Navien NFB Series Installation & Operation Manual page 99

200LP
Figure 6. Orifice Identification
8. Remove the Gas Orifice, ensure that the packing is properly
seated inside the port, and then install the new Gas Orifice for
use with LP gas. Ensure that the Orifice is properly seated on
the packing inside the port before proceeding to the next step.
Packing
9. Replace the gas valve outlet adapter to its original position and
use all screws to secure all connections.
Do not overtighten as this may damage or crack
Note
the components.
10. Set the PCB Dip Switch to change the gas type. For LP, set Dip
Switch 2 #1 to ON. For NG, set DIP SW2 #1 to OFF.
WARNING
Ensure that you have turned off the power to the boiler before
accessing the DIP switches.
O
N
1 2 3 4 5 6
Switch Function Setting
Natural Gas (NG)
1 Gas Type
Propane Gas (LP)
200NG
O
N
1 2 3 4 5 6 7 8
1-OFF
1-ON
DANGER
When conversion is required, be sure to set the PCB DIP
●
switch 2 #1 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.
11. Turn on the gas and water supply to the boiler.
12. 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. Insert the Analyzer
Model Fuel
NG
NFB-175
LP
NG
NFB-200
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
value
2
Appendixes 99