Navien NCB-180 Service Manual page 32

14. Place the PCB assembly back on to the boiler and tighten
the three screws.
15. Check the labels carefully and then connect all the wires.
16. For LP, set DIP SW2 #2 to On. For NG, set DIP SW2 #3 to Off.
WARNING
Ensure that you have turned off the power to the boiler
before accessing the DIP switches.
DANGER
 When conversion is required, be sure to set the Front
Panel DIP switches according to the supply gas type.
 Failure to properly set the DIP switches could cause
carbon monoxide poisoning, resulting in severe
personal injury or death.
17. Turn on the gas and water supply to the boiler.
18. Measure and adjust the gas/air ratio.
Option 1. Using Combustion Analyzer (recommended)
a. Loosen the screw, rotate the plate and remove the
gasket to access the emissions monitoring port as
shown in Figure 7.
b. Insert the analyzer into the port (Figure 7).
Figure 7
Boiler Fuel
NG
NCB-180
LP
NG
NCB-210
LP
NG
NCB-240
LP
Table 2. CO
(CO values must be within 0.5% of the values listed.)
2
High fire Low fire
%CO %CO
2 2
8.9 9.5
10.2 10.8
8.9 9.5
10.2 10.8
8.9 9.5
10.2 10.8
and CO value
2