9
105605
OWNER’S MANUAL
1.
Frame in rough opening. The firebox
framing should be constructed of 2 x 4
lumber or heavier. Use dimensions in
Table 1 and rough opening layout in
Figure 8a. Adjust framing so that fire-
box flushes with finished wall surface.
If installing in a corner, use dimensions
in Figures 8b and 8c for rough opening.
2.
Install gas piping to firebox location.
See Installing Gas Line on page 11 and
Connecting to Gas Supply in log set
owner’s manual.
IMPORTANT:
If installing blower acces-
sory (Models FB36CB and FB42CA), see
Hard-Wiring Firebox, page 12.
Figure 8 - Rough Opening for Installing in Wall
BUILT-IN FIREBOX
INSTALLATION
Built-in installation of this firebox involves
installing firebox into a framed-in enclo-
sure. This makes the front of firebox flush
with wall. Optional brass trim accessories
are available (see Accessories, page 15). The
brass trim will extend past sides of firebox
approximately 1/2 inch. This will cover the
rough edges of the wall opening. If installing
a mantel above the firebox, you must follow
the clearances shown in Figure 7. Follow the
instructions below to install the firebox in
this manner.
FRONT WIDTH
DEPTH
MODEL #
(Inside to Inside)
HEIGHT
(Minimum)
FB36NCA
41
1
/
4
"
37"
20"
FB36CB
41
1
/
4
"
37"
20"
NLFB36NC
41
1
/
4
"
37"
20"
NLFB36C
41
1
/
4
"
37"
20"
FB42NC
47
1
/
4
"
37"
20"
FB42CA
47
1
/
4
"
37"
20"
ROUGH OPENING DIMENSIONS FOR BUILT-IN INSTALLATION
Depth
(Minimum)
Width
(Inside to Inside)
Height
TABLE 1
Figure 8a
36"
41-1/4"
50-29/32"
72"
45
°
TOP VIEW
FOR 36" MODEL
Height - 37" for F
35 1/2" f
55-5/32"
78"
39"
47-1/4"
45
°
TOP VIEW
FOR 42" MODELS
Height - 37" for FB4
35 1/2" for
Figure 8b
Figure 8c
INSTALLATION
Continued
Mantel Clearances for Built-In
Installation
If placing custom mantel above built-in
firebox, you must meet the minimum allow-
able clearance between mantel shelf and top
of firebox opening shown in Figure 7. These
are the minimum allowable mantel clear-
ances for a safe installation. Use larger clear-
ances wherever possible to minimize the
heating of objects and materials placed on
the mantel.
Figure 7 - Minimum Mantel Clearances for Built-In Installation
CAUTION: Do not allow the
vent-free gas log heater to touch
or extend beyond the fireplace
screen.
If your installation does not meet the above
minimum clearances in Figure 7, you must:
• raise the mantel to an acceptable height,
OR
• remove the mantel.
Continued
FOR 42" MODELS
Height - 37" for FB36NC
35
1
/
2
" for FB36CA
Supplied Firebox
Hood Must Be
Used at All Times
Wire-mesh
Screen
Firebox
Noncombustible
Material May
Project Off this
Surface above
the Firebox Hood
Mantel Shelf
13" 16" 19" 21"
2
1
/2
"
6"
8"
10"
,
,
,
Note: All vertical
measurements are
from top of fireplace
hood opening to bottom
of mantel shelf.
These minimum
clearances replace any
other recommended
clearances supplied with
your ANS Z21.11.2
approved gas logs.
Wall board or facing
material (above
firebox) may be of
combustible material,
including decorative
mantel ornaments or
other similar projec-
tions off of the facing
material.
Framing
Material
FOR 36" MODELS
Height - 37" for FB36NCA
and NLFB36NC
35
1
/
2
" for FB36CB
and NLFB36C