Buderus Logamax plus GB142-24 User manual

Please read thoroughly before installing and servicing
7215 0200 – 10/2007 US/CA (en) For registered installers
Installation instructions
Condensing gas boiler
Logamax plus GB142-24/30/45/60
CAUTION!
Before putting the boiler into operation read this manual carefully.
WARNING!
Improper installation, adjustment, alteration, service or maintenance
can cause injury, loss of life or property damage. Refer to this manual.
For assistance or additional information consult a qualified installer,
service agency or the gas supplier.
CAUTION!
The operating manual is part of the documentation that is delivered to
the installation's operator. Go through the information in this manual
with the owner/operator and make sure that he or she is familiar with
all the necessary operating instructions.
NOTICE!
In the Commonwealth of Massachusetts this boiler must be installed
by a licensed Plumber or Gas Fitter.
–Do not store or use gasoline or other flammable vapors and liquids
in the vicinity of this or any other boiler.
– What to do if you smell gas
•Do not try to light any boiler.
•Do not touch any electrical switch; do not use any phone in your
building.
•Immediately call your gas supplier from a neighbor’s phone.
Follow the gas supplier’s instructions.
•If you cannot reach your gas supplier, call the fire department.
– Installation and service must be performed by a qualified
installer, service agency or the gas supplier.
Warning: If the information in these instructions is not
followed exactly, a fire or explosion may result caus-
ing property damage, personal injury or loss of life.

Preface
2 Installation instructions Logamax plus GB142-24/30/45/60 • version 10/2007
Buderus • http://www.buderus.net We reserve the right to make any changes due to technical modifications!
About these instructions
These Installation Instructions contain important informa-
tion for the safe and professional installation, start-up and
maintenance of the boiler with boiler capacities 24, 30, 45
and 60 kW.
These Installation Instructions are intended for profes-
sional installers, who have the necessary training and
experience for working on heating and gas systems.
Subject to technical changes!
Slight changes may be made to the illustrations, process
steps and technical data as a result of our policy of
continuous improvement.
Updating of documentation
Please contact us if you have any suggestions for
improvements or corrections.

Contents
Installation Instructions Logamax plus GB142-24/30/45/60 • version 10/2007 3
We reserve the right to make any changes due to technical modifications! Buderus • http://www.buderus.net
1 Safety and general instructions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5
1.1 Designated use . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .5
1.2 Hazard definitions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .5
1.3 The following instructions must be observed. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .5
1.4 Observe these instructions for space heating water . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .6
1.5 Tools, materials and additional equipment . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .6
1.6 Disposal . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .6
2 Regulations and guidelines . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7
3 Product description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8
4 Dimensions and connections . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9
5 Packaging and transportation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11
5.1 Scope of delivery . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .11
5.2 Transporting the boiler. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .11
6 Installation. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12
6.1 Requirements for the installation room . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .12
6.2 Fitting the boiler . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .12
6.3 Making the gas connection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .13
6.4 Fitting the heating circuit supply and return pipes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .14
6.5 Combustion Air and Ventilation Openings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .17
6.6 Installation of the flue gas adapter (included in the scope of delivery) . . . . . . . . . . . . . . . . . . . . . . . . . . . .19
6.7 Installation of the Exhaust and Air Intake system. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .20
7 Connecting the condensate drain . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26
8 Electrical connections . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27
8.1 External connection board connections. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .27
9 Start-up procedure . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 30
9.1 Testing for gas leaks . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .31
9.2 Filling the boiler . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .31
9.3 Filling the condensate trap. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .32
9.4 Bleeding the gas supply valve . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .32
9.5 Checking the combustion air/flue gas connection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .32
9.6 Checking the orifices . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .33
9.7 Inlet gas pressure . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .33
9.8 Checking and adjusting the gas/air ratio . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .34
9.9 Carrying out a leak test in operating conditions. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .36
9.10 Measuring the carbon monoxide content (CO) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .36
9.11 Function testing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .36
9.12 Measuring the ionization current . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .37
9.13 Testing the Ignition Safety shut off device . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .38
9.14 Installing the casing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .38
9.15 Informing the owner, handing over the technical documents . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .38
10 BC10 basic controller. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 39
10.1 Operating the BC10 basic controller . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .39
10.1.1 Switching the heating system on and off . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 39
10.1.2 Displaying the operating conditions of the burner and resetting the burner or resetting burner faults . . . . . . 39
10.1.3 Displaying the heating system status and/or faults . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 40
10.2 Carrying out additional tasks . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .42
10.2.1 Carrying out a flue gas test . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 42
10.2.2 Selecting partial load operation (e. g. during flue gas testing). . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 42
10.2.3 Switching the heating system to manual mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 42

Contents
4 Installation Instructions Logamax plus GB142-24/30/45/60 • version 10/2007
Buderus • http://www.buderus.net We reserve the right to make any changes due to technical modifications!
10.3 Configuring the boiler . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 43
10.3.1 Adjusting the heating capacity. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 43
10.3.2 Setting the DHW temperature value . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 44
10.3.3 Entering the space heating water temperature . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 44
10.3.4 Setting the pump post-purge period . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 45
11 Shutting down the system . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 46
11.1 Shut down the heating system using the control unit . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 46
11.2 Shutting down the heating system in the event of an emergency . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 46
12 Inspection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 47
12.1 Preparing the boiler for inspection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 47
12.2 Visual inspection for general signs of corrosion . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 47
12.3 Internal leak testing. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 48
12.4 Measuring the ionization current. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 48
12.5 Measuring the inlet gas pressure . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 48
12.6 Checking and adjusting the gas/air ratio. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 48
12.7 Carrying out a gas leak test in operating conditions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 48
12.8 Measuring the carbon monoxide content (CO) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 48
12.9 Carrying out a pressure test of the heating system . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 48
12.10 Checking the functioning and the safety of the air intake and flue gas conduit . . . . . . . . . . . . . . . . . . . . . 48
12.11 Checking venting systems . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 48
13 Maintenance . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 49
13.1 Cleaning the heat exchanger, burner and condensate trap . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 49
13.2 Checking and adjusting the gas/air-ratio . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 51
14 Converting the boiler to propane . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 52
15 Appendix . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 54
15.1 Operating messages. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 54
15.2 Error messages . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 55
15.3 Technical specifications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 56
16 Reports . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 58
16.1 Start-up report. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 58
16.2 Inspection report . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 59
16.3 Maintenance report . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 60
17 Spare parts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 61
18 Index . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 65

Safety and general instructions 1
Installation instructions Logamax plus GB142-24/30/45/60 • version 10/2007 5
We reserve the right to make any changes due to technical modifications! Buderus • http://www.buderus.net
1 Safety and general instructions
Please observe these instructions in the interest of your
own safety.
1.1 Designated use
The boiler was designed for heating water for a central
heating system and generating domestic hot water.
The boiler is delivered with a BC10 basic controller and
the "Universal Automatic Burner Control Unit 3" (UBA 3)
pre-installed.
The boiler can be fitted with a modulating outdoor reset
control AM10 (scope of delivery), a room controller RC10
(optional), or an On/Off thermostat or relay panel end
switch (accessories).
1.2 Hazard definitions
The following defined terms are used throughout the docu-
mentation to bring attention to the presence of hazards of
various risk levels. Notices give important information
concerning the operation of the product.
1.3 The following instructions must be
observed
– The boiler must only be used for its designated
purpose, observing the Installation Instructions.
– Only use the boiler in the combinations and with the
accessories and spares listed.
– Other combinations, accessories and consumables
must only be used if they are specifically designed for
the intended application and do not affect the system
performance and the safety requirements.
– Maintenance and repairs must only be carried out by
trained professionals.
– You must report the installation of a condensing gas
boiler to the relevant gas utility company and have it
approved.
– You are only allowed to operate the condensing gas
boiler with the combustion air/flue gas system that has
been specifically designed and approved for this type of
boiler.
– Please note that local permission for the flue system
and the condensate water connection to the public
sewer system may be required.
You must also observe:
– the local building regulations stipulating the installation
rules.
– the local building regulations concerning the air intake
and outlet systems and the chimney connection.
– the regulations for the power supply connection.
– the technical rules laid down by the gas utility company
concerning the connection of the gas burner fitting to
the local gas main.
– the instructions and standards concerning the safety
equipment for the water/space heating system.
– the Installation Instructions for building heating
systems.
– The boiler must be located in an area where leakage of
the tank or connections will not result in damage to the
area adjacent to the boiler or to lower floors of the
structure. When such locations cannot be avoided, it is
recommended that a suitable drain pan, adequately
drained, be installed under the boiler. The pan must not
restrict combustion air flow.
– The boiler must be installed such that the gas ignition
system components are protected from water (dripping,
spraying, rain etc.) during boiler operation and service.
– The boiler must not be installed on carpeting.
– Do not restrict or seal any air intake or outlet openings.
DANGER:
Indicates the presence of hazards that will
cause severe personal injury, death or
substantial property damage.
WARNING:
Indicates the presence of hazards that can
cause severe personal injury, death or
substantial property damage.
CAUTION:
Indicates presence of hazards that will or
cause minor personal injury or property
damage.
CAUTION:
Risk of electric shock.
Indicates presence of hazards due to electric
shock.
NOTICE:
Indicates special instructions on installation,
operation or maintenance that are important
but not related to personal injury or property
damage.

Safety and general instructions1
6 Installation instructions Logamax plus GB142-24/30/45/60 • version 10/2007
Buderus • http://www.buderus.net We reserve the right to make any changes due to technical modifications!
– If you find any defects, you must inform the owner of the
system of the defect and the associated hazard in
writing.
1.4 Observe these instructions for space
heating water
Unsuitable heating system water can promote the forma-
tion of scale or sludge, which affects system efficiency.
It can also cause corrosion and reduce life of the heat
exchanger.
– You must follow Buderus guidelines for boiler water
quality.
– Thoroughly flush the system prior to filling.
– Use of a Buderus approved boiler cleaner is
recommended.
– Never use salt bedding exchangers to soften the water.
– Do not use inhibitors or other additives unless approved
by Buderus for that purpose!
– When frost protection of the heating system is desired,
only use Buderus-approved Aluminum-safe antifreeze.
– When using oxygen-permeable pipes, e. g. for floor
heating systems, you must separate the system using
heat exchangers.
– The maximum permissible flow rate of the
GB142-24/30 this is 11 GPM (gal./min.)(= 42 l/min.), for
the GB142-45 is 15 GPM (= 57 l/min.) and for the
GB142-60 is 20 GPM (= 76 l/min.).
1.5 Tools, materials and additional
equipment
For the installation and maintenance of the boiler you will
need the standard tools for space heating, gas and water
fitting.
In addition, a handtruck with a fastening belt is useful.
1.6 Disposal
– Dispose of the boiler packaging in an environmentally
sound manner.
– Dispose of components of the heating system (e. g.
boiler or control device), that must be replaced in an
environmentally responsible manner.
DANGER
if flammable gas explodes.
Beware if you smell gas: there may be an
explosion hazard!
Warning: If the information in these
instructions is not followed exactly, a fire
or explosion may result causing property
damage, personal injury or death.
zDo not store or use gasoline or other flam-
mable vapors and liquids in the vicinity of
this or any other boiler.
What to do if you smell gas
zDo not try to light any boiler.
zDo not touch any electrical switch; do not
use any phone in your building.
zImmediately call your gas supplier from
a neighbor’s phone. Follow the gas
supplier’s instructions.
zIf you cannot reach your gas supplier, call
the fire department.
Installation and service must be performed by
a qualified installer, service agency or the gas
supplier.

Regulations and guidelines 2
Installation instructions Logamax plus GB142-24/30/45/60 • version 10/2007 7
We reserve the right to make any changes due to technical modifications! Buderus • http://www.buderus.net
2 Regulations and guidelines
The installation must conform to the requirements of the
authority having jurisdiction or, in the absence of such
requirements, to the latest edition of the National Fuel Gas
Code, ANSI Z223.1. In Canada, installation must be in
accordance with the requirements of CAN/CSA B149.1,
Natural Gas and Propane Installation Code.
Where required by the authority having jurisdiction, the
installation must conform to the Standard for Controls and
Safety Devices for Automatically Fired Boilers, ANSI/
ASME CSD-1.
Install CO detectors per local regulations. Boiler requires
yearly maintenance, see maintenance section see
chapter 13 "Maintenance", page 49.
Operating Limits of the boiler:
Max. boiler temperature: 230 °F (110 °C)
Max. operating pressure: 44 psi (3 bar)
The hot water distribution system must comply with all
applicable codes and regulations. When replacing an
existing boiler, it is important to check the condition of the
entire hot water distribution system to ensure safe opera-
tion.
Massachusetts Installations Only:
For direct- vent boilers, mechanical-vent heating boilers or
domestic hot water equipment, where the bottom of the
vent terminal and the intake is installed below four feet
above grade the following requirements must be satisfied:
1) If there is not one already present, a carbon monoxide
detector and alarm shall be placed in a living area
outside the bedrooms. The carbon monoxide detector
and alarm shall comply with NFPA 720 (2005 Edition).
2) A carbon Monoxide detector and alarm shall be
located in the room that houses the boiler or
equipment and shall:
a) Be powered by in series on the same electrical
circuit as the boiler or equipment:
b) Have battery back-up power:
c) Meet ANSI/UL 2034 Standards and comply with
NFPA 720 (2005 Edition):
d) Have been approved and listed by a Nationally
Recognized Testing Lab:
3) A product-approved vent terminal must be used, and
if applicable, a Product approved air intake must be
used. Installation shall be in strict compliance with the
manufacturer's instructions. A copy of the installation.
4) A metal or plastic identification plate shall be mounted
at the exterior of the building, four feet directly above
the location of vent terminal. The plate shall be of
sufficient size to be easily read from a distance of eight
feet away, and read "Gas Vent Directly Below".
b) For direct-vent boilers mechanical-vent heating
boilers or domestic hot water equipment where the
bottom of the vent terminal and the intake is
installed four feet or above grade the following
requirements must be satisfied:
1) If there is not one already present, a carbon
monoxide detector and alarm shall be placed in
the living area outside the bedrooms, The carbon
monoxide detector and alarm shall comply with
NFPA 720 (2005 Edition).
2) A carbon monoxide detector shall:
a) Be located inn the area where the boiler or
equipment is located:
b) Have battery back-up power:
c) Be a minimum comply with NFPA 720
(2005 Edition).
3) A product-approved vent terminal must be used,
and if applicable, a product-approved air intake
must be used. Installation shall be in strict
compliance with the manufacturer's instructions.
A copy of the installation instructions shall remain
with the boiler or equipment at the completion of
the installation.

Product description3
8 Installation instructions Logamax plus GB142-24/30/45/60 • version 10/2007
Buderus • http://www.buderus.net We reserve the right to make any changes due to technical modifications!
3 Product description
Fig. 1 Logamax plus GB142-24/30 (left) and GB142-45/60 (right)
pos. 1: Drawer with control unit
pos. 2: Universal Burner Automat (UBA3)
pos. 3: Control unit BC10
pos. 4: Gas valve
pos. 5: Cover
pos. 6: Flue measuring points
pos. 7: Parallel flue
pos. 8: Burner
pos. 9: Latches of which two have locks
pos. 10: Sighting glass
pos. 11: Heat exchanger
pos. 12: Back cover
pos. 13: Air intake for the fan
pos. 14: Fan
pos. 15: Condensate trap
pos. 16: External Connection Board (under the cover)
pos. 17: Pressure sensor
1
2
3
9
11
13
14
9
16
15
5
8
1
4
10
12
13
14
2
3
5
4
67
9
11
9
8
10
12
16
15 17
7
6
Fig. 2 Basic Controller Logamatic BC10
pos. 1: Main switch
pos. 2: DHW temperature knob 1)
pos. 3: LED "DHW status"
pos. 4: Display
pos. 5: Space heating water temperature knob
pos. 6: LED "Heating system status"
pos. 7: Under the cover a RC system controller can be installed
pos. 8: LED "Burner Operation"
pos. 9: Service Tool connector
pos. 10: "Service" ebutton
pos. 11: "Chimney sweep" dbutton
pos. 12: "Reset" cbutton
1) ECO mode means that the temperature inside the hot water tank is 140 °F (60 °C), with a hysteresis ( Δ T) of 18 °F (10 °C) instead of 9 °F (5 °C)
190
170
150
130
90
110
140
130
120
90
100
110
4
7
2
1
5
812 1011
3 6
9

Dimensions and connections 4
Installation instructions Logamax plus GB142-24/30/45/60 • version 10/2007 9
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4 Dimensions and connections
Fig. 3 Dimensions and connections for boiler GB142-24/30 (dimensions in inches)
AA (A)
AKO (E)
GAS (D)
=
=
=
Flue gas connection (inside diameter 3'')
Condensate water outlet, Ø 1.3” (Ø 32 mm) outside
diameter
Gas connection, ¾” NPT
LA (B)
RK (G)
VK (F)
WB (C)
=
=
=
=
Air intake (inside diameter 3'')
Return, Ø 1.0” 1 (Ø 25.4 mm)
Supply, Ø 1.0” 1(Ø 25.4 mm)
Wall bracket
1One Ø 1.0” (Ø 25.4 mm) inside x 1'' NPT threaded compression fitting is delivered enclosed with boiler packaging
4" (100 mm)
12" (300 mm)
20" (500 mm)
6.2"
(158 mm)
0.25"
(6 mm)
1.8" (46 mm)
18.7" (475 mm)
> 6"
(150 mm)
2.2" (55 mm)
3" (75 mm)
3" (75 mm)
6" (150 mm)
1.2" (30 mm)
16" (420 mm)
7.5" (190 mm)
28" (712 mm)
4.7" (119mm)
4.3" (110 mm)13.2" (335 mm)
22" (560 mm)
3" (75 mm)
> 4"
(100 mm)
6" (150 mm)
DE FG
AB
C
NOTICE
Observe the lateral minimum distances of the
boiler (12” = 300 mm) and the necessary
distances (24” (600 mm) at the front and
4” (100 mm) at the top) for removing the casing
and for servicing.
Closet clearances are:
4” (100 mm) to the right, 4” (100 mm) at the top
and 6” (150 mm) to the left.

Dimensions and connections4
10 Installation instructions Logamax plus GB142-24/30/45/60 • version 10/2007
Buderus • http://www.buderus.net We reserve the right to make any changes due to technical modifications!
Fig. 4 Dimensions and connections for boiler GB142-45/60 (dimensions in inches)
AA (A)
AKO (E)
GAS (D)
=
=
=
Combustion air
Condensate water outlet, Ø 1.3” (Ø 32 mm)
Gas connection, ¾” NPT
LA (B)
RK (G)
VK (F)
WB (C)
=
=
=
=
Air intake
Return, Ø 1.0” 1(Ø 25.4 mm)
Supply, Ø 1.0” 1(Ø 25.4 mm)
Wall bracket
1One Ø 1.0” (Ø 25.4 mm) inside x 1'' NPT threaded compression fitting is delivered enclosed.
20.7" (526 mm)
1.2" (30 mm)
16" (420 mm)
7.5" (190 mm)
28" (712 mm)
4.7" (119 mm)
4.3" (110 mm)
13.2" (335 mm)
35.4" (900 mm)
9.7" (246 mm)
6.2"
(158 mm)
0.25"
(6 mm)
1.8" (46 mm)
18.7" (475 mm)
> 6"
(150 mm)
> 4"
(100 mm)
2.2" (55 mm) 3" (75 mm) 3" (75 mm)
DE F G
AB
C
4" (100 mm)
12" (300 mm)
20" (500 mm)
NOTICE
Observe the lateral minimum distances of the
boiler (12” = 300 mm) and the necessary
distances (24” (600 mm) at the front and
4” (100 mm) at the top) for removing the casing
and for servicing.
Closet clearances are:
4” (100 mm) to the right, 4” (100 mm) at the top
and 6” (150 mm) to the left.

Packaging and transportation 5
Installation instructions Logamax plus GB142-24/30/45/60 • version 10/2007 11
We reserve the right to make any changes due to technical modifications! Buderus • http://www.buderus.net
5 Packaging and transportation
5.1 Scope of delivery
The boiler is delivered fully assembled.
zWhen receiving the delivery, check if the packaging is
intact.
zCheck that all the items listed in see table 1 are included
in the delivery.
5.2 Transporting the boiler
zPackaged boilers must always be lifted and carried to
their destination by two people, or you must use a
handtruck or special equipment to transport them to their
destination.
zTransport the boiler to the room where it is to be installed.
Fig. 5 Items supplied with unit
Pos. Parts Quantity Packaging
1Boiler with casing 1 1 box
2Wall bracket 1
3Technical documents 1
including:
- User's Instructions
- Installation Instructions
- wall mounting template
- Servicing Instructions
3
4Compression fittings 2
5AM10 with outdoor sensor 1
6Flue gas adapter 1
7Propane conversion kit 1
8Boiler connection kit,
including the DHW sensor
1
9GB142 Boiler manifold
including:
- low loss header
- pressure relief valve
- tridicator
- DHW connections
- Grundfoss 15-58 3-speed
boiler circulator
- supply and return shutoff ball
valves
1
Table 1 Items supplied with unit
1The user’s instructions (in a special format) is located in the boiler
drawer
1
2
6
8
4
3
7
9
5
CAUTION
The boiler may be damaged when it is improp-
erly secured.
– Only transport the boiler using the right
transportation equipment, such as a
handtruck with a fastening belt or special
equipment for manoeuvering steps.
– During transportation the boiler must be
secured on the transportation equipment to
prevent it from falling off.
– Protect all parts against impacts if they are to
be transported.
– Observe the transportation markings on the
packaging.

Installation6
12 Installation instructions Logamax plus GB142-24/30/45/60 • version 10/2007
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6 Installation
6.1 Requirements for the installation room
6.2 Fitting the boiler
Observe the installation clearances of the combustion air/
flue gas system.
zRemove the packaging materials and dispose of them.
zUse the mounting template to mark the drill holes.
zInstall the wall bracket taking into account the necessary
service clearances.
zRemove the transport safety clamps (fig. 6).
DANGER
– Install the heating system in a frost-free
room.
– Do not store any flammable materials or
liquids in the immediate vicinity of the boiler.
– Never use any chlorinated detergents or
halogenated hydrocarbons (e. g. in
spraycans, solvents and detergents, paints,
adhesives).
– Do not allow too much dust to collect on the
boiler.
NOTICE
– To protect the connection orifice you must
not remove the styrofoam bottom panel.
– Do not lift the boiler by the drawer.
– Do not remove the transport safety clamps
(see fig. 6) from the drawer at this time.
– Protect the boiler and the combustion
air/flue gas orifice against pollution during
installation.
Fig. 6 Removing the transport safety clamps

Installation 6
Installation instructions Logamax plus GB142-24/30/45/60 • version 10/2007 13
We reserve the right to make any changes due to technical modifications! Buderus • http://www.buderus.net
zUse the radiator key to unlock the two latches a quarter
turn (fig. 7, pos. 1).
zOpen the latches (fig. 7, pos. 2).
zRemove the casing by lifting it upwards and then pulling
it forwards (fig. 7, pos. 3); do not hold the casing by the
latches.
zHold the boiler by the rear boiler casing and place it on
the wall bracket.
zLevel out the boiler.
6.3 Making the gas connection
zDetermine proper size gas pipe for the installation using
see table 2 and see table 3. Do not forget the pipe fitting
losses and observe proper size of the fittings.
zInstall the furnished ¾” gas cock on the gas connection.
zConnect the gas pipe to the gas cock (fig. 8, pos. 1) so
that it is free from any strain.
A sediment trap must be provided upstream of the gas
controls.
Fig. 7 Removing the casing
1
2
2
2
2
3
Fig. 8 Making the gas connection
1
DANGER
Only carry out work on gas lines if you are
licensed for such work.
Length of
pipe (feet)
Gas Volume Capacity
(ft3/ hr) 1
¾" 1" 1 ¼" 1 ½"
10 278 520 1,060 1,600
20 190 350 730 1,100
30 152 285 590 890
40 130 245 500 760
50 115 215 440 670
75 93 175 360 545
100 79 160 305 480
150 64 120 250 380
Table 2 Gas Pipe Capacity for different pipe sizes
1 Maximum pipe capacity in ft3/hr, based on a specific gravity of
.60 (42 mbar) and a inlet gas pressure of 14 inches W.C.
(35 mbar) or less and a pressure drop of .3 inches W.C. (20 mbar)
NOTICE
When installing the gas supply connection, it
must comply with local regulations or, if such
regulations do not exist, with the National Fuel
Gas Code, ANSI Z 223.1.
In Canada, the gas supply connection must
comply with local regulations or, if such regula-
tions do not exist, with CAN/CSA B149.1,
Natural Gas and Propane Installation Code.

Installation6
14 Installation instructions Logamax plus GB142-24/30/45/60 • version 10/2007
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6.4 Fitting the heating circuit supply and
return pipes
zFit a filling and drain cock in the heating system supply
pipe if required.
zAlso fit an adequately sized safety valve in the system
that meets all applicable codes and regulations.
zThoroughly flush all pipes and radiators. Use of a
Buderus approved boiler cleaner is recommended.
zRefer to the installation template for the pipe connection
dimensions.
zFit the compression fittings (fig. 9, pos. 1 and 2) first to
the Hydronic set (see fig. 10, 11 and 12) and then to the
boiler.
zConnect the expansion tank to the system.
zConnect the pipes so that they are free from strain.
Connecting boiler with DHW tank
zConnect the external hot-water tank according to the
Installation instructions of the hot-water tank and fittings
concerned.
Steel pipe
diameter
in inches
Equivalent length for Pipe Fittings in feet
Type of pipe fitting
90°-Elbow Tee
(flow thru
branch)
Gate valve Gas cocks
Equivalent length in feet
¾2.1 4.1 0.5 1.25
1 2.6 5.2 0.6 1.60
1 ¼ 3.5 6.9 0.8 2.15
1 ½ 4.0 8.0 0.9 2.50
Table 3 Equivalent length for pipe fittings in feet
Fig. 9 Pump manifold installation
pos. 1: Compression fitting (heating system supply pipe)
pos. 2: Compression fitting (heating system return pipe)
pos. 3: DHW supply
pos. 4: DHW return
pos. 5: Relief valve
2
1
3
4
5
NOTICE
– To protect the entire heating system we
recommend installing a dirt particle filter in
the return circuit. When retrofitting the boiler
to an existing heating system this filter is
required.
– Install shut-off valves immediately before and
after the dirt particle filter to allow the filter to
be cleaned.
NOTICE
When using oxygen-permeable pipes, e. g. for
radiant floor heating systems, you must sepa-
rate the system using heat exchangers.
Buderus recommends hydraulically isolating
snowmelt systems using heat exchangers.

Installation 6
Installation instructions Logamax plus GB142-24/30/45/60 • version 10/2007 15
We reserve the right to make any changes due to technical modifications! Buderus • http://www.buderus.net
Piping examples
The following illustrations are two Installation examples.
Piping and field components must be field verified.
zA hot water boiler installed above radiation level or as
required by the Authority having jurisdiction, must be
provided with a low water cutoff device either as a part of
the boiler or at the time of boiler installation.
Fig. 10 is a schematic representation of fig. 9.
Fig. 10 Schematic representation of the boiler with the
hydronic set
pos. 1: DHW supply
pos. 2: drain valve
pos. 3: pump manifold shut-off valves
pos. 4: secondary supply
pos. 5: DHW return
pos. 6: secondary return
GB142
GB142
GB142
FLUE GAS
PT
AIR INTAKE
pump manifold
1
4
5
6
2
3
NOTICE
The following illustrations are simplified concep-
tual illustrations only.
NOTICE
If this boiler is installed in a closed water supply
system with an external indirect DHW tank,
such as one having a backflow preventer in the
cold water supply line, means shall be provided
to control thermal expansion. Contact the water
supplier or local plumbing inspector on how to
control this situation.
Relief valve
The indirect DHW tank must have a tempera-
ture and pressure relief valve installed. The
relief valve shall comply with the Standard for
Relief Valves and Automatic Gas Shutoff
Devices for Hot Water Supply Systems, ANSI
Z21.22-CSA 4.4.
zInstall the relief valve according fig. 10.
The relief valve must comply with following
specifications:
– dimensions: height 2¼ inch (57.15 mm),
width 2 inch (50.8 mm).
– 30 Psi (2 bar) discharge pressure.
– discharge is ¾ inch (19.1 mm) female in
diameter.

Installation6
16 Installation instructions Logamax plus GB142-24/30/45/60 • version 10/2007
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Fig. 11 Schematic representation of the boiler with the
hydraulic set connected to an optional hot water tank
with one or multiple zones including one pump and
zone valves
pos. 1: pressure relief valve
pos. 2: PT meter (pressure and
temperature meter)
pos. 3: drain valve
pos. 4: DHW pump
pos. 5: secondary pump
pos. 6: shut-off valve
pos. 7: shut-off valve
pos. 8: zone valve
pos. 9: primary pump
GB142
GB142
GB142
Additional
Additional
DHW
DHW
Tank
Tank
Optional
DHW
Ta n k
Aditional zones
zones
Radiant
FLUE GAS
PT
AIR INTAKE
9
1
2
4
5
6
3
7
8
WARNING
No valve is to be placed between the relief valve
and the tank. Discharge of the relief valve must
be conducted to a suitable place for disposal
when relief occurs and no reducing coupling or
other restriction may be installed in the
discharge line.
Fig. 12 Schematic representation of the boiler with the
Hydronic set connected to an optional hot water tank
with one or multiple zones and zone pumps
pos. 1: pressure relief valve
pos. 2: PT meter (pressure and
temperature meter)
pos. 3: drain valve
pos. 4: DHW pump
pos. 5: shut-off valve
pos. 6: shut-off valve
pos. 7: zone pump
pos. 8: primary pump
GB142
GB142
GB142
Additional
Additional
DHW
DHW
Tank
Tank
Optional
DHW
Ta n k
Aditional zones
zones
Radiant
FLUE GAS
PT
AIR INTAKE
8
1
2
3
6
7
5
4
NOTICE
Primary boiler pump must have an internal
check valve.

Installation 6
Installation instructions Logamax plus GB142-24/30/45/60 • version 10/2007 17
We reserve the right to make any changes due to technical modifications! Buderus • http://www.buderus.net
6.5 Combustion Air and Ventilation
Openings
Provisions for combustion and ventilation air must be made
in accordance with section 5.3, Air for Combustion and
Ventilation, of the National Flue Gas Code, ANSI Z223.1, or
Sections 7.2, 7.3 or 7.4 of CAN/CGA B149, Installation
Codes, or applicable provisions of the local building codes.
CAUTION:
BOILER DAMAGE AND OPERATIONAL
FAILURES !
Due to insufficient or lacking openings for
combustion air and/or ventilation of the boiler
room.
Provisions for combustion air and ventilation are
always required, regardless whether the
combustion air is taken from the outside (sealed
combustion) or inside (room air for combustion).
Insufficient ventilation of the boiler room can
lead to high air temperatures. This can result in
boiler damage.
– Make sure that intake and exhaust openings
are sufficiently sized and no reduction or
closure of openings takes place.
– When the problem is not resolved, do not
operate the boiler.
– Please note these restrictions and its
dangers to the operator of the boiler.
WARNING:
BOILER DAMAGE !
due to contaminated air.
– Boiler must be clear and free from
combustible materials, gasoline and other
flammable vapors and liquids, and corrosive
liquids and vapors.
Never use chlorine and hydrocarbon
containing chemicals (such as spray
chemicals, solution and cleaning agents,
paints, glues etc) in the vicinity of the boiler.
– Do not store and use these chemicals in the
boiler room.
– Avoid excessive dust formation and build-up.
NOTICE
When one expects contaminated combustion
air (near swimming pools, chemical cleaning
operations and hair salons), sealed combustion
operation is recommended.

Installation6
18 Installation instructions Logamax plus GB142-24/30/45/60 • version 10/2007
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All Air from Inside the Building (room air)
The closet shall be provided with two permanent openings
communicating directly with an additional room(s). The total
input of all gas utilization equipment installed in the
combined space shall be considered in making this determi-
nation. Each opening shall have a minimum free area of
1 square inch per 1,000 Btu per hour of total input rating of
all gas utilization equipment in the confined space, but no
less than 100 square inches. One opening shall commence
within 12 inches (305 mm) of the top, and one opening shall
commence within 12 inches (305 mm) of the bottom of the
enclosure. The minimum dimension of air openings shall be
not less than 3 inches (75 mm).
All Air from Outdoor (sealed combustion)
The closet shall be provided with two permanent openings,
one commencing within 12 inches (305 mm) from the top,
and one commencing within 12 inches (305 mm) from the
bottom of the enclosure. The openings shall communicate
directly, or by ducts, with the outdoors or spaces (crawl or
attic) that freely communicate with the outdoors.
The minimum dimension of air openings shall be no less
than 3 inches (75 mm).
1. Where directly communicating with the outdoors, each
opening shall have a minimum free area of 1 square
inch per 4,000 Btu/hr of total input rating of all
equipment in the enclosure.
2. Where communicating with the outdoors through
vertical ducts, each opening shall have a minimum free
area of 1 square inch per 4,000 Btu/hr of total input
rating of all equipment in the enclosure.
3. Where communicating with the outdoors through
horizontal ducts, each opening shall have a minimum
free area of 1 square inch per 2,000 Btu/hr of total input
rating of all equipment in the enclosure.
4. Where ducts are used, they shall be of the same cross-
sectional area as the free area of the opening to which
they connect.
DANGER:
FIRE DANGER !
due to flammable materials or liquids.
– Do not store flammable materials and liquids
in the immediate vicinity of the boiler.

Installation 6
Installation instructions Logamax plus GB142-24/30/45/60 • version 10/2007 19
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6.6 Installation of the flue gas adapter
(included in the scope of delivery)
Before installing the exhaust and air intake system, it is
necessary to remove the transport safety device and to
install the flue gas adapter.
zRemove the transport safety device with the two screws
(see fig. 13).
zScrew on the flue gas adapter using six screws (see
fig. 14).
Fig. 13 Removing the transport safety device
NOTICE
The transport safety device has been installed
to prevent unwanted movement of the heat
exchanger during transport.
Fig. 14 Connecting the flue gas adapter

Installation6
20 Installation instructions Logamax plus GB142-24/30/45/60 • version 10/2007
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6.7 Installation of the Exhaust and Air Intake
system.
An optional concentric vent/air intake body (see fig. 18 and
26) can be used for the installation of a vertical venting
system as well as for a horizontal venting system.
The concentric vent/air intake body can be ordered by
Buderus Hydronic Systems, part no. BRYKGAVTO601CV.
Other optional vent kits are:
383-500-397 Plastic Vent Kit
PAZ1900019 V1000 Aluminum Vent Kit.
The boiler can also be operated with separate air intake and
exhaust piping (see fig. 19 and fig. 26).
The termination shall be at least 4 ft (1,220 mm) for the U.S.
and 6ft. (1,830 mm) for Canada away from a gas utility
meter, service regulator or the like (for room air applications
only).
The termination shall terminate at least 4 ft (1,220 mm)
below, 4 ft (1,220 mm) horizontally from, or 1 ft (305 mm)
above any door, window, or gravity air inlet into any building.
Vent must be at least 12 inches (305 mm) above grade,
anticipated snow line or roof surface (Canada 18” (457 mm)
minimum) (see fig. 16).
Vent termination must be at least 7 ft (2,135 mm) above
a public walkway (see fig. 17).
Vent must be 3 ft (915 mm)above any forced air intake
within 10 ft (3,050 mm) (see fig. 17).
Do not extend exposed vent pipe outside the building
beyond recommended distance. Condensate could freeze
and block vent pipe.
Vent should terminate at least 3 ft (915 mm) away from adja-
cent walls, inside corners and 5ft (1525 mm) below roof
overhang (see fig. 17).
It is not recommended to terminate vent above any door or
window, condensate can freeze causing ice formations.
Do not use chimney as a raceway if another boiler or fire-
place is vented into or through chimney.
NOTICE:
Consult local and state codes pertaining to
special building code and fire department
requirements. Adhere to national code require-
ments.
NOTICE:
Observe the listed maximum lengths of vent
system, which are boiler model dependent. The
maximum permissible lengths are listed in see
table 4, page 25.
Fig. 15 Vent pipes
1
2