Appendixes 63
c. Fully open a hot water fixture and set the boiler to operate
at 1-stage MIN mode (refer to table 2). Measure the offset
value at low fire and compare it to the values in Table 3. If
the offset value is out of range, the gas valve set screw will
need to be adjusted.
If adjustment is necessary, locate the set screw as shown
in Figure 10. Using a
5
/
32
in or 4mm Allen wrench, turn
the set screw no more than
1
/
4
turn clockwise to raise or
counterclockwise to lower the offset value.
Figure 10. Set Screw Location
Note
The set screw is located behind the screw-on
cover. This must be removed first.
d. At high fire, do not check the offset value and never adjust
the gas valve.
DANGER
Improper gas valve settings can cause severe personal injury,
death or substantial property damage.
17. Once the CO
2
or offset values have been confirmed, apply the
included conversion stickers to show that the appliance has
been converted to propane gas. Place these labels adjacent to
the rating plate as shown in Figure 11.
Orifice Size / Injecteur:
Min. 4.5 mm to Max. 4.8 mm
This unit has been
converted to Propane fuel
Cet appareil a ete converti au Propane
Manifold Gas Pressure /
Pression à la tubulure d’alimentation:
Min. -0.02 to Max. -0.66 inches WC
BTU Input / Debit calorifique:
Max. 180,000 - Min. 19,900 BTUh
Conversion Kit No.:
NAC-02
Inlet Gas Pressure / Pression d'entrée du gaz:
Min. 8.0 to Max. 13.0 inches
with Kit No. ________________________
This boiler was converted on
(name and address of organization making
this conversion, who accepts responsibility
for the correctness of this conversion)
______/______/______ to ____________ gas
by _________________________________
_________________________________
Figure 11. Proper Placement of Gas Conversion Labels
Option 2. Using Digital Manometer
a. Open the offset pressure port by loosening the screw two
turns as shown in Figure 9.
Digital pressure
manometer
Figure 9. Connect Digital Pressure Monometer
b. Connect a manometer to the offset pressure port. For dual
port manometers, use the positive pressure side.
Model
Kit Part No.
Gas Type
Offset
NCB-180
NAC-400
NG
-0.04 in ±0.01 in
NAC-04
LP
-0.03 in ±0.01 in
NCB-210
NAC-500
NG
-0.04 in ±0.01 in
NAC-05
LP
-0.02 in ±0.01 in
NCB-240
NAC-600
NG
-0.04 in ±0.01 in
NAC-06
LP
-0.02 in ±0.01 in
Table 3. Offset value for low fire
