Weil-McLain FLAME GUARDIAN WMBC-1A Control Supplement page 9

IV
10
LGB
(Series 2) — Control Supplement
Start-up
Turn off electrical power supply and gas supply to boiler before making the following connections
and adjustment. Failure to do so can cause severe personal injury, death or substantial property
damage.
1. Disable high fire by disconnecting the blue wire in the two-stage gas valve.
2. Connect manometer to gas manifold (manometer must be capable of measuring 0" to 14"
W.C.).
3. Turn on electrical power supply and gas supply to boiler.
4. Fire boiler, which will light off and remain on low fire.
5. While reading manometer, turn low fire adjustment screw clockwise (Figure 5) until pressure
reading is 1.2" W.C.
6. Turn off boiler.
Turn off electrical power supply and gas supply to boiler before the following steps. Failure to
do so can cause severe personal injury, death or substantial property damage.
7. Remove manometer from manifold and plug the tapping.
8. Reconnect the blue wire in the two-stage gas valve junction box.
9. Turn on electrical power supply and gas supply to boiler.
10. Follow operating instructions label on boiler to set boiler in operation.
Figure 8
Low fire adjustment
Low Fire Adjustment
Part Number 550-141-807/0298