Navien NCB300-28K, Service Manual

Page: 22 / 108

System Details 21
4.3 Gas Conversion
This boiler is configured for Natural Gas at the factory. If
conversion to Propane Gas is required, use the conversion kit
supplied with the boiler.
WARNING
This conversion kit must be installed by a qualified service
agency* in accordance with all applicable codes and
requirements of the authority having jurisdiction. The
information in these instructions must be followed to
minimises the risk of fire or explosion or to prevent property
damage or personal injury. The qualified service agency
is responsible for the proper installation of this kit. The
installation is not proper and complete until the operation
of the converted appliance is checked as specified in the
manufacturer’s instructions supplied with the kit.
* A qualified service agency is any individual, firm, corporation or
company which either in person or through a representative is
engaged in and is responsible for the connection, utilization, repair
or servicing of gas utilization equipment or accessories; who is
experienced in such work, familiar with all precautions required, and
has complied with all of the requirements of the authority having
jurisdiction.
Tools Required:
●
Phillips Screwdriver
●
Flathead Screwdriver
●
T15 Hexalobular Wrench
●
Combustion Analyser or Dual Port Manometer
●
Gas Leak Detector
Included Items:
●
Gas Orifice (refer to below table)
Model G20 G31
NCB300-28K Ø5.95 Ø4.75
NCB300-37K Ø6.35 Ø5.05
NCB300-41K Ø6.35 Ø5.05
Table 1. Orifice Size
●
Gas Pressure and Conversion Kit Number Labels
5. Loosen the screws indicated in the figure below and
connect a manometer to the pressure port. Reset the
manometer to zero before use.
Digital pressure
manometer
6. Re-open the manual gas valve and check for leaks.
7. Open multiple fixtures that have high flow rates, such
as bathtub and shower taps, to ramp the boiler up to its
maximum firing rate.
8. When the boiler reaches its maximum firing rate, check
the inlet gas pressure reading on the manometer. The gas
pressure must fall within the ranges specified on page 16.