151B0801 R5 3/28/2006
3
In the up flow position, the heat
exchanger support screw shown in the
picture may be removed. This may be
preferable if the furnace rear panel will
be inaccessible after installation. The
screw must be removed if the heat
exchanger must be removed from the
cabinet. Do not remove this screw if
installing furnace in a horizontal position.
HORIZONTAL INSTALLATION
O4HD
furnaces models are
assembled and shipped ready for
installation in the up-flow position.
The furnace may be installed in
either of the horizontal
positions; warm
air discharging left or warm air-
discharging right by following these
steps:
1. Rotate the furnace 90° to the
desired position.
2. Remove the three nuts fastening the
oil burner assembly to the furnace.
Rotate the oil burner assembly to be
in the normal upright position.
3. Re-align the oil burner assembly to
the combustion chamber (fire-pot),
and then secure into place with the
three nuts.
NON-SUSPENDED INSTALLATION
Maintain clearances to combustibles as
outlined in Table 1. Installation on a
combustible floor requires a clearance of
1 inch. Using a noncombustible material
such as one-inch thick channel iron or
similar material can do this. The furnace
must be supported in such a way as to
not allow twisting or sagging of the
cabinet. Suggestion; as a measure to
prevent fuel oil from accumulating in
locations other than the fire pot, as could
be the case in the event of nozzle drip,
install the furnace with an approximate 2
degree slope from the oil burner casing
towards the fire pot. Use shims made of
noncombustible material.
SUSPENDED INSTALLATION
Refer to Figure 1. Maintain clearances to
combustibles as outlined in Table 1. The
furnace may be suspended by field
fabricating a cradle of angle iron and
threaded rod. Secure the furnace with 2
inch minimum slotted angle or
equivalent, as shown in Figure 1. The
furnace must be supported in such a way
Table 1: Clearance to Combustibles
Furnace
O4HD
Location Upflow
Horizontal
Top
2 in.
2 in.
Bottom
0 in.
1 in.
S/A Plenum
1 in.
1 in.
Rear
1 in.
1 in.
Sides
1 in.
1 in.
Front 9
in.
1
9
in.
1
Flue Pipe
9 in.
9 in.
Enclosure Closet
Alcove
1
24” clearance is required for servicing.
Fig. 1:
Typical Suspended Application
Heat Exchanger Support Screw
