Navien NCB-24LDWE User manual

ƔThese appliances are for use with natural gas or LPG.
(An LPG conversion kit is included with the boiler.)
ƔType: B23-B33-B53-C13-C33-C43-C53-C63-C83
Gas Model GC Number
Natural Gas
NCB-24LDWE
NCB-28LDWE
NCB-34LDWE
NCB-40LDWE
47-709-01
47-709-02
47-709-03
47-709-04
LPG
NCB-24LDWE
NCB-28LDWE
NCB-34LDWE
NCB-40LDWE
47-709-05
47-709-06
47-709-07
47-709-08
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
ƔDo not try to light any appliances.
ƔDo not touch any electrical switch; do not use any phone in your building.
ƔImmediately call the National Gas Emergency Helpline on (Freephone) 0800 111999 or your gas
supplier froma 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 7
2.1 Items Included 7
2.2 Accessories 7
2.3 Technical Data 8
2.4 Components 11
2.5 Dimensions 15
2.6 Operating Modes 16
2.7 Installation Procedure 18
3. Installing the Boiler 19
3.1 Choosing an Installation Location 19
3.2 Mounting the Boiler to the Wall 21
4. Installing the System Piping 22
4.1 Installing a Space Heating System22
4.2 Installing a Domestic Hot Water (DHW) System23
4.3 Connecting the Condensate Drain Line 23
4.4 Pipe Dimensions and Water Pressure 24
4.5 Pressure Relief Valve 25
4.6 Filling the system25
4.7 Testing the Water System25
5. Connecting the Gas Supply 26
5.1 Gas Pipe Material 27
5.2 Propane Gas Installations (LPG) 27
5.3 Measuring the Inlet Gas Pressure 27
6. Flue System 29
6.1 Flue Terminal Positions 29
6.2 Selecting a Flue System30
6.3 Coaxial Systems31
6.4 Dual Duct Systems32
6.5 Measuring Flue Length 34
6.6 Terminating the Flue 34
7. Setting the DIP Switches 35
7.1 PCB DIP Switches 35
7.2 Front Panel DIP Switches 35
8. Connecting Electrical Supplies 36
8.1 Accessing the Terminal Strips 36
8.2 Connecting the Power Supply Cables 37
8.3 Connecting the RoomStat or OpenTherm38
8.4 Connecting the Outdoor Temperature Sensor 38
8.5 OpenTherm® Protocol 38
8.6 Connecting the Navien Smart RoomController
(Optional) 38
9. Installation Check list 39
10. Operating the Boiler 40
10.1 Turning the Boiler On or Off 40
10.2 Adjusting the Temperature 40
10.3 Viewing Basic Information 42
10.4 Setting the Operation Mode 42
10.5 Setting the Parameters 43
10.6 Resetting the Boiler 49
11. Maintaining the Boiler 50
11.1 Cleaning the Boiler 50
11.2 Draining the Boiler 50
11.3 Cleaning the Return Adapter Filter 51
11.4 Protecting the Boiler fromFreezing 51
11.5 Maintenance Schedules 52
12. Appendices 55
12.1 Gas Conversion 55
12.2 Cleaning the Heat Exchanger 61
12.3 Wiring Diagram64
12.4 Ladder Diagram65
12.5 Outdoor Temperature Sensor (Optional) 66

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:
ƔDo not try to light any appliances.
ƔDo not touch any electrical switches or
use landline phones.
ƔFroma neighbour’s phone, call
your gas provider and follow their
instructions.
ƔIf you cannot reach your gas provider,
call the fire department.
ƔDo 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.
ƔThe 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.
ƔVapours cannot be seen and are
heavier than air. They can travel long
distances along the ground and can be
carried fromother rooms to the boiler’s
main burner flame by air current.
ƔKeep all flammable products far
away fromthe 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 from8 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
ƔDo not store or use petrol or other
flammable liquids near this boiler.
Doing so may result in fire or explosion.
ƔDo not place combustibles, such as
newspapers or laundry, near the
boiler or flue system.
Doing so may result in a fire.
ƔDo 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.
ƔDo 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.
ƔDo 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.
ƔDo 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:
ƔUse the lowest operating temperature
setting necessary to provide
comfortably hot water.
ƔIf your household has children or
elderly or disabled residents, consider
using a lower temperature setting.
ƔRead all the instructions in this
manual carefully before changing the
temperature setting.
ƔFeel the water before using it on
children, the elderly, or the disabled.
DANGER
This boiler’s water temperature is set to
49°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
ƔDo not turn on the boiler unless
the water and gas supplies are fully
opened.
Doing so may damage the boiler.
ƔDo not turn on the water if the cold
water supply shut-off valve is closed.
Doing so may damage the boiler.
ƔDo not use this boiler for anything
other than its intended purpose, as
described in this manual.
ƔDo 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.
ƔWhen 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.
ƔDo not use unapproved replacement
or accessory parts.
Doing so may result in improper or
dangerous operation and will void the
manufacturer’s warranty.
ƔDo 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.
ƔThis 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
ƔIn 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
ƔThe boiler is equipped with an internal relief valve. All systems
must be capable of sustaining pressure of up to 3 bar.
ƔThe air vent is required in the systemduring 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 itemmatching 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 ISO16484 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.
EC Conformity Declaration
0063
Navien, hereby declares that the boiler models:
NCB-24LDWE, NCB-28LDWE, NCB-34LDWE, NCB-40LDWE
to which this declaration refers, conform to and comply with
the essential requirements of the following applicable European
Standards and Directives.
Gas appliances: Directive 2009/142/EC Standards EN 437 and
EN 15502
Boiler Eciency: Directives 92/42/EEC and
93/68/EEC
Regulation (EN) No. 813/2013
Standards EN 15502
Low voltage: Directives 73/23/EEC and
93/68/EEC Standard EN 60335-1, EN 60335-2-30,
EN 60335-2-51, EN 50165
Electro-magnetic Compatibility: Directive 2004/108/EC
Standards EN 55014
Pressure Vessels: Directive 97/23/EEC
Navien, manufactures its products using a Quality Assurance
system in compliance with Standard EN-ISO 9001:2000.

About the Boiler 7
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.
A
B
C
D
E
F
G
2015 811/2013
dB
kW
A++
A+
A
B
C
D
E
F
G
A
A
KD Navien NCB-24LDWE
XL
20
40
Installation & Operation
Manual, User’s Information
Manual
Boiler mounting plate Boiler registration / Installers
Club Card ErP Label
Wall mounting bracket Tapping screws &anchors Propane gas changing kit Electric cord
Pre-plumbing Kit
2.2 Accessories
The following optional accessories are available for the boiler:
Outdoor Temperature Sensor Smart RoomController
2. About the Boiler

8 About the Boiler
2.3 Technical Data
The following table lists the general specications for the boiler.
Specications Unit NCB-24LDWE NCB-28LDWE NCB-34LDWE NCB-40LDWE
Heat input range kW 20.0/4.2 24.0/4.2 29.0/5.1 34.0/4.0
DHW heat input range kW 24.0/4.2 28.0/4.2 34.0/5.1 40.0/4.0
Heat output range @ 80/60°C kW 19.5/3.9 23.4/3.9 28.3/4.9 33.2/3.8
DHW output range kW 23.8/4.1 27.7/4.1 33.7/5.0 39.6/3.9
Condensing heat output range @ 50/30°C kW 21.4/4.5 25.6/4.5 31.1/5.4 36.3/4.3
Full load eciency at Max./Min. output @ 80/60°C % 97.5/96.4 97.5/96.4 97.6/96.4 97.6/95.8
Full load eciency at Max./Min. output @ 50/30°C
(Condensing) % 106.9/107.8 106.6/107.8 107.3/106.9 106.9/106.9
Partial load (30%) eciency with 47°C return temp. % 101.9 103.1 102.0 103.1
Partial load (30%) eciency with 30°C return temp. % 108.6 108.9 108.5 108.8
Heat loss through the case with burner switched on % 0.1 0.1 0.1 0.1
Heat loss through the chimney with burner switched on % 1.6 1.8 1.5 1.9
Seasonal eciency rate (SEDBUK 2009) - 89.0 89.1 89.0 89.1
NOx Classication - Class 5
Category - II2H3P
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 6.0
Expansion vessel pre-charged pressure bar 1.0
Min. DHW working pressure bar 1.0 1.2 1.4 1.4
Min. DHW working ow l/min 2.0
Max. DHW working pressure bar 10
Adjustable DHW temperature range °C 30–65
DHW ow rate @ 25°C temp. rise. l/min 13.8 16.1 19.5 22.9
DHW ow rate @ 30°C temp. rise. l/min 11.5 13.4 16.2 19.1
DHW ow rate for kitchen @ 45°C temp. rise. l/min 7.6 8.9 10.8 12.7
Electrical power supply - 230 V/50 Hz
Nominal current A 0.6 0.6 0.62 0.62
Max. power consumption W 130
Appliance protection rating - IP X5D
Boiler mounting system type - Wall-mounted

About the Boiler 9
Specications Unit NCB-24LDWE NCB-28LDWE NCB-34LDWE NCB-40LDWE
Flue exhaust/Air intake system types - B23-B33-B53-C13-C33-C43-C53-C63-C83
Flue exhaust/Air intake system diameters mm Coaxial Ø60/100 and Ø80/125–Dual duct Ø80/80
Max. gas pipe pressure drop Pa 167 167 294 294
Max. horizontal coaxial length Ø60/100 m 20
Max. vertical coaxial length Ø60/100 m 21
Equivalent elbow length @ 90° Ø60/100 m 1.3
Equivalent elbow length @ 45° Ø60/100 m 1.0
Max. horizontal coaxial length Ø80/125 m 68
Max. vertical coaxial length Ø80/125 m 70
Equivalent elbow length @ 90° Ø80/125 m 2.2
Equivalent elbow length @ 45° Ø80/125 m 1.0
Equivalent length of adapter Ø60/100 => Ø80/125 m 0.5
Max. dual duct length Ø80/80 m 110
Equivalent elbow length @ 90° Ø80 m 2.2
Equivalent elbow length @ 45° Ø80 m 1.4
Hydraulic connection
diameter
Central Heating mm 22
DHW mm 15
Gas supply mm 22
Dimensions (Width x Depth x Height) mm 440 x 358 x 695 440 x 408 x 695
Total boiler weight (lift weight) Kg 38 38 42 42

10 About the Boiler
The following table lists the product information requirements (EU regulation No 811/2013 and No 813/2013)
KD Navien Symbol Unit NCB-24LDWE NCB-28LDWE NCB-34LDWE NCB-40LDWE
Condensing boiler YES YES YES YES
Low-temperature (**) boiler NO NO NO NO
B1boiler NONONONO
Cogeneration space heater NO NO NO NO
Combination heater YES YES YES YES
Rated heat output P
rated
kW 20 23 28 33
Seasonal space heating energy
eciency η
s
%92939393
Useful heat output
At rated heat output
and high-temperature regime (*) P
4
kW 19.5 23.4 28.3 33.2
At 30 % of rated heat output
and low-temperature regime (**) P
1
kW 6.5 7.8 9.4 11.1
Useful eciency
At rated heat output
and high-temperature regime (*) η
4
% 87.8 87.9 87.9 87.8
At 30 % of rated heat output
and low-temperature regime (**) η
1
% 97.8 98.1 97.7 98.0
Auxiliary electricity consumption
At full load elmax kW 0.036 0.045 0.048 0.045
At part load elmin kW 0.014 0.015 0.016 0.016
In standby mode P
SB
kW 0.003 0.003 0.003 0.003
Other items
Standby heat loss P
stby
kW 0.080 0.080 0.084 0.084
Ignition burner power
consumption P
ign
kW----
Annual energy consumption Q
HE
GJ 37 43 52 57
Sound power level, indoors L
WA
dB 50 52 54 52
Emissions of nitrogen oxides NO
x
mg/kWh 36 38 30 37
For combination heaters
Declared load prole XL XL XL XL
Daily electricity consumption Q
elec
kWh 0.307 0.300 0.209 0.214
Annual electricity consumption AEC kWh 66 65 45 46
Water heating energy eciency η
wh
%84848585
Daily fuel consumption Q fuel
kWh 22,830 22,718 22,726 22,608
Annual fuel consumption AFC GJ 17 17 17 17
Contact details Navien LTD, 3000 Hillswood Drive, Hillswood Business Park, Chertsey, Surrey, KT16 0RS, UK
(*) 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).
Specic precautions
Read the user’s information and installation manual before the application is assembled, installed or maintained.

About the Boiler 11
2.4 Components
The following diagramshows the key components of the boiler. Component assembly diagrams and particular parts lists are included in
the Appendices.
Fan & Motor
Front Panel
Flue Duct
Ignitor & Flame Rod
Circulation Pump
Condensate Trap
Mounting Frame
PCB
NCB-24/28/34LDWE

12 About the Boiler
NCB-24/28/34LDWE
Single Venturi
Mixing Chamber
Air Pipe
APS
Primary Heat Exchanger
Secondary Heat Exchanger
Return Adapter
Filter Assembly
3-way Valve
Space Heating Return
Pressure Relief Valve
Space Heating Supply
DHW Inlet
DHW Outlet
Hot Water Heat
Exchanger
Gas Valve

About the Boiler 13
NCB-40LDWE
Fan &Motor
Front Panel
Flue Duct
Ignitor &Flame Rod
Circulation Pump
Condensate Trap
Mounting Frame
PCB

14 About the Boiler
NCB-40LDWE
Dual Venturi
Mixing Chamber
Primary Heat Exchanger
Secondary Heat Exchanger
APS
Pressure Relief Valve
Return Adapter Filter Assembly
Space Heating Supply
DHW Inlet
Space Heating Return
DHW Outlet
Hot Water Heat Exchanger
3-Way Valve
Gas Valve

About the Boiler 15
2.5 Dimensions
The following diagrams show the dimensions of the boiler and the table lists the supply connections.
695 mm
440 mm
Supply Connections
Description Diameter
A Flue exhaust/Air intake Ø60/100,
Ø80/125
B Space heating supply 22 mm
C Hot water outlet (DHW) 15 mm
D Gas supply inlet 22 mm
E Cold water inlet (DHW) 15 mm
F Space heating return 22 mm
Overhead View
128 mm
160 mm
170 mm
200 mm
A
Bottom View
150 mm
75 mm 75 mm135 mm
*NCB-24LDWE/28LDWE: 358 mm
NCB
-
34LDWE/40LDWE: 408 mm
408 mm*
D E
BC F

16 About the Boiler
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 space heating
temperature setting automatically changes according to the
outdoor temperature and the current space heating system
application (systemload).
You can configure the Outdoor Reset Control settings on the
front panel by entering the Special Parameter Setting mode.
Refer to“10.5 Setting the Parameters”on page 43.
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 is
running in either the Minimum(MIN) or Maximum
(MAX) mode, or when the boiler’s front panel displays
a fault.
45 40 35 30 25 20 15 10 5 0 -5 -10 -15 -20 -25
185
194
176
167
158
149
140
131
122
113
104
95
86
77
68
59
50
113 104 95 86 77 68 59 50 41 32 23 14 5 -4 -13 °F
°C
85
90
80
75
70
65
60
55
50
45
40
35
30
25
20
15
10
°F °C
Absolute
MAX
Absolute
MIN
Outdoor
High MIN
Outdoor
Low MIN
High Mass Radiant
Low Mass Radiant
Cast Iron Baseboard
Custom
Radiator
Finned Tube Baseboard
Fan Coil
Space Heating Temperature Setting for the
Outdoor Reset Control Feature
The following tables list the default space heating temperature
range by systemheat load and the applicable outdoor
temperature ranges.
Note To connect the outdoor temperature sensor to the
boiler, carefully follow the connection instructions
provided in the“12.5 Outdoor Temperature Sensor
(Optional)”on page 66.
2.6 Operating Modes
2.6.1 Operating in Space Heating Mode
To operate the Space heating mode, press the Space heating
button on the front panel and select a heating temperature
setpoint higher than current heating temperature.
1. When the boiler detects a request for heating production
(fromthe installation’s roomthermostat, for example), the
3-way valve goes to heating position and the circulating
pump starts up.
2. 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
fromoverheating and reduces heat loss as much as possible.
3. 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 (minimum3 minutes), to protect
the boiler fromoverheating due to thermal inertia in the
installation.
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

About the Boiler 17
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
2.6.3 Operating in DHW Mode
To operate in DHW mode, press the DHW button on the front
panel and select a DHW temperature setpoint higher than
current DHW temperature.
1. 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.
2. The electronic control modulates the burner output in
order to constantly produce hot water at the temperature
required.
3. 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.
4. 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 ƔDHW 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.
ƔWhen the boiler water pressure drops below 0.4 bar
the automatic fill function is activated.

18 About the Boiler
2.7 Installation Procedure
The ow diagram below provides a step-by-step description of the recommended procedure for clear, easy installation of the NCB LDWE
boiler in its nal location. A detailed description is given of the procedure in the sequenced sections below:
Wall-mounting
»
Gas connection
»
Electrical connections
»
DIP switch settings
»
Final check
»
Water and condensate
pipe connection
»
Flue gases exhaustion
system installation
(if necessary)
»
Gas changeover
(if necessary)
»
Boiler operation
»
p. 19
p. 22
p. 26
p. 36
p. 35
p. 39 p. 40
p. 29
p. 55

Installing the Boiler 19
3.1 Choosing an Installation Location
When choosing an installation location, you must ensure
that the location provides adequate clearance for the boiler,
adequate flueing and drainage options, and sufficient access to
gas, water, and electrical supplies.
Carefully consider the following factors when choosing an
installation location:
Compliance Requirements
This boiler must be installed by qualified personnel in
compliance with the applicable Laws and Regulations.
In general, these Laws and Regulations are the Basic Gas
Installation Standards, the Heating, Air Conditioning and
Domestic Water Installation Regulation and all other local
regulations.
Access to Utilities
ƔWater–the installation location should be near where the
domestic water supply enters the building.
ƔGas–the installation location should be near where the gas
supply enters the building.
ƔElectricity–the installation location should be near where the
electrical supply enters the building.
Humidity and Contact with Water
When installing the boiler, avoid places with excessive humidity.
The boiler has electric gas ignition components. Water spray or
droppings can get inside the boiler and damage the ignition
system. The boiler must be installed in a way to ensure that
the gas ignition systemcomponents are protected fromwater
(dripping, spraying, rain, etc.) during operation and service.
If the boiler is installed in a very humid room(a shower room
or bathroom, for example), the Low Voltage regulation and
the Technical Building Code must be observed for correct
installation.
Proximity to Fixtures and Appliances
Install the boiler near fixtures that deliver or use hot water,
such as bathroom, kitchen, and laundry roomfaucets. Select
a location that minimises the water piping required between
major fixtures. If the distances are long or if the user requires
“instant“ hot water, installation of a recirculation line which
circulates domestic hot water back to the boiler fromthe
furthest fixture is recommended. Insulate as much of the hot
water supply and recirculation lines as possible. For more
information about the water supply, refer to "4.2 Installing a
Domestic Hot Water (DHW) System” on page 23.
Adequate Drainage
The boiler produces a significant amount of condensate during
operation. This condensate must be removed fromthe boiler,
and suitably treated if national legislation so requires. The boiler
should be located near a suitable drain and where damage from
a possible leak will be minimal. Installing the boiler in a location
without a drain will void the warranty and Navien will not be
responsible for water damage that occur as a result. For more
information about condensate drainage, refer to“4.3 Connecting
the Condensate Drain Line” on page 23.
The boiler must be located in an area where leakage of the unit
or connections will not result in damage to the area adjacent
to the appliance or to lower floors of the structure. When such
locations cannot be found, installation of an adequately drained
drain pan under the boiler is highly recommended. When
installing the drain pan, ensure that the installation does not
restrict combustion air flow.
Adequate Flue and Ventilation
The boiler must be installed in a sufficiently ventilated area with
openings directly to the outside of the building (as required by
the Gas Installations Regulation). The boiler must be located so
that the grilles of the premises are not obstructed and normal
boiler maintenance is possible even if installed between items
of furniture.
Select a location that requires minimal flue. Consider flue
restrictions caused by windows, doors, air intakes, gas meters,
foliage, and other buildings. For more information about flue
system, refer to “6. Flue System”on page 29.
To ensure adequate flue and ventilation, follow these guidelines:
ƔMaintain proper clearances fromany openings in the building.
ƔInstall the boiler with a minimumclearance of 300 mm above
an exterior grade or as required by local codes.
ƔDo not enclose the flue termination.
ƔInstall the exhaust flue in an area that is free fromany
obstructions, where the exhaust will not accumulate.
ƔDo not install the boiler where moisture fromthe exhaust may
discolor or damage walls.
ƔDo not install the boiler in bathrooms, bedrooms, or any
other occupied rooms that are normally kept closed or not
adequately ventilated.
The requirements and recommendations stipulated in the
Regulation for Heating Installations in Buildings (RITE) and any
other applicable legislation in this field must be observed.
3. Installing the Boiler

20 Installing the Boiler
Clearance from: Indoor Installation
Top 250 mm minimum
Front 600 mm minimum
Bottom200 mm minimum
Clean, debris and chemical-free combustion air
ƔDo not install the boiler in areas where dust and debris may
accumulate or where hair sprays, spray detergents, chlorine,
or similar chemicals are used.
ƔDo not install the boiler in areas where petrol or other
flammables are used or stored.
ƔEnsure that combustible materials are stored away from
the boiler and that hanging laundry or similar items do not
obstruct access to the boiler or its flue system.
Adequate installation clearances
CAUTION
Do not install the boiler on carpeting.
Install the boiler in an area that allows for service and
maintenance access to utility connections, piping, filters,
and traps. Based on the installation location, ensure that the
following clearances are maintained:
Top
Bottom
Front