8
441 01 2613 06
Specifications are subject to change without notice.
Typical Upflow Installation
Figure 3
25
−
23
−
17
VENT
SUPPLY
AIR
GAS SUPPLY
RETURN
AIR
Horizontal
If you purchased a multi
−
position furnace, it can be installed
horizontally in an attic, basement, crawl space, alcove, or
suspended from a ceiling in a basement or utility room in either a
right or left airflow position. (see
Figure 4
)
Horizontally installed furnaces may be vented out the top of the
unit or out the side facing up. See “
Side venting”
for instructions to
rotate the vent to the side.
The minimum clearances to combustibles
MUST
be maintained
between the furnace and adjacent construction, as shown in
Figure 1
and
Figure 2
.
ONLY
the corner of the cabinet is allowed
to contact the rafters as shown in
Figure 4
. All other clearances
MUST
be observed as shown in
Figure 1
and
Figure 2.
Typical Horizontal Installation
Figure 4
VENT
VENT
GAS SUPPLY
SUPPLY
AIR
RETURN
AIR
25-23-18a
OPTIONAL
VENT LOCATION
If the furnace is to be suspended from the floor joists in a basement
or crawl space or the rafters in an attic, it is necessary to use steel
pipe straps or an angle iron frame to attach the furnace. These
straps should be attached to the furnace bottom side with sheet
metal screws and to the rafters or joists with bolts. The preferred
method is to use an angle iron frame bolted to the rafters or joists.
If the furnace is to be installed at ground level in a crawl space,
consult local codes. A concrete pad 1
″
to 2
″
(25.4 to 50.8mm) thick
is recommended.
24
″
(609.6mm) is required between the front of the furnace and
adjacent construction or other appliances. This should be
maintained for service clearance.
Keep all insulating materials clear from louvered door. Insulating
materials may be combustible.
The horizontal furnaces may be installed directly on combustible
wood flooring or supports, however, it is recommended for further
fire protection cement board or sheet metal is placed between the
furnace and the combustible wood floor and extend 12
″
(304.8mm) beyond the front of the furnace louver door. (This is a
recommendation only, not a requirement).
This furnace
MUST
NOT
be installed directly on carpeting, tile or
other combustible material other than wood flooring or supports.
Downflow
FIRE HAZARD
Failure to follow this warning could result in personal
injury, death and/or property damage.
Place furnace on noncombustible subbase on
downflow applications, unless installing on
noncombustible flooring.
!
WARNING
If you purchased a Multi
−
position furnace (N8MP or *8MP) it may
be installed in a downflow configuration, (see
Figure 5
)
.
The
minimum clearances to combustible material
MUST
be
maintained between the furnace and adjacent construction, as
shown in
Figure 1
and
Figure 2
.
In addition to clearances in
Figure 1
and
Figure 2
, clearance for
the vent pipe must be considered.
A subbase for combustible floors
MUST
be used when the furnace
is installed as a downflow on combustible material. See “
Ductwork
and Filter”
(Downflow Section). The outlet flange must be bent flat
for downflow installation.
When installing a four
−
position furnace in the downflow position
(not the *8DNL furnace), the logo is to be repositioned so that it is
rightside
−
up as follows:
T8MPN/L
1. Find the door hardware kit that is stored in the furnace and
save it.
2. Carefully remove logo from the outside of burner compartment
door and save it.
3. Carefully remove two small plug buttons from outside of
blower compartment door and save them.
4. Remove two thumbscrews from blower compartment door .
5. Install two thumbscrews in holes at other end of blower
compartment door from where thumbscrews were removed.
6. Install new strip of rubber gasket on inside of blower
compartment door on edge that does not already have a
gasket.
7. Install logo retainer pins into holes in blower compartment door
from which plug buttons were removed.
8. Install plug buttons into holes in burner compartment door from
which logo was removed.
9. Install blower compartment door on furnace with bevel edge
and logo at top.
10. Install burner compartment door on furnace with bevel edge at
bottom.
N8MPN/L, C8MPN/L, H8MPN/L
1. Carefully remove logo from burner compartment door and
save it.
