Gas Line Connection; Millivolt - Vermont Castings NBST27 Installation Instructions Manual

NBST27 Unvented Gas Log Set
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 sulfide 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 flow 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 12
NOTICE: A qualified gas appliance installer must connect
the heater to the gas supply. Consult all local codes.
IMPORTANT: Hold heater valve firmly 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.
Stainless Flex-
ible Tube, Pipe
or Metal Tube
To
Heater Valve
Pipe Coupling
Manual Shut-off Valve
Figure 12 -
Gas Connection
FP2371
CHECk GAS TYPE: The gas supply must
be the same as stated on the heater's rat-
gas connect
ing plate. If the gas supply is different, DO
NOT INSTALL THE HEATER. Contact your
dealer for the correct model.
Connecting directly to an unregulated pro-
pane/LPG tank can cause an explosion.
12
Pipe
Possible Locations
for Pressure Tap-
ping Point
Gas
Supply
Inlet
FP2371
The heater gas inlet connection is a female 3/8" NPT at
the valve. The inlet connection is on the right side of unit
when facing the control. To connect from the opposite side,
rotate unit 180° or route the pipe under the rear portion of
the unit.
When tightening the joint to the valve, hold the valve
securely to prevent movement.
Test all gas connection 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.
MILLI-VOLT VALVE CONTROL
Figure 13
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 firmly to re-seal. Do not over torque. Check for gas
leaks.
Repeat process for "IN" port. Check "IN" port with unit set
on high with any other gas appliances in the house on or
cycling on. Pressure gauge readings should match max/min
requirements on data plate.
Test Port "OUT"
Figure 13 -
Pressure Test Point Location Millivolt Control
FP2372
millivolt valve

GAS LINE CONNECTION

FP2372
81D3032