19
Installation
I
NSTALLATION
U
SING
A B
LOCK
-O
FF
P
LATE
F
OR
USA O
NLY
:
If this unit is to be installed into a masonry fi replace or a zero-clearance fi replace with a direct connection
you must install a non-combustible seal-off device such as a block-off plate or damper adapter. By
installing a block-off plate you seal the chimney, ensuring that no smoke enters the home and sealing the
chimney to encourage draft. To construct a block-off plate follow the below steps.
1. Determine where the block-off plate will be installed; above the top of the fi rebox (it must be high
enough to easily install the connection pipe) but below the damper area. Look for a location that
A
B
C
D
Front of fireplace opening.
is level and in an area where the plate can be mounted
easily.
The measurement that will be needed are as followed (refer
to Figure 17 and 18):`
A - The width at the front of the fi rebox at the height where
the block-off plate will be installed.
B - The width at the back of the fi rebox at the height where
the block-off plate will be installed.
C - Then depth of the block-off needed (the distance
between A and B).
D - The distance of the center of the fl ue to the front of the
fi replace opening. Refer to Step 3.
NOTE
: In general masonry fi replaces have square fi reboxes
while zero-clearance (metal) fi replaces have domed fi rebox
tops. Therefore zero-clearance block-off plates may be more
diffi cult to install. Insulation may be used around the edges
to simplify sealing the plate.
2. Create a cardboard template of the dimensions with 2” (51
cm) wide fl anges on each side. These fl anges will be used to
mount the block-off plate to the inside of the fi rebox. Bend
the fl anges downwards on the template and place it inside
the fi replace. Continue on if the template fi ts correctly in
its planned location. If the template does not fi t, make a
new template with the required corrections until it does fi t
correctly.
3. With the template in place, mark the location for the center
of the fl ue pipe when the unit is in place. If installing a
1200 KI the distance will be approximately 8¼” or 9
15
/
16
”
back from the fi replace opening. If installing a 1700 KI the
distance will be approximately 12¾” or 14
7
/
16
” back from
the fi replace opening. Remove the template and cut a 6¼”
diameter hole centered on this mark.
4. Using the template make the block-off plate of 24 gauge or
thicker steel. Drill two (2) holes in each fl ange for mounting
the plate.
Figure 17: 3D of Dimensions needed from
the Fireplace.
Figure 18: Layout of the Block-Off Plate.