21
Setting gas and air flow rate
To perform the adjustments, unscrew the fixing screws and remove the burner cover.
Startup Output
The start-up heat output shall not exceed 120 kW (single stage burners) or 1/3 of nominal output (progressive or fully modulating bur-
ners). In order to comply with these requirements, burners are provided with butterfly valve and/or slow-opening safety valve. On pro-
gressive or modulating burners, the low flame ouptut must be higher than the minimum ouptut quoted in the performance curve
(page 10).
ATTENTION:
before starting the burner up, be sure that the manual cutoff valves are open and check that the pres-
sure upstream the gas train complies the value quoted on paragraph “Technical specifications”. Be sure that the
mains switch is closed.
ATTENTION:
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 gas decrease slowly until the normal combustion values are achieved.
WARNING: NEVER LOOSE THE SEALED SCREWS! OTHERWISE, THE DEVICE WARRANTY WILL BE IMMEDIA-
TELY INVALIDATE!
IMPORTANT! the combustion air excess must be adjusted according to the in the following chart:
Table 1:
Recommended combustion parameters
Fuel
Recommended (%) CO
2
Recommended (%) O
2
Natural gas
9 ÷ 10
3 ÷ 4.8
LPG
11 ÷ 12
2.8 ÷ 4.3
