Flushing Collector Box And Drainage System; Servicing Hot Surface Igniter - Carrier 58MVB Service And Maintenance Instructions

→
NOTE: Inspect combustion-air intake housing. If foamed gasket
was removed, check for any damage. If gasket is damaged in any
way, it must be repaired. To repair, remove damaged gasket
section, apply sealant releasing agent such as PAM cooking spray
or equivalent (must not contain corn nor canola oil, halogenated
hydrocarbons nor aromatic content, to prevent inadequate seal
from occurring) to burner box and apply a small bead of G.E. RTV
162, G.E. RTV 6702, or Dow-Corning RTV 738 sealant to edge of
combustion-air intake housing. (See Fig. 9.)
13. Refer to furnace wiring diagram and reconnect wires to flame
rollout switch, gas valve, igniter, and flame sensor.
14. Reconnect pressure switch tubes to gas valve and intake
housing. Refer to tube routing label on main furnace door for
proper tube location. (See Fig. 10.) Be sure tubes are not
kinked.
15. Turn on gas and electrical supplies to furnace.
16. Check furnace operation through 2 complete heat operating
cycles. Look through sight glass in burner enclosure to check
burners. Burner flames should be clear blue, almost transpar-
ent. (See Fig. 11.)
17. Check for gas leaks.
FIRE OR EXPLOSION HAZARD
Failure to follow the safety warnings exactly could result in
serious injury, death or property damage.
Never test for gas leaks with an open flame. Use a commer-
cially available soap solution made specifically for the
detection of leaks to check all connections.
18. Replace main furnace door.
SECONDARY HEAT EXCHANGERS
NOTE: The condensing side (inside) of the secondary heat
exchangers CANNOT be serviced or inspected. A small number of
bottom outlet openings can be inspected by removing the inducer
assembly. See Flushing Collector Box and Drainage System
section for details on removing inducer assembly.
Step 5—Flushing Collector Box and Drainage
System
1. Turn off gas and electrical supplies to furnace.
2. Remove main furnace door.
3. Disconnect inducer motor and pressure switch wires or
connectors.
4. Disconnect pressure switch tubes.
5. Disconnect vent pipe from inducer housing outlet by loosen-
ing coupling clamp on inducer outlet.
RTV
Fig. 9—Combustion-Air Intake Housing Gasket
PAM
Repair
6. Disconnect drain tube from inducer housing. (See Fig. 10.)
NOTE: Ensure the drain tube disconnected from the inducer
housing is higher than the collector box opening or water will flow
out of tube.
7. Remove inducer housing assembly by removing 4 bolts
attaching assembly to cell panel.
8. Flush inside of collector box with water until discharge from
condensate trap is clean and runs freely.
9. Inspect inside area of collector box for any pieces of foreign
materials and remove them if present.
UNIT DAMAGE HAZARD
Failure to follow this caution may result in furnace compo-
nent damage.
DO NOT use wire brush or other sharp object to inspect or
dislodge materials in secondary heat exchangers as cutting of
the secondary heat exchanger protective coating may occur.
Flush with water only.
10. Reassemble inducer assembly by reversing items 5-7. Tighten
the vent coupling clamp screw(s) to 15 in.-lb of torque.
→
NOTE: If seal between the inducer housing and the collector box
is damaged in any way, it must be repaired. To repair, apply
sealant releasing agent such as PAM cooking spray or equivalent
(must not contain corn nor canola oil, halogenated hydrocarbons
nor aromatic content, to prevent inadequate seal from occurring) to
inducer housing. (See Fig. 12.) Apply a small bead of G.E. RTV
162, G.E. RTV 6702, or Dow-Corning RTV 738 sealant to groove
in collector box.
11. Refer to furnace wiring diagram and reconnect wires to
inducer motor and pressure switches or connectors.
12. Reconnect pressure tubes to pressure switches. See diagram
on main furnace door for proper location of tubes. Be sure
tubes are not kinked. (See Fig. 10.)
13. Turn on gas and electrical supplies to furnace.
14. Check furnace operation through 2 complete heat operating
cycles. Check area below inducer housing, vent pipe, and
condensate trap to ensure no condensate leaks occur. If leaks
are found, correct the problem.
15. Check for gas leaks.
FIRE OR EXPLOSION HAZARD
Failure to follow the safety warnings exactly could result in
serious injury, death or property damage.
Never test for gas leaks with an open flame. Use a commer-
cially available soap solution made specifically for the
detection of leaks to check all connections.
16. Replace main furnace door.
Step 6—Servicing Hot Surface Igniter
BURN HAZARD
Failure to follow this caution may result in minor personal
injury.
Allow igniter to cool before removal. Normal operating
temperatures exceed 2000°F.
A93087
The igniter does NOT require annual inspection. Check igniter
resistance before removal.
7