INSTALLATION INSTRUCTIONS
Gas Furnace: N9MSE
440 01 4103 03
23
Specifications subject to change without notice.
Bottom Return Air Inlet
These furnaces are shipped with bottom closure panel installed
in bottom return
−
air opening. Remove and discard this panel
when bottom return air is used. To remove bottom closure
panel, perform the following:
1. Tilt or raise furnace and remove four (4) screws holding
bottom plate. (See
Figure 19
)
2. Remove bottom plate.
3. Remove bottom closure panel.
4. Reinstall bottom plate and screws.
HORIZONTAL INSTALLATION
NOTE
: The furnace must be pitched forward as shown in
Figure 18
for proper condensate drainage.
!
WARNING
FIRE, EXPLOSION, AND CARBON MONOXIDE
POISONING HAZARD
Failure to follow this warning could result in personal
injury, death, or property damage.
Do not install the furnace on its back or hang furnace with
control compartment facing downward. Safety control
operation will be adversely affected. Never connect
return
−
air ducts to the back of the furnace.
!
CAUTION
MINOR PROPERTY HAZARD
Failure to follow this caution may result in minor property
damage.
Local codes may require a drain pan under entire furnace
and condensate trap when a condensing furnace is used
in an attic application or over a finished ceiling.
The furnace can be installed horizontally in an attic or
crawlspace on either the left
−
hand (LH) or right
−
hand (RH)
side. The furnace can be hung from floor joists, rafters or
trusses or installed on a non
−
combustible platform, blocks,
bricks or pad.
Suspended Furnace Support
The furnace may be supported under the entire length of the
furnace with threaded rod and angle iron. (See
Figure 25
)
Secure angle iron to bottom of furnace as shown.
Platform Furnace Support
Construct working platform at location where all required
furnace clearances are met. (See
Table 1
and
Figure 26
) For
furnaces with 1
−
in. (25 mm) clearance requirement on side, set
furnace on non
−
combustible blocks, bricks or angle iron. For
crawlspace installations, if the furnace is not suspended from
the floor joists, the ground underneath furnace must be level
and the furnace set on blocks or bricks.
Figure 25
Suspended Furnace Installation
2
−
in.
(51 mm)
A11155
COMBUSTION
−
AIR PIPE
(SEE VENTING SECTION)
NOTE: Local codes may require a drain pan and condensate trap when a condensing furnace is installed over a finished
ceiling.