Buderus Logano GE434 Technical specifications

6302 5450 – 02/2003 GB For heating engineers
Please read carefully prior to installation and maintenance.
Commissioning and
maintenance instructions
Logano GE434
Gas-fired special boiler

Overview
2
We reserve the right to make any changes due to technical modifications.
Commissioning and maintenance instructions Logano GE434 Gas-fired special boiler • Issue 02/2003
Buderus Heiztechnik GmbH • http://www.heiztechnik.buderus.de
Subject to technical modifications.
Constant development may lead to minor deviations in
the illustrations, functional steps and specifications from
those described/shown.
Updating your documentation
Please let us know if you have any suggestions which
would improve our documentation or if you have noticed
any errors.
About these instructions
This manual lists the gas types applicable to each
country, which only apply to those countries.
These installation and maintenance instructions contain
important information for the safe and appropriate initial
start-up and maintenance of the Logano GE434 gas-
fired special boiler.
These installation and maintenance instructions are
designed for specialists, who, due to their vocational
training and experience, are knowledgeable in handling
heating systems and gas installations.
This document also refers to accessories which may be
used in conjunction with the boiler installation. Observe
the appropriate installation instructions when installing
such accessories.
For information about the standard delivery, handling,
installation and electrical connection see the boiler
installation instructions.
This product meets all fundamental
requirements of applicable European
Directives:
Its conformity has been verified. All
associated documents and the original
Declaration of Conformity are available from
the manufacturer.
PLEASE NOTE
Observe all standards and guidelines
applicable to the operation of this system
in your country.

Index
3
We reserve the right to make any changes due to technical modifications.
Commissioning and maintenance instructions Logano GE434 Gas-fired special boiler • Issue 02/2003
Buderus Heiztechnik GmbH • http://www.heiztechnik.buderus.de
1 General . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .5
2 Safety . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .7
2.1 Correct use . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .7
2.2 Notes structure . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .7
2.3 Please observe these notes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .8
2.4 Tools, materials and accessories . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10
2.5 Disposal . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10
3 Product description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11
4 Specification . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12
5 Boiler connection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14
5.1 Notes regarding the flue pipe connection and flue gas monitoring . . . . . . . . . . . . . 14
5.1.1 Flue gas connection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14
5.1.2 Flue gas monitor. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14
5.2 Notes for the connection of the boiler to the pipework . . . . . . . . . . . . . . . . . . . . 15
5.2.1 Heating return . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15
5.2.2 Heating flow . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15
5.3 Filling the boiler and checking connections for leaks . . . . . . . . . . . . . . . . . . . . . 16
5.4 Gas pipe connection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17
5.5 Electrical connection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17
6 Heating system start-up . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18
6.1 Commissioning . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19
6.1.1 Recording gas characteristics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19
6.1.2 Making the heating system operational . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19
6.1.3 Checking all gas pipes for leaks . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19
6.1.4 Purging the gas supply pipe . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20
6.1.5 Checking the air supply/ventilation and flue pipe connections . . . . . . . . . . . . . . . . . . 21
6.1.6 Checking the system equipment . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22
6.1.7 Starting the heating system and commissioning the burner. . . . . . . . . . . . . . . . . . . . 24
6.1.8 Checking the mains gas pressure . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25
6.1.9 Checking for leaks during operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26
6.1.10Recording actual values . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27
6.1.11Installing the side panels . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 32
6.1.12Informing the system user and handing over all technical documentation . . . . . . . . . . . . 32
6.2 Commissioning report . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 33
7 Shutting down the heating system . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 34
7.1 Shutting down the heating system via the control device . . . . . . . . . . . . . . . . . . 34
7.2 Shutting down the heating system in emergencies . . . . . . . . . . . . . . . . . . . . . . 34
8 Heating system inspection and maintenance . . . . . . . . . . . . . . . . . . . . . . 35
8.1 General notes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 35

Index
4
We reserve the right to make any changes due to technical modifications.
Commissioning and maintenance instructions Logano GE434 Gas-fired special boiler • Issue 02/2003
Buderus Heiztechnik GmbH • http://www.heiztechnik.buderus.de
8.2 Preparing the boiler for cleaning . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 35
8.3 Cleaning the boiler . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 36
8.3.1 Cleaning the boiler with cleaning brushes . . . . . . . . . . . . . . . . . . . . . . . . . . . . 36
8.3.2 Wet-cleaning the boiler. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 38
8.4 Cleaning the gas burner . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 40
8.5 Internal leak test . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 41
8.6 Checking and correcting the heating system water pressure . . . . . . . . . . . . . . . 42
8.7 Checking the nozzle pressure . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 43
8.8 Inspection and maintenance reports . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 45
9 Converting the boiler to a different gas type . . . . . . . . . . . . . . . . . . . . . . 48
9.1 Conversion within a gas family . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 48
9.2 Conversion to a different gas type . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 49
10 Correcting burner faults . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 53
10.1 Burner faults on boilers with analog burner control unit (burner control unit TFI 812). 53
10.2 Burner faults on boilers with digital burner control unit (burner control unit MPA 50) . 54
11 Troubleshooting . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 55
11.1 Analog burner control unit . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 55
11.2 Digital burner control unit . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 57
12 Boiler operating conditions for countries outside the EU . . . . . . . . . . . . 61
12.1 Power supply conditions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 61
12.2 Boiler room conditions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 62
12.3 Conditions for air supply and flue pipes. . . . . . . . . . . . . . . . . . . . . . . . . . . . . 63
12.4 Conditions for fuel – natural gas H (physical requirements) . . . . . . . . . . . . . . . . 63
12.5 Conditions for fuel – natural gas H (chemical requirements) . . . . . . . . . . . . . . . . 64
12.6 Conditions for fuel – LPG butane/propane mixtures (chemical requirements) . . . . . 64
12.7 Conditions for fuel – LPG propane (chemical requirements) . . . . . . . . . . . . . . . . 64
12.8 Conditions for hydraulics and water quality . . . . . . . . . . . . . . . . . . . . . . . . . . 65
12.9 Operating conditions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 66
13 Keyword index . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 67
14 Declaration of conformity . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 71

General 1
5
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Commissioning and maintenance instructions Logano GE434 Gas-fired special boiler • Issue 02/2003
Buderus Heiztechnik GmbH • http://www.heiztechnik.buderus.de
1 General
PLEASE NOTE
Observe all standards and guidelines
applicable to the operation of this system
in your country.
Please note the details on the boiler type
plate. These are decisive and must be
observed.
Observe Chapter 12 "Boiler operating
conditions for countries outside the EU" on
page 61, if the boiler is used in countries
outside the European Union.
Operating conditions Dimension Notes - More detailed requirements
Maximum flow temperature
Tmax/TS
°C 100 - 120 The maximum permissible flow temperature may, in compliance
with national regulations, be limited to a value within this range.
Safety limit (high limit safety cut-out).
Max. possible flow temperature = safety limit (STB) -18 K
Example:
Safety limit (STB) = 100 °C
Flow temperature = 100 °C - 18 K = 82 °C.
Permissible operating pressure
PMS:
bar max. 6
Maximum time constant
High limit safety cut-out:
s max. 40
Maximum time constant
Control thermostat
smax. 40
Type - - B11, B11BS
Tab. 1 Boiler operating conditions

General1
6
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Commissioning and maintenance instructions Logano GE434 Gas-fired special boiler • Issue 02/2003
Buderus Heiztechnik GmbH • http://www.heiztechnik.buderus.de
Gas categories in countries subject to EN 437
(countries of the EU)
For country-specific details see the relevant national
regulations.
Gas categories in countries outside the sphere of
EN 437 (countries outside the EU)
For countries outside the European Union observe the
details in Chapter 12 "Boiler operating conditions for
countries outside the EU", page 61.
List of countries
Country Gas category Supply pressure
in
mbar
DK, FI, IT, SE I2H 20
BE I2E(R)B 20; 25
DE II2ELL3P 20; 50
AT, CH II2H3P 20; 50
CZ II2H3P 18; 37
ES, GB, IT, PT II2H3P 20; 37
GR II2H3B/P 20; 50
FR II2Esi3P 20; 25, 37
LU II2E3B/P 20; 50
HU II2HS3P 25; 50
NL II2L3P 25; 50
Tab. 2 Gas categories acc. to EN 437 (countries of the EU)
Country Gas category Supply pressure
in
mbar
BR, EE I2H 20
BY, CN, HR, RO, RU,
SI, TR, UA
II2H3P 20; 50
SK, TR II2H3P 20; 37
BA, BG, HR, TR II2H3B/P 20; 50
PL GZ 50, propane 20; 36
Tab. 3 Gas categories in countries outside the European
Union
Country
abbreviation
Country
AT Austria
BA Bosnia-Herzegovina
BE Belgium
BG Bulgaria
BR Brasil
BY Belarus
CH Switzerland
CN China
CZ Czech Republic
DE Germany
DK Denmark
EE Estonia
ES Spain
FI Finland
FR France
GB Great Britain
GR Greece
HR Croatia
HU Hungary
IE Ireland
IT Italy
LU Luxembourg
NL Netherlands
PL Poland
PT Portugal
RO Rumania
RU Russia
SE Sweden
SI Slovenia
SK Slovakia
TR Turkey
UA Ukraine
Tab. 4 List of countries

Safety 2
7
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Commissioning and maintenance instructions Logano GE434 Gas-fired special boiler • Issue 02/2003
Buderus Heiztechnik GmbH • http://www.heiztechnik.buderus.de
2 Safety
For your own safety, observe these safety instructions.
2.1 Correct use
The Logano plus GE434 gas-fired special boiler is
designed for generating heating water and DHW, for
example, the central heating of detached homes or
apartment buildings.
This boiler may be equipped with the Logamatic 4000
control system.
Design and operation of the Logano GE434 atmospheric
gas-fired special boiler comply with the general
requirements of the Gas Equipment Directive
90/396/EWC, taking EN 656 into account. The
requirements of the Efficiency Directive 92/42/EWC (low
temperature boilers) are met.
2.2 Notes structure
Two levels of danger are identified and signified by the
following symbols:
Further symbols identifying dangers and user notes:
WARNING!
RISK TO LIFE
Identifies possible dangers emanating
from a product, which might lead to
serious injury or death if appropriate care
is not taken.
CAUTION!
RISK OF INJURY/
SYSTEM DAMAGE
Identifies potentially dangerous situations,
which might lead to medium or slight
injuries or to material losses.
WARNING!
RISK TO LIFE
from risk of electric shock.
PLEASE NOTE
User tip for the optimum utilisation and
setting of the control(s) plus useful
information.

Safety2
8
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Commissioning and maintenance instructions Logano GE434 Gas-fired special boiler • Issue 02/2003
Buderus Heiztechnik GmbH • http://www.heiztechnik.buderus.de
2.3 Please observe these notes
Observe the following during installation and operation:
–Local Building Regulations concerning boiler room
installations.
–Local Building Regulations regarding air supply and
extract equipment as well as connection to a
chimney.
–Regulations for the electrical connection to the mains
power supply.
–The technical rules of the gas supply company
regarding the connection of a gas burner to the mains
gas supply.
–Regulations and standards regarding safety
equipment of water-filled heating systems.
–Installation instructions for heating engineers.
The following applies to Poland (PL):
In accordance with the Polish standard PN-91/B-0214,
section 2.5, boilers > 100 kW must be equipped with a
low water indicator (in the heating flow). Install the low
water indicator on-site between the boiler connection
and the first shut-off valve.
PLEASE NOTE
Only use original Buderus components.
Damage caused by the use of parts not
supplied by Buderus are excluded from
the Buderus warranty.
WARNING!
RISK TO LIFE
through the explosion of volatile gases.
There is a risk of explosion if you can smell
gas.
!Keep naked flames away. Do not
smoke.
Do not use lighters.
!Avoid sparks!
Do not operate electrical switches,
including telephone, plugs or door-
bells.
!Close the main gas shut-off valve.
!Open windows and doors.
!Warn all occupants, but do not use
doorbells.
!Call your gas supplier from outside the
building!
!If you hear gas escaping, immediately
leave the building, prevent others from
entering and notify the police and fire
brigade from outside the building.
WARNING!
RISK TO LIFE
through the explosion of volatile gases.
!Work on gas components must only
be carried out by qualified and
authorised personnel.
WARNING!
RISK TO LIFE
from electric shock when the control
device is open.
!Before you open the control device:
Isolate the heating system from the
mains power supply using the heating
system emergency stop switch or by
extracting the mains fuse.
!Safeguard the heating system against
unintentional re-connection.

Safety 2
9
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Commissioning and maintenance instructions Logano GE434 Gas-fired special boiler • Issue 02/2003
Buderus Heiztechnik GmbH • http://www.heiztechnik.buderus.de
Air supply and flue pipe in the boiler room
WARNING!
RISK TO LIFE
through poisoning.
Insufficient ventilation can lead to
dangerous flue gas leaks.
!Never close air ducts and vent
apertures or reduce their size.
!The boiler must not be operated,
unless you immediately remedy the
fault.
!Inform the system user, in writing of
the fault and associated danger.
WARNING!
RISK OF FIRE
through flammable material or liquids.
!Never store flammable materials or
liquids in the immediate vicinity of the
boiler.
WARNING!
RISK TO LIFE
through toxic flue gases
!Ensure that, during the burner
operation, there is no mechanical air
handling equipment inside the boiler
room, which might withdraw
combustion air from the boiler room,
e.g. cooker hoods, dryers, ventilation
equipment.
WARNING!
RISK TO LIFE
through toxic flue gases.
!Only operate these boilers with a
chimney or flue gas system, which
supplies the stated draught during
operation.
CAUTION!
SYSTEM DAMAGE
through frost.
The heating system can freeze up, if the
control device has been switched off.
!Protect your heating system against
frost damage, where temperatures
below zero are expected.
!With the control device switched OFF,
drain the water from the boiler, the
DHW cylinder and the pipework of the
heating system and, as far as possible.
from the drinking water pipes.
WARNING!
RISK TO LIFE
through poisoning.
Unauthorised access to the flue gas
monitoring can cause a risk to life through
escaping flue gas.
!Never repair the flue gas monitoring
system.
!Only use original spare parts as
replacements.
!After the replacement, fit the sensor
into its appropriate position.

10
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Commissioning and maintenance instructions Logano GE434 Gas-fired special boiler • Issue 02/2003
Buderus Heiztechnik GmbH • http://www.heiztechnik.buderus.de
Safety2
2.4 Tools, materials and accessories
For the installation and maintenance of the boiler, you
require standard tools, as used in central heating as well
as gas and water installations.
The following may also prove useful:
–sack trolley with strap
2.5 Disposal
!Dispose of the boiler packaging in an
environmentally responsible manner.
!Dispose of all boiler components (e.g. boiler or
control device) which must be replaced, via an
authorised disposal site.
WARNING!
RISK TO LIFE
through toxic flue gases.
The chimney function or the flue pipe may
be faulty, if the flue gas monitor trips
frequently.
!Repair the fault and carry out a function
test, if the flue gas monitor trips
frequently.
WARNING!
RISK TO LIFE
through toxic flue gases.
!Ensure that the boiler is not equipped
with a thermostatic shut-off damper
downstream of the draught hood.

Product description 3
11
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Commissioning and maintenance instructions Logano GE434 Gas-fired special boiler • Issue 02/2003
Buderus Heiztechnik GmbH • http://www.heiztechnik.buderus.de
3 Product description
The Logano GE434 (Fig. 1) boiler comprises a r.h. and
a l.h. boiler block, each of which is equipped with a
separate gas burner.
The main components of this boiler are:
–Boiler blocks (Fig. 1, Item 5) and gas burner (Fig. 1,
Item 1).
The boiler blocks transfer the heat generated by the
burners to the heating water.
–Boiler casing (Fig. 1, Item 2) and thermal insulation
(Fig. 1, Item 5).
The boiler casing and thermal insulation prevent
energy loss.
–Control device (Fig. 1, Item 3), auxiliary control
device and two burner control units (one burner
control unit for each burner).
The control device and the burner control unit
monitor and control all electrical boiler components. Fig. 1 Logano GE434
Item 1: R.h. gas burner
Item 2: Boiler casing
Item 3: Control panel
Item 4: Boiler front panel
Item 5: R.h. boiler block with thermal insulation
3
4
1
2
5

12
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Commissioning and maintenance instructions Logano GE434 Gas-fired special boiler • Issue 02/2003
Buderus Heiztechnik GmbH • http://www.heiztechnik.buderus.de
Specification4
4 Specification
1 Relative to 15 °C gas temperature and 1013 mbar air pressure
Specification - Logano GE434 gas-fired special boiler
Boiler size kW 150 175 200 225 250 275 300 325 350 375
Boiler sections Num-
ber
2 x 7 2 x 8 2 x 9 2 x 10 2 x 11 2 x 12 2 x 13 2 x 14 2 x 15 2 x 16
Rated Partial
load
kW 75.0 87.5 100.0 112.5 125.0 137.5 150.0 162.5 175.0 187.5
output Full
load
kW 150.0 175.0 200.0 225.0 250.0 275.0 300.0 325.0 350.0 375.01
Combustion Partial
load
kW 81.0 94.5 108.0 121.5 134.5 148.0 161.5 175.0 188.5 202.0
output Full
load
kW 162.0 189.0 216.0 243.0 269.0 296.0 323.0 350.0 377.0 404.02
Flue gas Partial
load
°C 84 72 75 78 76 76 77 91 81 84
temperature 3Full
load
°C 116 104 110 117 103 109 113 116 121 124
Flue gas Partial
load
kg/s 0.0798 0.1187 0.1146 0.1197 0.1510 0.1612 0.1671 0.1958 0.2053 0.2090
mass flow rate Full
load
kg/s 0.0925 0.1382 0.1393 0.1405 0.1903 0.1938 0.1997 0.2398 0.2432 0.2497
CO2 content Partial
load
%4.0 3.1 3.7 4.0 3.5 3.6 3.8 3.5 3.6 3.8
Full
load
%7.2 5.5 6.3 7.1 5.7 6.2 6.6 5.9 6.3 6.6
Draught Pa 3
CE designation, boiler CE-0085 AS 0285
Tab. 5 Specification
1 Alternative for Spain (ES): 370 kW (rated output)
2 Alternative for Spain (ES): 399 kW (combustion output)
3 Acc. to DIN EN 656. The minimum flue gas temperature for the chimney calculation acc. to DIN 4705 is approx. 6 K lower.
Boiler size Main gas nozzle designation Rated gas nozzle pressure1
kW
Natural gas
H
(G20)
Natural gas
L
(G25)
LPG
Propane
P
(G31)
LPG
B/P
(G30)
Natural gas
H
(G20)
mbar
150 - 375 295 340 190 180 14
Tab. 6 Main gas nozzle and rated gas nozzle pressure

Specification 4
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Commissioning and maintenance instructions Logano GE434 Gas-fired special boiler • Issue 02/2003
Buderus Heiztechnik GmbH • http://www.heiztechnik.buderus.de
Boiler
size
Nozzle pressure
LPG
Propane
P (G 31)
Supply pressure
(Flow pressure)
58 - 37 36 35 34 33 32 31 30 29 28 27
kW mbar mbar mbar mbar mbar mbar mbar mbar mbar mbar mbar
150 - 375 35 34 33 32 31 30 29 28 27 26 25
Tab. 7 Nozzle pressure for LPG P subject to the supply pressure
Boiler
size
Nozzle pressure
LPG
Butane/propane mixtures
B/P (G 30)
Supply pressure
(Flow pressure)
58 - 37 36 35 34 33 32 31 30 29 28 27
kW mbar mbar mbar mbar mbar mbar mbar mbar mbar mbar mbar
150 - 375 31.5 31.5 31.5 31.5 31 30 29 28 27 26 25
Tab. 8 Nozzle pressure for LPG B/P subject to the supply pressure
Gas throughput
Boiler size Natural gas
H
(G20)
Natural gas
L
(G25)
LPG
Propane
(G31)
LPG
B/P
(G30)
kW m³/h m³/h kg/h kg/h
150 16.2 18.9 12.6 12.8
175 19.0 22.0 14.7 14.9
200 21.7 25.2 16.8 17.0
225 24.4 28.3 18.9 19.2
250 27.0 31.4 20.9 21.2
275 29.7 34.5 23.0 23.3
300 32.4 37.7 25.1 25.5
325 35.1 40.8 27.2 27.6
350 37.8 44.0 29.3 29.7
375 40.5 47.1 31.4 31.9
Tab. 9 Gas throughput

Boiler connection5
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Commissioning and maintenance instructions Logano GE434 Gas-fired special boiler • Issue 02/2003
Buderus Heiztechnik GmbH • http://www.heiztechnik.buderus.de
5 Boiler connection
This chapter details how you connect your boiler
properly
–on the flue gas side
–on the water side (heating water and DHW)
–on the gas side
–to the electrical mains supply.
5.1 Notes regarding the flue pipe
connection and flue gas monitoring
5.1.1 Flue gas connection
Observe the following during the installation of the flue
gas connection:
–The flue pipe cross-section must comply with all
current regulations.
–Select the shortest possible flue pipe run.
–Route flue pipes inclined to the chimney.
–Never fit thermostatically controlled flue gas dampers
into flue pipes.
5.1.2 Flue gas monitor
Check, whether because of the building utilisation or
regional/national regulations, flue gas monitoring
equipment is required.
!If necessary, install such equipment in accordance
with current regulations.
Type B11 (excl. flue gas monitoring)
Only install boilers without flue gas monitoring
equipment in rooms, which are not part of the living
accommodation of the building and which are provided
with ventilation in accordance with current regulations,
e.g. boiler rooms.
Type B11BS (incl. flue gas monitoring)
Flue gas monitoring equipment may be required in
accordance with regional or national regulations or laws,
e.g. when boilers are operated in living accommodation,
similar utility rooms or in an attic installation.
The flue gas monitor interrupts the gas supply, should
flue gas enter the boiler room. The burner will then be
switched OFF.
WARNING!
RISK TO LIFE
through poisoning.
Unauthorised access to the flue gas
monitoring can cause a risk to life through
escaping flue gas.
!Never repair the flue gas monitoring
system.
!Only use original spare parts as
replacements.
!After the replacement, fit the flue gas
temperature sensor into its appropriate
position.
WARNING!
RISK TO LIFE
through poisoning.
Insufficient ventilation can lead to
dangerous flue gas leaks.
!Never close or obstruct air ducts and
vent apertures or reduce their size.
!The boiler must not be operated,
unless you immediately remedy the
fault.
!Inform the system user in writing of the
fault and its associated dangers.

Boiler connection 5
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Commissioning and maintenance instructions Logano GE434 Gas-fired special boiler • Issue 02/2003
Buderus Heiztechnik GmbH • http://www.heiztechnik.buderus.de
5.2 Notes for the connection of the boiler to the pipework
Please observe the following note regarding the boiler
connection to the pipework. These notes are important
for fault-free operation.
5.2.1 Heating return
!Connect the heating system return stress-free to the
boiler return = RK (Fig. 2, Item 3).
5.2.2 Heating flow
!Connect the heating system flow stress-free to the
boiler flow = VK (Fig. 2, Item 2).
CAUTION!
SYSTEM DAMAGE
through leaking connections.
!Connect the pipes without stress to the
boiler connections.
PLEASE NOTE
To prevent boiler contamination through
the water system, we strongly recommend
the on-site installation of a dirt trap.
Fig. 2 Water connections
Item 1: Fill and drain connection = EL
Item 2: Boiler flow = VK
Item 3: Boiler return = RK
1
23
1

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Commissioning and maintenance instructions Logano GE434 Gas-fired special boiler • Issue 02/2003
Buderus Heiztechnik GmbH • http://www.heiztechnik.buderus.de
Boiler connection5
5.3 Filling the boiler and checking connections for leaks
Before commissioning, check the heating system for
leaks to avoid leaks occurring during operation.
!Fill the heating system via the on-site boiler fill and
drain valve in the heating return with fill water.
!Vent the heating system during filling.
!Check all connections for leaks.
CAUTION!
SYSTEM DAMAGE
through overpressure during leak testing.
Pressure, control and safety equipment
may be damaged through excessive
pressure.
!Ensure that, when you carry out a leak
test, no pressure, control or safety
equipment is fitted, which cannot be
shut off towards the boiler water space.
CAUTION!
SYSTEM DAMAGE
through temperature stresses.
!Only fill the system when cold (the flow
temperature should be a maximum of
40 °C).

Boiler connection 5
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Commissioning and maintenance instructions Logano GE434 Gas-fired special boiler • Issue 02/2003
Buderus Heiztechnik GmbH • http://www.heiztechnik.buderus.de
5.4 Gas pipe connection
Make the gas connection in accordance with all locally
applicable regulations.
!Install the gas shut-off valve into the gas supply pipe.
!Connect the gas pipe without stress to the gas
connector (Fig. 3, Item 1).
5.5 Electrical connection
For details about the electrical mains supply see the
boiler installation instructions, chapter 7 "Installing
control devices".
Boiler size kW Gas connection
150 - 225 2 x Rp ¾"
(225) 250 - 375 2 x Rp 1 ¼"
Tab. 10 Gas connection
Fig. 3 Making the gas connection (viewed from the back)
Item 1: Gas connection (l.h. and r.h. gas burner)
11
PLEASE NOTE
Buderus recommends the installation (in
accordance with local regulations) of a gas
filter into the gas supply pipe.

Heating system start-up6
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Commissioning and maintenance instructions Logano GE434 Gas-fired special boiler • Issue 02/2003
Buderus Heiztechnik GmbH • http://www.heiztechnik.buderus.de
6 Heating system start-up
This chapter details how to properly commission the
heating system.
!Clean burners contaminated through building work
before commissioning the heating system (see
Chapter 8.2 "Preparing the boiler for cleaning",
page 35 and following).
CAUTION!
BOILER DAMAGE
through excessive dust and airborne seed.
!Do not operate the boiler where heavy
dust contamination persists, e.g.
through building work inside the boiler
room.
!Ensure that incoming combustion air is
not contaminated with excessive dust
from dirt roads and paths or through
dusty production or processing
installations, e.g. quarries, mines, etc.
!Ensure that incoming combustion air is
not contaminated with excessive
airborne seed from composite
blossom. Where necessary, prevent
such contamination through the use of
air filters.
CAUTION!
BOILER DAMAGE
through contaminated combustion air.
!Ensure adequate air supply.
!Ensure that chlorinated cleaning
agents or halogenated hydrocarbons
(as, for example, contained in spray
cans, solvents or cleaning agents,
paints and adhesives) are not used or
stored in the boiler room.
WARNING!
RISK TO LIFE
through toxic flue gases
!Ensure that, during the burner
operation, there is no mechanical air
handling equipment inside the boiler
room, which might withdraw
combustion air from the boiler room,
e.g. cooker hoods, dryers, ventilation
equipment.
PLEASE NOTE
To reach components which are vital for
commissioning, the central and read side
panels and the front panel must be
removed.
The bottom of the central and rear side
panels are secured with screws.

Heating system start-up 6
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Commissioning and maintenance instructions Logano GE434 Gas-fired special boiler • Issue 02/2003
Buderus Heiztechnik GmbH • http://www.heiztechnik.buderus.de
6.1 Commissioning
Please complete the commissioning report on page 33
after completing the work described in the following.
6.1.1 Recording gas characteristics
Ask your gas supplier for the gas characteristics (Wobbe
index and calorific value).
6.1.2 Making the heating system operational
Carry out the following steps to prepare the heating
system for operation:
!Set the red needle (Fig. 4, Item 1) of the heating
system pressure gauge to the required minimum
pressure of 1 bar.
!Check the heating system water pressure (see
Chapter 8.6 "Checking and correcting the heating
system water pressure", page 42).
6.1.3 Checking all gas pipes for leaks
Check the gas supply pipe for leaks before
commissioning the heating system, and confirm this
step in the commissioning report.
Fig. 4 Pressure gauge for sealed heating systems
Item 1: Red needle
Item 2: Pressure gauge needle
Item 3: Green field
3
1
2
PLEASE NOTE
Slowly fill in water, if you have noticed
water losses.
WARNING!
RISK TO LIFE
through the explosion of volatile gases.
Leaks may have been created on pipes
and fittings following the commissioning
and maintenance work.
!Carry out a proper leak test.
!Only use approved leak test agents to
discover leaks.

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Commissioning and maintenance instructions Logano GE434 Gas-fired special boiler • Issue 02/2003
Buderus Heiztechnik GmbH • http://www.heiztechnik.buderus.de
Heating system start-up6
!If necessary, disconnect your heating system from
the mains electricity supply.
!Check the new pipe section, incl. the immediate seal
at the gas train for external leaks. The test pressure
on the gas train inlet must be no higher than
150 mbar.
6.1.4 Purging the gas supply pipe
Carry out the following steps on the l.h. and the r.h. gas
burner.
!Release the plug on the test port for gas supply
pressure and venting (Fig. 5, Item 1) on the gas train
by two turns, and connect the hose.
!Slowly open the mains gas shut-off valve.
!Purge the gas supply pipe.
CAUTION!
SYSTEM DAMAGE
through short circuits.
!Cover areas at risk before searching for
leaks.
!Never apply leak detector spray to
cableways, plugs or electrical leads.
Never let any spray drop down onto
such areas.
Fig. 5 Purging the gas supply pipe
Item 1: Test port for gas supply pressure and venting
1