Lennox SLP99UHV Series Unit Information page 72

Condensate Hose Screens
Hose
FIGURE 60
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 disas-
sembling unit. Use papers or protective covering in front of
furnace 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.
Remove 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 exiting exhaust pipe for removal of the
fitting.
11 - Mark and disconnect all combustion air pressure
tubing from cold end header collector box.
12 - Mark and remove wires from pressure switches.
Remove pressure switches. Keep tubing attached
to pressure switches.
13 - Disconnect the 4-pin plug from the combustion
air inducer. Remove two screws which secure
combustion air inducer to collector box. Remove
combustion air inducer assembly. Remove ground
wire from vest panel.
14 - Remove cold end header box.
15 - Remove electrical junction box from the side of the
furnace.
16 - Mark and disconnect any remaining wiring to
17 - Remove the primary limit from the vestibule panel.
18 - Remove two screws from the front cabinet flange
Hose
19 - Remove screws along vestibule sides and bottom
20 - Back wash heat exchanger with soapy water
21 - Thoroughly rinse and drain the heat exchanger.
22 - Reinstall heat exchanger into cabinet making sure
23 - Re-secure the supporting screws along the vestibule
24 - Reinstall cabinet screws on front flange at blower
25 - Reinstall the primary limit on the vestibule panel.
26 - Route heating component wiring through hole in
27 - Reinstall electrical junction box.
28 - 27 - Reinstall the cold end header box.
29 - Reinstall the combustion air inducer. Reconnect the
30 - Reinstall pressure switches and reconnect pressure
31 - Carefully connect combustion air pressure switch
32 - Reconnect condensate drain line to the cold end
33 - Use securing screws to reinstall flue collar to the top
34 - Replace flexible exhaust adapter on combustion air
35 - Reinstall burner box assembly in vestibule area.
36 - Reconnect flame roll-out switch wires.
37 - Reconnect sensor wire and reconnect 2-pin plug
38 - Secure burner box assembly to vestibule panel
Page 72
heating compartment components. Disengage
strain relief bushing and pull wiring and bushing
through the hole in the blower deck.
at the blower deck. Spread cabinet sides slightly to
allow clearance for removal of heat exchanger.
which secure vestibule panel and heat exchanger
assembly to cabinet. Remove two screws from
blower rail which secure bottom heat exchanger
flange. Remove heat exchanger from furnace
cabinet.
solution or steam. If steam is used it must be below
275°F (135°C) .
Soap solutions can be corrosive. Take care to rinse
entire assembly.
that the clamshells of the heat exchanger assembly
are resting in the support located at the rear of the
cabinet. Remove the indoor blower to view this area
through the blower opening.
sides and bottom to the cabinet.
deck.
blower deck and reinsert strain relief bushing.
4-pin plug to the wire harness.
switch wiring.
hosing from pressure switches to proper stubs on
cold end header collector box.
header box.
cap on the furnace. Reconnect exhaust piping and
exhaust drain tubing.
inducer and flue collar. Secure using two existing
hose clamps.
from ignitor.
using four existing screws. Make sure burners line
up in center of burner ports.