Buderus Logano GB125 BE US User manual

For contractors
Please read carefully prior
to installation and servicing.
CAUTION!
Observe the safety instructions of this installation
and maintenance manual before placing the boiler
in operation.
DANGER!
If installation, adjustment, modification, operation or
maintenance of the heating system is carried out by
an unqualified person, this may result in danger to
life and limb or property damage.
The directions of this installation and maintenance
manual must be followed precisely.
If you require assistance or further information, con-
tact a qualified installer or an appropriate service
provider.
CAUTION!
The operating manual is a component of the techni-
cal documentation and must be handed over to the
operator of the heating system.
Discuss the instruction in this manual with the ow-
ner or operator of the heating system to ensure that
they are familiar with all information required for
operation of the heating system.
Installation and
Maintenance Instructions
Oil condensing boiler
Logano GB125 BE US/CA
6 720 649 307 - 2011/07 US/CA

Contents
Logano GB125 BE US/CA - Subject to technical modifications.
2
Contents
1 Safety instructions and explanation of
symbols 3
1.1 Safety instructions 3
1.2 Explanation of symbols 4
2 Product description 5
2.1 Intended use 5
2.2 Standards, regulations and code compliance 5
2.3 Notes on installation and operation 5
2.4 Product description 6
2.5 Boiler water quality 7
2.6 Tools, Materials and Accessories 7
2.7 Scope of delivery 7
2.8 Dimensions and specifications 8
2.9 Conditions for operation 9
2.9.1 General operating conditions 9
2.9.2 Conditions for the boiler room and the
environment 10
2.9.3 Fuel conditions 10
2.9.4 Power supply conditions 10
2.9.5 Conditions for hydraulic system and water
quality 10
2.10 Disposal 11
3 Moving the boiler 12
3.1 Reducing the boiler weight for handling
purposes 12
3.2 Lifting and carrying the boiler 13
3.3 Moving the boiler with hand truck 13
4 Placing the boiler 14
4.1 Wall clearances 14
4.2 Reversing the burner door 15
4.3 Mounting the adjustable feet
(included with B-kit) 16
4.4 Positioning and leveling the boiler 16
5 Installing the boiler 17
5.1 Flue pipe installation 17
5.2 Test ports 18
5.3 Installation options 20
5.4 Making the water connections 22
5.4.1 Installing B-kit 22
5.4.2 Mounting the drain valve
(included with B-kit) 23
5.4.3 Installation of system components 23
5.5 Filling the heating system and checking
for leaks 24
5.6 Connecting the fuel supply 25
5.7 Bleed off condensate 25
5.8 Electrical supply connections 27
5.8.1 Installing the control panel 27
5.8.2 Installing the temperature sensor assembly 28
5.8.3 Power connection and connections of
additional components 29
5.8.4 Installing cable strain relief 30
5.9 Installing the back boiler cover 30
6 Starting up the heating system 31
6.1 Bringing the system up to operating
pressure 31
6.2 Testing safety valve 32
6.3 Checking position of heat exchanger baffles 32
6.4 Preparing the heating system for operation 32
6.5 Starting up the control panel and the burner 33
6.6 Taking measurements 33
6.7 Checking the manual reset high limit (STB) 34
6.8 Installing the burner hood 34
6.9 Commissioning log 35
7 Shutting down the heating system 36
7.1 Normal shut-down 36
7.2 Shutting down the heating system in an
emergency 36
7.2.1 Action in an emergency 36
8 Heating system inspection 37
8.1 Why is regular maintenance important? 37
8.2 Preparing the boiler for inspection 37
8.3 Cleaning the boiler 38
8.3.1 Cleaning the boiler with cleaning brushes 38
8.3.2 Wet cleaning (chemical cleaning) 39
8.4 Cleaning the heat exchanger system 40
8.5 Cleaning the neutralizing system and trap 42
8.6 Checking the air supply hose 44
8.7 Check heating system operating pressure 44
8.8 Test safety valve 45
8.9 Concentric supply air and flue gas routing 45
8.10 Air supply system 45
8.11 Inspection and maintenance reports 46
9 Troubleshooting 49
10 Examples of installations 50
11 Spare parts 53
12 Wiring diagrams 61
Index 62

1
Safety instructions and explanation of symbols
Logano GB125 BE US/CA - Subject to technical modifications. 3
1 Safety instructions and explanation of symbols
1.1 Safety instructions
If you smell flue gas
BSwitch off the boiler (Æpage 36).
BOpen windows and doors.
BInform an authorized heating contractor.
Risk of poisoning. An insufficient supply of air can
result in dangerous escape of flue gas.
BNever close off or reduce the size of air intake and
outlet openings.
BThe boiler must not be operated until the obstruction
has been removed.
BEnsure that no mechanical air-extraction equipment
draws air from the boiler room, e.g. kitchen vent hood,
clothes dryer, central vacuum system, etc.
BInform the system user in writing of an existing problem
and associated dangers.
Danger from escaping flue gases
BMake sure that the vent pipes and gaskets are not
damaged.
BUse silicone as sealing compound.
BNever operate this boiler with a barometric or a
thermally-controlled vent damper.
BConnect only one boiler to each venting system or
chimney flue.
BThe venting system piping must not feed into another
air extraction duct.
BDo not route the venting system piping through or
inside another duct used for exhaust air or other flue
gases.
BTo prevent the combustion gases from reaching the
boiler room, the siphon must always be filled with
water.
Dangers posed by explosive and combustible
materials
BDo not use or store easily-combustible materials
(paper, lace curtains, clothing, thinners, paints, etc.)
near the boiler.
BMaintain a clearance of 16 inches (40.6 cm) from the
boiler.
Combustion air
BKeep the supply of combustion air free of corrosive
substances (e.g. halogenated hydrocarbons that
contain chlorine or fluorine compounds). This will help
prevent corrosion.
Danger from electrical shock
BBefore opening the boiler:
Disconnect the heating system from the electrical
power supply by means of the emergency shutoff
switch or the heating system circuit breaker on the
main fuse panel.
BIt is not sufficient just to switch off the control panel.
BTake measures to ensure that the heating system
cannot be switched on again unintentionally.
Installation
BCorrect and proper installation and adjustment of the
burner and the control panel are the fundamental
requirements for safe and economical operation of the
boiler.
BThe boiler may only be installed or maintained by an
approved heating contractor.
BDo not modify any parts that carry flue gases.
BOnly qualified electricians are permitted to carry out
electrical work. Follow applicable code.
BThe hot water tank may only be used for heating
domestic hot water.
BNever shut off safety valves!
Water may escape from the safety valve when it is
being heated.
Danger due to failing to consider your own safety in
an emergency such as a fire
BNever put yourself at risk of fatal injury. Your own safety
must always take the highest priority.

1Safety instructions and explanation of symbols
Logano GB125 BE US/CA - Subject to technical modifications.
4
Inspection/maintenance
Heating systems must be maintained regularly.
This way, they maintain a high level of efficiency and low
fuel consumption.
You will achieve a high level of operational safety.
And you will obtain the cleanest possible combustion.
BRecommendation for customers: take out a
maintenance and inspection contract with an approved
heating contractor covering annual inspection and
condition-based maintenance.
BMaintenance and repairs may only be carried out by an
approved heating contractor.
BHave any faults corrected immediately in order to
prevent damage to the system.
BUse 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
BExplain to the customer how the boiler works and how
to operate it.
BInform the customer that he/she must not carry out any
alterations or repairs.
1.2 Explanation of symbols
Signal words are used to indicate the seriousness of the
ensuing risk if measures for minimizing damage are not
taken.
•Caution indicates that minor damage to property may
occur.
•Warning means that minor injury or severe property
damage may occur.
•Danger means that severe injury may occur. Very
serious cases may result in death.
Notes contain important additional information.
Notes do not contain any warnings or information about
hazards or risks.
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 gray background.
Notesare identified in the text by this symbol.
They are separated by horizontal lines above
and below the text.

2
Product description
Logano GB125 BE US/CA - Subject to technical modifications. 5
2 Product description
This installation and maintenance manual contains
important information for the safe and correct installation,
initial start-up and maintenance of this boiler.
The Logano GB125 BE oil-fired condensing boiler is
generally referred to below simply as the boiler.
These installation and maintenance instructions are
designed for specialists, who – through their vocational
training and experience –are knowledgeable in handling
heating systems and DHW installations.
This boiler must only be installed with one of the Buderus
supplied concentric supply air and flue gas routing
systems.
• Concentric air supply and flue pipe exiting through
external wall
• Concentric supply air and flue gas routing via roof
• Concentric supply air/flue gas routing through a flue
inside a duct
This boiler produces significant amounts of acidic flue gas
condensate while in operation. Condensate may cause
damage to sewer pipes and septic systems, and disposal
may be subject to local regulations. In the absence of
such regulations Buderus recommends a condensate
neutralization kit.
The boiler must draw all combustion air from the outside.
2.1 Intended use
The boiler is designed for the central heating and indirect
heating of domestic hot water (e.g. in a hot water tank), for
instance in single family homes or multi-family buildings.
2.2 Standards, regulations and code
compliance
2.3 Notes on installation and operation
When installing and operating the heating system
observe the following:
• The local building codes regarding the installation
• The local building codes regarding combustion air
supply and venting systems, and the chimney
connection
• Regulations governing power connection to the power
supply
• The regulations and standards relating to the safety
systems for the water heating system
Other important information
• Only operate the boiler with the combined combustion
air/flue venting system specifically designed and
approved for it.
• Follow the local code when connecting the
condensate outlet to the public sewer system.
It is the installer's responsibility to ensure the
installation and operation of this heating
system meets all applicable federal, state,
and local codes.
The boiler must be installed by a qualified
installer and in accordance with all
requirements of NFPA-31, "Installation of Oil-
Burning Equipment". Installation must
comply with all local and national legal
requirements and the regulations of all
institutions having legislative authority with
regard to the installation of oil-fired boilers.
For Canada, the guidelines of the CSA/CGA
B139 Installation Code apply.

2Product description
Logano GB125 BE US/CA - Subject to technical modifications.
6
2.4 Product description
This boiler is an oil-fired condensing boiler with
modulating control of boiler water temperature.
The boiler consists of:
• Control panel
• Boiler casing
• Boiler block with thermal insulation
• Burner
• Heat exchanger system
The control panel monitors and controls all electrical
boiler components.
The boiler casing prevents heat loss and reduces noise.
The boiler block transfers the heat generated by the
burner to the boiler water. The insulation prevents energy
loss.
Fig. 1 Boiler with burner
1Control panel
2Boiler casing
3Boiler block with thermal insulation
4Burner hood
5Burner
Fig. 2 Rear view with heat exchanger (thermal
insulation not shown)
1Heat exchanger system

2
Product description
Logano GB125 BE US/CA - Subject to technical modifications. 7
2.5 Boiler water quality
Poor water quality can damage heating systems due to
scale formation and corrosion. (Tab. 8, page 10).
2.6 Tools, Materials and Accessories
For the installation and maintenance of the boiler, you
need standard tools used for central heating and DHW
systems, plus metric wrenches and metric Allen
wrenches.
The following may also prove useful:
• Hand truck with securing strap or Buderus boiler cart
• Wood battens
• Cleaning brushes and/or chemical cleaning agent for
wet cleaning
2.7 Scope of delivery
BAfter delivery, check all packaging for perfect
condition.
BCheck the delivery for completeness.
CAUTION: Risk of system damage due to
unsuitable boiler water!
BWhen using oxygen-permeable pipes, e.
g. for radiant floor heating systems, you
must separate the system using heat
exchangers. Unsuitable heating system
water promotes sludge formation and
corrosion. This can result in heat
exchanger malfunction and damage.
Component Qty Packaging
Boiler block 1 1 pallet
Boiler casing, factory-
installed on the boiler
block
Burner hood, factory-
installed on the boiler
block
Heat exchanger system,
factory-installed on the
boiler block
Oil burner with factory-
installed burner door
Air supply hose, factory-
installed
Siphon 1 1 bag1)
1) Under the burner hood
B-kit components:
• Conversion nipple
(1¼ " NPT)
• 30 psi safety valve
• Drain valve (¾ ")
• Pressure/temperature
gauge
• Double nipple
(1¼ " NPT × R1¼ )
• 90°-elbow (1¼ ” NPT)
• 90°-elbow (¾ " NPT)
• Screw set (for burner
mounting)
• Adjustable feet
1 1 foil
package1)
Control panel 1 1 box
Tigerloop oil filter and
de-aerator
11box
Technical documentation 1 bag
Tab. 1 Scope of delivery

2Product description
Logano GB125 BE US/CA - Subject to technical modifications.
8
2.8 Dimensions and specifications
Fig. 3 Connections and dimensions (measurements in inches)
VK = Boiler supply
RK = Boiler return
EL = Boiler drain (connection for drain valve)
Dimensions and connections:
6 720 649 309-01.1ITL
Boiler type Unit GB125/22 BE GB125/30 BE GB125/35 BE
Boiler sections 344
Rated heat output (gross output)
131/86 °F
MBtu/hr 76 102 124
Rated heat output (net IBR rating)
131/86 °F
MBtu/hr 67 90 109
Rated heat output/heating capacity
(gross output)176/140 °F
MBtu/hr 75 100 121
Rated heat output
(net IBR rating)176/140 °F
MBtu/hr 65 87 105
Rated thermal input/burner input MBtu/hr 81 108 131
AFUE % 91.2 91.1 91.0
Flue gas temperature 176/140 °F °F (°C) 176 (80) 176 (80) 192 (89)
Boiler water content gal (l) 8.7 (35.6) 11.8 (44.9) 11.8 (44.9)
Gas volume of combustion chamber and heat
exchanger
cu. ft.
(l)
1.5 (42.9) 2.0 (57.9) 2.0 (57.9)
Oil consumption/oil firing rate gph (l/h) 0.60 (2.3) 0.75 (2.9) 0.95 (3.6)
Flue gas resistance in. W.C.
(Pa)
0.08" - 0.14" W.C. (20 - 35)
Heat exchanger water pressure drop
(DeltaT = 18 °F)
ft. of
head
(mbar)
1.8' (54) 2.0' (60) 2.7' (81)
Maximum supply temperature1)
1) Safety limit (manual reset high limit, STB)
Maximum permitted supply temperature = manual reset high limit (STB) – 32 °F
Example: manual reset high limit (STB) = 212 °F, maximum possible supply temperature = 212 - 32 = 180 °F
The safety limit must comply with the requirements applicable in your country.
°F (°C) 212 (100)
Maximum operating pressure psi (bar) 44 (3)
Maximum time constant of thermostat and
manual reset high limit (STB)
s40
Tab. 2 Technical specifications

2
Product description
Logano GB125 BE US/CA - Subject to technical modifications. 9
2.9 Conditions for operation
Maintaining the specified operating conditions will enable
the boiler to provide a high level of reliability and long
service life. Some details relate only to operation with
Logamatic control panels from Buderus.
2.9.1 General operating conditions
Boiler type Unit GB125/22 BE GB125/30 BE GB125/35 BE
Boiler overall length (L) Inches 37 1/2" 42 3/8" 42 3/8"
Boiler block length (LK) Inches 25 3/4" 30 1/2" 30 1/2"
Combustion chamber length Inches 16" 20 1/2" 20 1/2"
Combustion chamber length Inches 10 5/8"
Burner door thickness Inches 2 1/3"
Distance between boiler feet (FL)Inches 16 1/8" 20 7/8" 20 7/8"
Net weight1) lbs 423 503 503
Tab. 3 Dimensions, weight and other data for boilers with burners
1) Weight incl. packaging material approx. 6-8 % more.
CAUTION: Risk of system damage if
operating conditions are not maintained.
Extreme divergence from the stated
conditions may cause irreversible damage to
individual components of the boiler.
BThe information on the rating plate is
definitive.
Operating conditions
Min. boiler water tempera-
ture
Operating interruption
(complete boiler shutdown)
Heating zone with
heating zone mixing valve1) Min. return temperature
In combination with Logamatic control panel for variable low-temperature operating modes, such as Logamatic 2107.
No requirements. Operating
temperatures are safeguarded
by the Logamatic control
panel. 2)
Automatically by Logamatic control
panel
Not required but recommended with
low-temperature heating system design
130/113 °F.
Required with:
• Radiant floor heating system
• Systems with large water capacity:
> 115 gal/MBH
(1 MBH = 100,000 Btu/hr)
No requirements
Tab. 4 General operating conditions
1) A heating zone with a mixing valve improves controllability and is specifically recommended for systems with several heating zones.
2) If the control panel does not influence the heating zones or a heating zone actuating component (e.g. Pumplogic), the burner ON mode must
reach an operating temperature of 122 °F within 10 min by restricting volume flow.

2Product description
Logano GB125 BE US/CA - Subject to technical modifications.
10
2.9.2 Conditions for the boiler room and the environment
2.9.3 Fuel conditions
2.9.4 Power supply conditions
2.9.5 Conditions for hydraulic system and water quality
Operating conditions Notes – Requirement in greater detail
Temperature in the boiler room 40 to 104 °F
(5 to 40 °C)
Relative humidity max. 90 % No condensation or precipitation inside the boiler room
Dust/airborne particles −Excessive dust inside the boiler room must be avoided when the boiler is operat-
ing, e.g.:
• Dust from building work
Combustion air supplied from outside must not be excessively loaded with dust
or airborne seed; if necessary, air filters should be installed to prevent this:
• Air supply contaminated with dust from dirt roads and paths.
• Air supply contaminated with dust from production and processing facilities, e.g. quar-
ries, mines, etc.
• Airborne particles from thistles and similar
Halogenated-hydrocarbon com-
pounds
−The combustion air must be free from halogen-hydrocarbon compounds.
• Identify the source of halogen-hydrocarbon compounds and seal it off. Where this is
impossible, route combustion air from areas that are not contaminated by halogen-
hydrocarbon compounds.
Small animals −Prevent small animals from entering the boiler room, particularly through the air inlet vents –
by installing screens.
Fire safety −Maintain clearances between the boiler and flammable materials in accordance with local
regulations. A minimum clearance of 16” is required. Never store flammable materials or liq-
uids in the vicinity of the boiler.
Flooding −In case of an acute risk of flooding, disconnect the boiler in time from its fuel and power
supply before water enters the room. Any general and burner components or control equip-
ment that comes into contact with water must be replaced before starting up again.
Tab. 5 Boiler room and ambient conditions
Country All countries
Fuels #2 Fuel oil ASTM D396-05 Type 2
Approved for B5 Fuel Oil (5% biodiesel (B100) according ASTM D6751)
Remarks The burner may only be operated with the specified fuel. Clean and service once a year. Check that the entire
system functions properly at the same time. Immediately remedy faults.
Tab. 6 Country-specific fuels and remarks
Operating conditions Notes – Requirement in greater detail
Line voltage 110 – 120 V The outer casing/boiler must be grounded to protect people and in order to function correctly.
Circuit breaker 10 A
Frequency 60 Hz
Protection class −IP 40 (protected against contact by entry of foreign objects > 0.04 inches Ø (> 1 mm Ø ), no
waterproofing)
Tab. 7 Power supply
Operating conditions Notes – Requirement in greater detail
Operating pressure (above atmo-
spheric)
15 – 44 psi
(1 to 3 bar)
Maximum 30 psi with the supplied safety valve.
Permissible test pressure 45 – 58 psi
(3 to 4 bar)
Safety temperature limitation by TR
temperature controller
122 – 194 °F
(50 to 90 °C)
Safety temperature limitation by man-
ual reset high limit (STB)
212 °F
(100 °C)
Water quality −The heating system may only be filled and topped up with water of domestic water qual-
ity. We recommend a pH level of 8.2 – 9.5.
Tab. 8 Hydraulics and water quality

2
Product description
Logano GB125 BE US/CA - Subject to technical modifications. 11
2.10 Disposal
BDispose of boiler packaging in an environmentally-
responsible manner.
BAll heating system components that have to be
replaced should be disposed of in environmentally-
responsible manner at an authorized disposal site.

3Moving the boiler
Logano GB125 BE US/CA - Subject to technical modifications.
12
3 Moving the boiler
This section details how to move the boiler safely.
3.1 Reducing the boiler weight for handling purposes
If required, you can reduce the weight of the boiler by
removing the burner hood and door.
BUnscrew the burner hood screws.
BLift burner hood slightly and pull forwards to remove.
BBefore removing the burner door: unplug the burner
plug from the burner controller.
Fig. 4 Removing burner hood
BUnscrew two hex bolts at the sides.
BOpen the boiler door.
BLift the burner door off its hinges.
Fig. 5 Removing the burner door
CAUTION: Risk of system damage from
impact shocks!
Fragile components could be damaged.
BFollow the transport instructions on the
packaging.
Protect connectors against contamination if
the boiler is not immediately put into
operation.
Dispose of packaging in an environmentally-
responsible manner.
Prevent the burner door from falling over and
damaging the burner and burner tube.
7 747 019 141-04.1RS

3
Moving the boiler
Logano GB125 BE US/CA - Subject to technical modifications. 13
3.2 Lifting and carrying the boiler
The boiler can be held and carried at the grip positions
shown (Fig. 6).
BUnscrew the transit screws.
Fig. 6 Lifting and carrying the boiler
3.3 Moving the boiler with hand truck
Moving the boiler with hand truck (Fig. 7)
BPlace the hand truck (e.g. boiler trolley or sack truck) at
the back of the boiler.
BBoiler, securing on the hand truck.
BMove the boiler to the installation location.
Fig. 7 Moving the boiler with a boiler hand truck
The boiler is secured to the pallet by 2
screws for transportation purposes.
WARNING: Risk of injury from carrying
heavy loads!
BAlways lift and move the equipment with
the assistance of another person using the
grip positions shown.
7 747 019 141-05.1RS
WARNING: Risk of injury if load is
inadequately secured during transportation!
BUse suitable means of transportation, e.g.
the Buderus boiler hand truck with strap.
BSecure the load against falling.
You can order the boiler hand truck from your
Buderus distributor.
The boiler trolley can also be used to facilitate
work on the underneath of the boiler, e.g.
fitting the adjustable feet (ÆChapter 4.3,
page 16).

4Placing the boiler
Logano GB125 BE US/CA - Subject to technical modifications.
14
4 Placing the boiler
This section describes how to install and place the boiler
in the boiler room.
4.1 Wall clearances
Wherever possible, position the boiler with the
recommended wall clearances. Reducing the minimum
clearances makes the boiler more difficult to access.
The boiler base or foundation must be perfectly flat and
level.
The burner door is factory-installed with the hinges on the
right. The burner door can be converted to left-hand
closing.
Fig. 8 Wall clearances in the boiler room (boiler
positioned on the right-hand side)
CAUTION: Risk of system damage due to
freezing!
BInstall the heating system in a frost-free
room.
Dimen-
sion Wall clearance
A Recommended 40"
Minimum 27"
B Recommended 27"
Minimum 16"
C Recommended 28"
Minimum 20"
D Recommended 16"
Minimum 6"
L ÆChapter 2.8, page 8
Tab. 9 Recommended and minimum wall clearances
(dimensions in inches).
The boilers are designed for a side clearance
of 6".
Where applicable, allow extra wall
clearances for additional components such
as DHW tank pipe connections, flue silencer,
other flue components, etc.
WARNING: Risk of fire from flammable
materials or liquids!
BClearances less than 6" must comply with
local and statutory codes.
BMake sure that there is a sufficient
clearance between combustible materials
and the chimney connection as specified
by NFPA 31 (distance of 18 ").
BThe floor must comply with the
requirements of NFPA 31.

4
Placing the boiler
Logano GB125 BE US/CA - Subject to technical modifications. 15
4.2 Reversing the burner door
The burner door is factory-installed with the hinges on the
right – the burner door opens to the right. You can change
the burner door hinges over to the left-hand side if
required to suit the installation site.
Requirement: the burner hood must have been removed
first (ÆChapter 3.1, page 12).
BRemoving the burner door (ÆChapter 3.1, page 12).
BUnscrew the hex bolts [1] and remove the hinge pins
[2].
BFix the hinge pins [2] on the left-hand side of the boiler
using the hex bolts.
Fig. 9 Reversing the burner door (boiler block
attachments)
1Hex bolts
2Hinges
BUnscrew the hex bolts [1] and remove the hinge barrels
[2].
BFix the hinge barrels [2] on the left-hand side of the
burner door [3] using the hex bolts.
BHang the burner door [3] by locating the hinge barrels
[2] on the hinge pins [4].
BCheck that the heat exchanger baffles are placed
horizontally (ÆChapter 6.3, page 32).
BClose the burner door [3] and secure with the two hex
bolts. Tighten the hex bolts evenly (approx. 90 lbs in) so
that the burner door seals properly.
Fig. 10 Reversing the burner door (door attachments)
1Hex bolts
2Hinge barrels
3Burner door
4Hinges
5Heat exchanger baffle plates
7 747 019 141-08.1RS
12 21
If the burner door hinges have been changed
over to the left-hand side, the burner cable
must be disconnected from the burner before
opening the burner door.
7 747 019 141-09.1RS
1
4
5
2
3

4Placing the boiler
Logano GB125 BE US/CA - Subject to technical modifications.
16
4.3 Mounting the adjustable feet (included with B-kit)
Level the boiler by turning the adjustable feet to prevent
air pockets becoming trapped inside the boiler.
Requirement: the burner hood or burner door panel must
have been removed first (ÆChapter 3.1, page 12).
BTilt the boiler with the aid of a hand truck or trolley (Æ
Chapter 3.3, page 13) or place a wooden batten
underneath to jack it up.
BScrew in adjustable feet [2] ¼ " – 1/8".
BGently set the boiler down.
Fig. 11 Fitting the adjustable feet
(burner not shown)
1Angle bracket
2Adjustable feet
4.4 Positioning and leveling the boiler
BPosition the boiler in its final location.
BLevel the boiler by rotating the adjustable feet as
required and using a level.
Fig. 12 Leveling the boiler
If the boiler is mounted on top of a horizontal
hot water tank the adjustable feet are not
used.
7 747 019 141-10.1RS
1
2
Protect boiler connections from damage and
dirt if the boiler is not to be installed
immediately.
7 747 019 141-11.1RS

5
Installing the boiler
Logano GB125 BE US/CA - Subject to technical modifications. 17
5 Installing the boiler
This section details how to install your boiler correctly.
This involves the following steps:
• Flue pipe installation
• Providing air supply for combustion
• Making the water connections
• Making the electrical connections
• Connecting the fuel supply
5.1 Flue pipe installation
The overall burner air supply/boiler flue pipe system
conforms to the types of oil combustion equipment listed
in the table below.
Observe the national standards and regulations for
operating oil-fired appliances.
DANGER: Risk of fatal injury from toxic flue
gases!
BNever connect more than one boiler to a
flue system – regardless of whether the
flue is vertical or horizontal.
BCommon venting systems can cause
damage to property and personal injury.
BDo not route the flue system through
another flue system that is in use, e.g. a
masonry chimney connected to a wood
stove.
BFollow the instructions of the flue pipe
manufacturer.
The boiler must be installed by a trained and
certified installer in accordance with all
requirements of NFPA-31, "Installation of Oil-
Burning Equipment". Installation must
comply with all local and national codes
applicable to the installation of oil-fired
boilers.
In Canada, the requirements of CSA/CGA-
B139 Installation Code apply.
The GB125 boiler is approved for zero (0")
clearance between its concentric vent pipe
and combustibles.
Because of the tight construction of modern
houses, this boiler must draw all air supply for
combustion from outside (RLU).
Installa-
tion type Combustion air supply and flue system
I
or
HT-K
Concentric supply air and flue pipe exiting
through external wall. Combustion air supply
and flue systems are part of the combustion
equipment.
II
or
DO
Concentric supply air and flue gas routing
via roof. Combustion air supply and flue sys-
tems are part of the combustion equipment.
III
or
GA-K
Concentric air/flue gas routing through a flue
inside a duct. The space around the vent
pipe is used for combustion air.
Tab. 10 Types of installation

5Installing the boiler
Logano GB125 BE US/CA - Subject to technical modifications.
18
5.2 Test ports
Flue gas readings and combustion air temperature
readings are taken exclusively at the dedicated testing
ports.
Follow the directions in the instructions for the Logatop
BE oil burner.
Fig. 13 Installing the flue/air connector (included with
the venting system)
1Air intake test port
2Flue gas test port
6 720 649 309-03.1ITL
1
2

5
Installing the boiler
Logano GB125 BE US/CA - Subject to technical modifications. 19
Choice of installation site for side-wall flue termination
Choosing the right location for the terminal is critical to
proper functioning of the appliance. As well as the
minimum clearances (ÆFig. 14), the following rules must
be observed:
Fig. 14 Minimum clearances for side wall terminations
1. The termination should not face the prevailing wind
direction.
2. The termination must be installed in such a way that the
flue gases can disperse freely without re-entering the
building.
3. The termination must be at least 2 ft from adjacent
buildings and it must not be possible for the flue gas to
enter adjacent buildings.
4. Where the building adjoins public walkways, the
termination must be located at least 7 ft above ground.
Make sure that freezing condensate does not
constitute a hazard.
5. The termination must never be located below building
overhangs, roof eaves, porches, enclosed spaces or
lower parts of the building that could prevent
unrestricted outflow of the flue gases.
6. The termination must never be located within 3 ft of
inside corners of buildings and never less than 2 ft from
outside corners of buildings.
7. If there is a fan-assisted air intake vent within 10 ft, the
termination must be at least 3 ft above it.
8. The termination must be at least 4 ft below, 1 ft above
or 4 ft horizontally from doors, windows or air inlet
vents.
9. The termination must be at least 1 ft above ground and
snow line, and protected from falling and accumulating
snow, ice, leaves or debris.
10. The termination should be at least 3 ft from any type
of building opening, oil tank filling or venting apparatus,
and 6 ft from gas meters and similar equipment.
11. The position of the termination should be chosen so
that the last horizontal section of pipe slopes
downwards to the inside by ¼ " per ft. The flue terminal
itself must also be inclined at ¼ " per ft to the inside so
that any condensate drains inwards.
Concentric
wall terminations
on the house wall
at least 1 ft above grade
and snow line
Concentric wall terminations on the house wall
Concentric
wall terminations
on the house wall
6 720 641 158-20.1TL
.
.
Forced Air Inlet
Gravity Air Inlet
must be at least 3 ft above forced air inlets within 10 ft.

5Installing the boiler
Logano GB125 BE US/CA - Subject to technical modifications.
20
5.3 Installation options
The GB125 boiler is approved with the following flue gas
systems available from Buderus:
Table 12, page 21 shows the maximum permissible vent
length for the different types of systems.
Types of installation Description
I
or
HT-K
Concentric air supply and
flue pipe exiting through
external wall.
Horizontal direct vent concentric
combustion air and venting pipe
system.
II
or
DO
Concentric supply air and
flue gas routing via roof.
Vertical concentric supply air and
flue gas routing.
III
or
GA-K
Concentric air/flue gas
routing through a flue
inside a duct.
Flue pipe inside an existing masonry
chimney similar to a liner. Chimney
chase used as a raceway to bring in
combustion air. Concentric supply
air and flue gas routing from the
chimney to the boiler.
Tab. 11 Installation options
To prevent reverse flow of flue gas into the air
intake even with wind influence, the included
wall terminations must be used.
Installation type III or GA-K may not be
suitable for homes with a double flue chimney
where the second flue is used with a second
combustion appliance.