4. Connect supply- and return-air ducts.
5. Install 24- X 24-in. sheet metal shield on platform in front of
louvered control panel as shown in Fig. 8.
Step 7—Horizontal Furnace Crawlspace Installation
Do not install the furnace on its back; safety control operation
will be adversely affected. Never connect return-air ducts to
the sides or back of the furnace. Failure to follow this warning
could result in fire, personal injury, or death.
The furnace can be installed horizontally with either the LH or RH
side up. In a crawlspace, the furnace can either be installed on
suitable blocks or pad (see Fig. 9.) or hung from the floor joist.
(See Fig. 10). The furnace can be suspended from each corner by
hanger bolts (4 each 3/8-in. all-thread rod) cut to desired length, 1
X 3/8-in. flat washer, 3/8-in. lockwasher, and 3/8-in. nut. Dimples
are provided for hole locations. (See Fig. 1.)
Since horizontal crawlspace installation is very similar to the attic
installation, refer to Step 6. The installation of a sheet metal shield
in front of the louvered control panel is covered in Step 6. For a
crawlspace installation, this same sheet metal shield must be
installed above the louvered control panel. Extend the sheet metal
shield over the furnace top far enough to cover the gas pipe entry
hole.
Step 8—Filter Arrangement
Never operate unit without a filter or with filter access door
removed. Failure to follow this warning could result in fire,
personal injury, or death.
The 2 factory-supplied filters are shipped in the blower compart-
ment. After the return-air duct has been connected to the furnace,
install the filters in a V-formation inside the return-air plenum. See
Fig. 11 and Table 4 for horizontal applications. Horizontal filter
retainers must be field supplied. See Fig. 12 for downflow
applications.
Step 9—Gas Piping
Gas piping must be installed in accordance with national and local
codes. Refer to the current edition of the NFGC.
Canadian installations must be installed in accordance with NSC-
NGPIC and all authorities having jurisdiction.
Refer to Table 5 for recommended gas pipe sizing. Risers should
be used to connect to the furnace and to the meter.
If a flexible connector is required or allowed by the authority
having jurisdiction, black iron pipe shall be installed at the
gas valve and extend a minimum of 2 in. outside the furnace
casing.
Use the proper length of pipes to avoid stress on the gas
control manifold. Failure to follow this warning could result
in a gas leak, causing fire, explosion, personal injury, or
death.
Connect the gas pipe to the furnace using a backup wrench to
avoid damaging gas controls.
Never purge a gas line into a combustion chamber. Never use
matches, candles, flame, or other sources of ignition to check
for gas leakage. Use a soap-and-water solution to check for
gas leaks. Failure to follow this warning could result in fire,
explosion, personal injury, or death.
Joint compounds (pipe dope) should be applied sparingly and only
to the male threads of the joints. This pipe dope must be resistant
to the action of propane gas.
An accessible manual shutoff valve MUST be installed upstream
of the furnace gas controls and within 72 in. of the furnace. A
1/8-in. NPT plugged tapping, accessible for test gage connection,
MUST be installed immediately upstream of the gas supply
connection to the furnace and downstream of the manual shutoff
valve. Place a ground joint union between the gas control manifold
and the manual shutoff.
Install a sediment trap in the riser leading to the furnace. The trap
can be installed by connecting a tee to the riser leading from the
furnace. Connect a capped nipple into the lower end of the tee. The
capped nipple should extend below the level of the gas controls.
(See Fig. 13.)
Piping should be pressure tested in accordance with local and
national plumbing and gas codes before the furnace has been
attached. If the pressure exceeds 0.5 psig (14-in. wc), the gas
supply pipe must be disconnected from the furnace and capped
before the pressure test. If the test pressure is equal to or less than
0.5 psig (14-in. wc), turn off electric shutoff switch located on the
gas valve before the test. It is recommended that the ground joint
union be loosened before pressure testing.
After all connections have been made, purge the lines and check
for gas leakage with regulated gas supply pressure.
A93043
FRONT
BACK
FRONT
B
A
C
K
Fig. 9—Horizontal Installation on Blocks
A95235
9
