Fireplace Preparation; Before Fully Installing The Unit; Vented Application Installation; Nb, Nbsc Models - Monessen Hearth NB18 Installation And Operating Instructions Manual

FIREPLACE PREPARATION

WARNING
Before installing in a solid fuel burning fireplace,
The chimney flue and firebox must be cleaned of
soot, creosote, ashes and loose paint by a qualified
chimney cleaner.
WARNING
This appliance is for installation only in a solid
fuel burning fireplace (masonry fireplace or
manufactured fireplace) with a working flue and
constructed of noncombustible material.
Exception: DO NOT install this appliance in a factory-
built fireplace that includes instructions stating that
it has not been tested or should not be used with
unvented gas logs. This log set may be installed as
a vented log set.

BEFORE FULLY INSTALLING THE UNIT:

•
Turn OFF the gas supply to the fireplace or firebox.
•
Seal any fresh air vents and/or ash clean-out doors
located on the floor or wall of the fireplace. If left
unsealed, drafting may cause pilot outage or soot-
ing. Use a heat resistant sealant. Do not seal the
chimney flue damper.
VENTED APPLICATION INSTALLATIONS —
NB & NBSC ONLY
Manual and millivolt controlled gas logs may be installed as
a vented decorative log set in compliance with ANSI Z21.60
and National Fuel Gas Code, Section 6.6. Since, the gas
logs are operated with the damper open, non-com-
bustible material and minimum mantel requirements
do not apply.
NOTE: The use of a thermostat is prohibited in vented log
applications.
Monessen • NB18/24 Gas Log Set Installation/Owner's Manual • 81D0107 • Rev I • 01/19
12

Before installing the appliance:

•
Turn off gas supply to fireplace or firebox.
•
Have the fireplace floor and chimney professionally
cleaned to remove ashes, soot, creosote or other
obstructions. Have this cleaning performed annually
after installation.
•
Seal any fresh air vents or ash clean-out doors
located on floor or wall of fireplace. If not, drafting
may cause pilot outage or sooting. Use a heat-re-
sistant sealant.
Install and operate the appliance as directed in this
manual.

DAMPER STOP INSTALLATION

A damper stop must be provided with the unit. Contact your
dealer to obtain one. The damper stop must be installed as
shown in Figure 13 to prevent full closure of the fireplace
damper blade and provide a minimum 29 square inch flue
opening.
FP2263
Figure 13 -
FP2263
Damper Stop Installation.
Damper stop install
NB18/NB24 Gas Log Set
Damper Stop
Damper