Flushing Collector Box And Drainage System - Carrier Deluxe 58MVB Service And Maintenance Instructions

CAUTION
!
UNIT MAY NOT OPERATE
Failure to follow this caution may result in improper or
intermittent unit operation.
The ground wire from the gas valve MUST be attached to
the burner box attachment screw.
NOTE: Be sure burner box gasket is installed between burner
box and cell panel. (See Fig. 6.) If gasket is damaged, replace it.
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 operat-
ing cycles. Look through sight glass in burner enclosure to
check burners. Burner flames should be clear blue, almost
transparent. (See Fig. 11.)
17. Check for gas leaks.
WARNING
!
FIRE OR EXPLOSION HAZARD
Failure to follow this warning could result in personal
injury, death or property damage.
Never test for gas leaks with an open flame. Use a
commercially 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 loos-
ening coupling clamp on inducer outlet.
RTV
Fig. 9 --- Combustion- -Air Intake Housing
Gasket 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 for-
eign materials and remove them if present.
CAUTION
!
UNIT DAMAGE HAZARD
Failure to follow this caution may result in furnace
component 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 in-
ducer motor and pressure switches or connectors.
12. Reconnect pressure tubes to pressure switches. See dia-
gram 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 operat-
ing 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.
7
PAM
A93087