Heat Controller 80+ AFUE Installation Instructions Manual page 25

CAUTION:
To prevent damage to the unit or internal
components, it is recommended that two
wrenches be used when loosening or tightening
nuts. Do not over tighten!
6. Using two wrenches, separate the ground-joint union
in the gas supply piping at the furnace.
7. Remove the piping between the gas valve and the
ground-joint union. (If applicable).
8. Remove all screws securing the burner assembly to
the furnace.
9. Carefully remove the burner assembly from the furnace.
DO NOT DAMAGE THE IGNITER wHILE REMOVING
THE BURNER ASSEMBLY.
10. Inspect the burners for accumulated dust or debris.
If necessary carefully clean them with a soft wire
brush and a vacuum cleaner. DO NOT DAMAGE THE
IGNITER wHILE CLEANING THE BURNER.
11. Replace all the parts in reverse order that they were
removed.
12. Follow the lighting instructions found on the furnace
door to return the furnace to operation. Verify proper
operation after servicing.
Cleaning of Flue Passages - If the flue passages must
be cleaned, follow the steps below. See Figure 20 (page
35) for component location.
1. Shut off the gas supply to the furnace at the meter or
at the manual valve in the gas supply piping.
2. Turn off all power to the furnace and set the thermostat
to the lowest temperature setting.
3. Remove the blower door from the furnace.
4. Turn the gas control switch to the OFF position.
5. Disconnect the wires from the gas valve, flame sensor,
inducer, flame roll-out switch, limit switch, pressure
switch and igniter.
6. Remove the silicone rubber tube from the inducer.
7. Using two wrenches, separate the ground-joint union
in the gas supply piping at the furnace.
8. Remove the piping between the gas valve and the
ground-joint union. (If applicable).
9. Remove all screws securing the burner assembly to
the furnace.
10. Carefully remove the burner assembly from the furnace.
DO NOT DAMAGE THE IGNITER wHILE REMOVING
THE BURNER ASSEMBLY.
11. GUH80A models - Remove all screws securing the
inducer assembly to the vent pipe running out of the
furnace
GDD80A models - Remove all screws securing the
combustion air tube assembly to the vent pipe running
out of the furnace.
12. Remove all screws securing the inducer assembly to
the collector pan.
13. GUH80A models - Carefully remove the inducer
assembly from the furnace.
GDD80A models - Carefully remove the inducer
assembly and combustion tube assembly from the
furnace. DO NOT BREAK THE SEALS AT EACH
END OF THE COMBUSTION AIR TUBE.
14. Remove all screws securing the collector pan to the
furnace.
15. Remove the collector pan and gasket from the furnace.
16. Attach a round wire brush to a length of high grade
stainless steel cable. Attach the other end of the cable to
a variable speed reversible drill. Slowly insert and rotate
the cable into the top portion of the heat exchanger.
Operate the drill alternating between forward and
reverse, working the cable in and out several times to
obtain sufficient cleaning. Repeat this sequence for
each heat exchanger tube.
17. Remove all loosened debris from the heat exchanger
tubes using a vacuum cleaner.
18. Using a bright light, check the condition of the upper
and lower sections of the heat exchanger tubes.
19. Inspect the burners for accumulated dust or debris. If
burners must be cleaned, see pages 24 & 25.
20. Replace all the parts in reverse order that they were
removed.
21. Check gaskets for damage and replace if needed.
22. Follow the lighting instructions found on the furnace
door to return the furnace to operation. Verify proper
operation after servicing.
Vent System - Check the vent pipe and/or chimney for
corrosion or debris. Any corroded section of vent pipe
must be replaced, and any obstruction or blockage must
be removed prior to operating the furnace.
wARNING:
Holes in the vent pipe or heat exchanger can
cause combustion products to enter the home.
Replace the vent pipe or heat exchanger if leaks
are found. Failure to prevent the circulation
of combustion products into the living space
can create potentially hazardous conditions
including carbon monoxide poisoning that
could result in personal injury or death.
Heat Exchanger & Burner Maintenance - The furnace
should operate for many years without soot buildup in the
flue passageways, however, the flue, vent system, and
burners should be inspected and cleaned (if required) by
a qualified service technician annually to ensure continued
safe operation. Pay attention to any deterioration from
corrosion or other sources.
Lubrication - The bearings in the blower motor and
inducer blower used in these furnaces are pre-lubricated
and sealed by the manufacturer. No further oiling of the
bearings is required for the life of the motor.
25