Navien NCB500-2S/37K, Руководство по обслуживанию

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System Details 23
d. After Gas Setup Wizard is done, operate at minimum
mode.
Note
For operation mode selection, refer to “4.4.8.5
Setting the Special Operation Modes” on
page 37.
e. Fully open several hot water fixtures and set the boiler
to operate at DHW maximum mode (refer to “4.4.8.5
Setting the Special Operation Modes” on page 37).
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, and proceed Gas Setup Wizard.
Note
For proceeding Gas Setup Wizard for gas type
selection, refer to “4.4.4 Start-Up Wizard” on
page 26.
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
NCB500-2S/37K
NCB500-2S+/41K
Max. 22,360 26.0 26.8 2.870 0.273
Min. 3,870 4.5 4.6 1.944 0.185