Instruction Manual

Table Of Contents
REPLACEMENT ALUMINIZED PRIMARY HEAT EXCHANGER: Installation Instructions
Manufacturer reserves the right to change, at any time, specifications and designs without notice and without obligations.
2
A11361
Fig. 1 – Loosen Vent Pipe Clamp
A11443
Fig. 2 – Burner Assembly / Manifold Assembly / Gas Valve
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 furnace
casing.
4. Loosen clamp for the vent pipe at vent elbow on the inducer
assembly. See
Fig. 1.
5. Remove remaining vent pipe through 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. 2.
1. Disconnect the gas pipe from gas valve and remove pipe from the
furnace casing.
2. Disconnect the connector harness from gas valve (Modulating 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 roll-out switches.
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.
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. 1.
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.
3. Remove the screws that attach the pressure switch assembly to the
inducer.
Table 1 – Kit Contents
Description Quantity
Hex Head 8A 1/2-in. Screws 43 - 61
Screws 8 - 12
Heat Exchanger & Panel Assembly 1
Gasket 2
Collector Box Gasket 1
Cell Panel Insulation 1
Instructions 1
Table 2 – Where Used
Input Casing Width Kit Number
26,000 14-3/16 (360)
347329-758-CBP
40,000
14-3/16 (360)
17-1/2 (445)
60,000
14-3/16 (360) 347329-752-CBP
17-1/2 (445) 347329-763-CBP
21 (533) 347329-761-CBP
80,000
17-1/2 (445)
347329-764-CBP
21 (533)
100,000 21 (533) 347329-756-CBP
120,000 24-1/2 (662) 347329-757-CBP
140,000 24-1/2 (662) 347329-759-CBP
Inducer Mounting Screw
Pressure Switch
Inducer Mounting Screw
Remove Vent Elbow
Vent Elbow Clamp
Remove Tube(s) from
Standoffs
Inducer Mounting Screw
Inducer Mounting Screw
Pressure Switch
Mounting Screw
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.