Version 1.4
28 NCB-E Service Manual
O-ring
Gas Orifice
Packing
Figure 5. Exploded View of Gas Pipe Assembly
DANGER
See Figure 5. Inspect the O-ring between the gas valve and
gas valve inlet adapter whenever they are disassembled.
The O-ring must be in good condition and must be installed.
Failure to comply will cause a gas leak, resulting in severe
personal injury or death.
240LP
240NG
Figure 6. Orifice Identification
11. 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 LP conversion for
installation.
Remove two
2 screws here
Figure 4. Access to Gas Orifice in Fan Assembly
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 NCB-E boilers are shipped ready to fire natural gas
ONLY.
