Buderus Logano G225 Quick guide

For contractors
Please read carefully before
use.
Installation and service
instructions
Fan-assisted
low temperature/
condensing boiler
6 720 615 876-00.1RS
Logano G225/Logano plus
GB225 with BE burner
6 720 616 282 - 02/2008 EN

Contents
Logano G225/Logano plus GB225 - We reserve the right to make any changes due to technical modifications.
2
Contents
1 General safety instructions and
explanation of symbols 4
1.1 Safety instructions 4
1.2 Explanation of symbols 5
2 Product details 6
2.1 EU Declaration of Conformity 6
2.2 Intended use 6
2.3 Standards, regulations and directives 6
2.4 Notes on installation and operation 6
2.5 Heating system water quality 6
2.6 Tools, materials and equipment 6
2.7 Disposal 7
2.8 Product description 8
2.9 Contents 9
2.10 Dimensions and specifications 10
2.10.1 Logano G225 BE dimensions 10
2.10.2 Boiler room and ambient conditions 11
2.10.3 Conditions for combustion air supply 12
2.10.4 Conditions for fuel 12
2.10.5 Conditions for the power supply 13
2.10.6 Conditions for the system configuration and
water quality 13
3 Transporting the boiler 14
4 Boiler positioning 15
5 Boiler block assembly 16
5.1 Assembly when delivered in sections 16
5.1.1 Preparation of boiler sections 16
5.1.2 Driving nipples home 17
5.1.3 Preparing the centre section 18
5.1.4 Inserting the packing cord 18
5.1.5 Knocking the centre section into place 19
5.1.6 Boiler section alignment 19
5.1.7 Joining the boiler sections at the upper
and lower boiler hubs with nipples 20
5.1.8 Fitting the anchor rods 22
5.1.9 Installation of the feed pipe and connection
profile 23
5.1.10 Fitting the temperature sensor 25
5.1.11 Fitting the flue outlet 26
5.1.12 Closing the boiler hubs 26
5.2 Checking for leaks 27
5.2.1 Preparing for a leak test 27
5.2.2 Carrying out the leak test 27
5.3 Installation of pre-assembled boiler heat
exchanger 28
5.4 Assembly steps for boilers supplied in
sections and as ready assembled block 28
5.4.1 Fitting the adjustable feet 28
5.4.2 Inserting the hot gas baffle plates 28
5.4.3 Installing the burner door 29
5.4.4 Installing the boiler casing 30
5.5 Positioning and levelling the boiler 37
6 Installing the boiler 38
6.1 Installing the flue pipe 38
6.1.1 Flue pipe sealing collar for negative pressure
flue (pressure at boiler outlet < 0 mbar) 38
6.1.2 Flue pipe sealing collar for positive pressure
flue (pressure at boiler outlet > 0 mbar) 39
6.2 Fitting the water connections 39
6.2.1 Connecting the central heating flow
and return 39
6.2.2 Connecting the safety flow and return 40
6.2.3 Connecting the DHW cylinder 40
6.2.4 Fitting the boiler fill & drain valve
(not supplied) 40
6.3 Filling the heating system and checking
for leaks 41
6.4 Connecting the fuel supply 42
6.5 Electricity connection 42
6.5.1 Fitting the control unit 42
6.5.2 Connecting the mains power supply and other
components 43
6.5.3 Fitting a strain relief 43
6.6 Installing casing parts 44
7 Commissioning the heating system 45
7.1 Bringing the system up to operating pressure 45
7.2 Preparing the heating system for operation 46
7.3 Switching on the heating system 46
7.4 Starting the burner 46
7.5 Raising the flue gas temperature 47
7.5.1 Removing hot gas baffle plates 47
7.5.2 Removing the hot gas check plate 47
7.6 Installing the burner hood 48
7.7 Setting the room controller/control unit 48
7.8 Commissioning report 49
8 Shutting down the heating system 50
8.1 Normal shutdown 50
8.2 Shutting down the heating system
in emergencies 50
8.2.1 What to do in an emergency 50
9 Heating system servicing 51
9.1 Why is regular servicing important? 51
9.2 Preparing the boiler for servicing 51

Contents
Logano G225/Logano plus GB225 - We reserve the right to make any changes due to technical modifications. 3
9.3 Cleaning the boiler 52
9.3.1 Cleaning the boiler with cleaning brushes 52
9.3.2 Wet cleaning (chemical cleaning) 53
9.4 Checking the heating system operating
pressure 54
9.5 Servicing and maintenance reports 55
10 Troubleshooting 58
Index 59

1General safety instructions and explanation of symbols
Logano G225/Logano plus GB225 - We reserve the right to make any changes due to technical modifications.
4
1 General safety instructions and explanation of symbols
1.1 Safety instructions
If you smell flue gas
VSwitch off the heating system (Æpage 50).
VOpen windows and doors.
VInform an authorised contractor.
Risk of poisoning. An insufficient supply of air can
result in dangerous escape of flue gas.
VEnsure that air inlet or outlet vents are not closed off or
their size is reduced.
VEnsure that no mechanical air extraction equipment
draws combustion air from the boiler room, e.g. cooker
extractor hoods, tumble dryers, ventilation equipment.
VOnly operate the boiler with chimneys that provide the
required draught during operation.
VThe boiler must not be operated until any deficiency
has been rectified.
VInform the system operator in writing of the problem
and associated danger.
Danger from escaping flue gases
VEnsure that the flue pipes and seals are not damaged.
VUse silicon as sealing compound.
Dangers posed by explosive and easily
combustible materials
VNever use or store combustible materials (paper, lace
curtains, clothing, thinners, paints, etc.) in the vicinity of
the boiler.
Combustion air
VKeep the combustion air free of corrosive substances
(e.g. halogenated hydrocarbons that contain chlorine
or fluorine compounds). In that way you will prevent
corrosion.
Risk of electric shock when the boiler is open
VBefore opening the boiler:
Disconnect the heating system from the power supply
by means of the emergency stop switch or the relevant
circuit breaker in the main fuse board.
VIt is not sufficient just to switch off the control unit.
VSafeguard the heating system to prevent unintentional
re-connection.
Danger due to short-circuits
To prevent short circuits:
VOnly use genuine Buderus wiring.
Installation and conversion
VCorrect and proper installation and adjustment of the
burner and the control unit are the fundamental
requirements for safe and economical operation of the
boiler.
VThe boiler may only be installed or converted by an
approved heating contractor.
VNever modify any parts that carry flue gas.
VOnly qualified electricians are permitted to carry out
electrical work. Installation regulations must be
complied with.
VWith open flue appliances: do not cover or reduce
the size of air vents in doors, windows or walls. If
draught-proof windows are fitted, ensure there is an
adequate supply of combustion air to the room.
VThe DHW cylinder may only be used for storing
domestic hot water.
Inspection/maintenance
Heating systems must be regularly maintained.
In that way, you will obtain a high level of efficiency and
low fuel consumption.
You will achieve a high level of operational safety and
reliability.
And you will obtain the cleanest possible combustion.
VRecommendation for users: take out a maintenance
and service contract with an approved heating
contractor covering annual servicing and demand-
dependent maintenance.
VServicing and repairs may only be carried out by a
approved heating contractor.
VHave any faults immediately rectified to prevent
damage to the system.
VThe operator is responsible for the general and
environmental safety of the heating system.
VUse only genuine spare parts. Damage caused by the
use of parts not supplied by Buderus is not covered by
the Buderus warranty.
Instructing the customer
VExplain to the customer how the boiler works and how
to operate it.
VInform the customer not to carry out any alterations or
repairs.

1
General safety instructions and explanation of symbols
Logano G225/Logano plus GB225 - We reserve the right to make any changes due to technical modifications. 5
1.2 Explanation of symbols
The terms indicate the seriousness of the ensuing risk if
measures for minimising losses are not taken.
–Caution means that minor material losses may occur.
–Warning means that minor injury or severe material
losses may occur.
–Danger means that severe injury may occur. Very
serious cases may result in death.
Notes contain important information for situations in
which there is no risk to the user or the appliance.
Cross-references to particular places in the document or
to other documents are marked with an arrow Æ.
Warnings are indicated by a warning
triangle and a grey background.
Notes are identified in the text by this
symbol. They are bounded by horizontal lines
above and below the text.

2Product details
Logano G225/Logano plus GB225 - We reserve the right to make any changes due to technical modifications.
6
2 Product details
These installation and servicing instructions contain
important information regarding the safe and proper
installation, commissioning and servicing of the boiler.
Product designation:
Logano G225 = fan-assisted, low temperature boiler
Logano plus GB225 = fan-assisted, low temperature
condensing boiler (complete system consisting of Logano
G225 with fitted oil condensing heat exchanger)
The Logano G225 fan-assisted, low temperature boiler
and the Logano plus GB225 fan-assisted, low
temperature condensing boiler are generally referred to in
the remainder of this document simply as the boiler.
These installation and servicing instructions are intended
for qualified heating contractors, who – as a result of their
technical training and experience – are skilled in dealing
with heating systems and oil installations.
2.1 EU Declaration of Conformity
The design and operation of this product conforms to
European Directives and the supplementary national
requirements. Its conformity is demonstrated by the
CE designation. You can view the Declaration of
Conformity on the Internet at www.buderus.de/konfo
or request a copy from your local Buderus office.
2.2 Intended use
The boiler is designed for heating central heating system
water and indirect heating of domestic hot water (e.g. in a
DHW cylinder) in detached houses or apartment
buildings.
Please note the details on the rating plate and the
specifications (ÆChapter 2.10, page 10) to ensure the
correct use of this appliance.
2.3 Standards, regulations and
directives
2.4 Notes on installation and operation
When installing and operating the heating system
observe the following:
– Local building regulations regarding the installation
conditions
– Local building regulations regarding air supply and
venting systems and the chimney flue connection
– Regulations governing electrical connection to the
mains power supply
– Regulations and standards relating to the safety
systems for the central heating system
– Remember that regional approvals may be required for
the flue system and connecting the condensate outlet
to the public sewer system.
2.5 Heating system water quality
As pure water cannot be used for heat transfer, water
quality is important. Poor water quality can damage
heating systems due to scale formation and corrosion.
2.6 Tools, materials and equipment
For the installation and maintenance of the boiler, you will
need the standard tools used for central heating, gas and
water systems plus set of a metric open-ended spanners
and Allen keys.
The following may also prove useful:
– Sack truck with securing strap or Buderus boiler trolley
–Timbersupports
– Cleaning brushes and/or chemical cleaning agent for
wet cleaning
The operations to be carried out for assembly
and installation are identical for the Logano
G225 and the Logano plus GB225 and are
described in these instructions for the
Logano G225.
The differing dimensions, technical
specifications and wall clearances, and the
additional operations for commissioning,
maintenance and servicing of the Logano
plus GB225 can be found in the enclosed
supplement.
Observe all standards and guidelines
applicable to the installation and operation of
this heating system in the country in which it
is used.
Caution: Risk of system damage due to
unsuitable heating system water.
VIf oxygen-permeable pipes are used, e.g.
for underfloor heating systems, the
systems must be separated from one
another by heat exchangers. Unsuitable
heating system water promotes sludge
and corrosion formation. That may result in
heat exchanger malfunction and damage.

2
Product details
Logano G225/Logano plus GB225 - We reserve the right to make any changes due to technical modifications. 7
If the boiler is delivered in sections, you will also require
the following:
– Size 1.2 compression tool (compression tool docu-
mentation)
– Flat board
– White spirit
– Installation kit (accessory)
– Steel hammer and wooden or rubber mallet
– Half-round bastard file
– Screwdriver (Philips and flat head)
– Flat chisel
– Spanners, sizes 13 mm, 19 mm, 24 mm and 36 mm,
and socket size 19 mm
– Support wedge, flat iron
– Cleaning rags and cloth
– Fine emery cloth
– Wire brush
– Lubricating oil
– Spirit level, ruler, chalk, straight edge
– Blanking flange with vent facility (for pressure test)
2.7 Disposal
VDispose of boiler packaging in an environmentally
responsible manner.
VAll heating system components that have to be
replaced should be disposed of in an environmentally
responsible manner at an authorised disposal site.

2Product details
Logano G225/Logano plus GB225 - We reserve the right to make any changes due to technical modifications.
8
2.8 Product description
The G225 boiler is a fan-assisted, low temperature boiler
and the GB225 boiler is fan-assisted, low temperature
condensing boiler; both of them feature modulating
control of boiler-water temperature.
The boiler comprises:
– Control unit [1]
– Boiler casing [2]
– Boiler heat exchanger and insulation [3]
– Burner [4]
– Heat exchanger system (GB225 only)
The control unit [1] monitors and regulates all electrical
boiler components.
The boiler outer casing [2] prevents heat loss and acts as
a noise insulator.
The boiler heat exchanger [3] transfers the heat
generated by the burner to the heating water.
The insulation [3] prevents radiation losses.
Fig. 1 G225/GB225 boiler
1Control unit
2Boiler casing
3Boiler heat exchanger and insulation
4Burner
5Burner hood
6 720 615 876-01.1RS
1
2
3
4
5

2
Product details
Logano G225/Logano plus GB225 - We reserve the right to make any changes due to technical modifications. 9
2.9 Contents
VUpon delivery, check that the packaging is
undamaged.
VCheck that all components have been delivered.
Boiler as assembled block
Boiler supplied in sections
Component
Quan-
tity Packaging
Boiler block 1 1 pallet
Boiler casing 1 1 box
Thermal insulation 1 1 shrink-
wrapped pack
Burner, burner hood,
burner door and fixings1),
technical documentation
for burner and boiler.
1) The adjustable feet are packed with the burner hood
11box
Control unit, technical
documentation for
controller
11box
Tab. 1 Contents
Component
Quan-
tity Packaging
Front and rear boiler sec-
tions
11pallet
Centre sections loose
Furniture 1 1 box
Boiler casing 1 1 box
Thermal insulation 1 1 shrink-
wrapped pack
Burner, burner hood,
burner door and fixings1),
technical documentation
for burner and boiler.
1) The adjustable feet are packed with the burner hood
11box
Control unit, technical
documentation for
controller
11box
Tab. 2 Contents

2Product details
Logano G225/Logano plus GB225 - We reserve the right to make any changes due to technical modifications.
10
2.10 Dimensions and specifications
2.10.1 Logano G225 BE dimensions
Fig. 2 Connections and dimensions (sizes in mm)
Connections (for sizes see tables below):
VK = Boiler flow
RK = Boiler return
EL = Boiler drain (connection for drain tap)
VS = DHW cylinder flow
RS = DHW cylinder return
VSL = Pressure relief flow pipe (connection for automatic air
vent valve provided by installer)
Connections and sizes:
6 720 615 876-02.1RS
Boiler size 45 55 68
Oil burner Type BE2.3-45 BE2.3-55 BE2.3-68
Boiler sections Number 456
Rated output KW 45 55 681)
1) 65 kW (for Spain)
Combustion output KW 48.1 59.0 73.02)
2) 69.8 kW (for Spain)
Boiler water content lApprox. 61 Approx. 73 Approx. 85
Gas content l68.8 85.1 101.4
Flue gas temperature3)
3) Flue gas temperature to EN 303.
°C 165 180 180
Flue gas mass flow rate kg/s 0.0197 0.0242 0.02994)
4) 0.0287 kg/s (for Spain)
CO2content, oil %13.5
Available draught Pa 50 50 30
Flue gas back pressure mbar 0.35 0.20 0.35
Permissible flow temperature5)
5)Safety limit (high limit safety cut-out, STB)
Maximum possible flow temperature = Safety limit (STB) - 10 K
Example: Safety limit (STB) = 100 °C, maximum possible flow temperature = 100 - 10 = 90 °C
The safety limit must meet the national regulations of the country concerned.
°C 100
Permissible operating pressure bar 4
Maximum time constant of temperature control s≤1
Maximum time constant of temperature
monitor and high limit safety cut-out (STB)
s≤1.2
Power supply rating 230 VAC, 50 Hz, 10 A IP 40
Tab. 3 Specifications

2
Product details
Logano G225/Logano plus GB225 - We reserve the right to make any changes due to technical modifications. 11
2.10.2 Boiler room and ambient conditions
Boiler size 45 55 68
Boiler overall length (L) mm 1102 1222 1342
Boiler heat exchanger length (LK) mm 626 746 866
Boiler section handling clearance
(width/height/depth)
mm 460/820/150
Boiler heat exchanger handling clearance
(width/height/depth)
mm 460/820/LK
Combustion chamber length mm 548 668 788
Combustion chamber diameter mm 337
Burner door depth mm 95
Distance between boiler feet (FL)mm 455 575 695
Net weight1) kg 246 291 336
Tab. 4 Dimensions, weight and other details
1) Weight inc. packaging approx. 6 – 8 % greater.
Operating conditions Notes - detailed requirements
Temperature in the installation
room
+5 to +40 °C
Relative air humidity max. 90 % No condensation or dripping damp inside the boiler room
Dust/airborne seed −When the boiler is in operation, it is essential to prevent excessive dust levels in
the boiler room, e.g.
– building dust through very dusty building work
The supply of combustion air must not contain excessive amounts of dust or
airborne seed; if necessary, entry should be prevented by means of air filters,
e.g.:
– Air supply loaded with dust from dirt roads and paths.
– Air supply contaminated with dust from production and processing facilities, e.g.
quarries mines, etc.
– Airborne seed from plants.
Halogenated hydrocarbon
compounds
−The combustion air must be free of halogen-hydrocarbon compounds.
– Identify the source of halogenated hydrocarbon compounds and eliminate their ingress.
Where this is impossible, route combustion air from areas which are not contaminated
by halogenated hydrocarbon compounds.
Observe the following:
– Buderus catalogue - Heating Technology Germany
– Code of Practice K3 in the Buderus catalogue
Fans, which extract air from the
installation room.
−While the burner is in operation, no mechanical air extraction equipment that draws air from
the boiler room must be operated, e.g.:
– cooker hood
–dryer
– ventilation equipment
Small animals −Prevent small animals from entering the boiler room, particularly through the air inlet vents –
by fitting the vents with grilles.
Fire safety −Maintain clearances between the boiler and flammable materials in accordance with local
regulations. A minimum clearance of 40 cm should always be maintained. Never store
flammable materials or liquids in the vicinity of the boiler.
Flooding −If flooding is imminent, disconnect the boiler in good time from its fuel and power supply
before water enters the room. Any general and burner components or control equipment,
which come into contact with water, must be replaced before re-commissioning.
Tab. 5 Installation room and environment

2Product details
Logano G225/Logano plus GB225 - We reserve the right to make any changes due to technical modifications.
12
2.10.3 Conditions for combustion air supply
2.10.4 Conditions for fuel
Country-specific fuels
Operating conditions
Boiler output (in case of
multi-boiler systems = total output)
Air intake flow cross-sectional area in cm2
(clear area)
Air intake flow cross-sectional
area for combustion air drawn
from outside (divided between
max. two apertures)
<50kW min.150cm
2
> 50 kW min. 150 cm2plus 2 cm2for each kW
in excess of 50 kW
Tab. 6 Combustion air supply – observe national regulations for boilers which draw their air supply from the boiler
room.
Operating conditions Notes – detailed requirements
Permissible fuels for boilers
with Logatop oil burner
– Boilers with a built-in oil burner may only be run on domestic fuel oil (DIN 51603). The
kinematic viscosity of the oil must not exceed 6 mm2/s (at 20 °C). That is equivalent to a
Redwood I viscosity of 41.0 s (UK) or Sayboldt viscosity of 45.5 s (USA). If oil of poorer
quality is used, the service/cleaning intervals should be reduced accordingly.
Contamination – Technically free of contamination (e.g. dust, moisture, fluids), i.e. continuous operation will
not result in any accumulations likely to restrict the flow through valves or filters.
Tab. 7 Fuels and remarks
Country Germany
Fuels Domestic fuel oil type EL to DIN 51 603
Remarks The boiler may only be operated with the specified fuel.
Country Austria
Fuels EL fuel oil
Remarks The boiler may only be operated with the fuel specified.
The requirements as per Art. 15 a B-VG regarding emissions and efficiency are satisfied.
Country Switzerland
Fuels EL fuel oil
Remarks The boiler may only be operated with the fuel specified.
The output figures shown in the table "Specifications" are rated output figures.
In some cases, the actual figures attained in practice will be below those stated to comply with LRV
requirements within the specified output range.
Tab. 8 Country-specific fuels and remarks

2
Product details
Logano G225/Logano plus GB225 - We reserve the right to make any changes due to technical modifications. 13
2.10.5 Conditions for the power supply
2.10.6 Conditions for the system configuration and water quality
Operating conditions Notes – detailed requirements
Supply voltage 195 – 253 V The outer casing/boiler must be earthed for safety reasons and to function correctly.
Fuse 10 A
Frequency 47.5 – 52.5 Hz Sine wave
Enclosure rating −IP40 (protected against penetration by foreign bodies > 1 mm dia., not protected against
water ingress)
Tab. 9 Mains power supply
Operating conditions Notes – detailed requirements
Operating pressure (above
atmospheric)
0.5 – 4.0 bar
Permissible testing pressure 1.0 – 5.2 bar
Protection against excess
temperatures via TR thermostat
50–90°C
Protection against excess
temperatures via STB high limit
safety cut-out
100 °C
Water quality −The heating system may only be filled and topped up with water of domestic water quality.
We recommend a pH value of 8.2 – 9.5.
Tab. 10 System configuration and water quality

3Transporting the boiler
Logano G225/Logano plus GB225 - We reserve the right to make any changes due to technical modifications.
14
3 Transporting the boiler
This chapter details how you safely transport your boiler.
Caution: Risk of system damage from
impact shocks.
Fragile components could be damaged.
VObserve the transport instructions on the
packaging.
Protect boiler connections from damage and
dirt if the boiler is not to be installed
immediately.
Dispose of packaging in an environmentally
responsible manner.
Warning: Risk of injury if load is
inadequately secured during transportation.
VUse suitable means of transportation, e.g.
the Buderus boiler hand truck with strap.
VSecure the load against falling.

4
Boiler positioning
Logano G225/Logano plus GB225 - We reserve the right to make any changes due to technical modifications. 15
4 Boiler positioning
This section explains how to erect and position the boiler
in the boiler room.
Wall clearances
Wherever possible, position the boiler with the
recommended wall clearances. Reducing the clearances
to the minimum makes the boiler more difficult to access.
The boiler base or foundation must be perfectly flat and
level.
At the factory, the burner door hinges are fitted on the
right hand side. The burner door can be reversed so as to
hinge on the left.
Fig. 3 Boiler room clearances (boiler positioned on the
left-hand or right-hand side)
Caution: Risk of system damage due to
frost!
VSet up the heating system in a room safe
from the risk of frost.
Dimen-
sion Wall clearance
A Recommended 1300
minimum 1000
B Recommended 700
minimum 400
C Recommended 400
minimum 100
LÆChapter 2.10.1, page 10
Tab. 11 Recommended and minimum wall clearances
(dimensions in mm)
6 720 615 876-03.1RS
Where applicable, allow extra wall
clearances for additional components such
as DHW cylinder, pipe connections, flue
silencer or other flue components, etc.

5Boiler block assembly
Logano G225/Logano plus GB225 - We reserve the right to make any changes due to technical modifications.
16
5 Boiler block assembly
The on-site installation is carried out using individual
sections if, because of physical limitations, a boiler block
cannot be handled as a complete unit.
For details of assembling the remainder of the boiler if the
heat exchanger is delivered pre-assembled,
ÆChapter 5.4, page 28.
Fig. 4 Fully assembled boiler heat exchanger
1Foundation/installation location
2Drain
3Rear section
4Flue outlet
5Connecting block
6Centre sections
7Anchor rods
8Front section
9Burner door
5.1 Assembly when delivered in
sections
VAssemble all boiler sections in accordance with the
following instructions and illustrations.
5.1.1 Preparation of boiler sections
VLay rear section [2] across two wooden battens [3].
VClean the boiler bosses [1] with emery paper and a rag.
VRemove any burrs which might have been created with
a file.
VClean the joint lip/groove [4] using a wire brush and
rag.
Fig. 5 Filing off flash
1Boiler bosses
2Rear section
3Wooden battens
4Joint lip
Warning: Risk of injury if load is
inadequately secured during transportation.
VUse suitable means of transportation, e.g.
the Buderus boiler hand truck with strap.
VSecure the load against falling.
6 720 615 876-04.1RS
1
2
3
4
5
67
8
7
9
Warning: Health risk and risk of injury from
release of vapours and easily combustible
cleaning agents.
VEnsure adequate ventilation inside the
boiler room when using red lead putty,
adhesives and cleaning agents.
VWhen using a cleaning agent, avoid naked
flames, glowing embers and sparks.
VObserve the manufacturer's handling and
safety instructions.
6 720 615 876-05.1RS
3
4
1
1
2

5
Boiler block assembly
Logano G225/Logano plus GB225 - We reserve the right to make any changes due to technical modifications. 17
VClean the sealing faces of the boiler bosses [1] with a
cloth soaked in white spirit.
VEvenly coat the boiler boss sealing faces with red lead
putty.
VCoat the joint lip/groove [2] with adhesive (primer).
Fig. 6 Coating the boiler hubs with red lead putty
1Boiler boss sealing face
2Packing groove
5.1.2 Driving boss liners home
VClean the boss liners with a cloth soaked in white spirit.
VEvenly coat the boss liners with red lead putty.
VInsert the boss liners straight into the upper and lower
hub of the rear section and hammer home securely with
alternate heavy blows.
VRemove any burrs with a file.
Fig. 7 Driving boss liners home
1Boss liner in the upper boiler hub
2Boss liner in the lower boiler hub
2
1
1
6 720 615 876-06.1RS
Leave the two boss liners protruding approx.
30 mm from the boiler boss in each case.
6 720 615 876-07.1RS
2
1

5Boiler block assembly
Logano G225/Logano plus GB225 - We reserve the right to make any changes due to technical modifications.
18
5.1.3 Preparing the centre section
Prepare the centre section in the same way as the rear
section (Æ5.1.1, page 16).
Fig. 8 Preparing the centre section
1Boiler boss sealing face
2Packing grooves
5.1.4 Inserting the packing cord
VUnroll the required length of packing cord from the roll
supplied.
VPeel the backing paper from the packing cord, as you
insert the cord into the packing groove.
VInsert the flexible packing cord into the packing groove,
starting in the upper boiler hub area, and lightly press
in.
VWhere the 2 ends meet, overlap the packing cord by
2 cm and press firmly together.
Fig. 9 Inserting the packing cord
6 720 615 876-08.1RS
2
1
1
Caution: Risk of system damage due to
leaking boiler sections.
VTo ensure that the joint faces between the
boiler sections are properly sealed, the
packing cord must not be stretched
during fitting.
VCarefully insert the packing cord into the
boiler packing grooves.
6 720 615 876-09.1RS

5
Boiler block assembly
Logano G225/Logano plus GB225 - We reserve the right to make any changes due to technical modifications. 19
5.1.5 Knocking the centre section into place
VTurn the centre section around and locate with the
upper and lower boiler hubs on the boss liners of the
rear section.
VDrive the centre section onto the rear section [2] using
a wooden or a rubber mallet [1].
Fig. 10 Knocking the centre section into place
1Wooden or rubber mallet
2Rear section
5.1.6 Boiler section alignment
VRight the part assembled block comprising two boiler
sections.
VPosition a flat board [1] underneath the centre section
[2] so that the boiler heat exchanger is slightly tilted to
the rear for the subsequent assembly process.
Fig. 11 Righting the part assembled block
1Flat board
2Centre section
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Warning: Risk of injury due to inadequately
secured boiler sections.
VSecure the partly assembled boiler heat
exchanger against tipping over.
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5Boiler block assembly
Logano G225/Logano plus GB225 - We reserve the right to make any changes due to technical modifications.
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5.1.7 Joining the boiler sections at the upper and
lower boiler bosses with boss liners
Fig. 12 Assembling the pull rods
1Pull rod threaded connection (incorrectly joined)
2Pull rod threaded connection (correctly joined)
VPush one pull rod each through the lower and the
upper boiler hub of the part assembled block.
Fig. 13 compression tool fitted to the top boiler boss
1Compression unit
2Pressure plate (dia. 135 × 25, top boiler boss)
3Brace plate (dia. 135 x 25, top boiler boss)
4Wedge
5Pull rod in the upper boiler hub
Caution: Risk of boiler damage due to
unsuitable compression tool.
VUse only the size 1.2 compression tool
suitable for your boiler (Æobserve
documentation supplied with
compression tool).
Caution: Risk of damage to compression
tool
The compression tool may be damaged or
destroyed, if you compress pull rods with
loose threaded connections.
VAfter each compression operation, check
the screwed joints of the pull rods [1, 2]
and tighten if necessary.
The pull rods [2] is correctly assembled
when it is fully fitted together and no
thread is visible.
VKeep the thread of the compression tool
clean. Dirty threads can cause damage to
the compression tool when in use.
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Caution: Risk of boiler damage due to
incorrectly positioned pressure plate.
If the pressure plate is seated against the
joint lip/groove of the boiler section during
the compression operation, the joint may be
damaged and subsequently leak.
VEnsure that the pressure plate is seated
flat against the boiler boss.
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