Oil Furnace Owner Information
506792-01B Page 3 of 6Issue 1216
Upow Units
To replace the lter in an upow unit, refer to the following
directions and Figure 2.
Side Return
To replace the lter in a furnace with an external lter rack
or cabinet on either side of the furnace cabinet:
1. Turn off the power to unit.
2. The lter(s) may be removed by sliding toward the front.
Replace in a reverse procedure.
Bottom Return
To replace the lter in a furnace with a bottom return air:
1. Turn off the power to unit.
2. Remove lower front panel by lifting up and pulling out.
3. The lter(s) may be removed by sliding toward the front.
Replace in a reverse procedure.
Basement Units
To replace the lter in a basement unit (see Figure 3):
1. Turn off power to unit.
2. Remove lower rear panel by lifting up and pulling out.
3. The lter(s) may be removed by sliding out through the
rear of the furnace. To reinsert, place lter on the two
lter supports and slide into unit.
Restore power to the furnace after the door or panel has
been replaced and check furnace for proper operation. If
the unit does not operate, call your dealer for service.
Lubrication
Lubrication of the bearings in the circulating air blower motor
and the combustion blower motor is not recommended.
Side Return
Bottom Return
R/A
Duct
Fi lter Rack
Filter
(slides in from front of unit)
Filter
Base
Side
Panel
Front
Panel
Upow Units: Filter Replacement
Figure 2
Filter
Rear
Of
Furnace
Filter
Supports
Basement Units: Filter Replacement
Figure 3
The unit may contain either a disposable lter or a permanent
lter. The type of lter may be indicated on a label attached
to the lter. If a disposable lter is provided, replace with the
same type and size as the original lter. If a permanent lter
is provided, clean lter and place back in furnace. To clean
a permanent lter, shake lter to remove excess dirt and/
or use a vacuum cleaner. Wash lter in soap or detergent
water and replace after lter is dry.
If your air distribution system has a central return air lter-
grille, you do not need a lter in your furnace. Be sure to
clean the lter-grille as recommended above.
Dirty lters are the most common cause of inadequate
heating or cooling performance. A clogged lter will not
permit adequate airow. This can cause heat exchanger
failure or cooling coil freeze-up along with the accompanying
costly service calls.
The dealer may have changed the filter size, so the
information provided in Table 1 may not apply to your
installation.
Always measure the original lter and replace with the same
size and type.
Table 1
Factory-Supplied Filters
Models BOLHF and BOLHR are not equipped with factory-supplied
lters. The lters for these units are supplied in the eld.
Models Size
BOLUF 16” X 25”
BOLBF, BOLBR (57/72, 84/95) 18” X 19”
BOLBF, BOLBR (112/125) 19” X 21”
BOLBR (140/168) 20-1/8” X 22-7/16
BOLBR (168/196) 24-5/8” X 24-3/8”