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The modification must be performed by the qualified gas installer only, according
to the technical data, by replacement of the nozzle in the main burner and
adjustment of the nozzle in the ignition burner.
Replacement of the nozzle in the main burner (fig. 10)
Fig. 10
a) Remove the burner ring (1) .
b) Unscrew the fixing bolt (2) which holds the
burner and is accessible from below.
c) Dismantle a complete air mixing chamber (3)
by turning it counterclockwise.
d) Release the main burner nozzle from the nozzle
bracket (4) and replace it with the nozzle
designed for the relevant type of gas (data
related to the nozzle are shown in the table 3
“Characteristics of burners and nozzles”).
e) Install the removed parts in the reverse order.
Table 3: Characteristics of nozzles and burners
Rated
power
Gas
type
Pressure
(mbar)
Main
burner
nozzle
Ø (mm)
Ignition
burner
nozzle
Ø (mm)
Primary
air
chamber
H (mm)
Secondary
air
chamber
Nozzle
bypass
11.5 kW
G30
-31
28-30/37
1.80
0.20
12
opened
Ø 0.95
50/50
1.60
0.20
12
opened
Ø 0.85
13 kW
G20
20
3.05
adjustable
5
closed
adjustable
G25
20
3.30
adjustable
5
closed
adjustable
25
3.15
adjustable
5
closed
adjustable
Low flame
power
Gas consumption
3.00 kW
G30 0.907 kg/h
G31 0.893 kg/h
G20 1.376 m
3
/h
G20 1.376 m
3
/h
G25 1.600 m
3
/h