Bryant Series G Service And Maintenance Procedures Manual
service and
350MAV
maintenance procedures
4-WAY MULTIPOISE
FIXED-CAPACITY DIRECT-VENT
CONDENSING GAS FURNACE
WARNING: ELECTRICAL SHOCK, FIRE,
OR EXPLOSION HAZARD
Failure to follow safety warnings exactly could result in
dangerous operation, serious injury, death, or property
damage.
Improper servicing could result in dangerous operation,
serious indury, death, or property damage.
Before servicing, disconnect all electrical power to furnace.
When servicing controls, label all wires prior to disconnecting. Reconnect wires correctly.
Verify proper operation after servicing.
WARNING: The ability to properly perform maintenance on this equipment requires certain expertise, mechanical skills, tools, and equipment. If you do not
possess these, do not attempt to perform any maintenance
on this equipment other than those procedures recommended in the User’s Manual. FAILURE TO FOLLOW
THIS WARNING COULD RESULT IN POSSIBLE
DAMAGE TO THIS EQUIPMENT, SERIOUS PERSONAL INJURY, OR DEATH.
WARNING: 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
other volatile fluids.
3. Paint thinners and other painting compounds, paper
bags, or other paper products.
Failure to follow this warning can cause corrosion of
the heat exchanger, fire, personal injury, or death.
NOTE: Read the entire instruction manual before starting the
installation.
This symbol → indicates a change since the last issue.
TABLE OF CONTENTS
SAFETY CONSIDERATIONS.....................................................1
GENERAL......................................................................................2
ELECTROSTATIC DISCHARGE (ESD) PRECAUTIONS........2
CARE AND MAINTENANCE.....................................................2
Cleaning and/or Replacing Air Filter.......................................3
Blower Motor and Wheel Maintenance...................................3
Cleaning Burners ......................................................................4
Cleaning Heat Exchangers........................................................5
Primary Heat Exchangers....................................................5
Secondary Heat Exchangers................................................6
Series G
Cancels: SP05-47 SP05-52
8-02
A93040
Flushing Collector Box and Drainage
System.......................................................................................6
Servicing Hot Surface Ignitor ..................................................7
Electrical Controls and Wiring.................................................8
Checking Heat Tape Operation
(If Applicable)...........................................................................8
Winterizing................................................................................8
WIRING DIAGRAM.....................................................................9
TROUBLESHOOTING .................................................................9
Status Codes..............................................................................9
Component Test........................................................................9
SAFETY CONSIDERATIONS
Recognize safety information. This is the safety-alert symbol
When you see this symbol on the furnace and in instructions or
manuals, be alert to the potential for personal injury.
Understand the signal words DANGER, WARNING, and CAUTION. These words are used with the safety-alert symbol. DANGER identifies the most serious hazards which will result in severe
personal injury or death. WARNING signifies hazards which
could result in personal injury or death. CAUTION is used to
identify unsafe practices which would result in minor personal
injury or product and property damage. NOTE is used to highlight
suggestions which will result in enhanced installation, reliability,
or operation.
Installing and servicing heating equipment can be hazardous due to
gas and electrical components. Only trained and qualified service
agency personnel should install, repair, or service heating equipment.
Untrained personnel can perform basic maintenance functions
such as cleaning and replacing air filters. All other operations must
be performed by trained and qualified service agency personnel.
When working on heating equipment, observe precautions in the
literature, on tags, and on labels attached to or shipped with the
unit and other safety precautions that may apply.
Follow all safety codes including the National Fuel Gas Code
(NFGC) NFPA 54-1999/ANSI Z223.1-1999 in the USA; National
Standard of Canada, Natural Gas and Propane Installation Code
.
—1—
CSA B149.1-00 (NSCNGPIC) in Canada; and the Installation
Standards, Warm Air Heating and Air Conditioning Systems
(NFPA 90B) ANSI/NFPA 90B. In Canada, refer to the
CAN/CGA-B/49.1- and .2-M95 National Standard of Canada,
Natural Gas and Propane Installation Codes (NSCNGPIC). Wear
safety glasses and work gloves. Have a fire extinguisher available
during start-up and adjustment procedures and service calls.
GENERAL
These instructions are written as if the furnace is installed in an
upflow application. An upflow furnace application is where the
blower is located below the combustion and controls section of the
furnace, and conditioned air is discharged upward. Since this
furnace can be installed in any of the 4 positions shown in Fig. 2,
you may need to revise your orientation to component location
accordingly.
HIGH EFFICIENCYGAS FURNACE• VARIABLECAPACITYSYSTEM
THE INTELLIGENT HEATING MACHINE
ELECTROSTATIC DISCHARGE (ESD) PRECAUTIONS
CAUTION: Electrostatic discharge can affect electronic
components. Take precautions during furnace installation
and servicing to protect the furnace electronic control.
Precautions will prevent electrostatic discharges from
personnel and hand tools which are held during the
procedure. These precautions will help to avoid exposing
the control to electrostatic discharge by putting the
furnace, the control, and the person at the same electro-
static potential.
1. Disconnect all power to the furnace. DO NOT TOUCH
THE CONTROL OR ANY WIRE CONNECTED TO THE
CONTROL PRIOR TO DISCHARGING YOUR BODY’S
ELECTROSTATIC CHARGE TO GROUND.
2. Firmly touch a clean, unpainted, metal surface of the
furnace chassis which is close to the control. Tools held in
a person’s hand during grounding will be satisfactorily
discharged.
3. After touching the chassis you may proceed to service the
control or connecting wires as long as you do nothing that
recharges your body with static electricity (for example; DO
NOT move or shuffle your feet, DO NOT touch ungrounded objects, etc.).
4. If you touch ungrounded objects (recharge your body with
static electricity), firmly touch furnace again before touching control or wires.
5. Use this procedure for installed and uninstalled (ungrounded) furnaces.
6. Before removing a new control from its container, discharge your body’s electrostatic charge to ground to protect
the control from damage. If the control is to be installed in
a furnace, follow items 1 through 5 before bringing the
control or yourself into contact with the furnace. Put all
used AND new controls into containers before touching
ungrounded objects.
7. An ESD service kit (available from commercial sources)
may also be used to prevent ESD damage.
Fig. 1—Multipoise Furnace in Upflow Orientation
EFFICIENCY
RATING
CERTIFIED
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REGISTERED QUALITY SYSTEM
A98308
CERTIFIED
—2—
CARE AND MAINTENANCE
For continuing high performance and to minimize possible furnace
failure, it is essential that maintenance be performed annually.
Consult your local dealer about proper maintenance and maintenance contract availability.
AIRFLOW
UPFLOW
HORIZONTAL
RIGHT
AIRFLOW
A93041
AIRFLOW
HORIZONTAL
LEFT
DOWNFLOW
AIRFLOW
Fig. 2—Multipoise Orientation
WASHABLE
FILTER
FILTER
SUPPORT
FILTER
RETAINER
WASHABLE FILTER OR
DISPOSABLE MEDIA FILTER
IN FILTER CABINET
Fig. 3—Bottom Filter Arrangement
A00232
WARNING: Turn off the gas and electrical supplies to
the unit before performing any maintenance or service.
Follow the operating instructions on the label attached to
the furnace. Failure to follow this warning could result in
personal injury or death.
The minimum maintenance that should be performed on this
equipment is as follows:
1. Check and clean or replace air filter each month as needed.
2. Check blower motor and wheel for cleanliness annually.
3. Check electrical connections for tightness and controls for
proper operation each heating season. Service as necessary.
4. Check for proper condensate drainage. Clean as necessary.
5. Check for blockages in combustion-air and vent pipes
annually.
6. Check burners for cleanliness annually.
CAUTION: Personal injury could result from sharp
metal edges, etc. Use care and wear protective clothing
safety glasses, and gloves when removing parts.
I. CLEANING AND/OR REPLACING AIR FILTER
The air filter arrangement may vary depending on the application
or orientation. Filter could be located in furnace blower compartment or in filter cabinet.
WARNING: Never operate unit without a filter or with
the blower access panel removed. Failure to follow this
warning could result in a fire or personal injury.
CAUTION: Operating a unit without a filter or with the
blower access door removed could cause damage to the
furnace blower motor. Dust and lint on internal parts of
furnace can cause a loss of efficiency.
NOTE: If the filter has an airflow direction arrow, the arrow must
point toward the blower.
To clean or replace filters, proceed as follows:
WASHABLE
FILTER
IN FURNACE
FILTER
RETAINER
WASHABLE FILTER OR
DISPOSABLE MEDIA
FILTER IN FILTER CABINET
Fig. 4—Filter Installed for Side Inlet
A00233
If filter is installed in filter cabinet adjacent to furnace:
1. Turn off electrical supply to furnace.
2. Remove filter cabinet door.
3. Slide filter out of cabinet.
4. If equipped with permanent, washable filter, clean filter by
spraying cold tap water through filter in opposite direction
of airflow. Rinse filter and let dry. Oiling or coating of the
filter is not recommended.
5. If equipped with factory specified disposable media filter,
replace only with a factory-authorized media filter of the
same size.
6. Slide filter into cabinet.
7. Replace filter cabinet door.
8. Turn on electrical supply to furnace.
If filter is installed in furnace blower compartment:
1. Turn off electrical supply to furnace.
2. Remove main furnace door and blower access panel.
3. Release filter retainer wire. (See Figs. 3 or 4.)
4. Slide filter out of furnace.
5. Furnaces are equipped with permanent, washable filter(s).
Clean filter by spraying cold tap water through filter in
opposite direction of airflow.
6. Rinse filter and let dry. Oiling or coating filter is not
recommended.
7. Slide filter into furnace.
8. Recapture filter retainer wire.
9. Replace blower access panel and main furnace door.
10. Turn on electrical supply to furnace.
II. BLOWER MOTOR AND WHEEL MAINTENANCE
To ensure long life, economy, and high efficiency, clean accumulated dirt and grease from blower wheel and motor annually.
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.
The following items should be performed by a qualified service
technician.
Clean blower motor and wheel as follows:
—3—
1. Turn off electrical supply to furnace.
2. Remove main furnace door and blower access panel.
3. Disconnect blower motor wires from furnace control.
Field thermostat connections may need to be disconnected
depending on their length and routing.
4. Remove control box mounting screws, and position control
box, transformer, and door switch assembly to right side of
furnace casing.
5. If condensate trap is located in left- or right-hand side of
furnace casing, proceed to item 6, otherwise remove trap
and tubing as described below (see Fig. 8, top left):
a. Disconnect field drain connection from condensate trap.
b. Disconnect drain and relief port tubes from condensate
trap.
c. Remove condensate trap from blower shelf.
6. Remove screws securing blower assembly to blower shelf
and slide blower assembly out of furnace.
7. Clean blower wheel and motor by using a vacuum with soft
brush attachment. Be careful not to disturb balance weights
(clips) on blower wheel vanes. Do not bend wheel or blades
as balance will be affected.
8. 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 and blower housing so each
arm is positioned at the same hole 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. Motor mounts need not be
removed from motor.
f. Remove blower wheel from housing.
CAUTION: The blower wheel should not be dropped or
betn as balance will be affected.
g. Clean wheel per instructions on degreaser cleaner. Do
not get degreaser in motor.
9. Reassemble motor and blower wheel by reversing items 8b
through 8f. Ensure wheel is positioned for proper rotation.
Be sure to attach ground wire. Tighten set-screw to 140 to
160 in.-lb torque.
10. Reinstall blower assembly in furnace.
11. Reinstall control box, transformer, and door switch assembly on blower shelf.
12. Reinstall condensate trap and tubing if previously removed.
a. Reinstall condensate trap in hole in blower shelf.
b. Connect condensate trap drain tubes. See Fig. 8 or tubing
diagram on main furnace door for proper tube location.
NOTE: Ensure tubes are not kinked or pinched, as this will affect
operation.
(1.) Connect 1 tube (blue or blue and white striped)
from collector box.
(2.) Connect 1 tube (violet or unmarked) from inducer
housing.
(3.) Connect 1 tube (relief port, green or pink) from
collector box.
c. Connect field drain to condensate trap.
13. Reconnect wires.
Refer to furnace wiring diagram and connect thermostat
leads if previously disconnected. (See Fig. 15.)
NOTE: Refer to Table 1 for motor speed lead reconnection if
leads were not identified before disconnection.
CAUTION: Heating speed selection MUST be adjusted
to provide proper temperature rise as specified on the
rating table. Failure to adjust the heating speed may
shorten heat exchanger life.
TABLE 1—SPEED SELECTION
COLOR SPEED
Black High Cool
Yellow (When Present) Medium High Spare
Blue Medium Low Heat
Red Low Spare
White Common Com
FACTORY
ATTACHED TO
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 perroming
a componenet self-test as shown at the bottom of Service
Label. (See Fig. 17.)
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 warning could result in personal injury or death.
15. If furnace is operating properly, release blower access door
switch, replace blower access door, and replace main
furnace door.
III. 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.
CAUTION: Label all wires prior to disconnection when
servicing controls. 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.
—4—
7. Remove screws that secure manifold to burner box. (See
Fig. 5.)
NOTE: Do not remove burner box from cell panel.
8. Remove manifold, orifices, and gas valve as 1 assembly.
9. Remove screws attaching burner assembly in burner box.
10. Remove burner assembly from burner box.
NOTE: All burners are attached to burner bracket and can be
removed as 1 assembly.
11. Clean burners with soft brush and vacuum.
12. Reinstall manifold, orifice, and gas valve assembly in
burner box. Ensure manifold seal grommet is installed
properly and burners fit over orifices.
13. Reconnect wires to gas valve. Refer to furnace wiring
diagram for proper wire location.
14. Reinstall burner box pressure tube to gas valve regulator
fitting.
15. 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.
WARNING: Gas valve switch MUST be facing forward
or tilted upward. Failure to follow this warning could
result in property damage, personal injury, or death.
16. Replace burner box cover.
17. Turn on gas and electrical supplies to furnace.
WARNING: FIRE OR EXPLOSION HAZARD
Failure to follow the safety warnings exactly could result
in serious 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. A fire
or explosion may result causing property damage, personal injury, or loss of life.
18. Check for gas leaks.
19. Replace main furnace door.
IV. CLEANING HEAT EXCHANGERS
The following items should be performed by a qualified service
technician.
A. 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.
CAUTION: Label all wires prior to disconnection when
servicing controls. Wiring errors can cause improper and
hazardous operation. .
MANIFOLD
MOUNTING
SCREW
Fig. 5—Burner Box Assembly
CELL
PANEL
MANIFOLD
GAS VALVE
REGULATOR
FITTING
GAS VALVE
A96304
3. Disconnect wires or connectors to flame rollout switch, gas
valve, igniter, and flame sensor.
4. Disconnect combustion-air intake pipe from intake housing.
5. Remove the pressure switch tube from intake housing.
6. Remove screws attaching intake housing to burner box, and
rotate intake housing away from burner box for removal.
7. Using backup wrench, disconnect gas supply pipe from gas
valve.
8. Disconnect pressure tubing from gas valve.
9. Remove 2 screws attaching top filler panel and rotate
upwards to gain access to screws attaching burner box to
cell panel.
10. Remove screws attaching burner box to cell panel. (See Fig.
5.)
NOTE: Burner box cover, manifold, gas valve, and burner
assembly should be removed as 1 assembly.
11. Clean heat exchanger openings with a vacuum and a soft
brush. (See Fig. 6.)
NOTE: After cleaning, inspect the heat exchangers to ensure they
are free of all foreign objects that may restrict flow of combustion
products.
12. Reverse items 4 through 10 for reassembly.
—5—
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