Maintenance - Lennox EL280UH110P60C Unit Information

VI−MAINTENANCE
WARNING
Disconnect power before servicing unit.
CAUTION
Label all wires prior to disconnection when servicing
controls. Wiring errors can cause improper and dan-
gerous operation. Verify proper operation after ser-
vicing.
At the beginning of each heating season, a qualified techni-
cian should check the system as follows:
A−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.
B−Filters
All EL280UH(X) filters are installed external to the unit. Fil-
ters should be inspected monthly. Clean or replace the fil-
ters when necessary to ensure that the furnace operates
properly. Replacement filters must be rated for high veloc-
ity airflow.
C−Flue and Chimney
Check the flue pipe, chimney and all connections for tight-
ness and to make sure there is no blockage.
A Disconnected Vent" warning sticker should be attached
to a visible area of the plenum near the vent pipe. If the
sticker is not legible or missing, order kit 66W04 for re-
placement stickers.
D−Electrical
1 − Check all wiring for loose connections.
2 − Check for the correct voltage at the furnace (furnace
operating). Correct voltage is 120VAC + 10%
3 − Check amp−draw on the blower motor with inner blow-
er access panel in place.
Motor Nameplate__________Actual__________
E−Heat Exchanger and Burners
Cleaning the Heat Exchanger and Burners
NOTE − Use papers or protective covering in front of the fur-
nace during cleaning.
1 − Turn off both electrical and gas power supplies to fur-
nace.
2 − Remove flue pipe and top cap (some applications top
cap can remain) from the unit.
3 − Label the wires from gas valve, rollout switches, prima-
ry limit switch and make−up box then disconnect them.
4 − Remove the screws that secure the combustion air in-
ducer/pressure switch assembly to the collector box.
Carefully remove the combustion air inducer to avoid
damaging blower gasket. If gasket is damaged, it must
be replaced to prevent leakage.
5 − Remove the collector box located behind the combus-
tion air inducer. Be careful with the collector box gas-
ket. If the gasket is damaged, it must be replaced to
prevent leakage.
6 − Disconnect gas supply piping. Remove the screw se-
curing the burner box cover and remove cover. Re-
move the four screws securing the burner manifold as-
sembly to the vestibule panel and remove the assem-
bly from the unit.
7 − Remove screws securing burner box and remove
burner box.
8 − NOX units only − Remove screw securing NOX insert.
Remove NOX insert. See figure 2.
9 − Remove screws from both sides, top and bottom of
vestibule panel.
10 −Remove heat exchanger. It may be necessary to
spread cabinet side to allow more room. If so, remove
five screws from the left side or right side of cabinet.
See figure 3.
11 − Backwash using steam. Begin from the burner opening
on each clam. Steam must not exceed 275°F.
12 −To clean burners, run a vacuum cleaner with a soft brush
attachment over the face of burners. Visually inspect in-
side the burners and crossovers for any blockage
caused by foreign matter. Remove any blockage. Figure
1 shows burner detail.
13 −To clean the combustion air inducer visually inspect and
using a wire brush clean where necessary. Use com-
pressed air to clean off debris and any rust.
14 −Reinstall heat exchanger in vestibule. (Replace the
five screws in the cabinet from step 10 if removed).
15 −NOx units only − Replace NOx inserts.
16 −Reinstall collector box and combustion air assembly.
Reinstall all screws to the collector box and combustion
air inducer. Failure to replace all screws may cause
leaks. Inspect gaskets for any damage and replace if
necessary.
17 −Reinstall burner box, manifold assembly and burner box
cover.
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