Carrier 070-08/024070 Installation, Start-Up, Operating And Service And Maintenance Instructions page 47

9/32"_
V5,16,,
HI
Fig. 58ilgniter PosRion=Top View
A05026
A05025
Fig. 5711gniter PosRion-Side View
quality combustion air, incorrect size or damaged maniR)ld ori-
rice(s), improper gas, or a restricted heat exchanger. Action nmst
be taken to correct the problem.
If it becomes necessary to clean the heat exchangers because of'
dust or corrosion, proceed as Ik}llows:
1. Turn OFF gas and electrical power to furnace.
2. Remove outer access door.
3. Disconnect vent connector l_'om lhrnace vent elbow.
4. For downflow or horizontal lhrnace having an internal vent
pipe, minove internal vent pipe within the casing.
5. Disconnect wires to the lollowing components. Mark wires to
aid in reconnection of (be carelhl when disconnecting wires
l)'om switches because damage may occur):
a. Dral) saleguard switch.
b. Inducer motor.
c. Pressure switch(es).
d. Limit overtemperature switch.
e. Gas valve.
f. Hot surface igniter.
g. Flame-sensing electrode.
b. Flame rollout switches.
6. Remove screws that fasten the collector box assembly to the
cell panel. Be carelhl not to damage the collector box. Inducer
assen-ibly and elbow need not be removed l]'om collector box.
7. Disconnect gas line from gas mani{bld.
8. Remove the 5 screws that attach the burner assembly to the
cell paneh The gas valve and individual burners need not be
ren-ioved from support assembly. Remove NOx bafl'les if
installed.
NOTE: Be very careful when removing burner assembly to avoid
breaking igniter. See Fig. 57 and 58 lot correct igniter location.
9. Using field-provided 25-caliber rille cleaning brush, 36-in.
long, 1/4" diameter steel spring cable, a variable speed,
reversible electric drill, and vacuum cleaner, clean cells as
lbllows:
a. Ren-iove metal screw fitting l_'om wire brush to allow
insertion into cable.
b. Insert the twisted wire end of brush into end of spring
cable, and crimp tight with crimping tool or crimp by
striking with ball-peen hammer. TIGHTNESS 1S VERY
IMPORTANT.
NOTE: The materials needed in item 9 can usually be purchased
at local hardware stores.
47
(l.) Attach variable-speed, reversible drill to the end of
spring cable (end opposite brush).
(2.) Insert brush end oI_cable into the outlet opening of cell
and slowly rotate with drill. DO NOT lorce cable.
Gradually insert cable into upper pass oI_celh (See Fig.
59.)
(3.) Work cable in and out of cell 3 or 4 times to obtain
sul'l]cient cleaning. DO NOT pull cable with great
lorce. Reverse drill and gradually work cable out.
(4.) Insert brush end of cable in burner inlet opening of
cell, and proceed to clean 2 lower passes of_ cell in
same manner as upper pass.
(5.) Repeat loregoing procedures until each cell in lhrnace
has been cleaned.
(6.) Using vacuum cleaner, remove residue from each cell.
(7.) Using vacuuln cleaner with sol_ brush attachment,
clean burner assembly.
(8.) Clean flame sensor with fine steel wool.
(9.) Install NOx baffles (if removed).
(lO.) Reinstall burner assembly. Center burners in cell
openings.
10. Remove old sealant from cell panel and collector box flange.
11. Spray releasing agent on the heat exchanger cell panel where
collector box assembly contacts cell panel.
NOTE: A releasing agent such as cooking spray or equivalent
(must not contain corn or canola oil, aromatic or halogenated
hydrocarbons or inadequate seal may occur) and RTV sealant
(G.E. 162, 6702, or Dow-Corning 738) are needed belore starting
installation. DO NOT substitute any other type of RTV sealant.
G.E. 162 (P771-9003) is available through RCD in 3-oz tubes.
12. Apply new sealant to flange of'collector box and attach to cell
panel using existing screws, making sure all screws are secure.
13. Reconnect wires to the lk)llowing components. (Use connec-
tion diagram on wiring label, if wires were not marked lot
reconnection locations.):
a. Drali saleguard switch.
b. Inducer motor.
c. Pressure switch(es).
d. Limit over-temperature switch.
e. Gas valve.
f. Hot surface igniter.
g. Flame-sensing electrode.
b. Flame rollont switches.
i. Install NOx baflles (if ren-ioved).
14. Reinstall internal vent pipe, if applicable.