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VII−MAINTENANCE
WARNING
ELECTRICAL SHOCK, FIRE,
OR EXPLOSION HAZARD.
Failure to follow safety warnings exactly could result
in dangerous operation, serious injury, death or prop-
erty 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 injury or
death.
Filters
All SLP98UHV filters are installed external to the unit. Fil-
ters should be inspected monthly. Clean or replace the fil-
ters when necessary to ensure proper furnace operation.
All SLP98UHV units use a 16 x 25 x1 filter.
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.
NOTE − After any heavy snow, ice or frozen fog event the
furnace vent pipes may become restricted. Always check
the vent system and remove any snow or ice that may be
obstructing the plastic intake or exhaust pipes.
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__________
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 and refill trap with water.
Cleaning Heat Exchanger
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 furnace access panels.
3 − Disconnect the 2−pin plug from the gas valve.
4 − Remove gas supply line connected to gas valve. Re-
move the burner box cover and remove gas valve/
manifold assembly.
5 − Remove sensor wire from sensor. Disconnect 2-pin
plug from the ignitor.
6 − Disconnect wires from flame roll−out switches.
7 − Remove four burner box screws at the vestibule panel
and remove burner box. Set burner box assembly
aside.
NOTE
− If necessary, clean burners at this time. Follow
procedures outlined in Burner Cleaning section.
8 − Loosen the clamps to the flexible exhaust coupling.
9 − Disconnect condensate drain line from the cold end
header box.
10 − Disconnect condensate drain tubing from flue collar.
Remove screws that secures the flue collar into place.
Remove flue collar. It may be necessary to cut the exit-
ing exhaust pipe for removal of the fitting.
11 − Mark and disconnect all combustion air pressure tub-
ing from cold end header collector box.
12 − Mark and remove wires from pressure switches. Re-
move pressure switches. Keep tubing attached to
pressure switches.
13 − Disconnect the 4-pin plug from the combustion air in-
ducer. Remove two screws which secure combustion
air inducer to collector box. Remove combustion air in-
ducer assembly. Remove ground wire from vest panel.
14 − Remove cold end header box.
15 − Remove electrical junction box from the side of the fur-
nace.
16 − Mark and disconnect any remaining wiring to heating
compartment components. Disengage strain relief
bushing and pull wiring and bushing through the hole in
the blower deck.
17 − Remove the primary limit from the vestibule panel.
18 − Remove two screws from the front cabinet flange at the
blower deck. Spread cabinet sides slightly to allow
clearance for removal of heat exchanger.
18 − Remove screws along vestibule sides and bottom
which secure vestibule panel and heat exchanger as-
sembly to cabinet. Remove two screws from blower rail
which secure bottom heat exchanger flange. Remove
heat exchanger from furnace cabinet.
19 − Back wash heat exchanger with soapy water solution
or steam.
If steam is used it must be below 275°F
(135°C) .
20 − Thoroughly rinse and drain the heat exchanger. Soap
solutions can be corrosive. Take care to rinse entire as-
sembly.
