Bryant 331JAV, 330JAV instruction manual Speed Selector, III. Cleaning Heat Exchanger

AUXILIARY

LIMIT

SWITCH

MOUNTING

SCREWS

RELIEF

BOX

FLUE

COLLAR

VENT PIPE

ENCLOSURE

CONTROL

DRAFT

SAFEGUARD

SWITCH

PRESSURE

SWITCHES

MANUAL

RESET

LIMIT

SWITCHES

NOTE: Refer to Table 1 for motor speed lead relocation if leads were not identified before disconnection.

TABLE 1—SPEED SELECTOR

		FACTORY-
COLOR	SPEED	ATTACHED
		TO
Black	High	Cool
Yellow (When Present)	Medium High	Spare
Blue	Medium Low	Heat
Red	Low	Spare
White	Common	COM
Orange (When Present)	Medium	Spare

CAUTION: Heating speed selection MUST be adjusted to provide proper temperature rise as specified on the rating plate. Failure to adjust the heating speed may shorten heat exchanger life.

14.Reinstall internal vent pipe and enclosure on downflow furnaces only by reversing items 3a through 3c.

NOTE: A releasing agent such as PAM cooking spray or equiva- lent (must not contain corn or canola oil, aromatic or halogenated hydrocarbons or inadequate seal may occur) and RTV sealant (G.E. 162, 6702, or Dow-Corning 738) are needed before starting installation. DO NOT substitute any other type of RTV sealant. G.E. 162 (P771-9003) is available through RCD in 3-oz tubes.

A99092

Fig. 6—Model 331JAV Downflow

7.Remove screws holding blower assembly to blower deck and slide blower assembly out of furnace.

8.Clean blower wheel and motor using a vacuum with soft brush attachment. Do not remove or disturb balance weights (clips) on blower wheel blades. The blower wheel should not be dropped or bent as balance will be affected.

9.If greasy residue is present on blower wheel, remove wheel from the blower housing and wash it with an appropriate degreaser. To remove wheel:

a.Mark blower wheel location on shaft before disassembly to ensure proper reassembly.

b.Loosen setscrew holding blower wheel on motor shaft.

NOTE: Mark blower mounting arms, motor, and blower housing so motor and each arm is positioned at the same location during reassembly.

c.Mark blower wheel orientation and cutoff plate location to ensure proper reassembly.

d.Remove screws securing cutoff plate and remove cutoff plate from housing.

e.Remove bolts holding motor mounts to blower housing and slide motor and mounts out of housing. Disconnect capacitor and ground wire attached to blower housing before removing motor.

f.Remove blower wheel from housing.

10.Reassemble motor and blower by reversing items 9a through 9f. Be sure to reattach ground wire.

11.Reinstall blower assembly in furnace.

12.Reinstall control box and support assembly in furnace.

13.Reconnect blower leads to furnace control and auxiliary limit switch leads (downflow only).

Refer to furnace wiring diagram, and connect thermostat leads if previously disconnected. (See Fig. 11.)

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15.Reinstall vent connector to furnace flue collar. After fully assembling vent connector to furnace flue collar, securely fasten vent connector to flue collar with 2 field-supplied, corrosion-resistant, sheet metal screws located 180 degrees apart and midway up the collar.

16.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 between heating and cooling by jumpering R to W and then R to Y on furnace control thermostat terminals.

WARNING: 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. Failure to follow this warn- ing could result in electrical shock, personal injury, or death.

NOTE: If thermostat terminals are jumpered before blower ac- cess door switch is closed, blower will run for 90 sec before beginning a heating or cooling cycle.

17.If furnace is operating properly, remove tape to release blower access door switch, replace blower access door.

III.CLEANING HEAT EXCHANGER

The following steps should be performed by a qualified service technician:

NOTE: If the heat exchangers get a heavy accumulation of soot and carbon, they 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, incorrect size, or damaged manifold orifice(s), improper gas, or a restricted heat exchanger. Action must be taken to correct the problem.

If it becomes necessary to clean heat exchanger because of light dust or corrosion proceed as follows: