Unigas G335A Installation Manual page 31

AIR FLOW AND FUEL ADJUSTMENT
WARNING! During commissioning operations, do not let the burner operate with insufficient air flow (danger of
formation of carbon monoxide); if this should happen, make the fuel decrease slowly until the normal combustion
values are achieved.
WARNING! the combustion air excess must be adjusted according to the values in the following chart.
Adjustments - brief description
The air and fuel rates adjustments must be performed at the maximum ouptput first ("high flame"): see the LMV related manual.

Check that the combustion parameters are in the suggested limits.

Check the flow rate measuring it on the counter or, if it was not possible, verifying the combustion head pressure by means of a dif-

ferential pressure gauge, as described on par. "Measuring the gas pressure in the combustion head".
Then, adjust the combustion values by setting the "gas/air" ratio" curvepoints (see the LMV related manual).

Set, now, the low flame output (according to the procedure described on the "Siemens LMV manual") in order to avoid the low

flame output increasing too much or that the flues temperature gets too low to cause condensation in the chimney.
Recommended combustion parameters
Recommended (%) CO
Fuel
Natural gas
Light oil
LPG
Recommended (%) O
2
9 ÷ 10
11.5 ÷ 13
11 ÷ 12
31
PART III: OPERATION
2
3 ÷ 4.8
2.9 ÷ 4.9
2.8 ÷ 4.3