Navien NCB300-28K User manual

Navien LTD
Building 2, Guildford Business Park, Guildford, GU2 8XH
TEL [phone] www.navien.co.uk
Getting Service
If your boiler requires service, you have several options for getting service:
●Contact an official Technical Assistance Service (TAS) at 0844 332 2323 or go to the website
(www.navien.co.uk).
For warranty service, always contact an official Technical Assistance Service (TAS) first.
●Contact the technician or professional who installed your boiler.
●Contact a Gas Safe Registered engineer.
When contacting an official Technical Assistance Service (TAS), please have the following information
available:
●Model number
●Serial number
●Date purchased
●Installation location and type
●Error code, if any appears on the front panel display
Condensing Combi Boiler
Installation & Operation
Manual
Version: 1.0(August, 2022)

●These appliances are for use with natural gas or LPG.
(An LPG conversion kit is included with the boiler.)
●Type: B23-C13-C33-C53-C83
Gas Model
Natural Gas
NCB300-28K
NCB300-37K
NCB300-41K
LPG
NCB300-28K
NCB300-37K
NCB300-41K
Keep this manual near this boiler for future reference
whenever maintenance or service is required.
Installation &
Operation
Manual
WARNING
If the information in these instructions is not followed exactly, a fire or explosion may
result, causing property damage or personal injury.
– Do not store or use petrol or other flammable vapours and liquids in the vicinity of this or any
other appliance.
– WHAT TO DO IF YOU SMELL GAS
●Do not try to light any appliances.
●Do not touch any electrical switch; do not use any phone in your building.
●Immediately call the National Gas Emergency Helpline on (Freephone) 0800 111999 or your gas
supplier from a neighbour’s phone. Follow the instructions received.
– Installation and service must be performed by a Gas Safe registered installer, service agency or
the gas supplier.
Condensing Combi Boiler

2 Contents
Contents
1. Safety Information 3
2. About the Boiler 8
2.1 Items Included 8
2.2 Accessories 8
2.3 Technical Data 9
2.4 Components 12
2.5 Dimensions 16
2.6 Operating Modes 17
2.7 Installation Procedure 19
3. Installing the Boiler 20
3.1 Choosing an Installation Location 20
3.2 Mounting the Boiler to the Wall 22
4. Installing the System Piping 23
4.1 Installing a Central Heating System 23
4.2 Installing a Domestic Hot Water (DHW) System 24
4.3 Connecting the Condensate Drain Line 25
4.4 Pipe Dimensions and Water Pressure 29
4.5 Pressure Relief Valve 29
4.6 Filling the System 29
4.7 Testing the Water System 30
5. Connecting the Gas Supply 31
5.1 Gas Pipe Material 32
5.2 Propane Gas Installations (LPG) 32
5.3 Measuring the Inlet Gas Pressure 32
6. Flue System 34
6.1 Flue Terminal Positions 34
6.2 Flue Installation 38
6.3 Measuring Flue Length 40
6.4 Terminating the Flue 41
7. Setting the DIP Switches 42
7.1 PCB DIP Switches 42
7.2 Front Panel DIP Switches 42
8. Connecting Electrical Supplies 43
8.1 Accessing the Terminal Strips 43
8.2 Connecting the Power Supply Cables 44
8.3 Connecting the Switched Live (230V) 45
8.4 Connecting the Room Stat or OpenTherm 45
8.5 Connecting the Outdoor Temperature Sensor 45
8.6 OpenTherm® Protocol 45
8.7 Connecting the Navien Smart Room Controller
(Optional) 46
8.8 Connecting the Navien Room Controller (Optional) 46
9. Installation Check list 47
10. Operating the Boiler 48
10.1 Using the Front Panel 48
10.2 Turning the Boiler On or Off 50
10.3 Adjusting the Temperature 50
10.4 Resetting the Boiler 51
10.5 Setting the CH Heat Demand 51
10.6 Accessing Basic Menu Items 52
10.7 Accessing Advanced Menu Items 54
10.8 Error Codes 57
11. Maintaining the Boiler 58
11.1 Cleaning the Boiler 58
11.2 Draining the Boiler 58
11.3 Cleaning the Return Adapter Filter 59
11.4 Protecting the Boiler from Freezing 59
11.5 Routine Servicing 60
12. Appendices 68
12.1 Gas Conversion 68
12.2 Wiring Diagram 73
12.3 Ladder Diagram 74
12.4 Outdoor Temperature Sensor (Optional) 75

Safety Information 3
The following safety symbols are used in this manual. Read and
follow all safety instructions in this manual precisely to avoid
unsafe operating conditions, fire, explosion, property damage or
personal injury.
DANGER
Indicates an imminently hazardous
situation which, if not avoided, could
result in severe injury or death.
WARNING
Indicates a potentially hazardous
situation which, if not avoided, could
result in injury or death.
CAUTION
Indicates a potentially hazardous
situation which, if not avoided, could
result in property damage.
DANGER
If you smell gas:
●Do not try to light any appliances.
●Do not touch any electrical switches or
use landline phones.
●From a neighbour’s phone, call
your gas provider and follow their
instructions.
●If you cannot reach your gas provider,
call the fire department.
●Do not return to your home until
authorised by your gas supplier or the
fire department.
Do not use or store flammable
products, such as petrol, solvents, or
adhesives in the same room or area as
the boiler.
●The boiler has a main burner flame that
can turn on at any time and can ignite
flammable vapours. Vapours from
flammable liquids can explode and
catch fire, causing severe burns.
●Vapours cannot be seen and are
heavier than air. They can travel long
distances along the ground and can be
carried from other rooms to the boiler’s
main burner flame by air current.
●Keep all flammable products far
away from the boiler and store them
in approved containers. Keep the
containers closed tightly and out of the
reach of children and pets.
1. Safety Information

4 Safety Information
WARNING
This appliance can be used by children
aged from 8 years and above and
persons with reduced physical, sensory
or mental capabilities or lack of
experience and knowledge if they have
been given supervision or instruction
concerning use of the appliance in a
safe way and understand the hazards
involved. Children shall not play with
the appliance. Cleaning and user
maintenance shall not be made by
children without supervision.
WARNING
●Do not store or use petrol or other
flammable liquids near this boiler.
Doing so may result in fire or explosion.
●Do not place combustibles, such as
newspapers or laundry, near the
boiler or flue system.
Doing so may result in a fire.
●Do not place or use hair sprays, spray
paints, or any other compressed
gases near the boiler or flue system,
including the flue termination.
Doing so may result in fire or explosion.
●Do not operate the boiler with the
front cover opened.
Doing so may result in fire or carbon
monoxide (CO) poisoning, which may
result in property damage or personal
injury.
●Do not operate this boiler without
proper flue system.
Doing so may result in fire or carbon
monoxide (CO) poisoning, which may
result in property damage or personal
injury.
●Do not touch the power cord or
internal components of the boiler
with wet hands.
Doing so may result in electric shock.

Safety Information 5
DANGER
HOT
BURN
To prevent burns:
●Use the lowest operating temperature
setting necessary to provide
comfortably hot water.
●If your household has children or
elderly or disabled residents, consider
using a lower temperature setting.
●Read all the instructions in this
manual carefully before changing the
temperature setting.
●Feel the water before using it on
children, the elderly, or the disabled.
DANGER
This boiler’s water temperature is set to
50°C at the factory for your safety and
comfort. Increasing the temperature
increases the risk of accidental scalding.
Water temperatures at or above 52°C
can cause instant scalding or severe
burns. Before you decide to change the
temperature setting, read the following
charts carefully.
Water
Temperature
Time in which a young child can suffer a
full thickness (3rd degree) burn
70°C Less than 1 second
60°C 1 second
55°C 10 seconds
49°C 10 minutes
37°C Very low scald risk
CAUTION
●Do not turn on the boiler unless
the water and gas supplies are fully
opened.
Doing so may damage the boiler.
●Do not turn on the water if the cold
water supply shut-off valve is closed.
Doing so may damage the boiler.
●Do not use this boiler for anything
other than its intended purpose, as
described in this manual.
●Do not remove the front cover unless
the power to the boiler is turned off
or disconnected.
Failure to do so may result in electric
shock.
●When servicing the controls, label all
wires prior to disconnecting them.
Failure to do so may result in wiring
errors, which can lead to improper or
dangerous operation. Verify proper
operation after servicing.
●Do not use unapproved replacement
or accessory parts.
Doing so may result in improper or
dangerous operation and will void the
manufacturer’s warranty.
●Do not place anything in or around
the flue terminals, such as a clothes
line, that could obstruct the air flow
in or out of the boiler.
●This boiler has been approved for
use the UK and Ireland only.
Using the boiler in any other country
will void the manufacturer’s warranty.

6 Safety Information
General Installation Guidelines
Navien ensures that this product contains no harmful
substances and that no harmful materials have been used in its
manufacture.
Current legislation must be taken into account on installing
this appliance, and it must be installed in a place with suitable
ventilation.
The boiler must be installed by an installer authorised by the
Ministry of Industry and it must be started up by an Official
Technical Assistance Service authorised by Navien.
The requirements included in the following regulations must be
observed on installing the boiler:
-The Gas Installation Regulation.
-The Technical Building Code.
-The Regulation for Heating Installations in Building.
-The Low Voltage Regulation.
Installation in hard water areas
●In areas with hard water (hardness exceeding 200 ppm), it is
important to install a scale reducer.
The advice of the local water authority should be sought.
Installing the system piping
●The boiler is equipped with an internal relief valve. All systems
must be capable of sustaining pressure of up to 3 bar.
●The air vent is required in the system during filling.
CAUTION
The boiler is equipped with an internal
bypass valve. The internal bypass valve
is not intended to replace an external
bypass valve. An external automatic
bypass valve is required if a zone valve
has been connected to the system.
Gas Conversion
The boiler is configured for natural gas. If LPG conversion is
required, use the conversion kit supplied with the boiler and
attach the item matching the LPG GC No. (included in the kit).
The Codes of good practice and regulations refer to the
latest versions of the same.
The installation must also comply with the following European
Standards:
Standard Description
UNE-EN 13831:2008 Closed expansion vessels with
diaphragm.
UNE-EN 1856 Metal chimneys
UNE-EN 13384 Chimneys
UNE-EN 13779 Ventilation
UNE-EN ISO 16484 Building control systems.
UNE-EN 14336 Heating systems in buildings.
UNE-EN 15502-1 Gas-fired heating boilers
Part 1: General Requirements and tests
UNE-EN 15502-2-1
Gas-fired heating boilers
Part 2-1: Specific standard for type
C appliances and type B2, B3 and B5
appliances of a nominal heat input not
exceeding 1000 kW
UNE-EN 13203:2007 Domestic Hot Water
UNE-EN 303-7:2008 Heating boilers.
UKCA/EC Conformity Declaration
0086 2797
Navien, hereby declares that the boiler models:
NCB300-28K, NCB300-37K, NCB300-41K
to which this declaration refers, conform to and comply with
the essential requirements of the following applicable European
Standards and Directives.
Gas appliances: Regulation (EU) 2016/426
Standards EN15502-1, EN15502-2-1 and EN437
Boiler Efficiency: Directive 92/42/EEC
Regulation (EU) No.813/2013
Standards EN15502-1, EN15502-2-1
Low voltage: Directive 2014/35/EU and
Standards EN 60335-1, EN 60335-2-102
Electro-magnetic Compatibility: Directive 2014/30/EU
Standards EN 55014
Pressure Vessels: Directive 2014/68/EU
Navien, manufactures its products using a Quality Assurance
system in compliance with Standard EN-ISO 9001:2015.

Safety Information 7
The Benchmark Scheme
Benchmark places responsibilities on both manufacturers
and installers. The purpose is to ensure that customers are
provided with the correct equipment for their needs, that it is
installed, commissioned and serviced in accordance with the
manufacturer’s instructions by competent persons and that it
meets the requirements of the appropriate Building Regulations.
The Benchmark Checklist can be used to demonstrate
compliance with Building Regulations and should be provided
to the customer for future reference.
Installers are required to carry out installation, commissioning
and servicing work in accordance with the Benchmark Code
of Practice which is available from the Heating and Hotwater
Industry Council who manage and promote the Scheme.
Visit www.centralheating.co.uk for more information.
Disposal of the Product
This product should be handed in at a designated collection
point, e.g. by handing it in at a duly authorised reseller when
purchasing a similar product, or at an authorised collection site
for recycling products which contains electrical and electronic
equipment (EEE) and batteries and accumulators. Because of the
potentially hazardous substances that usually accompany EEE,
improper handling of this type of waste could have a possible
impact on the environment and human health.
Your cooperation in the proper disposal of this product will
contribute to the effective usage of natural resources.
For more information on recycling this product, please contact
your city office, local waste disposal facilities, official service for
chemical waste or landfill site.

8 About the Boiler
2.1 Items Included
When you open the box, you will find the following items with the boiler. Check the box for each of the following items before installing
the boiler. If it seems like there is a problem, do not use the boiler. Contact your supplier. Keep the included items out of the reach of
children, as they can be dangerous. When you no longer wish to use the boiler, disable any parts that could be potentially hazardous.
Installation & Operation
Manual, User’s Information
Manual
Boiler mounting template ErP Label Wall mounting bracket
Tapping screws & anchors Propane gas changing kit Electric cord Pre-plumbing Kit
Condensate trap hose
2.2 Accessories
The following optional accessories are available for the boiler:
Smart Room Controller
(Smart Plus) Pipe Cover Stand off KIT Room Controller
2. About the Boiler

About the Boiler 9
2.3 Technical Data
The following table lists the general specifications for the boiler.
Specifications Unit NCB300-28K NCB300-37K NCB300-41K
Heat input range kW 24.7/4.3 26.8/4.6 26.8/4.6
DHW heat input range kW 28.0/4.3 37.0/4.6 41.0/4.6
Heat output range @ 80/60°C kW 24.0/4.2 26.0/4.5 26.0/4.5
DHW output range kW 28.0/4.3 37.0/4.6 41.0/4.6
Condensing heat output range @ 50/30°C kW 25.6/4.5 28.2/4.8 28.2/4.8
Full load efficiency at Max. output @ 80/60°C %88.4 88.4 88.4
Full load efficiency at Max. output @ 50/30°C
(Condensing) %106.5 106.5 106.5
Partial load (30%) efficiency with 30°C return temp. %108.5 108.5 108.5
Heat loss through the case with burner switched on %0.1
Seasonal efficiency rate (SEDBUK 2009) -88.9 89.0 89.0
NOx Classification -Class 6
Category -II2HY203P
Type -Heating and instantaneous hot water production
Heat output adjustment -Adjustable over entire Max./Min. output range
Type of heating installation -Close circuit
Max. heating operation pressure bar 2.5
Max. heating temperature °C 90
Adjustable heating temperature range °C 40-90
Expansion vessel volume L 6
Expansion vessel pre-charged pressure bar 1.0
Min. DHW working pressure bar 0.7 0.7 1.1
Min. DHW working flow l/min 2
Max. DHW working pressure bar 10
Adjustable DHW temperature range °C 30-65
DHW flow rate @ 25°C temp. rise. l/min 16.1 21.3 23.6
DHW flow rate @ 35°C temp. rise. l/min 11.5 15.2 16.8
DHW flow rate for kitchen @ 45°C temp. rise. l/min 9.0 11.8 13.1
Electrical power supply -230V/50Hz
Nominal current A0.6 0.6 0.6
Max. power consumption W130 130 130
Appliance protection rating -IPX4D
Boiler mounting system type -Wall-mounted
Flue exhaust/Air intake system types -B23-C13-C33-C53-C83

10 About the Boiler
Specifications Unit NCB300-28K NCB300-37K NCB300-41K
Flue exhaust/Air intake system diameters mm Coaxial Ø60/100 and Ø80/
125–Dual duct Ø80/80
Max. gas pipe pressure drop Pa 167 294 294
Max. horizontal coaxial length Ø60/100 m 8
Max. vertical coaxial length Ø60/100 m 8
Equivalent elbow length @ 90° Ø60/100 m1.3
Equivalent elbow length @ 45° Ø60/100 m1.0
Max. horizontal coaxial length Ø80/125 m27
Max. vertical coaxial length Ø80/125 m28
Equivalent elbow length @ 90° Ø80/125 m2.2
Equivalent elbow length @ 45° Ø80/125 m1.0
Equivalent length of adapter Ø60/100 => Ø80/125 m0.5
Max. dual duct length Ø80/80 m 9
Equivalent elbow length @ 90° Ø80 m2.2
Equivalent elbow length @ 45° Ø80 m1.4
Hydraulic connection diameter
Central Heating mm 22
DHW mm 15
Gas supply mm 22
Dimensions (Width x Depth x Height) mm 395 x 283 x 680
Total boiler weight (lift weight) kg 29 33 33

About the Boiler 11
The following table lists the product information requirements (EU regulation No 811/2013 and No 813/2013)
Specifications Unit NCB300-28K NCB300-37K NCB300-41K
Condensing boiler YES YES YES
Low-temperature (**) boiler NO NO NO
B1 boiler NO NO NO
Cogeneration space heater NO NO NO
Combination heater YES YES YES
Rated heat output P
rated
kW 24 26 26
Seasonal space heating energy efficiency η
s
%93 93 93
Useful heat output
At rated heat output and
high-temperature regime (*) P
4
kW 23.7 26.1 26.1
At 30 % of rated heat output and
low-temperature regime (**) P

kW 8.4 8.5 8.5
Useful efficiency
At rated heat output and
high-temperature regime (*) η
4
%88.3 88.4 88.4
At 30 % of rated heat output and
low-temperature regime (**) η
1
%97.8 97.6 97.6
Auxiliary electricity consumption
At full load elmax kW 0.039 0.034 0.034
At part load elmin kW 0.017 0.016 0.016
In standby mode P
SB
kW 0.003 0.003 0.003
Other items
Standby heat loss P
stby
kW 0.078 0.078 0.078
Ignition burner power consumption P
ign
kW 000
Annual energy consumption Q
HE
GJ 7.5 8.1 8.1
Sound power level, indoors L
WA
dB 52 47 47
Emissions of nitrogen oxides NO
x
mg/kWh 32.9 24.0 24.0
For combination heaters
Declared load profile XL XL XL
Daily electricity consumption Q
elec
kWh 0.183 0.168 0.182
Annual electricity consumption AEC kWh 39 36 39
Water heating energy efficiency η
wh
%84.1 83.9 83.1
Daily fuel consumption Q
fuel
kWh 23.2 23.3 23.5
Annual fuel consumption AFC GJ 18 18 18
Contact details Navien LTD, Building 2, Guildford Business Park, Guildford, GU2 8XH
(*) High-temperature regime means 60 °C return temperature at heater inlet and 80 °C feed temperature at heater outlet.
(**) Low temperature means for condensing boilers 30 °C, for low-temperature boilers 37 °C and for other heaters 50 °C return temperature (at heater inlet).
Specific precautions
Read the user’s information and installation manual before the application is assembled, installed or maintained.

12 About the Boiler
2.4 Components
The following diagram shows the key components of the boiler. Component assembly diagrams and particular parts lists are included in
the Appendices.
Fan & Motor
Front Panel
Ignitor & Flame Rod
Circulation Pump
Gas Valve
PCB
NCB300-28K

About the Boiler 13
Fan & Motor
Front Panel
Ignitor & Flame Rod
Circulation Pump
Gas Valve
PCB
NCB300-37K
NCB300-41K

14 About the Boiler
Single Venturi
Mixing Chamber
Primary Heat Exchanger
Secondary Heat Exchanger
Return Adapter
Filter Assembly
Gas Valve
Central Heating Return
Pressure Relief Valve
Central Heating Supply
DHW Inlet
DHW Outlet
3-Way Valve
NCB300-28K

About the Boiler 15
Single Venturi
Mixing Chamber
Primary Heat Exchanger
Secondary Heat Exchanger
Return Adapter
Filter Assembly
Gas Valve
Central Heating Return
Pressure Relief Valve
Central Heating Supply
DHW Inlet
DHW Outlet
3-Way Valve
NCB300-37K
NCB300-41K

16 About the Boiler
2.5 Dimensions
The following diagrams show the dimensions of the boiler and the table lists the supply connections.
395 mm
680 mm
Supply Connections
Description Diameter
AFlue exhaust/Air intake Ø60/100,
Ø80/125
BCentral heating supply 22 mm
CHot water outlet (DHW) 15 mm
DGas supply inlet 22 mm
ECold water inlet (DHW) 15 mm
FCentral heating return 22 mm
Overhead View
A
197.5 mm
282.2 mm
119 mm
Bottom View
E
BC D F
170.6 mm170.6 mm
91.5 mm91.5 mm100.1 mm100.1 mm
56 mm56 mm 65 mm65 mm 126 mm126 mm 65 mm65 mm
72.6 mm72.6 mm 31.7 mm31.7 mm
NCB300-28K
NCB300-37K
NCB300-41K

About the Boiler 17
Air InAir In
Exhaust
Gas
Blow Fan Ignitor
Gas
Valve
Gas
Inlet
Flow
Out
CH
Return
Three
-way
Valve
DHW Heat
Exchanger
Circulation
Pump
Heat
Exchanger
2.6.2 Operating According to Outdoor
Temperature Conditions
The Outdoor Reset Control feature may be used to enhance
energy efficiency while maintaining optimal heating
performance. With the Outdoor Reset Control, the central
heating temperature setting automatically changes according to
the outdoor temperature and the K-Factor setting.
You can configure the Outdoor Reset Control settings on the
front panel in the Central Htg Operation menu. Refer to“10.6.2
Setting the Central Heating Temperature”on page 52.
Note The Outdoor Reset Control feature requires
installation of an outdoor temperature sensor, and it
only works when the boiler is running in the normal
operation mode. It does not work when the boiler’s
front panel displays a fault.
2.6 Operating Modes
2.6.1 Operating in Central Heating Mode
To operate the central heating mode:
1. Press the Menu button ( ) to access the CH temperature
setting mode.
2. Select a heating temperature setpoint higher than current
heating temperature.
●When the boiler detects a request for heating production
(from the installation’s room thermostat, for example), the
3-way valve goes to heating position and the circulating
pump starts up.
●If the boiler water temperature is lower than the desired
temperature setpoint, the boiler ignites and heats up the
heating installation until the selected boiler temperature
is reached. The boiler’s electronic control modulates
the burner output to adapt to the installation’s heat
requirements at all times and so that the installation’s
water temperature remains constant. This prevents the
installation from overheating and reduces heat loss as
much as possible.
●When there is no further heating demand (e.g. when
the desired ambient temperature selected on the room
thermostat is reached), the burner is extinguished (if it was
ignited) and the circulation pump continues to run during
the post-circulation time (minimum 3 minutes), to protect
the boiler from overheating due to thermal inertia in the
installation.

18 About the Boiler
●When there is no further DHW demand, the burner
switches off and the 3-way valve remains in DHW mode
position during a wait time (5 minutes by default), so that
it can work more efficiently and provide more flexibility if
the taps are continuously turned on and off.
●When the wait time has elapsed, the 3-way valve returns
to the Heating mode position and the boiler is ready to
provide heating.
Note ●DHW priority: Whenever a hot water tap is turned
on in the home, the boiler begins to run in DHW
mode and the heating function is deactivated until
all the taps are turned off again.
●When the boiler water pressure drops below
0.4 bar, follow the instruction“4.6 Filling the System”
to fill the boiler system.
Exhaust
Gas
Blow Fan
Air InAir In
Ignitor
Gas
Valve
Gas
Inlet
DHW Out
Cold
Water In
Three
-way
Valve
DHW Heat
Exchanger
Circulation
Pump
Heat Exchanger
The following table lists the central heating temperature
range by k-factor setting value and the applicable outdoor
temperature range.
20 15 10 5 0 -10 -15 -20 -25
-5
20
30
40
50
60
50
70
80
90
4 3.5 3 2.5 2
1.5
1.2
0.6
1
0.2
Outdoor Temperature (ºC)
Outdoor Temperature Compensation
Heating flow temperature (ºC)
Note To connect the outdoor temperature sensor to the
boiler, carefully follow the connection instructions
provided in the“12.4 Outdoor Temperature Sensor
(Optional)”on page 75.
2.6.3 Operating in DHW Mode
To operate the DHW mode:
1. Press the menu button ( ) twice to access the DHW
temperature setting mode.
2. In the DHW Operation menu, select“1. DHW Set Temp”and
select a DHW temperature setpoint higher than current
DHW temperature.
●When a hot water tap is turned on in the home, the boiler
flow meter detects DHW demand, the 3-way valve goes
to DHW mode and the circulation pump starts up, which
makes the water in the boiler primary circuit flow through
the DHW heat exchanger, producing instant hot water.
●The electronic control modulates the burner output in
order to constantly produce hot water at the temperature
required.

About the Boiler 19
2.7 Installation Procedure
The flow diagram below provides a step-by-step description of the recommended procedure for clear, easy installation of the NCB300
boiler in its final location. A detailed description is given of the procedure in the sequenced sections below:
Wall-mounting
»
Gas connection
»
Electrical connections
»
Flue gases exhaustion
system installation
»
Water and condensate
pipe connection
»
Gas changeover
(if necessary)
»
Final check
»
Boiler operation
»
p. 20
p. 23
p. 31
p. 43
p. 47 p. 48
p. 34
p. 68