Setting Equipment - Lennox SL280UHV Installation Instructions Manual

Setting Equipment

WARNING
Do not install the furnace on its front or its back. Do
not connect the return air ducts to the back of the fur-
nace. Doing so will adversely affect the operation of
the safety control devices, which could result in per-
sonal injury or death.
The SL280UHV gas furnace can be installed as shipped
in either the upflow position or the horizontal position.
Select a location that allows for the required clearances
that are listed on the unit nameplate. Also consider gas
supply connections, electrical supply, vent connection,
and installation and service clearances [24 inches (610
mm) at unit front]. The unit must be level.
NOTE − Units with 1/2 hp blower motors are equipped with
three flexible legs and one rigid leg. See figure 6. The rigid
leg is equipped with a shipping bolt and a flat white plastic
washer (rather than the rubber mounting grommet used
with a flexible mounting leg). The bolt and washer must
be removed before the furnace is placed into opera-
tion. After the bolt and washer have been removed, the rig-
id leg will not touch the blower housing.
remove shipping bolt and washer
FIGURE 6
SL280UHV07036A and
SL280UHV09036B WITH 1/2 HP
BLOWER MOTOR
RIGID LEG
Upflow Applications
Allow for clearances to combustible materials as indicated
on the unit nameplate. Minimum clearances for closet or al-
cove installations are shown in figure 7.
Upflow Application Installation Clearances
Left Side
Type of Vent
Connector
Top
*Front
Back
Sides
Vent
Floor
*Front clearance in alcove installation must be 24 in. (610 mm).
Maintain a minimum of 24 in. (610 mm) for front service access.
** 3−1/4 in. if single wall vent pipe is used.
‡For installation on a combustible floor, do not install the furnace
directly on carpeting, tile or other combustible materials other
than wood flooring.
†Left side requires 3 inches if a single wall vent is used on 14−1/2
inch cabinets, or 2 in. if a single wall vent is used on 17−1/2 in. cabi-
nets.
Page 9
Top
Right Side
AIR FLOW
Bottom
Type C Type B1
1 in. (25 mm) 1 in. (25 mm)
2−1/4 in. (57 mm)** 2−1/4 in. (57 mm)
0
0†
6 in. (152 mm) 1 in. (25 mm)
0‡
FIGURE 7
0
0
0‡