Lennox G32V Series Service Literature page 51

16− Disconnect 9-pin plug from the blower compartment at
the blower deck.
17− Remove 9-pin plug above the blower deck.
18− Remove the limit switch and the pressure switch from
the vestibule panel.
19− Remove two (2) screws from the front cabinet flange at
the blower deck. Remove front screws from cabinet at
blower deck on left and right sides. Cabinet sides must
be slightly spread to clear heat exchanger passage.
20− Remove screws along vestibule sides and bottom
which secure vestibule panel and heat exchanger as-
sembly to cabinet. Remove heat exchanger then re-
move cold end header box.
21− Back wash heat exchanger with soapy water solution
or steam. If steam is used it must be below 275_F
(135_C) .
22− Thoroughly rinse and drain the heat exchanger. Soap
solution can be corrosive so take care that entire as-
sembly is completely rinsed.
23− Re−install heat exchanger into cabinet making sure
that the clamshells of the heat exchanger assembly
are resting in the notches of the support located at the
rear of the cabinet. This can be viewed by removing the
indoor blower and examining through the blower open-
ing.
24− Re-secure the supporting screws along the vestibule
sides and bottom to the cabinet.
25− Re-install cabinet screws on sides and front flange at
blower deck.
26− Re-install the limit switch and pressure switch (−75 unit
will have a second switch) on the vestibule panel.
27− Re-install 9-pin plug to blower deck and connect it to
the 9-pin plug from below the blower deck.
28− Re-install the combustion air blower. Be careful that
the plastic orifice on the blower inlet has not fallen out.
See figure 1. Reconnect the 3-pin plug to the wire har-
ness. Re-install the flue transition in the cabinet and re-
attach the drain tube. Route the drain tube below the
combustion air blower housing and to the elbow on the
cold header (collector) box trap. See figure 31.
29− Re-install condensate line with adapter to condensate
trap. Use fresh Teflon tape to ensure a leak−free joint.
Re-connect to condensate line outside of the unit.
30− Re-install the burner box. Tighten the screws holding
the support bracket. It is important that the glass fiber
gasket not be damaged so it will provide a continuous
seal between the burner box and the vestibule panel.
31− Reconnect pressure switch tubing by connecting the
tubing from the burner box to the barb on the bottom
and the tubing from the combustion air blower to the
barb on the top. See figure 31.
Note−G32V−75 units will have two pressure switches.
32− Reconnect the sensor and ignitor wires.
33− Re-install top cap to unit.
34− Re-install electrical connections to gas valve. Brown
wire to H1, yellow wire to C2 and orange wire to M. Re-
connect wires to flame roll-out switch.
NOTE − Unit is polarity-sensitive. 120V supply wiring
must be installed correctly.
35− Reconnect main gas line to gas valve.
36− Re-install field make-up box if removed.
37− Re-install exhaust pipe/flue collar and secure flue col-
lar to the unit top cap using existing screw. Insert the
bottom of the flue collar into the top of the flue transition
and tighten hose clamp.
38− Re-install intake pipe fitting to burner box with screws.
39− Replace both upper and lower access panels.
40− Refer to instruction on verifying gas and electrical con-
nections when re-establishing supply.
41− Following lighting instructions from installation manu-
al, light and run unit for 5 minutes to ensure heat ex-
changer is clean, dry and operating safely.
Cleaning the Burner Assembly
1 − Turn off electrical and gas power supplies to furnace.
Remove upper and lower furnace access panels.
2 − Disconnect the gas supply line to gas valve. Depend-
ing on gas plumbing installation, the gas manifold may
move aside enough that breaking the union may not be
necessary.
3 − Remove five (5) screws from edges of burner box cov-
er.
4 − Loosen two (2) screws on bottom of burner box front.
The cover is key holed at these screw point so screws
do not need to be removed. Pull off cover and set
aside.
6 − Mark gas valve wires and disconnect them from valve.
7 − Mark and disconnect sensor wire from the burner box
at the SureLight control. Disconnect 2-pin plug from
the ignitor at the burner box.
8 − Loosen two (2) screws at the gas manifold support
bracket.
9 − Pull on the left side of the gas manifold and follow with
tension to the right side. The manifold support bracket
will be free of the mounting screws on the vestibule
panel. Set the gas manifold/gas valve assembly aside.
Take care not to damage foam gaskets on each end of
the gas manifold.
10− Using a 1/4" nut driver, remove the burner mounting
screws from underneath the burners.
11− While supporting ignitor and sensor lines at the grom-
met, grasp burners and simultaneously pull burners
and grommet out of the burner box.
12− Remove ignitor and sensor assemblies from burners
using a 1/4" nut driver to remove two screws from each
bracket.
13− Clean burner by running a vacuum with a soft brush at-
tachment over face of burners. Visually inspect inside of
burners and crossovers for any blockage caused by for-
eign matter. Remove any blockage.
14− Re-install ignitor and sensor bracket assemblies on
burners.
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