Carrier 58DHL - Manual (Page 9)

(4.) Remove metal screw fitting from wire brush to
allow insertion into cable,
b. Clean each heat exchanger ceU.
(1.) Attach variable-speed reversible drill to end of
spring cable (end opposite brush).
(2.) Insert brush end of cable into upper opening of
cell and slowly rotate with drill. Do not force
cable. Gradually insert at least 3 feet of cable
into two upper passes of cell. See Fig. 18.
(3.) Work cable in and out of ceU three or four times
to obtain sufficient cleaning. Do not puU cable
with great force. Reverse drUl and graduaUy
work cable out.
(4.) Remove burner assembly and flame radiators.
(Identify gas valve leads.)
(5.) Insert brush end of cable in lower opening of
ceU, £md proceed to clean two lower passes of
ceU in same manner as two upper passes.
(6.) Repeat the foregoing procedures untU each ceU
in furnace has been deemed.
(7.) Using vacuum cleaner, remove residue from
each ceU.
(8.) Using vacuum cleemer with soft brush attach­
ment, clean burner assembly.
(9.) ReinstaU flame radiators and burner assembly.
Care must be exercised to center the flame radi­
ators in the ceU openings. Refer to furnace wir­
ing diagram when reconnecting gas valve leads.
11. After cleaning flue openings, check sealant on flue col­
lector to ensure that it has not been damaged. If new
sealant is needed, contact your Distributor.
12. ReinstaU flue choke. Be sure aU screws are in place and
tight.
13. Clean and replace flue coUector assembly, making sure
aU eight screws etre secure.
14. Replace four screws that secure the reUef box to blower
shelf.
15. Reconnect two wires to safeguard switch.
16. Reconnect wire harness edge connector to side of
inducer control box.
17. Reconnect vent pipe to relief box, reinstall pipe
enclosure.
18. Replace blower door only.
19. Turn on power and gas.
20. Set thermostat and check furnace for proper operation.
21. Check for gas leaks.
22. Replace control door.
A WARNING
Never use a match or other open flame to check for gas
leaks. Use a soap-and-water solution. A failure to
adhere to this warning can cause a fire, personal injury,
or death.
D. Pilot
Check the pUot and clean if necessary at the beginning of
each heating season. The pUot flame should be high enough
for proper impingement of the safety element and to Ught
the burners. Remove the accumulation of soot emd carbon
from the safety element or sensing probe. See Fig. 19 and
check electrode position.
E. Electrical Controls and Wiring
NOTE:
There may be more than one electrical supply to
unit.
With power disconnected to unit, check aU electrical connec­
tions for tightness. Tighten aU screws on electrical connec­
tions. If any smoky or burned connections are noticed, dis­
assemble the connection, clean aU parts and strip wire, and
reassemble properly and securely. Electrical controls are dif­
ficult to check without proper instrumentation; therefore,
reconnect electrical power to unit and observe unit through
one complete operating cycle. If there are any discrepancies
in the operating cycle, contact your Dealer and request
service.
A79080
Fig. 18—Cleaning Heat Exchanger Cell Fig. 19—Position of Electrode to Pilot