Advertisement
Pressure Switch Removal
NOTE: There are two types of pressure switches. The modulating
pressure switch assembly has three pressure switches. Two are
side- -by- -side with the third switch mounted to the back of one of
the switches.
All other furnaces have two pressure switches mounted
back- -to- -back.
The tube for the front pressure switch connects the switch to the
port on the collector box. For PSC inducers only, the tube for the
switch mounted on the back connects the switch to the port on the
inducer assembly.
1. Remove the front pressure switch tube from the port on the
collector box. See Fig. 3.
2. Disconnect the pressure switch harness (modulating only)
from the main wiring harness or remove the individual
wires from the front pressure switch (non- -modulating).
Not the location of the wires for reassembly.
CAUTION
!
UNIT OPERATION HAZARD
Failure to follow this caution may result in improper furnace
operation or failure of furnace.
Label all wires prior to disconnection when servicing controls.
Wiring errors can cause improper and dangerous operation.
3. Remove the screws that attach the pressure switch assembly
to the inducer.
4. Remove the back pressure switch tube that connects to the
inducer assembly.
5. Remove the wires from the back pressure switch. Note the
location of the wires for reassembly. (PSC only).
6. If the relief tube for the condensate trap is routed across the
inducer assembly, remove the tube from the port on the
collector box and from the stand- -offs on the inducer and
move the tube aside.
7. Set the pressure switches aside.
Inducer Assembly Removal
NOTE: See Fig. 3 for inducer assembly detail and component
locations.
1. Remove the door bracket from the front edge of the blower
shelf.
2. Remove the wires that connect the main wiring harness to
the inducer motor harness.
3. Remove the condensate trap relief tube from the port on the
collector box an the stand- -offs on the inducer housing.
4. Remove the screws from the tabs on inducer assembly that
secures the inducer to the collector box. Note: there is one
mounting tab directly under the vent elbow.
5. Remove the inducer assembly and set aside.
6. To avoid double gasketing and leakage, check to make sure
the drain gaskets for the inducer and the inducer inlet gasket
are not still attached to the collector box.
7. Remove any adhered gaskets from the front of the collector
box. Verify old gaskets are re- -usable or obtain new gaskets
from the distributor. Apply gaskets to the rear of the induc-
er housing and set aside for reassembly later.
Condensate Drain and Trap Removal
NOTE: If the condensate trap is removed, a new gasket between
the trap and collector box is required. Obtain one from your local
distributor. See Fig. 1 and Fig. 3.
1. Disconnect external drain from condensate drain elbow or
drain extension pipe inside the furnace and set aside.
2. Disconnect the condensate trap relief hose from collector
box port and the molded retainer clips on the inducer hous-
ing.
NOTE: If condensate has a heat pad attached to the trap, trace the
wires for the pad back to the connection point and disconnect the
wires for the heat pad.
3. Remove the screw that secures the condensate trap to the
collector box, remove the trap and set aside.
4. Rinse condensate trap in warm water until trap is clean.
5. Clean relief port on Condensate Trap with a thin wire or
paper clip, rinse with warm water and set aside.
6. Flush condensate lines with warm water.
7. Shake trap dry.
Remove J- -box and Main Harness
1. Remove the screw that secures the J- -box cover to the J- -box
bracket. See Fig. 2.
2. Disconnect the field wiring from the factory wiring and re-
move the ground wire from the green ground screw on the
J- -box bracket.
3. Remove factory wiring from the J- -box.
4. Disconnect the factory wires from the main limit switch.
5. Remove the screw that secures the door switch to the
blower shelf and the blower shelf door bracket. Remove
the screws from the blower shelf door bracket, and set the
bracket aside.
6. Remove main harness from the slot in the blower shelf.
Collector Box Removal
1. Remove the screws that secure the collector box to the heat
exchanger cell panel and set aside.
2. Remove collector box gasket and discard.
3. Flush out the Collector Box with warm water including the
tube ports. Clean tube ports on Collector Box with a thin
wire or paper clip, rinse with warm water and set aside.
Heat Exchanger Assembly Removal
CAUTION
!
CUT HAZARD
Failure to follow this caution may result in personal injury.
Sheet metal parts may have sharp edges or burrs. Use care and
wear appropriate protective clothing and gloves when
handling parts and servicing furnaces.
1. Remove the screws that attach the filler plate to the bottom
edge of the condensing heat exchanger assembly and cas-
ing.
2. Remove screws that secure the heat exchanger assembly to
the furnace casing. Do not remove the screws around the
burner inlets that attaches the primary inlet panel to the inlet
plate of the primary heat exchanger.
3. Pull assembly out of casing until the back edge of the heat
exchanger is resting on the front edge of the blower shelf.
4. Lift the heat exchanger assembly out of the casing and set
aside.
Remove Coupling Box
1. Remove the screws that secure the finger baffle from the
Coupling Box Cover. See Fig. 5.
2. Remove the screws that secure the Coupling Box Cover to
the rear of the Heat Exchanger Assembly.
3. Starting at the upper beveled edge of the coupling box, use
a putty knife or gasket scraper to get between the coupling
box cover and the Primary Cell Outlet panel to break the
silicone seal between the parts.
4. Pry upwards with the putty knife as you move around the
Coupling Box cover.
5. Once the Coupling Box cover is sufficiently loosened, re-
move the coupling box cover from the rear of the Heat Ex-
changer Assembly. See Fig. 4.
3
Advertisement
