Bryant GAS-FIRED INDUCED-COMBUSTION FURNACES 373LAV Guide

USER’S INFORMATION MANUAL
MODELS 373LAV, 376CAV
DOWNFLOW/HORIZONTAL and
383KAV, 395CAV UPFLOW GAS FURNACE
NOTE TO INSTALLER:
This manual must be left with the
equipment user.
Upflow
Downflow/
Horizontal
USER’S INFORMATION MANUAL
— Do not store or use gasoline or other flammable
vapors and liquids in the vicinity of this or any
other appliance.
— WHAT TO DO IF YOU SMELL GAS:
— Do not try to light any appliance.
— Do not touch any electrical switch; do not use
any phone in your building.
• Immediately call your gas supplier from a
neighbor’s phone. Follow the gas supplier’s
instructions.
• If you cannot reach your gas supplier, call the
fire department.
— Installation and service must be performed by a
qualified installer, service agency or the gas
supplier.
WARNING: If the information in this man-
ual is not followed exactly, a fire or explosion may
result causing property damage, personal injury
or loss of life.
!
Do not use this furnace if any part has been under
water. Immediately call a qualified service technician
to inspect the furnace and to replace any part of the
control system and gas control which has been under
water.

2
WELCOME TO
TODAY’S
GENERATION OF
COMFORT
Congratulations!Your new, higher
efficiency gas furnace is a sound
investment which will reward you
and your family with years of warm
memories winter after winter.
Not only is your new furnace energy
efficient, it is also extremely reliable.
Spend just a few minutes with this
booklet to learn about the operation
of your new furnace—and the small
amount of maintenance it takes to
keep it operating at peak efficiency.
Years went into the development of
your new furnace. Take a little time
now to assure its most efficient oper-
ation for years to come.
1
MODEL 383KAV and 395CAV
Upflow Furnace
2
MODEL 373LAV and 376CAV
Downflow/Horizont
al
Furnace
UPFLOW FURNACE
COMPONENTS
Relief Box
Rating Plate
Gas Valve Control Knob or Electric Switch
(On/Off)
Gas Valve
Gas Burner
Flame Sensor
Filter Retainer
Air Filter
Blower and Blower Motor
Blocked Vent Safeguard Tube and Switch
Gas Manifold
Manual Reset Limit Switch
Hot Surface Ignitor
Blower Door Safety Switch
3
1
2
3
4
5
6
7
8
9
10
11
12
13
14
11
1
10
12
3
4
8
7
5
13
9
6
2
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4
DOWNFLOW/HORIZONTAL
FURNACE COMPONENTS
Manual-Reset Auxiliary Limit Switch
(When Used)
Blower and Blower Motor
Relief Box
Gas Valve Control Knob or Electric Switch
(On/Off)
Gas Valve
Gas Burner
Rating Plate
Blower Door Safety Switch
Blocked Vent Safeguard Tube and Switch
Gas Manifold
Manual Reset Limit Switch (2)
Hot Surface Ignitor
Flame Sensor
1
2
3
4
5
6
7
8
9
10
11
12
13
IMPORTANT FACTS
Your furnace must have adequate air-
flow for efficient combustion and safe
ventilation. Do not enclose it in an
airtight room or “seal’’ it behind solid
doors. To minimize the possibility of
serious personal injury, fire, damage
toyour furnace,or improperoperation;
carefully follow these safety rules:
•Keep the area around your furnace
freeofcombustiblematerials,gasoline,
and other flammable liquids and
vapors.
5
•Do not cover the furnace, store trash
or debris near it, or in any way block
the flow of fresh air to the unit.
•Combustion air must be clean and
uncontaminated with chlorine or fluo-
rine. These compounds are present in
many products around the home, such
as: water softener salts, laundry
bleaches,detergents,adhesives,paints,
varnishes, paint strippers, waxes, and
plastics.
Make sure the combustion air for your
furnace does not contain any of these
compounds. During remodeling be
sure the combustion air is fresh and un-
contaminated. If these compounds are
burned in your furnace, the heat ex-
changers and metal vent system may
deteriorate.
•A furnace installed in the attic or
other insulated space must be kept free
and clear of the insulating material.
Examine the furnacearea when install-
ing the furnace or adding more insula-
tion. Some materials may be
combustible.
NOTE: Do not use this furnace if any
parthasbeenunderwater.Immediately
call a qualified service technician to in-
spect the furnace and to replace any
part of the control system and any gas
control which has been under water.
NOTE: The qualified installer or
agency must use only factory-
authorized re-placement parts, kits,
and accessories when modifying or
repairing this product.
This furnace contains safety devices
whichmust bemanuallyreset. Ifthe fur-
nace is left unattended for an extended
period of time, have it checked periodi-
cally for proper operation. This precau-
tion will prevent problems associated
withnoheat,suchas frozenwaterpipes,
etc. See “BeforeYou Request a Service
Call’’ section in this manual.
SAFETY
CONSIDERATIONS
Installing and servicing heating
equipment can be hazardous due to
gas and electrical components. Only
trained and qualified personnel should
install, repair, or service heating
equipment.
Untrainedpersonnel can performbasic
maintenance functions such as clean-
ing and replacing air filters. All other
operations must be performed by
trained service personnel. Observe
safety precautions in this manual, on
tags, and on labels attached to the fur-
nace and other safety precautions that
may apply.
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—DAN-
GER, WARNING, and CAUTION.
These words are used with the
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10
8
9
12
13
7
6
5
4
3
2
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safety-alert symbol. DANGER identi-
fiesthemostserioushazardswhich
will
result in severe personal injury or
death. WARNING signifies hazards
which
could resultinpersonalinjuryor
death. CAUTION is used to identify
unsafe practices which
would result in
minor personal injury or product and
property damage.
STARTING YOUR
FURNACE
Instead of a continuously burning pilot
flame, your furnace uses an automatic
hot surface ignition system to light the
burners each time the thermostat sig-
nals the furnace to start.
Follow these
important safeguards:
•Never attempt to manually light the
burnerswith a match orothersourceof
flame.
6
•Read and follow the operating in-
structionsonthefurnace,especiallythe
item that reads as follows:
Wait 5 minutes to clear out any gas.
Then smell for gas, including near the
floor. If you smell gas,
STOP! Follow
“B’’ in the safety information above on
this label. If you don’t smell gas, go to
the next step.
•If a suspected malfunction occurs
with your gas control system, such as
the burners do not light when they
should, refer to the shutdown proce-
dures on the furnace, or in the next sec-
tion, to turn off your system, then call
your dealer as soon as possible.
•
CHECK AIR FILTER: Before at-
tempting to start your furnace, be sure
the furnace filter is clean and in place.
(See the maintenance section of this
manual.) Then proceed as follows:
7
STEPS FOR STARTING
YOUR FURNACE
1.Set your room thermostat to the
lowest temperature setting. (See
Fig. 7.)
2.Close the external manual gas
valve. (See Fig. 8.)
3.Turn OFF the electrical supply to
your furnace. (See Fig. 9.)
8
9
10
WARNING
Should overheating occur, or
the gas valve fail to shut off the
gas supply, turn off the manual
gas valve (See Fig. 8) to the fur-
nace BEFORE turning off the
electrical supply. A failure to
follow this warning could re-
sult in a fire or explosion, and
personal injury or death.
!
®
11
4. Remove the furnace access door(s).
a. Downflow/Horizontal—remove
blower door after removing
2 screws first, then remove the
control door. (See Fig. 10.)
b. Upflow—remove control door.
(See Fig. 11.)
5.The gas valve will have EITHER a
control knob or control switch to
turn off and on. Turn the control
knob or switch on the gas valve to
the OFF position and wait 5 min-
utes. (See Fig. 12 or 13.)
6.After waiting 5 minutes, turn the
control knob or switch on the gas
valve to the ON position. (See Fig.
14 or 15.)
7.Replace the access door(s). See
Fig. 16 for upflow and Fig. 17 for
downflow. Replace control door
first on downflow furnaces. Then
replace blower door (secure with
2 screws).
8.Turn ON the electrical supply to
the furnace. (See Fig. 18.)
9.Open the external manual gas
valve. (See Fig. 19.)
10.Set the room thermostat to a tem-
perature slightly above the room
temperature. This will automati-
callysignalthe furnacetostart.The
inducermotorwillstart,andthehot
surface ignitor will energize. When
hot, the ignitor will have an orange
glow.
12
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14
16
18 19
11. After 15 to 70 sec, the gas valve
permits gas to flow to the main
burners where it is ignited. Hot
flames begin to warm the furnace’s
heat exchanger. After a time delay
of approximately 45 sec, the fur-
nace blower is switched on.
NOTE: If the main burners fail to ig-
nite, the furnace control system will go
through3 moreignitioncycles.Then, if
burners fail to ignite, the system will
lockout.Iflockoutoccurs,ortheblower
doesn’t come on—shut down your fur-
nace and call your dealer for service.
12. Set your thermostat to the tempera-
ture that satisfies your comfort re-
quirements. SUGGESTION:
Setting the thermostat back a few
degrees—andcompensatingforthe
difference with warmer clothing—
can make a big difference in your
fuel consumption on extremely
cold days. The few degrees at the
top of your thermostat “comfort
level’’ are the most costly degrees
to obtain.
When the room temperature drops
below the temperature selected on
the thermostat, the furnace will be
switched on automatically. When the
room temperature reaches the degree
selected on the thermostat, the furnace
will be switched off automatically.
Some thermostats have a “fan’’ mode
with 2 selections:AUTO or ON.When
set on AUTO, the furnace blower cy-
cles on and off, controlled by the ther-
mostat. In the ON position, the furnace
blower runs continuously except for a
45-sec delay at the “call for heat.’’This
keeps the temperature level in your
home more evenly balanced. It also
continuously filters the indoor air.
SHUTTING DOWN
YOUR FURNACE
Should you ever suspect a malfunction
in your furnace, you will need to turn
the furnace off. The following proce-
dures must be followed:
1. Set your room thermostat to
the lowest temperature setting.
(See Fig. 20.)
2. Close the external manual gas
valve. (See Fig. 8 on page 4.)
3. Turn OFF the electrical supply to
your furnace. (See Fig. 21.)
4. Remove the control access door on
your furnace. (See Fig. 10 or 11.)
On upflow furnaces, removing the
blower access door is not required.
O
P
E
N
ON
13
15
O
F
F
2
3
1
M
P
ON
O
F
F
C
ON
OFF
OR
O
F
F
2
3
1
M
P
ON
O
F
F
C
ON
OFF
OR
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6
5. Turn the control knob or switch on
the gas valve to the OFF position.
(See Fig. 22 or 23.)
20
21
22
23
6. Replace the control access door.
(See Fig. 16 or 17.)
7. If the furnace is being shut down
because of a malfunction, call your
dealer as soon as possible.
®
FF
O
PERFORMING ROUTINE
MAINTENANCE
With the proper maintenance and care,
yourfurnacewilloperateeconomically
and dependably. Basic maintenance,
which can easily be accomplished by
someone who follows the directions, is
found on this and the following pages.
However, before beginning mainte-
nance, follow these safety precautions:
FILTERING OUT
TROUBLE
Adirtyfilter willcauseexcessivestress
on the furnace blower motor and can
cause it to overheat and automatically
shut down. The furnace filter should be
checkedevery3or4weeksandcleaned
if necessary. If installed with factory
specifieddisposablemediafilter,check
orreplacefilterbeforeeachheatingand
cooling season. Replace disposable
media filter at least once a year.
If installed with factory specified dis-
posable media filter, check or replace
filter before each heating and cooling
season.Replacedisposablemediafilter
at least once a year.
Ifyour furnace filterneeds replacing,be
sure to use the same size and type of fil-
ter that was originally supplied. Use the
Furnace Filter Table and compare your
furnace size with the proper filter size.
Theairfilterforupflowfurnacesisnor-
mally located in the blower compart-
ment (See Fig. 03.) or in the factory-
supplier filter cabinet attached to the
side or bottom of the blower cabinet.
Filters for the downflow furnaces are
normally located in the return-air ple-
num above the blower. If air filter has
been installed in another location, con-
tact your dealer for instructions. To in-
spect, clean, and/or replace the air
filter(s). follow these steps:
UPFLOW FURNACES ONLY:
1. Turn off electrical supply to fur-
nace. (See Fig. 9)
2. Remove door/access panel.
•AIR FILTER(S) LOCATED IN
BLOWER COMPARTMENT
Remove control and blower access
doors. (See Fig. 10 and 11)
•AIR FILTER LOCATED IN FIL-
TER CABINET
Remove filter cabinet door (See
Fig. 30 and 31)
NOTE: It will be necessary toremove1
thumbscrew
24
25
WARNING
Turn off electrical power sup-
ply to your furnace before re-
moving the access doors to
service or perform mainte-
nance. A failure to follow this
warning could result in per-
sonal injury or death.
CAUTION
Although special care has
been taken to minimize sharp
edges, be extremely careful
when handling parts or reach-
ing into the furnace.
!
!
CAUTION
Never operate your furnace
without a filter in place. Doing
so may damage the furnace
blower motor. An accumula-
tion of dust and lint on internal
parts of your furnace can
cause a loss of efficiency.
!
O
F
F
2
3
1
M
P
ON
O
F
F
C
ON
OFF
OR

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3. Remove air filter from furnace.
•AIR FILTER LOCATED IN
BLOWER COMPARTMENT:
a) Slide filter retainer sideways un-
til it is free of latch. (See Fig. 24)
b) Gently remove air filter and
carefully turn the dirty side up
(if dirty) to avoid spilling dirt
from the filter. (see Fig. 25)
•AIR FILTER LOCATED IN FIL-
TER CABINET:
a) Slide air filter out of furnace.
Keep dirty side up (if dirty) to
avoid spilling dirt. (See Fig. 32
and 33)
26
4. Inspect the filter. If torn, replace it.
NOTE: If washable filter that was
shipped with the furnace has been re-
placed by:
a) Factory specified disposable
media filter –Do not clean. If
dirty, replace only with media
filter having the same part num-
ber and size. Install with airflow
direction arrow pointing to-
wards blower.
b) Electronic air cleaner (EAC) –
Refer to EAC owner’s Manual
for maintenance information.
5. Wash filter (if dirty) in sink, bath-
tub, or outside with a garden hose.
Always use cold tap water. A mild
liquid detergent may be used if nec-
essary. Spraywaterthrough filterin
the opposite direction of airflow.
Allow filter to dry.
6. Reinstall clean air filter
7. Reinstall filter retainer (for blower
compartment locations only)
8. Replace control and blower doors
(SeeFig.16and17)orfiltercabinet
door (Fig. 34 and 35)
9. Turnon electricalsupply tofurnace
(see Fig 18).
NOTE: For upflow models only—if
side return ducts are used, 2 filters may
be required in some models. The pro-
cedure listed above may be used to
remove side filters.
27 28
DOWNFLOW/HORIZONTAL
FURNACES ONLY
:
Two filters are located in the return-air
plenum above the blower (above line-
of-sight) resting in the V-shaped chan-
nel on top of the furnace. (See Fig. 27.)
1. Turn OFF electrical supply to the
furnace. (See Fig. 21.)
2. Remove blower access door after
removing 2 screws.
3. Remove the left-side filter by tip-
ping the filter toward the center—
raiseitfrom theV-shaped channelin
which it rests. (See Fig. 27 and 28.)
4. Lower filter down along side of the
blower and remove from the furnace.
5. To remove the second filter, lift
fromV-shapedchannelandremove
the same way as left side filter.
6. Inspect the filters. If torn, replace
the filter.
7. Wash the filters (if dirty) in a sink,
bathtub, or outside with a garden
hose.Always use cold tap water.A
mild liquid detergent may be used
if necessary. Spray water through
thefilterintheoppositedirectionof
airflow. Allow filter to dry.
8. Reinstall clean filters.
9. Replaceblowerdoor(securewith 2
screws) and turn ON electrical
power to your furnace.
UPFLOW FURNACE
AIR FILTER TABLE
DOWNFLOW/HORIZONTAL
FURNACE FILTER TABLE
* Factory provided with the furnace.
Filters may be field modified by cutting filter
material and support rods (3) in filters. Alternate
sizes and additional filters may be ordered from
your dealer.
COMBUSTION AREA
AND VENT SYSTEM
Inspect the combustion area and vent
system before each heating season.An
accumulation of dirt, soot, or rust can
mean a loss of efficiency and improper
performance. Buildups on the main
burners can cause faulty firing. This
“delayed ignition’’ is characterized by
an alarmingly loud sound. If your fur-
nacemakesaloud noisewhenthemain
burners are ignited, shut down the fur-
nace—call your servicing dealer.
Use your flashlight and follow these
steps for inspecting the combustion
area and vent system of your furnace:
1. Turn off the electrical supply to the
furnace and remove the access
doors. (See Fig. 9 and 10, or 11.)
2. Carefully inspect the gas burner
(see Fig. 29) for dirt, rust, or scale.
Then inspect the relief box, flue
AIR FILTER LOCATED IN BLOWER COMPARTMENT
FURNACE
CASING
WIDTH
FILTER SIZE (IN.)
FILTER
TYPESide Return Bottom Return
14-3/16 (1)16x25x1* (1)14x25x1*Cleanable
17-1/2 (1)16x25x1* (1)16x25x1**Cleanable
21 (1)16x25x1*(1)20x25x1* Cleanable
24-1/2 (1 or 2) 16x25x1 (1)24x25x1**Cleanable
AIR FILTER LOCATED IN FILTER CABINET
FILTER
CABINET
HEIGHT (IN) FILTER SIZE (IN.) FILTERTYPE
16 (1) 16 x 25 x 1* or (1) 16 x 25 x 4-5/16 Cleanable Disposable
20 (1) 20 x 25 x 1* or (1) 20 x 25 x 4-5/16 Cleanable Disposable
24 (1) 24 x 25 x 1* or (1) 24 x 25 x 4-5/16 Cleanable Disposable
FURNACE
CASING
WIDTH FILTER SIZE FILTER TYPE
14-3/16 (2)16x20x1* Cleanable
17-1/2 (2)16x20x1* Cleanable
21 (2)16x20x1* Cleanable
24-1/2 (2) 16x20x1* Cleanable
CAUTION
Use care when cutting support
rods in filters to protect
against flying pieces and
sharp rod ends. Wear safety
glasses, gloves, and appropri-
ate protective clothing. Failure
to follow this caution could re-
sult in personal injury.
!

8
connection area, and the vent pipe
for rust.
29
NOTE: If dirt, rust, soot, or scale accu-
mulations are found, call your servic-
ing dealer. DO NOT OPERATE THE
FURNACE.
3. Inspect the vent pipe for a sag,
holes, or a disconnection.A hori-
zontal vent pipe must slope up-
ward. If rusty joints or seams, or
signs of water leakages are found
call your dealer for service.
4. Replace the access doors and re-
store electrical power to the fur-
nace. Be sure bottom door flange is
inside of the furnace casing. (See
Fig. 16, 17, and 26.)
5. Start the furnace and observe its
operation. If possible, watch the
burner flames. Are they burning
brightblue?Ifnot(orifyou suspect
some other malfunction), call your
servicing dealer.
30
31
32
33
34
35
BEFOREYOU REQUEST
A “SERVICE CALL”
BEFOREYOU CALL FOR
SERVICE, CHECK FOR
SEVERAL EASILY SOLVED
PROBLEMS:
•Check for sufficient airflow. Check the
air filter for dirt. Check for blocked re-
turn-airorsupply-airgrilles.Besurethey
areopenandunobstructed.Ifthisisn’tthe
cause, call your servicing dealer.
If your furnace isn’t operating at all,
check the following list for easily
solved problems:
•Is your thermostat set above room
temperature? Is the HEAT mode
selected?
•Is the electrical power supply switch
ON?Isthebloweraccessdoorfirmlyin
place? Are any fuses blown? (There is
a fuse on the furnace control board.)
Has a circuit breaker tripped?
•Is the manual shutoff valve in the gas
supply pipe leading to the furnace
WARNING
If holes are found—or if the
vent pipe is obstructed or is
not connected—toxic fumes
can escape into your home. DO
NOT OPERATE YOUR FUR-
NACE. Call your dealer for ser-
vice. A failure to follow this
warning could result in per-
sonal injury or death.
!

9
open? Does the lever point in the same
direction that the pipe runs (open)? Or
is it at right angles (closed)?
NOTE: Before proceeding with the
next checks, turn OFF the electrical
power supply to the furnace. Remove
the access doors.
•Is the control knob or switch on the
gas valve turned to the ON position? If
this or the preceding check shows an
interruption in the gas supply, make
sure the gas has not been shut off for
safety reasons. If nothing else seems to
be wrong, follow the startup proce-
dures found on pages 4 and 5 of this
booklet.
•If for some reason the vent is
blocked,thedraftsafeguardswitchwill
shut off the furnace. Reset the switch
by pushing the button located on top of
the switch. (See page 2 or 3 for switch
location.)
If the switch trips a second time, turn
off the furnace and call for service.
DOWNFLOW/HORIZONTAL
ONLY—Check the manual-reset aux-
iliary limit switch (when used) located
on the blower housing. If the blower
motorfails,this switch willshutoffthe
furnace. Reset it by pushing the button
on the switch. If it trips again, turn off
the furnace and call for service.
•Check the manual-reset limit
switch(es) located near the burners. If
the furnace has experienced a high-
temperature condition, due to inade-
quate combustion air, these switches
will shut off the furnace. Reset the
switch(es)bypushingthebuttononthe
switch. If the switch trips a second
time, turn off the furnace and call for
service.
•Ifyourfurnacestillfailstooperate,call
yourservicingdealerfortroubleshooting
and repairs. Tell your dealer the model
and serial numbers for your furnace.
(You shouldhavethem recorded onpage
12 of this booklet.) By knowing exactly
which furnace you have, the dealer may
be able to offer suggestions over the
phone, or save valuable time through
knowledgeable preparation for the ser-
vice call.
REGULAR DEALER
MAINTENANCE
In addition to the type of routine main-
tenance you might be willing to do,
your furnace should be inspected
regularly by a properly trained service
technician. An annual inspection (or
biennial inspection, at least) should
include the following:
1. Inspection of all flue product pas-
sages—including the burners, heat
exchanger, relief box, and vent
pipe.
2. Inspection of all combustion
and ventilation air passages and
openings.
3. Close check of all gas pipes
leading to (and inside of) your
furnace.
4. Inspection, cleaning, and lubrica-
tion (when required) of the blower
motor and wheel.
NOTE: Refer to the unit Service Proce-
dures for blower motor oiling informa-
tion. When required, the motor
must be oiled by a qualified service
technician.
5. Routine inspection and cleaning/
replacement of the air filter.
6. Inspection of all supply- and
return-air ducts for obstructions,
air leaks, and insulation.Any prob-
lems found should be resolved at
this time.
7. Inspection of furnace installation
for proper support and any obvi-
ous deterioration of the furnace.
The support must be sound and
without sags, gaps, cracks, etc.,
around the furnace base so as to
provide an air seal between the
support and furnace.
8. A check for loose connections
attaching individual components.
Inspection of all electrical wiring
and their connections.
9. Operational check of the furnace
itself to determine working condi-
tion. Repair or adjustment should
be made at this time.
Ask your servicing dealer for
further details about an economical
service contract that covers seasonal
inspections.

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12 Cancels:OM04-33 OM04-35
© 2000 Bryant Heating & Cooling Systems, 7310 W.Morris St. Indpls., IN 46231 PRINTED IN U.S.A. Catalog No. 5337-309 10-00
INSTALLATION DATA
Date Installed
Dealer Name
Address
City
State Zip
Telephone
FURNACE
Product No.
Model No.
Serial No.
SPLIT-SYSTEM
OUTDOOR UNIT:
Product No.
Model No.
Serial No.
INDOOR COIL:
Product No.
Model No.
Serial No.