Buderus Logamax plus GB142-24 User guide

Please read thoroughly before installing and servicing
7212 9700 – 12/2004 US/CA(EN) For registered installers
Installation and Servicing instructions
Condensing gas heater
Logamax plus GB142-24/30/45/60
CAUTION!
Before putting the appliance 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:
This manual must be retained for future reference.
–Do not store or use gasoline or other flammable vapors and
liquids in the vicinity of this or any other appliance.
– What to do if you smell gas
•Do not try to light any appliance
•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
causing property damage, personal injury or death.

2
We reserve the right to make any changes due to technical modifications!
Installation and Servicing instructions Logamax plus GB142-24/30/45/60 • Version 12/2004
Buderus Hydronic Systems • http://www.buderus.net
Preface
About these instructions
These Installation and Servicing Instructions contain
important information for the safe and professional
installation, start-up and maintenance of the appliance
with appliance capacities 24, 30, 45 and 60 kW.
These Installation and Servicing Instructions are
intended for specialist installers, who have the neces-
sary 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
3
We reserve the right to make any changes due to technical modifications!
Installation and Servicing Instructions Logamax plus GB142-24/30/45/60 • Version 12/2004
Buderus Hydronic Systems • 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 heating
system 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 appliance . . . . . . . . . . . . . . 11
6 Installation . . . . . . . . . . . . . . . . . . . . . . . . . . 12
6.1 Requirements for the installation room . . . . . 12
6.2 Fitting the appliance. . . . . . . . . . . . . . . . . . . . 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) . . . . . . . . . 18
6.7 Installation of the Exhaust and
Air Intake system. . . . . . . . . . . . . . . . . . . . . . 18
7 Connecting the condensate water drain . . 23
8 Electrical connections. . . . . . . . . . . . . . . . . 24
8.1 External connection board connections. . . . . 24
9 Start-up procedure. . . . . . . . . . . . . . . . . . . . 27
9.1 Testing for gas leaks . . . . . . . . . . . . . . . . . . . 28
9.2 Filling the appliance . . . . . . . . . . . . . . . . . . . . 28
9.3 Filling the condensate trap. . . . . . . . . . . . . . . 29
9.4 Venting the gas supply valve . . . . . . . . . . . . . 29
9.5 Checking the combustion air/flue gas
connection . . . . . . . . . . . . . . . . . . . . . . . . . . . 30
9.6 Checking the orrifices . . . . . . . . . . . . . . . . . . 30
9.7 Inlet gas pressure . . . . . . . . . . . . . . . . . . . . . 30
9.8 Checking and adjusting the gas/air ratio . . . . 31
9.9 Carrying out a tightness test in operating
conditions. . . . . . . . . . . . . . . . . . . . . . . . . . . . 33
9.10 Measuring the carbon monoxide
content (CO) . . . . . . . . . . . . . . . . . . . . . . . . . 33
9.11 Function testing . . . . . . . . . . . . . . . . . . . . . . . 33
9.12 Measuring the ionization current . . . . . . . . . . 33
9.13 Installing the casing . . . . . . . . . . . . . . . . . . . . 35
9.14 Informing the owner, handing over the
technical documents . . . . . . . . . . . . . . . . . . . 35
10 BC10 basic controller . . . . . . . . . . . . . . . . . 36
10.1 Operating the BC10 basic controller . . . . . . . 36
10.1.1 Switching the heating system on and off . . . . 36
10.1.2 Displaying the operating conditions of
the burner and resetting the burner or
resetting burner faults . . . . . . . . . . . . . . . . . . 36
10.1.3 Displaying the heating system status
and/or faults. . . . . . . . . . . . . . . . . . . . . . . . . . 37
10.2 Carrying out additional tasks . . . . . . . . . . . . . 39
10.2.1 Carrying out a flue gas test . . . . . . . . . . . . . . 39
10.2.2 Selecting partial load operation
(e. g. during flue gas testing) . . . . . . . . . . . . . 39
10.2.3 Switching the heating system to
manual mode. . . . . . . . . . . . . . . . . . . . . . . . . 39
10.3 Configuring the appliance . . . . . . . . . . . . . . . 40
10.3.1 Adjusting the heating capacity. . . . . . . . . . . . 40
10.3.2 Setting the DHW temperature value . . . . . . . 41
10.3.3 Entering the heater water temperature . . . . . 41
10.3.4 Setting the pump post-purge period . . . . . . . 41
11 Shutting down the system . . . . . . . . . . . . . 43
11.1 Shut down the heating system using
the control unit. . . . . . . . . . . . . . . . . . . . . . . . 43
11.2 Shutting down the heating system
in the event of an emergency . . . . . . . . . . . . 43
12 Inspection . . . . . . . . . . . . . . . . . . . . . . . . . . 44
12.1 Preparing the appliance for inspection . . . . . 44
12.2 Visual inspection for general signs of
corrosion . . . . . . . . . . . . . . . . . . . . . . . . . . . . 44
12.3 Internal tightness testing . . . . . . . . . . . . . . . . 45
12.4 Measuring the ionization current . . . . . . . . . . 45
12.5 Measuring the inlet gas pressure . . . . . . . . . 45
12.6 Checking and adjusting the gas/air ratio . . . . 45
12.7 Carrying out a gas tightness test in
operating conditions . . . . . . . . . . . . . . . . . . . 45
12.8 Measuring the carbon monoxide
content (CO) . . . . . . . . . . . . . . . . . . . . . . . . . 45
12.9 Carrying out a pressure test of the
heating system . . . . . . . . . . . . . . . . . . . . . . . 45
12.10 Checking the functioning and the safety
of the air intake and flue gas conduit. . . . . . . 45
12.11 Checking venting systems. . . . . . . . . . . . . . . 45
13 Maintenance. . . . . . . . . . . . . . . . . . . . . . . . . 46
13.1 Cleaning the heat exchanger, burner
and condensate trap . . . . . . . . . . . . . . . . . . . 46
13.2 Checking and adjusting the gas/air-ratio . . . . 48
14 Servicing . . . . . . . . . . . . . . . . . . . . . . . . . . . 49
14.1 Checking the UBA3 fuse;
replace if necessary . . . . . . . . . . . . . . . . . . . 49
14.2 External connection board fuse . . . . . . . . . . . 49
14.3 Checking the fan unit; 120 VAC control . . . . 50
14.4 Checking the fan unit;
Supply cord (120 VAC) . . . . . . . . . . . . . . . . . 51
14.5 Checking the fan unit; Tacho cable . . . . . . . . 52
14.6 Replacing the fan unit . . . . . . . . . . . . . . . . . . 52
14.7 Checking the supply/return/safety/
hot-water temperature sensors . . . . . . . . . . . 53
14.8 Replacing the supply/return/safety sensors . 54
14.9 Checking the supply/return/
safety sensors cable . . . . . . . . . . . . . . . . . . . 55
14.10 Checking the hot surface ignitor; Control . . . 56
14.11 Checking the hot surface ignitor; resistance . 57

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Installation and Servicing Instructions Logamax plus GB142-24/30/45/60 • Version 12/2004
Buderus Hydronic Systems • http://www.buderus.net
Contents
14.12 Checking the hot surface ignitor;
Supply cord . . . . . . . . . . . . . . . . . . . . . . . . . . 57
14.13 Replacing the hot surface ignitor . . . . . . . . . 58
14.14 Testing the ionization current . . . . . . . . . . . . 59
14.15 Checking the ionization electrode; cable . . . 60
14.16 Checking the ionization electrode;
replace if necessary . . . . . . . . . . . . . . . . . . . 61
14.17 Checking the gas control valve; cable
connections. . . . . . . . . . . . . . . . . . . . . . . . . . 62
14.18 Checking the gas control valve; Control . . . . 62
14.19 Checking the gas control valve; Cable
connection between gas control valve
and UBA3 installation base . . . . . . . . . . . . . . 62
14.20 Ohming out the gas control valve . . . . . . . . . 64
14.21 Replacing the gas control valve . . . . . . . . . . 65
14.22 Checking the control unit;
connections to the appliance . . . . . . . . . . . . 68
14.23 Transformer; checking and if necessary
replacing . . . . . . . . . . . . . . . . . . . . . . . . . . . . 70
14.24 Automatic air purging system; replacing . . . . 72
14.25 Burner; replacing. . . . . . . . . . . . . . . . . . . . . . 73
14.26 Sight glass; replacing . . . . . . . . . . . . . . . . . . 76
14.27 Condensate trap; replacing. . . . . . . . . . . . . . 77
14.28 Pressure sensor; replacing . . . . . . . . . . . . . . 77
14.29 Heat exchanger; replacing . . . . . . . . . . . . . . 78
14.30 UBA3; replacing . . . . . . . . . . . . . . . . . . . . . . 85
15 Converting the appliance to propane
or high altitude conversion . . . . . . . . . . . . 86
16 Appendix . . . . . . . . . . . . . . . . . . . . . . . . . . . 87
16.1 Operating messages. . . . . . . . . . . . . . . . . . . 87
16.2 Error messages. . . . . . . . . . . . . . . . . . . . . . . 88
16.3 Technical specifications . . . . . . . . . . . . . . . . 89
17.1 Start-up report. . . . . . . . . . . . . . . . . . . . . . . . 91
17.2 Inspection report . . . . . . . . . . . . . . . . . . . . . . 92
17.3 Maintenance report . . . . . . . . . . . . . . . . . . . . 93
18 Spare parts . . . . . . . . . . . . . . . . . . . . . . . . . 94
19 Index. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 97

Safety and general instructions 1
5
We reserve the right to make any changes due to technical modifications!
Installation and Servicing Instructions Logamax plus GB142-24/30/45/60 • Version 12/2004
Buderus Hydronic Systems • 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 appliance was designed for heating water for a
heating system and generating hot water e.g. for
domestic purposes.
The appliance is delivered with a BC10 basic controller
and the "Universal Automatic Burner Control Unit 3"
(UBA3) pre-installed.
The appliance can be fitted with a modulating room ther-
mostat from the RC series or an On/Off thermostat or
relay panel end switch (24 V) (accessories).
1.2 Hazard definitions
The following defined terms are used throughout the
documentation to bring attention to the presence of
hazards of various risk levels. Notices give important
information concerning the life of the product.
1.3 The following instructions must be
observed
– The appliance must only be used for its designated
purpose, observing the Installation and Servicing
Instructions.
– Only use the appliance 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
authorized professionals.
– You must report the installation of a condensing gas
heater to the relevant gas utility company and have it
approved.
– You are only allowed to operate the condensing gas
heater with the combustion air/flue gas system that
has been specifically designed and approved for this
type of appliance.
– 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/heating system.
– the Installation Instructions for building heating
systems.
– The appliance must be located in an area where
leakage of the tank or connections will not result in
damage to the area adjacent to the appliance or to
lower floors of the structure. When such locations
cannot be avoided, it is recommended that a suitable
drain pan, adequately drained, be installed under the
appliance. The pan must not restrict combustion air
flow.
– Do not restrict or seal any air intake or outlet
openings.
– If you find any defects, you must inform the owner of
the system of the defect and the associated hazard in
writing.
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 elec-
tric shock.
NOTICE:
Indicates special instructions on installa-
tion, operation or maintenance that are
important but not related to personal injury
or property damage.

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Installation and Servicing Instructions Logamax plus GB142-24/30/45/60 • Version 12/2004
Buderus Hydronic Systems • http://www.buderus.net
Safety and general instructions1
1.4 Observe these instructions for
heating system water
– Thoroughly flush the system prior to filling.
Only use untreated main water to fill and top off the
system.
– Do not use salt bedding exchangers to soften the
water.
– Do not use inhibitors or other additives!
– No Toxic chemicals such as used for boiler treatment,
shall be introduced into the portable water used for
space heating.
– The maximum permissible flow rate of the
GB142-24/30 this is 11 GPM (gal./min.), for the
GB142-45 is 15 GPM and for the GB142-60 is
20 GPM.
– When using oxygen-permeable pipes, e. g. for floor
heating systems, you must separate the system using
heat exchangers. Unsuitable heating system water
promotes the formation of sludge and corrosion.
This may damage the heat exchanger or affect its
operation.
1.5 Tools, materials and additional
equipment
For the installation and maintenance of the appliance
you will need the standard tools for central heating, gas
and water fitting.
In addition, a handtruck with a fastening belt is very
useful.
1.6 Disposal
– Dispose of the appliance packaging in an
environmentally sound manner.
– Dispose of components of the heating system
(e. g. appliance or control device), that must be
replaced, by handing them in to an authorized
recycling facility.
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
flammable vapors and liquids in the
vicinity of this or any other appliance.
What to do if you smell gas
zDo not try to light any appliance.
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
7
We reserve the right to make any changes due to technical modifications!
Installation and Servicing Instructions Logamax plus GB142-24/30/45/60 • Version 12/2004
Buderus Hydronic Systems • http://www.buderus.net
2 Regulations and guidelines
The installation must be 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/CGA B149.1 or 2 Installation Code for Gas Burning
Appliances and Equipment.
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. Appliance
requires yearly maintenance, see maintenance section
see chapter 13 "Maintenance", page 46
Operating Limits of the appliance:
Max. appliance temperature: 220 °F (105 °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 appliance, it is important to check the condition
of the entire hot water distribution system to ensure safe
operation.

8
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Installation and Servicing Instructions Logamax plus GB142-24/30/45/60 • Version 12/2004
Buderus Hydronic Systems • http://www.buderus.net
Product description3
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)
1
2
3
6
9
11
13
14
9
16
15
7
5
8
1
4
10
12
13
14
2
3
5
4
67
9
11
9
8
10
12
16
15
Fig. 2 Basic Controller Logamatic BC10
pos. 1: Main switch
pos. 2: DHW temperature knob
pos. 3: LED "DHW status"
pos. 4: Display
pos. 5: Heating water temperature knob
pos. 6: LED "Heating system status"
pos. 7: Under the cover a RC system controller can be installed.
Only when the appliance is used for outdoor weather responsive
operation.
pos. 8: LED "Burner Operation"
pos. 9: Service Tool connector
pos. 10: "Service" button
pos. 11: "Chimney sweep" button
pos. 12: "Reset" button Switching the heating system on and off
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
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Installation and Servicing Instructions Logamax plus GB142-24/30/45/60 • Version 12/2004
Buderus Hydronic Systems • http://www.buderus.net
4 Dimensions and connections
Fig. 3 Dimensions and connections for appliance 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 1.1” 1(Ø 28 mm)
Supply, Ø 1.1” 1(Ø 28 mm)
Wall bracket
1One Ø 1.1” (Ø 28 mm) inside x 1'' NPT threaded compression fitting is.
12" (300 mm)
4" (100 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" (119 mm)
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
appliance (4” = 100 mm) and the necessary
distances (24” (600 mm) at the front and
12” (300 mm) at the top) for removing the
casing and service accessibility.
Closet clearances are:
4” (100 mm) to the right, 4” (100 mm) at the top
and 6” (150 mm) to the left.

10
We reserve the right to make any changes due to technical modifications!
Installation and Servicing Instructions Logamax plus GB142-24/30/45/60 • Version 12/2004
Buderus Hydronic Systems • http://www.buderus.net
Dimensions and connections4
Fig. 4 Dimensions and connections for appliance 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 1.1” 1(Ø 28 mm)
Supply, Ø 1.1” 1(Ø 28 mm)
Wall bracket
1One Ø 1.1” (Ø 28 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)
12" (300 mm)
4" (100 mm)
20" (500 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
NOTICE
Observe the lateral minimum distances of the
appliance (4” = 100 mm) and the necessary
distances (24” (600 mm) at the front and
12” (300 mm) at the top) for removing the
casing and service accessibility.
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
11
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Installation and Servicing Instructions Logamax plus GB142-24/30/45/60 • Version 12/2004
Buderus Hydronic Systems • http://www.buderus.net
5 Packaging and transportation
5.1 Scope of delivery
The appliance is delivered fully assembled.
zWhen receiving the delivery, check if the packaging
is intact.
zCheck that all the items listed in table 1 are included
in the delivery.
5.2 Transporting the appliance
zPackaged heaters 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 appliance to the room where it is to be
installed.
Fig. 5 Items supplied with unit
Pos. Parts Quantity Packaging
1Appliance with casing 1 1 box
2Wall bracket 1
3Technical documents 1
including:
- User's Instructions
- Installation and Servicing
instructions
- wall mounting template
3
4Compression fittings 2
5Room thermostat 1
6Flue gas adapter 1
Table 1 Items supplied with unit
1The user’s instructions (in a special format) is located in the
appliance drawer
1
2
3
5
4
6
CAUTION
The appliance may be damaged when it is
improperly secured.
– Only transport the appliance using the right
transportation equipment, such as a
handtruck with a fastening belt or special
equipment for manoeuvering steps.
– During transportation the appliance 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.

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Installation6
6 Installation
6.1 Requirements for the installation
room
6.2 Fitting the appliance
Observe the installation distances 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 neces-
sary service clearances.
zRemove the transport safety clamps (fig. 6) taking
into account the necessary service clearances.
DANGER
– Install the heating system in a frost-free
room.
– Do not store any flammable materials or
liquids in the immediate vicinity of the
appliance.
– 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
appliance.
NOTICE
– To protect the connection orifice you must
not remove the styropor bottom panel.
– Do not lift the appliance by the drawer.
– Do not remove the transport safety clamps
(see fig. 6) from the drawer at this time.
– Protect the appliance and the combustion
air/flue gas orifice against pollution during
installation.
Fig. 6 Removing the transport safety clamps

Installation 6
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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 it by the
latches.
zHold the appliance by the rear appliance casing and
place it on the wall bracket.
zLevel out the appliance.
6.3 Making the gas connection
zDetermine proper size gas pipe for the installation
using table 2 and 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 connec-
tion.
zConnect the gas pipe to the gas cock (fig. 8, pos. 1)
so that it is free from any strain.
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 conduits and
fittings 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 .5 psi (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
regulations do not exist, with
CSA/CGA-B149 Installation Guidelines.

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Installation6
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 a safety valve in the system.
zThoroughly flush all pipes and radiators.
zRefer to the installation template for the pipe connec-
tion 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 appliance.
zConnect the expansion tank to the system.
zConnect the pipes so that they are free from strain.
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
– Piping and components connected to the
water appliance for the space heating
application are suitable for use with potable
water.
– A water appliance which will be used to
supply potable water shall not be
connected to any heating system or
component(s) previously used with a
nonpotable water heating appliance.
NOTICE
– To protect the entire heating system we
recommend installing a dirt particle filter in
the return circuit. When connecting the
appliance to an existing heating system this
filter must definitely be installed.
– Install shut-off valves immediately before
and after the dirt particle filter to enable the
filter to be cleaned.
NOTICE
When using oxygen-permeable pipes, e. g. for
floor heating systems, you must separate the
system using heat exchangers.

Installation 6
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Installation and Servicing Instructions Logamax plus GB142-24/30/45/60 • Version 12/2004
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Appliance with external tank
zConnect the external hot-water tank according to the
Installation instructions of the hot-water tank and
fittings concerned.
Piping examples
The following illustrations are two Installation examples.
Piping and field components must be field verified.
zInstall a low water cut-off (LWCO) when required by
local code or when the appliance is installed above
piping level.
Fig. 10 is a schematic representation of fig. 9.
Fig. 10 Schematic representation of the appliance 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
GB142GB142
FLUE GAS
PT
AIR INTAKE
pump manifold
1
4
5
6
2
3
NOTICE
The following illustrations are simplified
conceptual illustrations only.
NOTICE
If this water heater is installed in a closed water
supply system, 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.
The seperate storage vessel must have a
temperature 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.
When the system requires water for space
heating at temperatures higher than required
for other uses, a means such as a mixing valve
shall be installed to temper the water for those
uses in order to reduce scald hazard potential.

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Installation6
Fig. 11 Schematic representation of the appliance 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
DHW
Tank
Optional
DHW
Tank
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 appliance 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
DHW
Tank
Optional
DHW
Tank
Aditional zones
zones
Radiant
FLUE GAS
PT
AIR INTAKE
8
1
2
3
6
7
5
4
NOTICE
Primary pump and DHW tank pump must
have an internal check valve.

Installation 6
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Installation and Servicing Instructions Logamax plus GB142-24/30/45/60 • Version 12/2004
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6.5 Combustion Air and Ventilation
Openings
CAUTION:
APPLIANCE DAMAGE AND OPERA-
TIONAL FAILURES !
Due to insufficient or lacking openings for
combustion air and/or ventilation of the
appliance room.
Provisions for combustion air and ventila-
tion 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 appliance
room can lead to high air temperatures.
This can result in appliance 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 appliance.
– Please note these restrictions and its
dangers to the operator of the appliance.
WARNING:
APPLIANCE DAMAGE !
due to contaminated air.
– Appliance 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 appliance.
– Do not store and use these chemicals in
the appliance room.
– Avoid excessive dust formation and
build-up.
NOTICE
When one expects contaminated combus-
tion air (near swimming pools, chemical
cleaning operations and hair salons),
sealed combustion operation is recom-
mended.
DANGER:
FIRE DANGER !
due to flammable materials or liquids.
– Do not store flammable materials and
liquids in the immediate vicinity of the
appliance.

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Installation6
All Air from Inside the Building (room air)
The closet shall be provided with two permanent open-
ings 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
determination. 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
(300 mm) of the top, and one opening shall commence
within 12 inches (300 mm) of the bottom of the enclo-
sure. 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 open-
ings, one commencing within 12 inches (300 mm) from
the top, and one commencing within 12 inches
(300 mm) from the bottom of the enclosure. The open-
ings shall communicate directly, or by ducts, with the
outdoors or spaces (crawl or attic) that freely communi-
cate 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.
6.6 Installation of the flue gas adapter
(included in the scope of delivery)
Before installing the exhaust and air intake system it is
necessay to install the flue gas adapter (see fig. 13).
zScrew on the flue gas adapter using six screws.
6.7 Installation of the Exhaust and Air
Intake system.
Fig. 13 Connecting the flue gas adapter
NOTICE:
Consult local and state codes pertaining to
special building code and fire department
requirements. Adhere to national code
requirements.

Installation 6
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An optional concentric vent/air intake body (see fig. 15,
pos. 1) 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.
The appliance can also be operated with separate air
intake and exhaust piping (see fig. 18 and fig. 20).
The termination shall be at least 3 ft (910 mm) away from
a gas utility meter, service regulator or the like (for room
air applications only).
The termination shall terminate at least 4 ft (1220 mm)
below, 4 ft (1220 mm) horizontally from, or 1 ft (305 mm)
above any door, window, or gravity air inlet into any
building.
All vent pipes must be glued, except for the flue gas
adapter (fig. 14, pos. 1) which is screwed into place and
the first connection to the flue gas adapter (fig. 14,
pos. 2). Installed you can slide the pipe onto the adapter,
properly supported and the exhaust pipe must be
pitched a minimum of a ¼ inch per foot back to the appli-
ance. This allows the condensate to drain away.
All combustion air and vent pipe materials and fittings
must comply with the following:
NOTICE:
Observe the listed maximum lengths of
vent system, which are appliance model
dependent. The maximum permissible
lengths are listed in table 4, page 22.
Fig. 14 Vent pipes
1
2
Item Material United states Canada
Vent or air pipe
and fitting
PVC schedule 40 ANSI/ASTM D1785
CSA or ULC
certified only
PVC-DWV ANSI/ASTM D2665
CPVC schedule 40 ANSI/ASTM F441
ABS-DWV schedule 40 ANSI/ASTM D2661
Pipe
cement/primer
PVC ANSI/ASTM D2564
CPVC ANSI/ASTM F493
ABS ANSI/ASTM D2235
NOTICE
Do not use cellular core pipe.
NOTICE
Ensure that a condensate drain is always
installed at the exhaust connection see
Chapter “7 Connecting the condensate
water drain” on page 23

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Installation6
Below are approved examples of vertical and
horizontal venting installation
Fig. 15 Vertical venting system (sealed combustion)
INTAKE
EXHAUST
10"- 0" MIN
(250 mm - 0 mm MIN)
12" (300 mm) OVER MAXIMUM
SNOW LEVEL OR 24" (600 mm)
WHICHEVER IS
GREATER
3" (80 mm)
3" (80 mm)
1
Fig. 16 Vertical venting system (room air only)
INTAKE
EXHAUST
10"- 0" MIN
(250 mm - 0 mm MIN)
12" (300 mm) OVER MAXIMUM
SNOW LEVEL OR 24" (600 mm)
WHICHEVER IS
GREATER
3" (80 mm)
Fig. 17 Vertical parallel venting system (sealed combustion)
INTAKE
EXHAUST
10"- 0" MIN
(250 mm - 0 mm MIN)
12" (300 mm) OVER MAXIMUM
SNOW LEVEL OR 24" (600 mm)
WHICHEVER IS
GREATER
3" (80 mm)
3" (80 mm)