Bryant Heating and Cooling System 315A Gas Furnace Maintenance

WARNING : FIRE OR EXPLOSION HAZARD Failure to follow this warning could result in personal injury, death and/or property damage. Never store anything on, near, or in contact with the furnace, such as:

1. Spray or aerosol cans, rags, brooms, dust mops, vacuum cleaners, or other cleaning tools. 2. Soap powders, bleaches, waxes or other cleaning compounds, plastic or plastic containers, gasoline, kerosene, cigarette lighter fluid, dry cleaning fluids, or

For continuing high performance and to minimize possible furnace failure, periodic maintenance must be performed on this furnace. Consult your local dealer about proper frequency of maintenance and the availability of a maintenance contract.

WARNING: ELECTRICAL SHOCK AND FIRE HAZARD Failure to follow this warning could result in personal injury, death, and/or property damage. Turn off the gas and electrical supplies to the furnace and install lockout tag before performing any maintenance or s

WARNING: CARBON MONOXIDE POISONING AND FIRE HAZARD Failure to follow this warning could result in personal injury, death and/or property damage. Never operate furnace without a filter or with filter access door removed.

CAUTION: CUT HAZARD Failure to follow this caution may result in personal injury. Sheet metal parts may have sharp edges or burrs. Use care and wear appropriate protective clothing, safety glasses and gloves when handling parts, and servicing furnaces.

The minimum maintenance on this furnace is as follows:

Cleaning and/or Replacing Air Filter

The air filter arrangement will vary depending on the application. NOTE: If the filter has an airflow direction arrow, the arrow must point towards the blower.

CAUTION: CUT HAZARD Failure to follow this caution may result in personal injury. Sheet metal parts may have sharp edges or burrs. Use care and wear appropriate protective clothing, safety glasses and gloves when handling parts, and servicing furnaces.

Media cabinet filter procedures:

Blower Motor and Wheel

WARNING: ELECTRICAL SHOCK HAZARD Failure to follow this warning could result in personal injury or death. Blower access door switch opens 115--v power to control. No component operation can occur unless switch is closed. Caution must be taken when manuall

NOTE: The blower wheel should not be dropped or bent as balance will be affected.

The following steps should be performed by a qualified service agency.

Table 16 – Filter Size Information -- In. (mm)

The inducer and blower motors are pre--lubricated and require no additional lubrication. These motors can be identified by the absence of oil ports on each end of the motor.

Clean blower motor and wheel as follows:

For downflow or horizontal furnaces having vent pipes within the furnace that pass in front of the blower access door:

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

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

WARNING: 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 unless switch is closed. Exercise caution to avoid

NOTE: If R--W/W1 thermostat terminals are jumpered at the time blower access door switch is closed, blower will run for 90 sec before beginning a heating cycle.

Downflow or horizontal furnaces with vent pipe through furnace only:

Cleaning Heat Exchanger

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

NOTE: If the heat exchangers get a heavy accumulation of soot and carbon, they should be replaced rather than trying to clean them thoroughly. A build--up of soot and carbon indicates that a problem exists which needs to be corrected, such as improper adj

Fig. 54 -- Igniter Position -- Side View

Fig. 55 -- Igniter Position -- Top View

If it becomes necessary to clean the heat exchangers because of dust or corrosion, proceed as follows:

Disconnect wires to the following components. Mark wires to aid in reconnection (be careful when disconnecting wires from switches because damage may occur):

NOTE: Be very careful when removing burner assembly to avoid breaking igniter. See Fig. 54--55 for correct igniter location.

Using field--provided 25--caliber rifle cleaning brush, 36--in. (914 mm) long, 1/4--in. (6 mm) diameter steel spring cable, a variable speed, follows:

NOTE: The materials needed in item 9 can usually be purchased at local hardware stores.

Fig. 56 -- Cleaning Heat Exchanger Cell

NOTE: A releasing agent such as cooking spray or equivalent (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 installat

Reconnect wires to the following components (Use connection diagram on wiring label, if wires were not marked for reconnection locations.):

WARNING: FIRE OR EXPLOSION HAZARD Failure to follow this warning could result in personal injury, death, and/or property damage. Never purge a gas line into a combustion chamber. Never test for gas leaks with an open flame. Use a commercially available so

Sequence of Operation

NOTE: Furnace control must be grounded for proper operation or else control will lock out. Control is grounded through green/yellow wire routed to gas valve and burner box screw. Using the schematic diagram in Fig. 53, follow the sequence of operation thr

NOTE: If a power interruption occurs during a call for heat (W/W1 or W/W1--and--W2), the control will start a 90--second blower--only ON period two seconds after power is restored, if the thermostat is still calling for gas heating. The amber LED light wi

NOTE: The low--heat only switch SW1--2 selects either the low--heat only operation mode when ON, (see item 2. below) or the adaptive heating mode when OFF in response to a call for heat. (See Table 10.) When the W2 thermostat terminal is energized it will

a. Inducer Prepurge Period