HEATED PASS THROUGH
INSTALLATION, OPERATION, SERVICE, AND PARTS
5
G.
Disconnect the plate ground wire from the push-on terminal on the back wall of the air
tower.
H.
Using a thin, sharp knife inserted between the plate and the HPT chassis, carefully cut
the silicon adhesive between the plate and the sides of the chassis.
I.
Pry up one end of the plate, lifting it away from the chassis.
NOTE:
The plate is held
in place by acrylic tape and it will be difficult to break the bond between the plate and
the chassis.
J.
Remove the acrylic tape from the frame to prevent rebounding while servicing the unit.
K.
Remove the three screws in the air heater shield and remove the shield to expose the
heater.
L.
Disconnect the air heater leads from terminal J2 on the controller board and from the
solid state relay (see Wiring Diagram on Page 7), and lift the heater from its bracket.
M.
Install the replacement heater and connect the leads to terminal J2 on the controller
board and to the lower left terminal of the solid state relay.
N.
Apply new acrylic tape to the HPT chassis, then stand the plate on its edge against the
blower side of the unit.
O.
Once the plate is properly aligned with the chassis, gently lower it into place.
P.
Reconnect the plate ground wire to the push-on terminal on the back wall of the air
tower.
Q.
Inspect the gaskets on the bottom of the cowl assembly and air tower assembly for
damage. If necessary, remove the old gasket material, clean the surfaces thoroughly,
and apply new gaskets.
R.
Slip the slotted brackets on the front section of the air tower assembly up and under the
nuts on the tower mounting screws. Push inward and down to ensure that the front
section is properly seated.
S.
Check for gaps in the seal between the front section of the air tower assembly and the
plate. If a gap is present, remove the front section and apply a second gasket over the
one already in place and reseat the front section.
T.
Once the front section is properly positioned and seated, tighten the nuts on the
mounting studs to pull it flush against the back of the tower assembly.
U.
Carefully lower the cowl into position and check for a proper seal between the cowl and
the plate. Install another gasket over the one already in place if there are gaps between
the base of the cowl and the plate.
V.
Carefully turn the unit on its side and reinstall the five screws removed in Step B.
W.
After the cowl is in place, reseal around the edges of the plate with RTV #108 silicone
rubber compound, P/N 811-0511.
6.4
Replacing the Blower Assembly
A.
Disconnect the unit from the electrical power source.
B.
Remove the cowl, front section of the air tower, and the plate from the unit per Steps B
through J in procedure 6.3 above.
C.
Remove the four
5
⁄
16
-inch nuts that hold the blower bridge in place and remove the
bridge from the unit.
D.
Remove the four
5
⁄
16
-inch nuts securing the blower assembly to the chassis.
NOTE:
A
magnetized nut driver makes this task much easier.
E.
Lay a piece of cardboard on the plate to prevent scratching it, then lift the blower
assembly out of the unit and set it on the plate.
