Setting Equipment - Lennox SL280UHNV 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 furnace.
Doing so will adversely affect the operation of the safety
control devices, which could result in personal injury or
death.
The SL280UHNV 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 7.
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 operation. After the bolt and washer have
been removed, the rigid leg will not touch the blower
housing.
MODELS WITH 1/2 HP
remove shipping bolt and washer
FIgURE 7
BLOWER MOTOR
RIGID LEG
Upflow Applications
Allow for clearances to combustible materials as indicated
on the unit nameplate. Minimum clearances for closet or
alcove installations are shown in Figure 8.
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
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)
1 in. (25 mm) 1 in. (25 mm)
1 in. (25 mm) 1 in. (25 mm)
6 in. (152 mm) 1 in. (25 mm)
0‡
FIgURE 8
0‡