Maintenance; Blower Care; Filters Care; Winterizing And Condensate Trap Care - Lennox G43UF SERIES Unit Information

VI−MAINTENANCE
WARNING
ELECTRICAL SHOCK, FIRE,
OR EXPLOSION HAZARD.
Failure to follow safety warnings exactly could result
in dangerous operation, serious injury, death or
property damage.
Improper servicing could result in dangerous opera-
tion, serious injury, death, or property damage.
Before servicing, disconnect all electrical power to
furnace.
When servicing controls, label all wires prior to dis-
connecting. Take care to reconnect wires correctly.
Verify proper operation after servicing.
At the beginning of each heating season, system should be
checked as follows by a qualified service technician:
Blower
Check the blower wheel for debris and clean if necessary.
The blower motors are prelubricated for extended bearing
life. No further lubrication is needed.
WARNING
The blower access panel must be securely in place
when the blower and burners are operating. Gas
fumes, which could contain carbon monoxide, can
be drawn into living space resulting in personal inju-
ry or death.
Filters
Filters should be inspected monthly. Clean or replace the
filters when necessary to ensure proper furnace opera-
tion. Replacement filters must be rated for high velocity
airflow. Table 21 lists recommended filter sizes.
TABLE 21
Furnace Furnace
Cabinet Size
Side Return
17−1/2" 16 X 25 X 1 (1)
21" 16 X 25 X 1 (1)
24−1/2" 16 X 25 X 1 (2)
Exhaust and air intake pipes
Check the exhaust and air intake pipes and all connections
for tightness and to make sure there is no blockage.
Electrical
1 − Check all wiring for loose connections.
2 − Check for the correct voltage at the furnace (furnace
operating).
3 − Check amp−draw on the blower motor.
Motor Nameplate__________Actual__________
Filter Size
Bottom Return
16 X 25 X 1 (1)
20 X 25 X 1 (1)
24 X 25 X 1 (1)
Page 38

Winterizing and Condensate Trap Care

1 − Turn off power to the unit.
2 − Have a shallow pan ready to empty condensate water.
3 − Remove the drain plug from the condensate trap and
empty water. Inspect the trap then reinstall the drain
plug.
Cleaning Heat Exchanger
IMPORTANT
Safety glasses and surgical mask should be worn
when cleaning heat exchanger and or burner
assembly.
If cleaning the heat exchanger becomes necessary, follow
the below procedures and refer to figure 1 when disassem-
bling unit. Use papers or protective covering in front of fur-
nace while removing heat exchanger assembly.
1 − Turn off electrical and gas supplies to the furnace.
2 − Remove the upper and lower furnace access panels.
3 − Mark all gas valve wires and disconnect them from
valve.
4 − Remove gas supply line connected to gas valve. Re-
move gas valve/manifold assembly.
5 − Remove sensor wire from sensor. Disconnect 2-pin
plug from the ignitor.
6 − Disconnect wires from flame roll−out switch.
7 − Remove burner box front cover and remove burner
box screws at the vestibule panel. Set burner box as-
sembly aside.
NOTE − If necessary, clean burners at this time. Follow
procedures outlined in Burner Cleaning section.
8 − Loosen three clamps and remove flexible exhaust tee.
9 − Remove 3/8 inch rubber cap from condensate drain
plug and drain. Replace cap after draining.
10 − Disconnect condensate drain line from the conden-
sate trap. Remove condensate trap (it may be neces-
sary to cut drain pipe). Remove screws that secure
both condensate collars to either side of the furnace
and remove collars. Remove drain tubes from cold
end header collector box.
11 − Disconnect condensate drain tubing from flue collar.
Remove screws that secure both flue collars into
place. Remove flue collars. It may be necessary to cut
the exiting exhaust pipe for removal of the fittings.
12 − Disconnect the 2-pin plug from the combustion air in-
ducer. Disconnect the two wires to the secondary limit,
if applicable. Remove four screws which secure com-
bustion air inducer to collector box Remove combus-
tion air inducer assembly. Remove ground wire from
vest panel.
13 − Mark and disconnect combustion air pressure tubing
from cold end header collector box.
14 − Mark and remove wires from pressure switch. Re-
move pressure switch. Keep tubing attached to pres-
sure switch.
15 − Remove electrical junction box from the side of the fur-
nace.