Navien NCB300-28K, Installation & Operation Manual

Page: 33 / 82

32 Connecting the Gas Supply
5.1 Gas Pipe Material
WARNING
The boiler must be left running for 10 minutes before
checking the gas pressure, to obtain thermal equilibrium.
The gas installation pipes must be made of suitable materials
and comply with the applicable legislation to this respect.
The gas connection must be made using a rigid pipe, inserting a
shut-off valve between the boiler and the pressure regulator.
All the pipes must be suitably fixed in place.
5.2 Propane Gas Installations (LPG)
DANGER
●
Thoroughly check the seal and the drainage of the entire
installation, as a gas leak could cause serious damage.
●
If a propane-fired boiler is installed in an interior room
or compartment underground, one side of the building
must be open to the exterior.
●
If a gas tank is used, it must be installed in a cool,
shaded place away from direct sunlight. It must also
be thoroughly secured to prevent it from tipping over,
which could cause an explosion.
If the boiler is used with propane, a gas regulator suitable for this
type of gas must be installed. The connection and installation
must be made in accordance with the applicable regulations
and standards at the time of installation.
Note
The output pressure of the pressure regulator must be
in accordance with Standard EN 437.
5.3 Measuring the Inlet Gas Pressure
WARNING
The boiler cannot function properly without sufficient inlet
gas pressure. Measuring the inlet gas pressure should be
performed by a licensed professional only.
Natural Gas Connection
●
The gas supply must comply to the current Gas Safety
(Installation and Use) Regulations, in accordance with BS 6891.
●
The nominal inlet working gas pressure measured at the
appliance should be 21 mbar +/- 2 mbar for Natural gas (G20).
Allowing for the acceptable pressure loss of 1 mbar across
the installation pipework, it can be assumed that a minimum
permitted operating pressure of 18 mbar will be delivered
to the inlet of the appliance. (Reference BS 6400-1 Clause 6.2
Pressure Absorption).
●
When tested at the gas valve, the pressure drop from the
meter to the gas valve must not be more than 3 mbar.
Propane Gas Connection (LPG)
●
For use with propane gas, the LPG conversion kit has to be
installed, see separate conversion instructions.
●
The LPG installation must comply to the current Gas Safety
(Installation and Use) Regulations, in accordance with BS 6891.
●
Installing of a LPG installation should only be done by a
registered LPG installer.
●
The tank must be provided with a high pressure regulator with
a minimum capacity of 24 kg/h to reduce the tank pressure
from 5 to 1.5 bar. The 1.5 bar high pressure gas line should
have a minimum diameter of 15 mm. In the high pressure gas
line a house pressure regulator must be installed.
●
When tested at the gas valve, the pressure drop from the
pressure regulator to the gas valve must not be more than
2 mbar.
●
Each gas appliance which is connected to the propane
installation must be provided with its own house pressure
regulator. The house pressure regulator is a third party part.
The house pressure regulator must have a minimum capacity
of 10 kg/h/37 mbar and a CE certification.