Carrier 58TMA User Manual
Page 5
g. Flame-sensing electrode.
h. Wiring connectors leading to control.
6. Remove 8 screws that secure flue collector box to center
panel. Be careful not to damage sealant.
7. Remove complete inducer assembly from furnace, exposing
flue openings.
8. Using field-provided small wire brush, steel spring cable,
reversible electric drill, and vacuum cleaner, clean cells as
follows:
a. Assemble wire brush and steel spring cable.
(1.) Use 48 in. of 1/4-in. diameter high-grade steel spring
cable (commonly known as drain clean-out or Roto-
Rooter cable).
(2.) Use 1/4-in. diameter wire brush (commonly known as
25-caliber rifle cleaning brush).
NOTE:
The materials needed in items (1.) and (2.) can usually be
purchased at local hardware stores.
(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 IMPOR-
TANT.
(4.) Remove metal screw fitting from wire brush to allow
insertion into cable.
b. Clean each heat exchanger cell.
(1.) Attach variable-speed, reversible drill to end of spring
cable (end opposite brush).
(2.) Remove cell outlet plates. IMPORTANT: Replace
screws in center panel before cleaning.
(3.) Insert brush end of cable into upper opening of cell
and slowly rotate with drill. DO NOT force cable.
Gradually insert at least 36 in. of cable into 2 upper
passes of cell. (See Fig. 8.)
(4.) Work cable in and out of cell 3 or 4 times to obtain
sufficient cleaning. DO NOT pull cable with great
force. Reverse drill and gradually work cable out.
(5.) Remove burner assembly and cell inlet plates.
NOTE:
Be very careful when removing the burner assembly to
avoid breaking the ignitor. See Fig. 9 for the correct ignitor
location.
(6.) IMPORTANT: Replace screws in center panel and
cells before cleaning.
(7.) Insert brush end of cable in lower opening of cell, and
proceed to clean 2 lower passes of cell in same manner
as 2 upper passes.
(8.) Repeat foregoing procedures until each cell in furnace
has been cleaned.
(9.) Using vacuum cleaner, remove residue from each cell.
(10.) Using vacuum cleaner with soft brush attachment,
clean burner assembly.
(11.) Reinstall cell outlet plates and screws FIRST; then,
reinstall cell inlet plates and burner assembly. Care
must be exercised to center the burners in the cell
openings.
9. After cleaning flue openings, check sealant on flue collector to
ensure that it has not been damaged. If new sealant is needed,
contact your dealer or distributor.
10. Clean and replace flue collector assembly, making sure all 8
screws are secure.
11. Reinstall relief box.
12. Reconnect wires to the following components:
a. Draft safeguard switch.
b. Inducer motor.
c. Pressure switches.
d. Limit overtemperature switch(es).
e. Gas valve.
f. Hot surface ignitor.
g. Flame-sensing electrode.
h. Wiring connectors leading to control.
13. Reconnect vent pipe to relief box. When applicable replace
vent pipe enclosure.
14. Replace blower door only.
15. Turn power and gas to ON.
16. Set thermostat and check furnace for proper operation.
17. Verify blower airflow and speed changes between heating and
cooling.
Fig. 8—Cleaning Heat Exchanger Cell
A91252
Fig. 9—Position of Ignitor to Burner
A93347
BURNER
IGNITOR
11 32
"
7 8
"
C
L
C
L
IGNITOR
ASSEMBLY
CELL
PANEL
BURNER
13 32
"
HOT
SURFACE
IGNITOR
ASSEMBLY
5