Navien NPE Installation & Operation Manual page 74

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.
10. Turn on the gas and water supply to the water heater.
11. 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).
74 Appendixes
ON ON
1 2 3 4 5 6 7 8 9 10 1
NG LP
1 2 1
Figure 7
Water
Heater
2
NPE-150S
NPE-180A
NPE-180S
2
NPE-210A
NPE-210S
NPE-240A
NPE-240S
(CO values must be within 0.5% of the values listed.)
2
c. Fully open several hot water fixtures and set the
water heater to operate at 1-stage MIN mode (refer to
page 64). Measure the CO
If the CO
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
the set screw no more than
counterclockwise to lower the CO
Note
High fire
Fuel
%CO
2
NG 8.9
LP 10.2
NG 8.9
LP 10.2
NG 8.9
LP 10.2
NG 8.9
LP 10.2
Table 2. CO and CO value
2
value at low fire.
2
value is not within 0.5% of the value listed in
2
5 / in or 4 mm Allen wrench, turn
32
1
/ turn clockwise to raise or
4
value.
2
Figure 8. Set Screw Location
The set screw is located behind the screw-on
cover. This must be removed first.
Low fire
%CO
2
9.5
10.8
9.5
10.8
9.5
10.8
9.5
10.8