Unigas LMV5 Series Manual Of Installation - Use - Maintenance page 46

PART III: OPERATION
Adjusting the combustion head
Attention! if it is necessary to change the head position, repeat the air and fuel adjustments described above.
.The combustion head position affects the flame stability.The diffuser position must be set during the commissioning according to the
regulation needs. The diffuser position is factory set as shown in figure "A" (x = 10 mm). If different settings are required, it is possible
to change the position: loosen the VB screw and slightly move the combustion head backwards, turning clockwise the knob VRT.
Fasten VB screw when the adjustment is accomplished.
The diffuser position must be set during the commissioning according to the regulation needs. The diffuser position is factory set as
shown in figure "A" (x = 10 mm)
Depending on the boiler application, it is possible to act on the holes (figure B) to improve the flame stability and NOx, CO emission
values. If necessary, close/open the holes in figure "B" using the screws kit given with the burner.
VB
VRT
"all-ahead" position
A
B
A
46
"all-backwards" head position
X
x = 10 mm
B