3
S Wire terminal tightness
S Refrigerant charge level
S Evaporator coil cleaning
S Evaporator blower m otor amperage
Heating
S Heat exchanger flue passageways cleanliness
S Gas burner condition
S Gas manifold pressure
S Heating temperature rise
Economizer or Outside Air
Damper
S Inlet filters condition
S Check damper travel (economizer)
S Check gear and dampers for debris and dirt
Air Filters and Scr
eens
Each unit is equipped with return air filters. If the unit has
an economizer, it will also have an outside air screen. If a
manua l outside air damper is added, an inlet air screen
will also be present.
Each of these filters and screens will need to be
periodically replaced or cleaned.
Return Air
Filters
Return air filters are disposable fiberglass media type.
Access to the filters is through the small lift-- out panel
loca ted on the rear side of the unit, above the
evaporator/return air access panel. (See Fig. 1.)
To remove the filters:
1. Grasp the bottom flange of the upper panel.
2. Lift up and swing the bottom out until the panel dis-
engage s and pulls out.
3. Reach inside and extract the filters from the filter
rack.
4. Replace these filters as required with similar replace-
ment filters of same size.
To re--install the access panel:
1. Slide the top of the panel up under the unit top panel.
2. Slide the bottom into the side channels.
3. Push the bottom flange down until it contacts the top
of the lower panel (or economizer top).
IMPORTANT : DO NOT OPERATE THE UNIT
WITHOUT THESE FILTERS!
Outside Air
Hood
Outside air hood inle t screens are permanent
aluminum--mesh type filters. Check these for cleanliness.
Remove the screens when cleaning is required. Clean by
washing with hot low--pressure water and soft detergent
and replace all screens before restarting the unit. Observe
the flow direction arrows on the side of each filter frame.
Economizer Inlet Air Screen
This air screen is retained by spring clips under the top
edge of the hood. (See Fig. 3.)
17 1/4”
DIVIDER
BAROMETRIC
RELIEF
CLEANABLE
ALUMINUM
FILTER
FILTER
HOOD
FILTE
R
CLIP
OUTSIDE
AIR
C06027
Fig. 3 -- Filter Installation
To remove the filter, open the spring clips. Re--install the
filter by placing the frame in its track, then closing the
spring clips.
Manual Outside Air Hood Screen
This inlet screen is secured by a retainer angle across the
top edge of the hood. (See Fig. 4.)
C07156
Fig. 4 -- Screens Installed on Outdoor--Air Hood
(Sizes 7--1/2 to 12--1/2 Tons Shown)
To remove the screen, loosen the screws in the top retainer
and slip the retainer up until the filter can be removed.
580J