Buderus Logamax plus GB142-24 User manual

C
Propane Conversion Kit
Instruction
Condensing gas boiler
Logamax plus
Required Input Rates
This kit and instructions are for converting the GB142 model boilers
from Natural Gas to Liquid Propane.
GB142-24
84,800 btu/hr
GB142-30
106,000 btu/hr
GB142-45
149,000 btu/hr
GB142-60
214,800 btu/hr
Tab. 1
WARNING!
This conversion kit shall be installed by a qualified service agency in
accordance with the manufacturer's instructions and all applicable
codes and requirements of the authority having jurisdiction.
The information in these instructions must be followed to minimize
the risk of fire or explosion or to prevent property damage, personal
injury or death. The qualified service agency is responsible for the
proper installation of this kit.
The installation is not proper and complete until the operation of the
converted boiler is checked as specified in the manufacturer’s
instructions supplied with the kit.
Tab. 2
CAUTION!
The gas supply shall be shut off prior to disconnecting the electrical
power, before proceeding with the conversion.
GB142-24/30/45/60
7215 0100 (2011/11) US/CA

Contents
Logamax plus GB142-24/30/45/60 – 7215 0100 (2011/11)
2
Contents
1 Safety considerations . . . . . . . . . . . . . . . . . . . . . 3
1.1 Application purpose . . . . . . . . . . . . . . . . . 3
1.2 Hazard definitions . . . . . . . . . . . . . . . . . . . 3
2 Parts list for converting the boiler to propane . 4
3 LP conversion . . . . . . . . . . . . . . . . . . . . . . . . . . . 5
3.1 Testing for gas leaks . . . . . . . . . . . . . . . . . 6
3.2 Inlet gas pressure . . . . . . . . . . . . . . . . . . . 7
3.3 Checking and adjusting the gas/air ratio . 7
3.4 Carrying out a tightness test in operating
conditions . . . . . . . . . . . . . . . . . . . . . . . . . 8
3.5 Measuring the carbon monoxide content
(CO) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9
3.6 Lighting Instructions . . . . . . . . . . . . . . . . . 9
4 Operating Instructions . . . . . . . . . . . . . . . . . . . 10

1
Safety considerations
Logamax plus GB142-24/30/45/60 – 7215 0100 (2011/11) 3
1 Safety considerations
For use in Canada the conversion kit shall be carried out
in accordance with the requirements of the provincial
authorities having jurisdiction and in accordance with the
requirements of the CAN-B149.1 and CAN1-B149.2
Installation Code. See also E.I.V.
Please observe the following safety instructions.
1.1 Application purpose
This kit and instructions are for converting the
GB142-24/30/45/60 from Natural gas to Liquid
Propane.
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 operation of the product.
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.
DANGER:
due to explosion of gas.
BWork only on gas components when you
have a license to do so.
BNote that the assembly of gas and vent
connections, the initial start-up, the
electrical connections, the maintenance
and service can only be performed by a
licensed service contractor or technician.
DANGER:
due to electricity.
BPrior to doing any work on the heating
system, disconnect all electrical power to
the appliance at the emergency switch.
BIt is NOT sufficient to shut off only the
appliance control!
NOTICE
All service work on gas components must be
performed by a trained and qualified service
technician.

2Parts list for converting the boiler to propane
Logamax plus GB142-24/30/45/60 – 7215 0100 (2011/11)
4
2 Parts list for converting the boiler to propane
Conversion kit propane for the 24/30 kW # 76687
includes:
• orifice # 7099016 (dia. 3.35 mm / 0.131 inch)
•2o-rings
•bag
• these instructions
• label to be filled out and affixed to the boiler.
Conversion kit propane for the 45 kW # 76688 includes:
• orifice # 7099935 (dia. 4.05 mm / 0.158 inch)
•2o-rings
•bag
• these instructions
• label to be filled out and affixed to the boiler.
Conversion kit propane for the 60 kW # 7746900156
includes:
• orifice # 76690 (dia. 5.40 mm / 0.213 inch)
•2o-rings
•bag
• these instructions
• label to be filled out and affixed to the boiler
• diffuser plate.

3
LP conversion
Logamax plus GB142-24/30/45/60 – 7215 0100 (2011/11) 5
3LPconversion
To convert the boiler to propane, the following
instructions must be adhered to:
Shut down the boiler
BTurn off the gas supply.
BSwitch off the heating system using the main switch
(Æfig. 1).
BDisconnect the electrical power to the boiler.
BSet the thermostat or other operating control to lowest
setting.
Fig. 1
BRemove the casing (Æfig. 2).
Fig. 2
Changing the gas orifice
BLoosen the screw connection on the gas valve
(Æfig. 3, [1]) and pull the plug (Æfig. 3, [2]) from the
gas valve.
BPull both plugs from the fan unit (Æfig. 3, [3]).
BLoosen both retaining clips (Æfig. 3, [4]) on the burner
cover and remove the burner cover together with the
fan unit and the gas valve.
Fig. 3
BLoosen the 3 Phillips screws (Æfig. 4, [1]) and remove
the gas valve from the fan unit.
BRemove the gas orifice (Æfig. 4, [2]).
BFit the correct orifice for the new type of gas supply
(table 4). Make sure not to damage the O-rings.
BRe-assemble all parts in reverse order of disassembly.
BCarry out the start-up activities and complete a new
start-up report.
BAlso check all joints and gaskets affected by the
installation activities while carrying out the tightness
test in operating conditions.
DANGER:
if flammable gas explodes.
This appliance is NOT suitable for use with
gas mixtures such as Butane/Propane.
BOnly carry out work on gas conduits and
fittings if you are licensed for such work.
Reset
01
140
130
120
90
100
110
Aut
0
Eco
190
170
150
130
90
110
Aut
0
6720615033-002.1TD
1
GB142-24/30 GB142-45/60
72150100-002.1TD
GB142-24/30
GB142-45/60
4
4
1
2 3
1
2 3
4
4
7215 0100-003.1TD

3LP conversion
Logamax plus GB142-24/30/45/60 – 7215 0100 (2011/11)
6
BPlace a new sticker underneath the existing rating plate
sticker indicating the type of gas supply installed. Fill
out the required information on the conversion label.
Fig. 4
Installation of diffuser plate (GB142/60 model
only)
BRemove burner gasket (Æfig. 5, [1]).
BRemove gas-air distribution plate (Æfig. 5, [2]).
BIf present, remove old diffuser plate (Æfig. 5, [3]).
BAllways install the new diffuser plate of the conversion
kit propane 60 kW.
BReassemble new diffuser plate, gas-air distribution
plate and burner gasket.
BSecure the supplied LP conversion kit label to the
boiler next to its rating plate.
Fig. 5
3.1 Testing for gas leaks
Prior to start-up of the boiler you must check the external
tightness of the gas supply valve and confirm this in the
start-up report.
BDisconnect the heating system from the power supply.
BCheck the exterior tightness of new conduit sections
up to and including the direct sealing point on the gas
burner fitting. The maximum test pressure allowed on
the input of the gas burner fitting is 14 inch W.C.
(35 mbar).
BCheck the input rates after converting the boiler to LPG
to the values on the front page.
72150100-004.1TD
1.
2.
1
2
3
4
72150100-005.1
T
DANGER:
BCover unprotected boiler parts before
leak testing.
BDo not spray the leak testing agent onto
cables, plugs or electrical connection
lines. Do not allow it to drip onto them
either.
Boiler
capacity
Type of gas
supply
Gas orifice
diameter in mm
(inch)
Venturi
article
number
24 kW Natural gas 4.45 (0.174) 423.072A
LPG P 3.35 (0.131) 423.072A
30 kW Natural gas 4.45 (0.174) 423.072A
LPG P 3.35 (0.131) 423.072A
45 kW Natural gas 5.40 (0.213) 423.170A
LPG P 4.05 (0.158) 423.170A
60 kW Natural gas 7.50 (0.293) 423.173A
LPG P 5.40 (0.213) 423.173A
Table 4 Gas orifice diameter
DANGER:
Commissioning and maintenance activities
can cause leaks in pipe and screw
connections.
BCarry out a proper leak test.
BOnly use approved leak detection agents
for leak detection.

3
LP conversion
Logamax plus GB142-24/30/45/60 – 7215 0100 (2011/11) 7
3.2 Inlet gas pressure
BOpen at least one thermostatic radiator valve if present
to allow water to flow through the boiler. Do not switch
on the boiler.
BClose the gas shut-off valve. Loosen the screw plug on
the inlet gas pressure testing nipple by two turns
(Æfig. 6, [1]).
BConnect the pressure gauge connection hose to the
testing nipple (Æfig. 6, [2]).
BSlowly open the gas shut-off valve.
The boiler and its individual shutoff valve must be
disconnected from the gas supply piping system during
any pressure testing of that system at test pressures in
excess of ½ psi (3.5 kPa).
The boiler must be isolated from the gas supply piping
system by closing its individual manual shutoff valve
during any pressure testing of the gas supply piping
system at test pressures equal to or less than ½ psi
(3.5 kPa).
Fig. 6 Measuring the inlet gas pressure
BBriefly press on the control panel cover to open it.
Fig. 7 Opening the control panel
BSwitch on the heating system by setting the main
switch ato position "1" (Æfig. 11, page 10).
BPress the "Chimney Sweep" dbutton and hold it (for
approx. two seconds) until the display shows a decimal
point.
BMeasure the gas connection pressure as soon as the
"Burner" gLED lights and enter this value in the start-
up report.
The inlet gas pressure must be:
• for natural gas - min. 3.5 to 10.5 inch W.C. (8.7 to
26.1 mbar), nominal supply pressure 7.0 inch W.C.
(17.4 mbar)
• for LPG - min. 8.0 to 13.0 inch W.C. (19.9 to
32.3 mbar), nominal supply pressure 11.0 inch W.C.
(27.4 mbar).
BRepeatedly press the "Service" ebutton until the
temperature indication is displayed.
BPress the "Chimney Sweep" dbutton to end the
measurement procedure.
BClose the gas shut-off valve.
BRemove the connection hose again and tighten the
screw plug on the testing nipple.
BOpen the gas shut-off valve again.
3.3 Checking and adjusting the gas/air
ratio
BSwitch off bthe heating system using the main
switch .
BLoosen the screw plug on the measuring nipple for the
burner pressure by two rotations (Æfig. 8, [1]).
BSet the pressure gauge to zero.
BUse a hose to connect the plus terminal of the pressure
gauge to the burner pressure measuring nipple
(Æfig. 8, [2]).
72150100-006.1TD
1.
2.
6720615033-018.1TD
CAUTION
BContact the relevant gas utility company if
the required inlet gas pressure is not
available.
BInstall a gas pressure regulator before the
gas burner fitting if the supply pressure is
too high.

3LP conversion
Logamax plus GB142-24/30/45/60 – 7215 0100 (2011/11)
8
Fig. 8 Checking the gas/air ratio
BSwitch on athe heating system using the main
switch.
BPress the "Chimney Sweep" dbutton and hold it (for
approx. two seconds) until the display shows the
decimal point.
BPress and hold the "Chimney Sweep" and "Service"
d+ ebuttons (for approx. five seconds) until the
display shows "Lxx" (e. g. L80).
BSet the boiler to partial load "L30" by pressing the
"Chimney Sweep" dbutton (higher values) or the
"Reset" cbutton (lower values).
d= higher values, c= lower values
BRead out the differential pressure. The differential
pressure (pGas –p
Air) must be -0.02 inch W.C. (-
5 Pa) (± 0.02 inch W.C. = ± 5 Pa) (read-out on
pressure gauge: -0.04 – 0 inch W.C. = -10 - 0 Pa).
BEnter the value measured in the start-up report.
BIf the gas/air ratio is not correct it can be adjusted using
the adjustment screw (Æfig. 9, [2]). The adjustment
screw is located behind the cover screw.
Fig. 9 Setting the gas/air ratio
BRepeatedly press the "Service" ebutton until the
temperature indication is displayed.
BPress the "Chimney Sweep" dbutton until the
decimal point is cleared from the display.
BSwitch off bthe heating system using the main
switch.
BRemove the measurement set-up, tighten the screw in
the burner pressure measuring nipple.
BSwitch on athe heating system using the main
switch.
3.4 Carrying out a tightness test in
operating conditions
BCheck all gaskets and joints in the burner gas circuit for
leaks while the burner is operational, using a foaming
agent.
1
2
72150100-007.1TD
1
72150100-008.1TD
DANGER:
Leaks may be caused to pipes and screw
connections during start-up activities if
flammable gas explodes.
BOnly use approved leak detection agents
for leak detection such as a soapy water
solution.
CAUTION:
due to a short circuit.
BCover damageable parts before leak
testing.
BDo not spray the leak testing agent onto
cables, plugs or electrical connection
lines. Do not allow it to drip onto them
either.

3
LP conversion
Logamax plus GB142-24/30/45/60 – 7215 0100 (2011/11) 9
3.5 Measuring the carbon monoxide
content (CO)
BMeasure the carbon monoxide content on the flue gas
sampling point (Æfig. 10).
The CO values in an air-free condition must be below
400 ppm or 0.04 vol. %. Values of 400 ppm and up
indicate that the burner adjustment may be wrong, the gas
burner fitting or the heat exchanger are dirty or that there
may be burner faults.
BYou must establish and resolve the cause.
The boiler must be operational when you do this.
Fig. 10 Flue gas sampling point
3.6 Lighting Instructions
For your safety, read before lighting.
AThis boiler is equipped with an ignition device which
automatically lights the pilot. Do not try to light the pilot by
hand.
BCheck for smell of gas around the boiler area. Be sure
to smell next to the floor because some gas is heavier than
air and will settle on the floor.
CDo not use this boiler if any part has been under water.
Immediately call a qualified service technician to inspect
the boiler and to replace any part of the control system
and any gas control which has been under water.
WARNING:
due to not follow these instructions.
BIf you do not follow these instructions
exactly, a fire or explosion may result
causing property damage, personal injury
or loss of life.
BFollow these operating instructions.
72150100-009.1TD
DANGER:
What to do if you smell gas:
BNo open fire! Do not smoke!
BAvoid formation of sparks! Do not touch
any electric switch, phone, electric plug or
bell!
BShut off main gas supply.
BOpen windows and doors!
BNotify all occupants!
BLeave the building!
BImmediately call your gas supplier, heating
contractor or fire department from a
phone outside the building!

4Operating Instructions
Logamax plus GB142-24/30/45/60 – 7215 0100 (2011/11)
10
4 Operating Instructions
Start up the boiler
STOP
Read the safety precautions on page 9 of this manual.
BWait 5 minutes to clear out any gas. Then smell for gas,
including near the floor. If you smell gas, STOP!
Follow "B" in the safety information on page 9.
If you do not smell gas, go to the next step.
BFit the casing again.
BOpen the gas shut-off valve.
BSet the thermostat or other operation control to desired
setting.
BConnect the heating system to the power supply.
BSwitch on the heating system using the main switch
(Æfig. 11).
Fig. 11
Reset
01
140
130
120
90
100
110
Aut
0
Eco
190
170
150
130
90
110
Aut
0
72150100-010.1TD
12

Logamax plus GB142-24/30/45/60 – 7215 0100 (2011/11) 11
Notes

721.501A 0006
United States and Canada
Bosch Thermotechnology Corp.
50 Wentworth Avenue
Londonderry, NH 0 05
Tel. [phone]
Fax [phone]
www.buderus.us
U.S.A.
Products manufactured by
Bosch Thermotechnik GmbH
Sophienstrasse 0- 2
D- 5576 Wetzlar
www.buderus.com
Bosch Thermotechnology Corp. reserves the right
to make changes without notice due to continuing
engineering and technological advances.