6.4.4
Checking the air and gas pressure on the
combustion head
Connect pressure gauge to the relevant socket as shown in Fig. 30.
After checking the gas pressure, remember to
close the small bleed screw located on the plug.
DANGER
6.5
Final calibration of the pressure switches
6.5.1
Maximum gas pressure switch
Adjust the maximum gas pressure switch after performing all oth-
er burner adjustments with the maximum gas pressure switch set
to the end of the scale (Fig. 31).
With the burner operating at maximum output, lower adjustment
pressure by slowly turning the relative knob anticlockwise until
the burner locks out.
Turn the knob clockwise by 2 mbar and repeat the start-up of the
burner.
If the burner locks out again, turn the knob clockwise again by 1 mbar.
6.5.2
Minimum gas pressure switch
Adjust the minimum gas pressure switch after performing all the
other burner adjustments with the pressure switch set to the start
of the scale (Fig. 32).
With the burner operating at maximum output, increase adjust-
ment pressure by slowly turning the relative knob clockwise until
the burner locks out.
Then turn the knob anticlockwise by 2 mbar and repeat burner
start-up to ensure it is uniform.
If the burner locks out again, turn the knob anticlockwise again by
1 mbar.
20040563
Start-up, calibration and operation of the burner
+
_
Gas pressure
D8155
28
GB
+
Air pressure
_
D3856
D3855
Fig. 30
Fig. 31
Fig. 32