118 Appendixes
Figure 1. NFB-H Series Front cover
3. Remove the front cover and place it in a safe
location to prevent accidental damage.
4. With the internal components exposed, locate
the gas inlet pipe and the gas valve, as shown in
Gas Valve
Gas Inlet
Pipe
Figure 2. NFB-H Series Internal Components
5. Remove the clip at location A – the connection
above the gas valve where it connects to the gas
valve outlet adapter. See Figure 3 for reference.
Included Items:
●
Gas Orifice (Table 1)
●
Gas Pressure and Conversion Kit Number Labels
NFB-175H, NFB-200H Orifice Identification
Gas
Type
Natural Gas
Propane
Gas
Altitude
0-
5,399 ft
5,400-
10,100 ft
0-
10,100 ft
Orifice
GAS : NG
20052127A
4.8 / 7.90
GAS : NG(H)
20052133A
5.05 / 8.4
GAS : LP
20052143A
3.90 / 6.00
Factory
installed
For high
altitude
For
Propane
Orifice
Size
Ø4.8/Ø7.90 Ø5.05/Ø8.4 Ø3.90/Ø6.00
Table 1. Orifice Size
WARNING
●
Be careful not to confuse the PROPANE
CONVERSION KIT and HIGH ALTITUDE
CONVERSION KIT. Do NOT use the HIGH
ALTITUDE CONVERSION KIT for NG when
converting to Propane gas.
●
Make sure that the conversion is completed
with the proper orifice. If the installed orifice
does not conform to the specifications in
Table 1, incomplete combustion may occur,
resulting in personal injury or property
damage.
Procedure:
Note
The procedure below can be applied
to both Propane conversion and High
Altitude conversion. Distinguish the kit
supplied with the boiler before installing.
1. Turn off both gas and water supply to the boiler.
2. Unfasten the 4 latches (2 at the top and 2 at the
bottom) to remove the front cover and gain
access to the internal components. See Figure 1
for illustration of the front cover clamps.
Summary of Contents for NFB-175H
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