Flue Passages (Qualified Servicer Only)
The heat exchanger flue passageways should be inspected at the
beginning of each heating season. If necessary, clean the
passageways as outlined below.
1. Turn off the electrical power and gas supply to the furnace.
2. Disconnect the gas line and remove the burner/manifold
assembly by removing the screws securing the assembly to
the partition panel.
3. Disconnect the flue pipe system from the induced draft blower.
4. Remove the induced draft blower, drain and pressure tap
hoses from the recuperator coil front cover.
5. Remove the recuperator coil front cover to expose the coil
tubes and turbulators.
6. Remove the recuperator coil turbulators individually by slowly
pulling each turbulator forward firmly.
7. Clean the recuperator coil tubes using a long handle wire
brush, such as a gun cleaning brush.
8. Clean the primary heat exchanger tubes using a wire brush
attached to a length of high grade stainless steel cable, such
as drain cleanout cable. Attach a variable speed reversible
drill to the other end of the cable. Slowly rotate the cable with
the drill and insert it into one of the heat exchanger tubes.
While reversing the drill, work the cable in and out several
times to obtain sufficient cleaning. Repeat for each tube.
9. Clean the residue from the furnace by using a vacuum cleaner.
10. Replace the parts removed in the previous steps in reverse
11. Turn on electrical power and gas to furnace. Check for leaks
and proper unit operation.
12. Severe heat exchanger fouling is an indication of an
operational problem. Perform the checks listed in "Start-Up
Procedure and Adjustments" to reduce the chances of
Electrostatic Discharge (ESD) Precautions
NOTE: Discharge static electricity accumulated in the body
before touching the unit. An electrostatic discharge can adversely
affect electrical components.
Use the following steps during furnace installations and servicing
to protect the integrated control module from damage. By putting
the furnace, the control and the person at the same electrostatic
potential, these steps will help avoid exposing the integrated
control module to electrostatic discharge. This procedure is
applicable to both installed and uninstalled (ungrounded)
1. Disconnect all power to the furnace. Do not touch the
integrated control module or any wire connected to the
control prior to discharging your body's electrostatic charge
2. Firmly touch a clean, unpainted, metal surface of the furnace
away from the control. Any tools held in a person's hand
during grounding will be discharged also.
3. Service the integrated control module or connecting wiring
after following the discharge process in Step 2.
NOTE: Do not recharge your body with static electricity by
moving or shuffling your feet or touching ungrounded
objects. Repeat Step 2 if you touch an ungrounded object.
4. Follow steps 1 through 3 before removing a new control from
its container or installing the control on a furnace. Return any
old or new controls to their containers before touching any
Cycle the furnace with the thermostat at least 3 times. Verify
cooling and fan only operation.
Review the Owner's Manual with the homeowner and discuss
proper furnace operation and maintenance.
Leave literature packet near furnace.
When ordering any of the listed functional parts, be sure to
provide the furnace model, manufacturing and serial numbers
with the order.
Although only functional parts are shown in the parts list, all sheet
metal parts, doors, etc., may be ordered by description.
Parts are available from your distributor.
Functional Parts List
Gas Control Valve
Natural Gas Orifice
Propane Gas Orifice
Rollout Limit Switch
Primary Limit Switch
Auxiliary Limit Switch
Induced Draft Blower
The ignition control is equipped with a momentary pushbutton
switch that can be used to display the last 5 faults detected by
The control must be in Standby Mode (no thermostat inputs) to
use the feature. Depress the pushbutton switch for approximately
Release the switch when the LED display is turned off. The
diagnostic LED will then display the flash codes associated with
the last 5 detected faults. The order of display is the most recent
fault to the least recent fault.
Furnace lockout results when a furnace is unable to achieve
ignition after 3 attempts during a single call for heat. It is
characterized by a nonfunctioning furnace and a 1-flash
diagnostic LED code. If the furnace is in "lockout," it will (or can
be) reset in any of the following ways.
1. Automatic reset. The integrated control module will
automatically reset itself and attempt to resume normal
operations following a 1-hour lockout period.
2. Manual power interruption. Interrupt 115-volt power to the
furnace for 1 to 20 seconds.
3. Manual thermostat cycle. Lower the thermostat so that there
is no longer a call for heat for 1 to 20 seconds, and then reset
to previous setting.
NOTE: If the condition which originally caused the lockout still exists,
the control will return to lockout. Refer to the "Diagnostic Chart."
Before Leaving an Installation
Repair and Replacement Parts
Blower Mounting Bracket
Coil Front Cover
Integrated Control Module
Resetting from Lockout