9
Monessen • Mojo Installation/Owner’s Manual • 4623-900 Rev. D • 04/21
3
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.. See Figure 3.1.
Non-combustible 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 non-combustible material
height,
according to Figure 3.2 and
TABLE A
.
Non-combustible 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
“
Vented Applications Installations”
found on page 13.
FP2254
measure heat resist
Non-
combustible
Material
Measure
This
Distance
Heater in
Fireplace/
Firebox
Figure 3.2 - Measure Non-Combustible Material
Table A — Non-Combustible Material Requirements with No Mantel or Combustible Projection
Non-Combustible
Material Measurement
Requirements for Safe Installation
MJ22
MJ27
12" or more
Hood not required
Hood not required
8" or less than 12"
Hood not required
Extend non-combustible material to 12" or install hood.
Figure 3.6
Less than 8"
Extend non-
combustible material
to 8” AND install hood.
Figure 3.3
Extend non-combustible material to 8" AND install hood
Figure 3.5
.
OR
Extend non-combustible material to a height of at least 12".
Figure 3.6
42”
16”
Figure 3.1 - Sidewall and Ceiling Clearances
The dimensions shown in
Figures 3.1 through
3.8
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