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NB18/NB24 Gas Log Set
Monessen • NB18/24 Gas Log Set Installation/Owner's Manual • 81D0107 • Rev E • 04/18
CLEARANCES AND HEIGHT REQUIREMENTS
Sidewall and ceiling clearances:
The
sides
of the fire-
place opening must be
at least 16"
from any combustible
wall. The
ceiling
must be
at least 42"
from the top of the
fireplace opening.
Heat resistant material (minimum requirements) with
no wooden mantel or other combustible projection:
To install the gas logs into a fireplace with no wooden
mantel, shelf or other combustible projection above the
fireplace opening, measure the heat resistant material
height,
according to Figure 4 and
TABLE A
.
Heat resistant materials such as slate and marble must
be
at least 1/2" thick. Sheet metal should not be installed
onto combustible material.
IMPORTANT:
If you cannot meet these minimum clear-
ances you must operate the heater with chimney flue
damper open. Refer to “Installing Vented Applications”
found on page 17.
FP2254
measure heat resist
Heat resistant
Material
Measure
This
Distance
Heater in
Fireplace/
Firebox
FP2254
Figure 4 -
Measure Heat Resistant Material
Table A — Heat Resistant Material Requirements with No Mantel or Combustible Projection
Heat Resistant Material
Measurement
Requirements for Safe Installation
NB18
NB24
12" or more
Hood not required
Hood not required
8" or less than 12"
Hood not required
Extend heat resistant material to 12" or install hood.
Figure 4
Less than 8"
Extend heat resistant
Extend heat resistant material to 8" AND install hood
Figure 5
.
OR
Extend heat resistant material to a height of at least 12".
16"
42"
Figure 3 -
Sidewall and Ceiling Clearances
FP2253
The dimensions shown in
Figures 3 through 11
and
defined in the fireplace manufacturer's instructions
are minimum clearances to maintain when installing
this heater. Left and right clearances are determined
when facing the front of the heater.
When heater is installed into a ventless firebox,
minimum clearances, as specified by the ventless
firebox manufacturer, must be met.
Follow these instructions carefully to ensure safe
installation. Failure to follow instructions exactly
can create a fire hazard.
WARNING
Summary of Contents for BC18-R
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