B − Rear Return Air (Refer to figure 6)
REAR RETURN AIR FILTER BOX INSTALLATION
Duct System
Size and install supply and return air duct system using in-
UNIT
FILTER
ACCESS
PANEL
FOAM TAPE
(Apply to filter box)
FILTER
ACCESS
PANEL
RETURN AIR
FILTER BOX
FOUR FILTERS (Filters may be also installed through top of frame)
Supply Air Plenum
Furnaces installed without a cooling coil require the installa- tion of a removable access panel in the supply air duct. The access panel should be large enough to permit inspection (ei- ther by smoke or reflected light) of the heat exchanger for leaks after installation. The furnace access panel must al- ways be in place when the furnace is operating and it must not allow leaks into the supply air duct system.
In applications requiring air conditioning, see installation instructions provided with
Return Air Plenum
Return air must not be drawn from a room where this furnace, or any other gas appliance (i.e., a water heat- er), is installed. When return air is drawn from a room, a negative pressure is created in the room. If a gas ap- pliance is operating in a room with negative pressure, the flue products can be pulled back down the vent pipe and into the room. This reverse flow of the flue gas may result in incomplete combustion and the formation of carbon
REPOSITION REAR PANEL WITH FLANGES AS SHOWN. (Seal
FIGURE 6
1 − Determine the location of the furnace/filter box. NOTE − Filter box can be installed with right or left side filter access or
2 − Remove the
3 − Apply
4 − Position the filter box over the furnace return air open- ing. The top of the filter box should be in the
tion and the filter box and the furnace edges flush at the sides and bottom.
5 − Fasten using
6 − Install the four filters and the filter access door.
7 − Size the return air plenum to fit the filter box and then seal the joint air tight.
monoxide gas. This toxic gas might then be distributed throughout the house by the furnace duct system.
Size and install return air plenum as indicated in previous section.
Blower Motor / Drive Installation
A − Motor Installation
Refer to figure 7.
1 − Check the box on the rating plate to indicate which of the drive kits are being installed.
2 − Secure the blower motor to the motor base with the hardware provided.
3 − Slide the motor pulley onto the motor shaft and align with the blower pulley.
4 − Install the belt.
5 − Refer to
blower RPM setting and the following section for ad- justing belt tension.
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