Navien NCB-190/060H Installation & Operation Manual page 52

To connect the gas supply:
1. Determine the gas type and pressure for the
boiler by referring to the rating plate.
2. Perform a pressure test on the main gas supply
line.
3. Purge the gas line of any debris.
4. Determine the proper size and type for the gas
line. Refer to the tables that follow.
Refer to the instructions provided
Note
with the gas regulator for the
minimum pipe distance between the
regulator and the appliance.
5. Install certified full port valves on the gas supply
line and boiler.
6. Connect the gas supply line.
7. Test the supply line, all connection points, and
the boiler for gas leaks.
Tighten the boiler connection valves
Note
with care to avoid damage.
Gas Supply
Gas Inlet Adapter
Bottom View
52 Connecting the Gas Supply
●
●
Note
Gas Shut off
Valve
Union
Pipe size: 1 / "– 3 / "
2 4
(inner diameter)
CAUTION
Install a manual gas shut-off valve between
the gas supply line and the boiler.
A sediment trap must be provided upstream
of the gas controls.
Tighten the boiler connection valves
●
with care to avoid damage.
The gas connection fitting on all
●
boilers is / in.
3
4
/ in rigid pipe can be used; refer to
1
●
2
the sizing tables on the proceeding
pages for limitations. Do not use
corrugated connectors or tubing as
noise may occur.
Corrugated Connector
When using flexible gas lines, ensure
●
that the pipe's inner diameter and
connector is sufficient to supply the
required BTUs. Also, ensure that the
flexible line has no crimps or tight
bends in it, as this will restrict gas flow.
When using rigid pipe, Navien
●
recommends the installation of a
union on the gas supply line close
to the boiler, to facilitate any future
maintenance or service.
Check with the local jurisdiction to
●
verify whether the use of
is approved in the area.
/ in
1
2
/ " gas pipe
1
2