Installation guide

INSTALLATION INSTRUCTIONS Gas Furnace: (F/G)9MXT, (F/G)9MXE
24 440 01 4005 05
Specifications subject to change without notice.
when bottom return air is used. To remove bottom closure
panel, see Figure 21 and Figure 20.
HORIZONTAL INSTALLATION
NOTE: The furnace must be pitched forward as shown in
Figure 19 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 27)
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 28) 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 24 Duct Flanges
A10493
UPFLOW DOWNFLOW HORIZONTAL
YES
NO
NO
YES
YES
YES
NO
120°
MIN
YES
120°
MIN
YES
120°
MIN
90°
90°
PERFORATED
DISCHARGE DUCT
FLANGE