Gas Information; Gas Line Connection; Millivolt Valve Controls - Monessen Hearth NBST27NV-B Installation & Owner's Manual

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Gas Information

WARNING
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.
A. Gas Line Connection
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.
Figure 4.1 Gas Connection
WARNING
CHECK GAS TYPE: The gas supply must be the
same as stated on the heater's rating plate. If the
gas supply is different, DO NOT INSTALL THE
HEATER. Contact your dealer for the correct model.
14 Monessen • NBST27-B Gas Log Set Owner's /Installation Manual • 4615-900 Rev. D • 01/2020
WARNING
Connecting directly to an unregulated propane/
LPG tank can cause an explosion.
The heater gas inlet connection is a female 3/8" NPT at
the valve. The inlet connection is on the right side of unit.
To connect from the opposite side, rotate unit 180° or route
the pipe under the rear 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.
B. Millivolt Valve Control
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.