119
Appendixes
WARNING
●
DO NOT adjust or attempt to measure gas
valve outlet pressure. The gas valve is factory-
set for the correct outlet pressure. This setting
is suitable for natural gas and propane,
requiring no field adjustment.
●
Attempting to alter or measure the gas valve
outlet pressure could result in damage to
the valve, causing potential severe personal
injury, death or substantial property damage.
Navien NFB-H boilers are shipped ready to
fire natural gas ONLY.
O-ring
Packing
Gas Orifice
Figure 5. Exploded View of Gas Pipe Assembly
6. Find location B - the connection above the
gas valve where it is attached to the fan motor
assembly. Carefully remove the four screws
using a Phillips-head screwdriver and pull the
gas valve outlet adapter away from the fan
assembly to access the gas orifice.
Location B: Remove
4 screws here
Location A:
Remove the clip
here
Figure 3. Detaching the Gas Valve Outlet Adapter
from the Gas Valve and Fan Motor Assembly
7. Once the Gas Orifice is exposed, remove the two
screws that hold the part in place. Remove the
Gas Orifice from its housing and prepare the
new Gas Orifice for the Propane or High Altitude
conversion for installation.
Remove 2
screws here
Figure 4. Access to Gas Orifice in Fan Assembly
Summary of Contents for NFB-175H
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