Gas Line Connection; Check Gas Pressure; Millivolt - Monessen Hearth NB18 Installation Instructions Manual

GAS LINE CONNECTION

Use new black iron or steel pipe. Internally
tinned copper or copper tubing can be
used per National Fuel Code, section 2.6.3,
providing gas meets hydrogen sulfi de limits,
and where permitted by local codes. Gas
piping system must be sized to provide
minimum inlet pressure (Listed on Data
Plate) at the maximum fl ow rate (BTU/hr).
Undue pressure loss will occur if the pipe
is too small.
A manual shutoff valve must be installed
upstream of the appliance. Union tee
and plugged 1/8" NPT pressure tapping
point should be installed upstream of the
appliance. Figure 14
NOTICE: A qualifi ed gas appliance installer must connect
the heater to the gas supply. Consult all local codes.
IMPORTANT: Hold heater valve fi rmly with a wrench to
prevent movement when connecting to inlet pipe.
Always use an external regulator for all propane/LPG
heaters and high pressure one to two-pound systems
only, to reduce the supply tank pressure to a maximum of
13" w.c. This is in addition to the internal regulator in the
heater valve.
To Heater
Valve
Stainless
Flexible Tube
Manual Shutoff
Valve
Figure 14 -
Gas Connection
CHECK GAS TYPE: The gas supply must
be the same as stated on the heater's rat-
ing plate. If the gas supply is different, DO
NOT INSTALL THE HEATER. Contact your
dealer for the correct model.
81D0107
Locations
that the
Pipe Coupling
Pressure
Tapping
Point May Be
Pipe
Installed
Gas
Supply
Inlet
FP2265
Connecting directly to an unregulated pro-
pane/LPG tank can cause an explosion.
The heater gas inlet connection is a 3/8" NPT at the valve.
On all control type units, the inlet connection is on the right
side of unit. To connect from the opposite side, route the
pipe around the back portion of the unit.
When tightening up the joint to the valve, hold the valve
securely to prevent movement.
Test all gas joints from the gas meter to the heater valve
for leaks using a gas analyzer or soap and water solution
after completing connection. DO NOT USE AN OPEN
FLAME.
Check the gas pressure with the appliance burning and
the control set to HIGH.
MILLIVOLT VALVE CONTROL
Figure 15
The valve regulator controls the burner pressure which
should be checked at the pressure test point.
Turn captured screw counter clockwise two or three turns
and then place tubing to pressure gauge over test point
(Use test point "OUT" closest to control knob). After taking
pressure reading, be sure and turn captured screw clock-
wise fi rmly to re-seal. Do not over torque. Check for gas
leaks.
Test Port "OUT"
Figure 15 -
Pressure Test Point Location
Millivolt Control
NB18/NB24 Gas Log Set
FP2266
13