Advertisement
DESCRIPTION AND USAGE
Use this Condensing Heat Exchanger kit to replace a failed
condensing heat exchanger. This Condensing Heat Exchanger Kit
contains the following items. See Table 1 for kit contents.
Table 1 – Kit Contents
Description
HX & Panel Assy.
Containment Plate
Screw
Gasket
Coll. Box Gasket
Instructions
INSTALLATION
Unit Shut Down
1. Set room thermostat to lowest setting or "OFF."
2. Disconnect power at external disconnect, fuse or circuit
breaker.
3. Turn off gas at external shut- -off or gas meter.
4. Remove outer doors and set aside.
5. Turn electric switch on gas valve to OFF.
Vent Pipe Removal
NOTE: It will be necessary to remove the vent pipe from the
furnace in order to remove the heat exchanger.
1. Support the vent pipe as close to the furnace as possible to
prevent damage to the vent system.
2. Cut vent pipe with a hacksaw and move the remaining vent
pipe out of the way. Secure the vent pipe if necessary.
3. Loosen both clamps at the vent pipe support attached to fur-
nace casing.
4. Loosen clamp for the vent pipe at vent elbow on the inducer
assembly.
5. Remove remaining vent pipe through the top of the furnace
casing and set aside.
Manifold Removal / Burner Box Removal
NOTE: Use a back- -up wrench on the gas valve to prevent the
valve from rotating on the manifold or damaging the mounting to
the burner box. See Fig. 3.
1. Disconnect the gas pipe from gas valve and remove pipe
from the furnace casing.
2. Disconnect the connector harness from gas valve (Modulat-
ing only) or remove individual wires from terminals on gas
valve (All other models).
3. Disconnect the wires from gas valve, flame sensor and hot
surface igniter.
4. Remove wires from both rollout switches.
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.
5. Support the manifold and remove the 4 screws that secure
the manifold assembly to the burner box and set aside.
Note the location of the green and yellow ground wire for
reassembly later.
6. Support the burner box assembly and remove the screws
that attach the burner box to the heat exchanger cell panel.
7. Set the burner box assembly aside.
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.
Quantity
All other furnaces have two pressure switches mounted
1
back- -to- -back.
1
The tube for the front pressure switch connects the switch to the
2 Bags
port on the collector box. For PSC inducers only, the tube for the
2
switch mounted on the back connects the switch to the port on the
1
inducer assembly.
1
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.
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.
2
CAUTION
!
Advertisement
