AT, CH, CZ, ES, GB, SK
II2L3P G25/G31 25/37/50 mbar FR
20/30 mbar RO
II2E+3P G20/G31 20/25/37/50 mbar BE, FR
II2E(R)3P G20/G31 20/37/50 mbar BE
II2Esi3P G20/G25/G31 20/25/37/50 mbar FR
II2Er3P G20/G25/G31 20/25/37/50 mbar FR
II2ELL3P G20/G25/G31 20/50 mbar DE
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
compliance before any installation.
i

G-17
A-136280_EN ● A
Technical SpecificaTionS
Hydraulic Data N 300 FS
water content l75
 mbar 30,31
minimum operating pressure bar 0,8
maximum operating pressure bar 6
maximum boiler supply temperature °C 85
Pressure Drop Curve
Flow Rate N 300 FS
 m3/h 11,22
0
10
20
30
40
50
60
70
80
0 2 4 6 8 10 12 14 16 18
Pressure drop [mbar]
Flow rate [m3/h]

G-18 A-136280_EN ● A
InstructIons for the user
Safety Instructions for the User
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.

U-19
A-136280_EN ● A
InstructIons for the user
Periodic checks
îCheck regularly that the wa-
ter pressure of the system is
at least 1.2 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.
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.
i
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.

U-20 A-136280_EN ● A
InstructIons for the user
Starting the Appliance
The rst start-up of the boiler after its in-
stallation must be performed by a qual-
ied professional, according to the pro-
cedure in “Start-up and Combustion
Adjustments” on page I-53.
Conditions:
Procedure:
1. Make sure that the power supply cable is
connected to the boiler.
2.        
right side of the boiler.
When in the ON position, the switch
remains pushed in and is 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).
i
i
Stopping the Appliance
Conditions:
None
Procedure:
1. 
side of the boiler.
When in the OFF position, the switch
is released from its pushed in position.
Its built-in light goes o and the button
comes ush with the outer frame.
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
i