Navien NHB-055 Service Manual page 28

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. Set the Front Panel DIP Switch to change the gas type. For LP,
set DIP Switch 2 #2 to ON. For NG, set DIP Switch 2 #2 to OFF.
WARNING
Ensure that you have turne d off the power to the boiler before
accessing the DIP switches.
ON
1 2 3 4
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.
28 NHB Service Manual
ON
5 6 7 8 9 10 1 2
NG LP
ON ON
2 2
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 9.
b. Insert the analyzer into the port (Figure 9).
Figure 9 Insert the Analyzer
Model Fuel
NG
NHB-055
LP
NG
NHB-080
LP
NG
NHB-110
LP
NG
NHB-150
LP
Table 2. CO
values must be within 0.5% of the values listed.)
(CO
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
8.9 9.5
10.2 10.8
value
2
Version 1.0