Buderus Logano GC 124 II, Logano GC124 II-18, Logano GC124 II-25, Logano GC124 II-32 User Manual

Conversion instructions from
natural gas to propane

Gas boiler

WARNING!

This conversion kit must only be installed by a qua­lified heating contractor as specified by the manuf­acturer’s instructions and the applicable rules and
regulations of the local authorities. If these instruc­tions are not followed exactly, a fire, explosion or
release of carbon monoxide may occur with
serious property damage or loss of life and serious
injury. The heating contractor is liable for correct
conversion of the heating system with this conver­sion kit.

CAUTION!

Before converting the heating system to a different
type of gas the gas line must first be shut off and
then the power to the heating system must be dis­connected.

Note:

Please keep these instructions for future refer­ence.

Logano GC 124 II

In the Commonwealth of Massachusetts this boiler
must be installed by a licensed plumber or gas fit­ter.

6 720 804 435 (2012/09) EN-US

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Contents

Contents

1 Safety considerations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2

1.1 Key to symbols . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2

1.2 Safety instructions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2

2 Product information . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3

2.1 Correct use . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3

2.2 Scope of delivery . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3

3 Conversion to propane . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3

4 Start-up instructions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6

4.1 Starting up boiler . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6

4.1.1 Prepare pressure measurement . . . . . . . . . . . . . . . . . . . 6

4.1.2 Turning on heating system . . . . . . . . . . . . . . . . . . . . . . . . 6

5 Final start-up procedures . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7

1 Safety considerations

1.1 Key to symbols

Warnings

Warnings in this document are identified by a warning
triangle printed against a grey background.
Keywords at the start of a warning indicate the type and
seriousness of the ensuing risk if measures to prevent
the risk are not taken.

The following keywords are defined and can be used in this document:

• NOTE indicates a situation that could result in damage to property or
equipment.

• CAUTION indicates a situation that could result in minor to medium
personal injury.

• WARNING indicates a situation that could result in severe personal
injury or death.

• DANGER indicates a situation that will result in severe injury or death.

Important information

This symbol indicates important information where
there is no risk of personal injury or property damage.

Additional symbols

Symbol Explanation

B Step in an action sequence

Æ Cross-reference to another part of the document

• List entry
– List entry (second level)

Table 1

1.2 Safety instructions

Risk to life through the explosion of volatile gases

B Work on gas components must be carried out by qualified and

authorized personnel only.

Risk to life from electric shock.

B Disconnect the power supply to the heating system before conducting

any work on it, e.g. switch off the heating emergency switch outside
the boiler room.

B It is not sufficient just to switch off the control.

Logano GC 124 II – 6 720 804 435 (2012/09)2

2 Product information

T

2.1 Correct use

This conversion kit and the accompanying instructions are for
conversion of GC124 II special gas-fired boilers from natural gas to
propane.

Requirements

GC124 II–18
74 MBtu/hr

GC124 II-25
103 MBtu/hr

GC124 II-32

132.5 MBtu/hr

Table 2 Requirements

2.2 Scope of delivery

• Honeywell gas solenoid valve conversion kit
# 393 691, comprising:

– black safety screw
– pressure adjustment screw
– red spring
– yellow label for gas valve

• GC124 II: BBR 12 pilot gas orifice

• Main gas orifices and seals

• "Conversion to propane" label (to be filled out and attached to the

unit)

• Technical documents

3 Conversion to propane

For your own safety read the instructions before conversion.

WARNING: Risk to life through not observing the
conversion instructions.

B If you wish to convert the boiler for operation with

propane, the conversion from natural gas to propane
must be carried out first as specified by the attached
conversion instructions.

Fig. 1 Opening boiler front door

WARNING: Danger to life through fire or explosion.

B Never use excessive force on the ON/OFF knob

(Æ figure 2).

B Turn ON/OFF knob only by hand.
B Never use tools to turn knob.
B If you are unable to turn the knob by hand, do not try

to repair it.

B Call Buderus technical service for assistance.

Product information

6 720 804 435-01.1

2

The following instructions must be followed for conversion of the
boiler to propane:

B If the boiler was in operation, close the gas shut-off. Otherwise open

boiler front door.

B Set room thermostat (optional) to the lowest value.
B Disconnect the heating system from the power supply.
B Open boiler front door.

1

6 720 804 435-02.1T

Fig. 2 Gas valve

[1] ON/OFF knob (shown in ON position)

B Turn gas valve ON/OFF knob clockwise to OFF position. Do not use

force.

Logano GC 124 II – 6 720 804 435 (2012/09) 3

3

Conversion to propane

WARNING: Risk to life through the explosion of volatile

gases.
B Wait five (5) minutes until all gas residues have

dissipated. Check whether there is any smell of gas,
including at floor level. If you can smell gas, close the
gas shut-off and disconnect the heating system from
the power supply and contact the customer service
technician or the gas company.

B If there is no sign of a gas odor, continue with the next step.

Removing burner

B Secure gas manifold with wire or cord.
B Remove igniter cable from ignition module (Æ figure 3, [6]).
B Disconnect cable connector from bottom of gas valve

(Æ figure 3, [3]).

B Label cables to the flame roll-out switch, then remove cable

(Æ figure 3, [2]).

5

6

7

8

2

1

6 720 804 435-04.1T

Fig. 4 Removing burner

[1] Screw nuts (two)
[2] Screws on gas manifold on top of gas valve (four)

B Remove four (4) screws from gas manifold on top of gas valve.
B Remove two (2) screw nuts on burner tray and take out the tray.

9

Replacing main gas orifices

B Install the new main gas orifices and copper gasket. Check with

table 3 that the correct orifices for operation of the boiler are
installed.

4

3

Fig. 3 Front view

[1] Flame roll-out switch
[2] Flame roll-out switch cable
[3] Gas valve
[4] Gas supply pipe
[5] Aquastat
[6] Ignition module
[7] Igniter cable
[8] Gas valve cable connector
[9] Pilot line
[10] Igniter cable

1

2

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10

These orifice sizes are exclusively for installations 0­8500 feet above sea level.

Orifice sizes for propane
Model GC124-18 GC124-25 GC124-32
Orifice size 180 175 170
Qty 234

Table 3 Orifice sizes for propane

These values are applicable for the U.S.A. only.
for altitudes of 0 - 8500 ft.

Logano GC 124 II – 6 720 804 435 (2012/09)4