72 Appendices
d. After Gas Setup Wizard is done, operate at minimum
mode.
Note
For operation mode selection, refer to “10.7.3
Setting the Special Operation Modes” on
e. Fully open several hot water fixtures and set the boiler
to operate at DHW maximum mode (refer to “10.7.3
Setting the Special Operation Modes” on page 56).
Measure the CO
2
value at high fire.
If the CO
2
values do not match Table 2 at high fire,
do not adjust the gas valve. Check for the proper Gas
Orifice.
DANGER
Improper gas valve settings can cause severe personal injury
or substantial property damage.
c. Fully open several hot water fixtures and set the boiler
to operate.
Measure the CO
2
value at low fire.
If the CO
2
value is not within 0.5% of the value listed in
Table 2, the gas valve set screw will need to be adjusted.
If adjustment is necessary, locate the set screw as shown
in Figure 8. Using a T15 Hexalobular wrench, turn the
set screw no more than
1
/
4
turn clockwise to raise or
counterclockwise to lower the CO
2
value.
Figure 8. Set Screw Location
Note
The set screw is located behind the screw-on
cover. This must be removed first.
Model
Gas type
G20
G31
[20 mbar]
[37 mbar]
Output
Consumption
Gas flow
Gas flow
Load
Kcal/h
kW
kW
m
3
/h
m
3
/h
NCB300-28K
Max.
20,640
24.0
24.7
2.30
0.993
Min.
3,700
4.2
4.3
0.40
0.173
NCB300-37K
NCB300-41K
Max.
22,360
26.0
26.8
2.490
1.077
Min.
3,870
4.5
4.6
0.430
0.185
Summary of Contents for NCB300-28K
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