GMEC96 Installation Manual

17

(Upow / Horizontal models only)
-
izontal left side down installation or a vertical installation
using down – venting, an alternate combustion air opening
can be used. A locating dimple is located on the right side of
the furnace cabinet. The locating dimple is 1 7/8” measured
from the front edge of the cabinet in line with the knock
out. To use the alternate combustion air location:
1. Remove screws and combustion air flange from
cabinet.
2. Insert cabinet plug in unused combustion air hole.
3. Drill a pilot hole at the cabinet dimple (size dictated
by knockout tool used).
4. Use a knockout tool to create a 3” diameter hole
 
removed in step one.
Vent Pipe
Use alternate vent
& combination
air locations
Combustion Air Pipe
Field Supplied
Drain Tee on Vent Pipe
Condensate trapped
to prevent flue gas from escaping
and routed to field supplied
condensate disposal
1/4” per foot min.
slope to furnace
6’ Max.
Floor
B
a
s
e
m
e
n
t
/
C
r
a
w
l
s
p
a
c
e
DOWN VENTING UPFLOW MODEL FURNACES ONLY
All piping and fittings must be joined per material manufacturers specifications
to prevent separation and flue gas leaks.
Figure 12
B
E
SURE
NOT
TO
DAMAGE
INTERNAL
WIRING
OR
OTHER
COMPONENTS
WHEN
REINSTALLING
COUPLING
AND
SCREWS
.
CAUTION

Non-direct vent 
The vent pipe can be run horizontally with an exit through
the side of the building or run vertically with an exit through
the roof of the building. The vent can also be run through
an existing unused chimney; however, it must extend a min-
imum of 12 inches above the top of the chimney. The space
between the vent pipe and the chimney must be closed with a

Although non-direct vent installations do not require a
combustion air intake pipe, a minimum of one 90° elbow
should be attached to the furnace’s combustion air intake
if: an upright installation uses the standard intake location,
or a horizontal installation uses the alternate air intake lo-
cation. This elbow will guard against inadvertent blockage
of the air intake.