Ferroli SIGMA Installation And Servicing Instructions page 26

If inlet working pressure is ok using the test point on the gas valve marked OUT check the burner
pressure. Burner pressures for the required heat output can be obtained from fig. 4 a for natural gas
and fig. 4 b for LPG.
The burner pressure is adjusted by the pressure regulating screw on the gas valve see section 4.01 for detail.
Turn off the boiler and isolate the gas and electricity supplies.
9 emove the sealed compartment cover 4 screw .
10 emove the fan assembly and clean with a soft brush.
11 emove combustion chamber front panel 4 screws lift out ue hood and baf e plate.
1 lide the burner forward disconnect the lead from the spark electrode remove the burner and clean.
1 lean injector.
1 lean the heat exchanger with a suitable soft brush. DO NOT DAMAGE THE
out the combustion chamber.
1 E AMING seals on the room sealed compartment from panel and if necessary replace.
1 e assemble in reverse order.
1 e instate gas and electric supply.
1 ire the boiler and check all gas joint for soundness.
19 e check burner pressure.
0 heck ame picture and all controls for correct operation.
1 heck room sealed cover for leakage.
heck all safety devices for correct operating.
heck the gas rate to the boiler is correct.
If a combustion analyzer is to be used there are
top the lower one is for the ue gases the upper one for incoming air. The boiler should be operated for at
least 10 minutes before carrying out this test.
O/ O ratio should not exceed 0.004 prior to servicing and 0.008 immediately after servicing.
efit cover and leave boiler set to customer requirements.
Sigma
test point on the front of the room sealed cover at the
EA IN ULATION and clean