Bryant 574D - Manual (Page 24)

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housing, and slide motor and motor mount out of
housing.
2. Remove and clean blower wheel as follows:
a. Ensure proper reassembly by marking wheel orientation.
b. Lift wheel from housing. When handling and/or
cleaning blower wheel, be sure not to disturb balance
weights (clips) on blower wheel vanes.
c. Remove caked--on dirt from wheel and housing with a
brush. Remove lint and/or dirt accumulations from
wheel and housing with vacuum cleaner, using soft
brush attachment. Remove grease and oil with mild
solvent.
d. Reassemble wheel into housing.
e. Reassemble motor into housing. Be sure setscrews are
tightened on motor shaft flats and not on round part of
shaft.
f. Reinstall unit access panel.
3. Restore electrical power to unit. Start unit and check for
proper blower rotation and motor speeds during heating and
cooling cycles.
FLUE GAS PASSAGEWAYS
To inspect the flue collector box and upper areas of the heat
exchanger:
1. Remove the combustion blower wheel and motor assembly
according to directions in the Combustion--Air Blower
section.
2. Remove the 3 screws holding the blower housing to the flue
collector box cover (See Fig. 18--21).
3. Remove the 12 screws holding the flue collector box cover
(See Fig. 20--21) to the heat exchanger assembly. Inspect
the heat exchangers.
4. Clean all surfaces, as required, using a wire brush.
INDUCED DRAFT (COMBUSTION AIR) BLOWER
Clean periodically to assure proper airflow and heating efficiency.
Inspect blower wheel every fall and periodically during the heating
season. For the first heating season, inspect blower wheel
bimonthly to determine proper cleaning frequency.
To inspect blower wheel, remove draft hood assembly. Shine a
flashlight into opening to inspect wheel. If cleaning is required,
remove motor and wheel as follows:
1. Remove unit access panel (See Fig. 19).
2. Remove the 7 screws that attach induced--draft motor
mounting plate to blower housing (See Fig. 20).
3. Slide the motor and blower wheel assembly out of the
blower housing (See Fig. 20). Clean the blower wheel. If
additional cleaning is required, continue with Steps 4 and 5.
4. To remove blower, remove 2 setscrews.
5. To remove motor and cooling fan assembly, remove 4
screws that hold blower housing to mounting plate.
6. To reinstall, reverse the procedure outlined above.
LIMIT SWITCH
Remove unit access panel. Limit switch is located on the blower
partition.
BURNER IGNITION
Unit is equipped with a direct spark ignition 100 percent lockout
system. Ignition module is located in the control box (See Fig.
18).Module contains a self--diagnostic LED. During servicing,
refer to label diagram for LED interpretation.
If lockout occurs, unit may be reset by either momentarily
interrupting power supply to unit or by turning selector switch to
OFF position at the thermostat.
MAIN BURNERS
At the beginning of each heating season, inspect for deterioration
or blockage due to corrosion or other causes. Observe the main
burner flames and adjust, if necessary.
Removal of Gas Train
To remove the gas train for servicing:
1. Shut off main gas valve.
2. Shut off power to unit and install lockout tag.
3. Remove unit access panel (See Fig. 19).
4. Disconnect gas piping at unit gas valve.
5. Remove wires connected to gas valve. Mark each wire.
6. Remove ignitor and sensor wires at the ignitor module.
7. Remove the mounting screw that attaches the burner rack to
the unit base (See Fig. 18).
8. Slide the burner rack out of the unit (See Fig. 18 and 21).
9. To reinstall, reverse the procedure outlined above.
OUTDOOR COIL, INDOOR COIL, AND CONDEN-
SATE DRAIN PAN
Inspect the condenser coil, evaporator coil, and condensate drain
pan at least once each year.
The coils are easily cleaned when dry; therefore, inspect and clean
the coils either before or after each cooling season. Remove all
obstructions, including weeds and shrubs, that interfere with the
airflow through the condenser coil.
Straighten bent fins with a fin comb. If coated with dirt or lint,
clean the coils with a vacuum cleaner, using the soft brush
attachment. Be careful not to bend the fins. If coated with oil or
grease, clean the coils with a mild detergent and water solution.
Rinse coils with clear water, using a garden hose. Be careful not to
splash water on motors, insulation, wiring, or air filter(s). For best
results, spray condenser coil fins from inside to outside the unit. On
units with an outer and inner condenser coil, be sure to clean
between the coils. Be sure to flush all dirt and debris from the unit
base.
Inspect the drain pan and condensate drain line when inspecting
the coils. Clean the drain pan and condensate drain by removing all
foreign matter from the pan. Flush the pan and drain trough with
clear water. Do not splash water on the insulation, motor, wiring, or
air filter(s). If the drain trough is restricted, clear it with a
“plumbers snake” or similar probe device.
574D