6
Step 3 — Cleaning Burners
The following items should be performed by a qualified service
technician. If the burners develop an accumulation of light dirt or
dust, they may be cleaned by using the following procedure:
1. Turn off gas and electrical supplies to furnace.
2. Remove main furnace door.
3. Remove burner box cover.
4. Using backup wrench, disconnect gas supply pipe from fur-
nace gas control valve.
UNIT DAMAGE HAZARD
Failure to follow this caution may result in furnace
component damage.
Label all wires prior to disconnection when servicing
controls. Wiring errors can cause improper and dangerous
operation.
CAUTION
!
5. Remove wires from gas valve. Note location for reassembly.
6. Remove burner box pressure tube from gas valve regulator
fitting.
7. Unplug igniter from harness.
8. Remove igniter leads from slot in manifold grommet.
9. Remove screws that secure manifold to burner box. (See
Fig. 6.)
NOTE
: Do not remove burner box from cell panel.
10. Remove manifold, orifices, and gas valve as one assembly.
11. Remove screws attaching burner assembly in burner box.
NOTE
: Use care when removing and reinstalling burners not to
strike the hot surface igniter.
IGNIT ER WIRES MUST
BE PLACED
IN THIS SLOT
A05074
Fig. 7 -- Igniter Wire Placement
12. Remove burner assembly from burner box.
NOTE
: All burners are attached to burner bracket and can be
removed as one assembly.
13. Clean burners with soft brush and vacuum.
14. Reinstall manifold, orifice, and gas valve assembly in burn-
er box. Ensure manifold seal grommet is installed properly
and burners fit over orifices.
15. Reinsert the igniter wires in the slot in the manifold grom-
met, dressing the wires to ensure there is no tension on the
igniter itself. (See Fig. 7.)
ELECTRICAL SHOCK HAZARD
Failure to follow this warning could result in personal
injury or death.
Igniter wires must be securely placed in slot in manifold
grommet or else they could become pinched or severed
and electrically shorted.
!
WARNING
16. Reconnect wires to gas valve and igniter. Refer to furnace
wiring diagram for proper wire location.
17. Reinstall burner box pressure tube to gas valve regulator fit-
ting.
18. Reinstall gas supply pipe to furnace gas control valve using
backup wrench on gas valve to prevent rotation and im-
proper orientation.
NOTE
: Use propane gas resistant pipe dope to prevent gas leaks.
DO NOT use Teflon tape.
FIRE, EXPLOSION, UNIT DAMAGE HAZARD
Failure to follow this warning could result in personal
injury, death, or property damage.
Gas valve switch MUST be facing forward or tilted
slightly.
!
WARNING
19. Replace burner box cover.
20. Turn on gas and electrical supplies to furnace.
FIRE OR EXPLOSION HAZARD
Failure to follow this warning could result in personal
injury, death or property damage.
Never test for gas leaks with an open flame. Use a
commercially available soap solution made specifically
for the detection of leaks to check all connections.
!
WARNING
21. Check for gas leaks.
22. Replace main furnace door.
Step 4 — Cleaning Heat Exchangers
The following items should be performed by a qualified service
technician.
Primary Heat Exchangers
If the heat exchangers get an accumulation of light dirt or dust on
the inside, they may be cleaned by the following procedure:
NOTE
: If the heat exchangers get a heavy accumulation of soot
and carbon, both the primary and secondary heat exchangers
should be replaced rather than trying to clean them thoroughly due
to their intricate design. A build--up of soot and carbon indicates
that a problem exists which needs to be corrected, such as improper
adjustment of manifold pressure, insufficient or poor quality
combustion air, improper vent termination, incorrect size or
damaged manifold orifice(s), improper gas, or a restricted heat
exchanger (primary or secondary). Action must be taken to correct
the problem.
1. Turn off gas and electrical supplies to furnace.
2. Remove main furnace door.
PG
9M
AB
