SERVICING
73
Rev. 0
Reinstallation of New Heat Exchanger:
Note: Before installing new heat exchanger assembly, in-
spect gasket along inside rails. If the gasket needs replac-
ing, install the new pieces of gasket supplied with kit.
1. Slide new heat exchanger into cabinet and secure with
screws removed in Step 8 of removal procedures. Re-
install the permagum in the top and bottom corners be-
tween the heat exchanger and cabinet, that is used to
help seal the burner compartment area.
2. Next, reinstall top cover assembly to furnace cabinet
that was removed in Step 6 of removal procedures.
3. Reinstall the orifice shield and manifold assembly, pres-
sure switches and induced draft blower removed in Step
7 of removal procedures. Make sure wiring is placed
back in side clip and also reattach wires at manifold
with wire tires.
4. Reinstall inner vent/flue pipe (GUCA Only) with flue cou-
pling along with rubber elbow (Standard Vent/Flue Con-
nection) or rubber coupling (Alternate Vent/Flue Con-
nection) and attach to induced draft blower removed in
Step 5 of removal procedures.
5. Reconnect condensate drain lines to induced draft
blower and recuperator cover and then install conden-
sate drain trap removed in Step 4 of removal proce-
dures.
Note: The GCCA model furnace (Counterflow Installations)
can now be reinstalled into the installation.
6. Reconnect the attached ductwork along with combus-
tion air pipe (Direct Vent Only) and vent/flue pipe to fur-
nace removed in Step 3 of removal procedures. Also
reconnect the incoming electrical power lines (GCCA
Counterflow Installations).
7. Reinstall the inner gas supply piping and reconnect to
gas supply line removed in Step 2 of removal proce-
dures.
WARNING
To avoid the possibility of explosion or fire, never use
a match or open flames to test for leaks.
WARNING
Upon completion of the heat exchanger replacement,
carefully inspect the entire flue system both inside and
outside the furnace to assure it is properly sealed.
Leaks in the flue system can result in serious personal
injury or death due to exposure to flue products, in-
cluding carbon monoxide.
8. Turn on gas to furnace and check for leaks. If leaks are
found, repair and then reinstall burner compartment door
and blower compartment door.
9. Turn on electrical power and verify proper unit opera-
tion.
Note: Listed below are the complete unit checks that need
to be done after installation of a new heat exchanger as-
sembly:
1. Verify proper gas pressures (See
SERVICING section
S-12).
2. Verify proper duct static (See
SERVICING section S-
15).
3. Verify proper temperature rise (See
SERVICING sec-
tion
S-16).
4. Verify proper negative draw down from combustion
blower (See
SERVICING section S-17).