125
Appendixes
The DIP SW1 (Set of 6 Switches) on the circuit board
configures the operation status and model settings.
Model
Fuel
High fire
Low fire
%CO
2
%CO
2
NHB-055H
NG
8.9
9.5
LP
10.2
10.8
NHB-080H
NG
8.9
9.5
LP
10.2
10.8
NHB-110H
NG
8.9
9.5
LP
10.2
10.8
NHB-150H
NG
8.9
9.5
LP
10.2
10.8
Table 2. CO
2
value
(CO
2
values must be within 0.5% of the values
listed.)
c. Activate multiple zones and set the boiler to
operate at 1-stage MIN mode.
Note
For operation mode selection,
refer to “11.13.7 Setting the
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
5
/
32
in
or 4 mm Allen 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.
WARNING
To prevent serious injury or death:
●
ALWAYS check the panel DIP SW2 #1 (Set of
8 Switches) is set according to the supply gas
type.
●
For natural gas, only install the gas orifice for
high altitude when the boiler is installed at
above 5,400 ft.
●
Be careful to install the NATURAL GAS HIGH
ALTITUDE CONVERSION KIT and not to
confuse it with the PROPANE GAS & HIGH
ALTITUDE CONVERSION KIT.
●
Failure to properly install the High Altitude
Conversion Kit or to not use the appropriate
Altitude Settings could cause carbon
monoxide poisoning, resulting in serious
injury or death.
15. Turn on the gas and water supply to the boiler.
16. Measure and adjust the gas/air ratio.
Option 1. Using Combustion Analyzer
(recommended)
a. Remove the analyzer port’s cap.
b. Insert the analyzer into the port (Figure 7).
Figure 7. Insert the Analyzer
