Carrier 58DHL - Manual (Page 8)

The ability to properly perform maintenance on this equip­
ment requires certeun mechanical skUls and tools. If you do
not possess these, contact your Dealer for maintenance.
A WARNING
Turn off gas and electrical supphes to unit before per­
forming any meuntenemce or service on unit. Follow
relighting instructions on label attached to the front of
the furnace. A failure to adhere to this warning can
cause personal injury.
The minimum maintenance that should be performed on
this equipment is as follows:
1. Check and clean or replace air filter each month or as
required.
2. Check blower motor and wheel for cleanliness and lubri­
cation each heating and coohng season. Clean and
lubricate as necessary.
3. Check electrical connections for tightness and controls
for proper operation each heating season. Service as
necessary.
A WARNING
As with any mechanical equipment, personal injury can
result from sharp metal edges, etc.; therefore, be careful
when removing parts.
A. Air Filter
Each furnace accommodates two filters which are installed
in the return-air duct. See Figs. 10 and 11.
To clean or replace the filters, proceed as follows:
1. Disconnect electrical power before removing access
panel.
2. Remove upper access panel.
3. Reach up behind top plate, tUt filters toward center of
retum-air plenum, remove filters, and replace or clean
as needed.
4. Furnaces are equipped with permanent, washable fil­
ters. Clean those filters as follows:
a. Clean with tap water.
b. Rinse and let dry. No oiling or coating of filters is
required.
c. Reinstall filters with cross-hatch binding facing
blower.
B. Blower Motor and Wheel
1. Remove blower access panel.
2. Remove vent pipe enclosure.
3. Disconnect vent pipe and remove short piece of pipe
from furnace.
4. Disconnect wires from auxiliary limit on blower
housing.
NOTE:
For ease of blower removal, it may be necessary to
remove the control box on some sizes.
5. Remove blower assembly from furnace.
6. Remove motor from blower housing.
7. Lubricate motor using good grade of SAE 20 nondeter­
gent motor oil. Put one teaspoon, 5cc, ®/is oz., or 16 to 25
drops in each oil port.
8. Remove blower wheel from housing and clean by using
vacuum with soft brush attachment. Care must be
exercised not to disturb balance weights (chps) on
blower wheel vanes.
A CAUTION
Be sure the motor is properly positioned in the blower
housing. The motor oil ports must be at a minimum of
45° above the horizontal centerline of the motor after
the blower assembly has been reinstalled in the furnace.
Fig. 17—Dual Blower With Left-Hand
Housing and Wheel Removed
9. Reassemble furnace by reversing above procedures.
C. Cleaning Heat Exchanger
If it becomes necessary to clean the heat exchanger because
of carbon deposits, soot, etc., proceed as follows:
NOTE:
Deposits of soot and carbon indicate a problem
exists and needs correcting. Corrective action must be
taken to correct the problem.
1. Turn off gas and power to furnace.
2. Remove control and blower access doors.
3. Remove vent pipe enclosure and disconnect vent pipe
from rehef box.
4. Remove four screws that secure relief box to blower
shelf.
5. Disconnect two wires from safeguard switch.
6. Disconnect wire harness edge connector from side of
inducer control box.
7. Remove eight screws that secure flue collector box to
center panel. Use care not to damage sealant.
8. Remove complete inducer assembly from furnace,
exposing flue openings.
9. Remove flue choke.
10. Using field-provided small wire brush, steel spring
cable, reversible electric drill, and vacuum cleaner;
clean cells.
a. Assemble wire brush and steel spring cable.
(1.) Use 4 feet of V
4
-in. diameter high-grade steel
spring cable (commonly known as drain
cleanout or Roto-Rooter cable).
(2.) Use Vi-in. diameter wire brush (commonly known
as 25-caliber rifle cleaning brush).
NOTE:
The items called for in steps 1 and 2 can be pur­
chased at a local hardware store.
(3.) Insert twisted wire end of brush into end of
spring cable, and crimp tight with crimping tool
or strike with ball-peen hammer. Tightness is
very important.