035-19650-001 Rev. C (0404)
4
Unitary Products Group
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Check for dirt or lint on any surfaces or on components. Do not try
to clean any of the surfaces or components. Cleaning of the fur-
nace and its components must be done by a qualified service pro-
fessional.
If, during the inspection of your furnace, you find any of the following
conditions:
•
Excessive amounts of dust and lint on components.
•
Damaged or deteriorated components or surfaces.
•
Leaks or blockage in the vent pipe passages.
•
Water on any surface inside or outside of the furnace.
Do not operate the furnace, call a certified dealer / servicing contractor
to check and / or clean your furnace, or for more information if you have
questions about the operation of your furnace.
If all components appear to be in good operating condition, replace the
front panels. Turn ON the gas and electrical power supplies to the fur-
nace, and set thermostat to the desired temperature.
Air Filters
Dirty filters greatly restrict the flow of air and may cause damage to the
moving parts of the furnace. If the filters become clogged the heat
exchangers and blower motor could overheat resulting in a potentially
dangerous situation. The filters should be checked every 3 months. On
new construction, check the filters every week for the first four weeks
and every three weeks after that, especially if the indoor fan is running
continuously. When replacing the filter(s) you must use filters that are
the same size as those recommended in Table 1. Use the following pro-
cedure to determine the filter size. Never operate your furnace without a
suitable air filter.
1.
Measure the furnace width and use that measurement to deter-
mine the cabinet width.
•
A 14-1/2” wide cabinet is a “A” cabinet.
•
A 17-1/2” wide cabinet is a “B” cabinet.
•
A 21” wide cabinet is a “C” cabinet.
•
A 24-1/2” wide cabinet is a “D” cabinet.
2.
Locate the cabinet size on Table 1 then determine whether you
have a bottom or side return air duct using the following method.
a.
If the return air filter is on the left or right side of the furnace it
is a side return
b.
If the air filter is on the bottom of the furnace then you have a
bottom return.
C.
If the air filters are on the bottom and the side of the furnace
then you have a bottom and side return. You must replace
both air filters. Table 1 will indicate 2 filters by using brackets
with the number two (2).
D.
If the air filters are on both sides of the furnace then you have
a two sided return. You must replace both air filters. Table 1
will indicate 2 filters by using brackets with the number two
(2).
3.
After you determine the cabinet size and what return configuration
you have, look up the recommended filter size from Table 1.
Removing Filters
Internally Mounted Air Filters
Most upflow furnaces have their filters located on the side or bottom of
the furnace in a filter wire retainer located inside the blower compart-
ment. To check filters located in the blower compartment:
1.
Remove the upper furnace door by lifting up. Pull out bottom of
door and lower from furnace.
2.
Remove the blower compartment panel by lifting up.
3.
The filters will be located on the bottom or on one of the sides. To
remove bottom-mounted or side mounted filter (s) on all furnaces,
push the looped end of the filter retainer rod in, and then move the
retainer rod away from the filter.
4.
Reverse the procedure to reinstall filters.
Externally Mounted Air Filters
Some installations may have the air filter in a rack attached to the cas-
ing of the furnace or placed in the return air duct. You can gain access
to the filter by pulling on the door or unscrewing the retaining screw,
then slide the filter(s) out of its channel. Replace throw away filter(s)
with the same size new filter(s). Throw away filter(s) may be replaced
with cleanable filter(s) at this time. Cleanable filter(s) may be cleaned as
described in the manufacturer instructions or as described below and
then re-installed.
To replace the filter after cleaning you must do the following:
1.
Slide filter into place.
2.
Snap the door on or place the door in position and tighten the
retaining screws, if provided.
3.
Make sure the door is secure to the end of the filter rack.
How to Clean your Filter
High-velocity filters may be cleaned with a vacuum cleaner or washed
with a garden hose. Be sure to shake off excess water and allow filter to
completely dry before re-installing the filter.
Blower Care
Even with good filters properly in place, blower wheels and motors will
become dust laden after long months of operation. The entire blower
assembly should be inspected annually. If the motor and wheel are
heavily coated with dust, they can be brushed and cleaned with a vac-
uum cleaner. If the blower cannot be properly cleaned without removing
it from the furnace, then this service must be performed by a qualified
service agency.
FIGURE 6:
Upflow Internal Filter Retainer
TABLE 1:
Filter Sizes
Cabinet Size
Side (in)
Side (cm)
Bottom (in)
Bottom (cm)
B
16 x 25
40.6 x 63.5
14 x 25
35.5 x 63.5
B
16 x 25
40.6 x 63.5
14 x 25
35.5 x 63.5
C
16 x 25
40.6 x 63.5
16 X 25
40.6 X 63.5
C
16 x 25
40.6 x 63.5
16 x 25
40.6 X 63.5
C
(2) 16 x 25
(2) 40.6 x 63.5
20 X 25
50.8 x 63.5
D
(2) 16 x 25
(2) 40.6 x 63.5
20 x 25
50.8 x 63.5
Make sure you DO NOT move the clip on weight on the
indoor fan wheel when cleaning the wheel. This weight is
used to balance the wheel. Moving the weight will cause
the fan wheel to vibrate.
IF FILTER
PROVIDED
POSITION WIRE RETAINER
(IF PROVIDED) UNDER FLANGE
CLIPS
RIGHT SIDE
INSTALLATION
SHOWN
FURNACE
FRONT
