Lennox EL297UH110XV60C - Filter Inspection and Replacement; Heat Exchanger Cleaning

Page 84
Filters
All air lters are installed external to the unit. Filters should
be inspected monthly. Clean or replace the lters when
necessary to ensure proper furnace operation. TABLE 31
lists recommended lter sizes.
IMPORTANT
If a high e󰀩ciency lter is being installed as part of
this system to ensure better indoor air quality, the
lter must be properly sized. High e󰀩ciency lters
have a higher static pressure drop than standard
e󰀩ciency glass/foam lters. If the pressure drop is
too great, system capacity and performance may
be reduced. The pressure drop may also cause the
limit to trip more frequently during the winter and
the indoor coil to freeze in the summer, resulting in
an increase in the number of service calls.
Before using any lter with this system, check the
specications provided by the lter manufacturer
against the data given in the appropriate Lennox
Product Specications bulletin. Additional
information is provided in Service and Application
Note ACC002 (August 2000).
TABLE 31
Furnace
Cabinet Width
Filter Size
Side Return Bottom Return
17-1/2” 16 X 25 X 1 (1) 16 X 25 X 1 (1)
21” 16 X 25 X 1 (1) 20 X 25 X 1 (1)
24-1/2” 16 X 25 X 1 (2) 24 X 25 X 1 (1)
Exhaust and air intake pipes
Check the exhaust and air intake pipes and all connec-
tions 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 o󰀨 power to the furnace.
2 - Have a shallow pan ready to empty condensate
water.
3 - Remove the clean out cap from the condensate trap
and empty water. Inspect the trap then reinstall the
clean out cap.
Condensate Hose Screens (FIGURE 57)
Check the condensate hose screens for blockage and
clean if necessary.
1 - Turn o󰀨 power to the unit.
2 - Remove hoses from cold end header box. Twist
and pull screens to remove.
3 - Inspect screens and rinse with tap water if needed.
4 - Reinstall screens, reconnect hoses and turn on
power to unit.
Condensate Hose Screens
Hose
Hose
FIGURE 57
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 o󰀨 electrical and gas supplies to the furnace.
2 - Remove the furnace access panels.
3 - Disconnect the 2 wires from the gas valve.
4 - Remove gas supply line connected to gas valve.
Remove the burner box cover (if equipped) and
remove gas valve/manifold assembly.
5 - Remove sensor wire from sensor. Disconnect 2-pin
plug from the ignitor.
6 - Disconnect wires from ame roll-out switches.
7 - Disconnect combustion air intake pipe. It may be
necessary to cut the existing pipe to remove burner
box assembly.
8 - 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.
9 - Loosen the clamps to the exible exhaust coupling.
10 - Disconnect condensate drain line from the cold end
header box.
11 - Disconnect condensate drain tubing from ue
collar. Remove screws that secures the ue collar
into place. Remove ue collar. It may be necessary
to cut the exiting exhaust pipe for removal of the
tting.
12 - Mark and disconnect all combustion air pressure
tubing from cold end header collector box.
13 - Mark and remove wires from pressure switch
assembly. Remove the assembly. Keep tubing
attached to pressure switches.
14 - Disconnect the 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.
15 - Disconnect the condensate drain line.
16 - Remove cold end header box.