Weil-McLain LGB 6-20 Series - Manual (Page 4)

Part Number 550-141-816/0798 4
LGB-6 to LGB-20 Series 2 – Control Supplement
1. These instructions are for use with Propane Control Cartons as listed in Gas Control
Arrangement, Table 2 (page 2).
2. Remove jacket door(s) and access panel(s).
3. Disconnect wiring and tubing from existing pilot burner and main flame sensor.
4. Remove all burners. Remove 3.95 mm natural gas main burner orifices in manifold. Install
2.40 mm propane gas main burner orifices. Use pipe dope sparingly only on male ends.
Use pipe dope compatible with propane gases. Do not overtighten orifices.
5. Remove and discard existing electronic pilot burner from pilot burner tube. Replace with
electronic pilot burner in carton.
6. Attach Q327 standing pilot to burner tube in kit. Connect pilot tubing and thermocouple
to pilot.
7. Re-install burners. See Table 1 (page 2) for location of pilot burners and flame sensor(s).
8. Attach pilot switch box to jacket. See Figure 6 (page 12). Connect thermocouple to pilot
switch box. Cut 60” pilot tubing into 2 pieces to make connections from tee in pilot line to
pilot switch box and from pilot switch box to standing pilot.
9. Remove natural gas valve train.
10. Install propane gas valve train and fittings from carton (See page 5, section IV, paragraph
4 of this Supplement).
11. Re-install access panel(s).
12. See Figure 6, page 12 for propane piping.
13. Wire per wiring instructions and wiring diagrams, pages 5-9. Add splices as needed.
14. Attach:
a. 550-223-710 label at boiler operating instruction label. Place so that this label reads
first.
b. 550-223-796 label at rating label.
c. Wiring diagram over diagram on door (one on each base).
15. To place in operation, follow instructions on constant burner pilot light-up label and
boiler operating label.
16. Replace jacket doors.
II
Existing installation
Conversion from natural gas to propane gas
1. Install water or steam trim components as required by CSD-1 latest edition. See the boiler
manual for tapping locations.
a. Water boilers require:
• a manual reset high temperature limit control in addition to the standard
automatic reset limit control.
• a manual reset low water cutoff.
b. Steam boilers require:
• a manual reset high pressure limit control in addition to the standard automatic
reset limit control.
• a manual reset low water cutoff in addition to the standard automatic reset low
water cutoff.
III
Water and steam trim compo nents
This conversion is to be installed by a Weil-McLain distributor or other
qualified agency in accordance with the manufacturer’s instructions and all
codes and requirements of the authority having jurisdiction. Failure to
follow instructions could result in serious injury or property damage. The
qualified agency performing this work assumes responsibility for this
conversion.
For your safety, turn off electrical power supply before making any electrical
connections to avoid possible electrical shock hazard.