Unigas HTLX92R Installation Manual page 47

PART III: OPERATION
Adjusting the combustion head
CAUTION: perform these adjustments once the burner is turned off and cooled.
The combustion head position affects the flame stability. The burner is factory-adjusted with the combustion head in its "all-ahead"
position. Laboratory tests have shown that this is the optimal configuration to assure flame stability. 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.
VRT
VB
"all-backwards" head position
"all-ahead" position
Attention! if it is necessary to change the head position, repeat the air and fuel adjustments described above.
X B
x = 10 mm
B
A
A
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.
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