Cleaning Burners - Carrier 58MCB Service And Maintenance Instruction

13. Reconnect wires.
Refer to furnace wiring diagram, and connect thermostat leads if
previously disconnected. (See Fig. 21.)
NOTE: Refer to Table 1 for motor speed lead reconnection if
leads were not identified before disconnection.
UNIT DAMAGE HAZARD
Failure to adjust the heating speed may shorten heat ex-
changer life.
Heating speed selection MUST be adjusted to provide proper
temperature rise as specified on the rating plate.
Table 1—Speed Selection
COLOR
Black
Yellow (When Present) Medium High
Blue
Red
White
14. Turn on electrical supply. Manually close blower access door
switch. Use a piece of tape to hold switch closed. Check for
proper rotation and speed changes by performing a component
self-test as shown at the bottom of Service Label. (See Fig.
20.)
ELECTRICAL SHOCK HAZARD
Failure to follow this warning could result in personal injury
or death.
Blower access door switch opens 115-v power to furnace
control. No component operation can occur. Caution must be
taken when manually closing this switch for service purposes.
15. If furnace is operating properly, remove tape to release blower
access door switch, replace blower access door, and replace
main furnace door.
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
furnace gas control valve.
UNIT DAMAGE HAZARD
Failure to follow this caution may result in furnace compo-
nent damage.
Label all wires prior to disconnection when servicing con-
trols. Wiring errors can cause improper and dangerous
operation.
5. Remove wires from gas valve. Note location for reassembly.
6. Remove burner box pressure tube from gas valve regulator
fitting.
FACTORY
SPEED
ATTACHED TO
High Cool
Spare
Medium Low Heat
Low Spare
Common Com
MANIFOLD
MOUNTING
SCREW
Fig. 6—Burner Box Assembly
→
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.
12. Remove burner assembly from burner box.
NOTE: All burners are attached to burner bracket and can be
removed as 1 assembly.
13. Clean burners with soft brush and vacuum.
14. Reinstall manifold, orifice, and gas valve assembly in burner
box. Ensure manifold seal grommet is installed properly and
burners fit over orifices.
→
15. Reinsert the igniter wires in the slot in the manifold grommet,
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 electrical shock,
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.
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
fitting.
18. Reinstall gas supply pipe to furnace gas control valve using
backup wrench on gas valve to prevent rotation and improper
orientation.
NOTE: Use propane gas resistant pipe dope to prevent gas leaks.
DO NOT use Teflon tape.
5
CELL
PANEL
MANIFOLD
GAS VALVE
REGULATOR
FITTING
GAS VALVE
A96304