Sharp | R-340M W | Operating instructions | Sharp R-340M W Operating instructions

installation, start-up,
and operating instructions
340MAV
4-WAY MULTIPOISE
FIXED-CAPACITY DIRECT-VENT
CONDENSING GAS FURNACE
Series D
Cancels:
II 340M-40-2
II 340M-40-3
5-96
ama
®
CANADIAN GAS ASSOCIATION
A PP R O VED
R
A93040
As an ENERGY STARSM
Partner, BDP Company
has determined that this
product meets the ENERGY STAR guidelines
for energy efficiency.
NOTE: Read the entire instruction manual before starting the
installation.
This symbol → indicates a change since the last issue.
Index
Page
DIMENSIONAL DRAWING........................................................2
SAFETY CONSIDERATIONS .....................................................3
Clearances to Combustibles......................................................3
ELECTROSTATIC DISCHARGE (ESD) PRECAUTIONS ....3-4
INTRODUCTION ..........................................................................4
APPLICATIONS ......................................................................4-11
General ......................................................................................4
Upflow Applications..............................................................4-6
Downflow Applications.........................................................7-8
Horizontal Left (Supply-Air Discharge) Applications .........8-9
Horizontal Right (Supply-Air Discharge) Applications.....9-11
LOCATION ............................................................................11-12
General...............................................................................11-12
Furnace Location Relative to Cooling Equipment ................12
Hazardous Locations...............................................................12
INSTALLATION....................................................................13-16
Leveling Legs (If Desired) .....................................................13
Installation On a Concrete Slab .............................................13
Installation On a Combustible Floor (Downflow
Applications) ................................................................13-14
Installation In Horizontal Applications ..................................14
Filter Arrangement..................................................................15
Bottom Closure Panel.............................................................15
Gas Piping...............................................................................16
ELECTRICAL CONNECTIONS...........................................16-19
115-v Wiring......................................................................16-17
24-v Wiring.............................................................................17
Accessories..............................................................................19
DIRECT VENTING ...............................................................20-28
Removal of Existing Furnaces from
Common Vent Systems.....................................................20
Combustion-Air and Vent Piping .....................................20-25
Concentric Vent and Combustion-Air Termination
Kit Installation..............................................................25-28
Multiventing and Vent Termination.......................................28
CONDENSATE DRAIN ........................................................28-30
General ....................................................................................28
Application ..............................................................................28
Condensate Drain Protection.............................................28-30
CERTIFICATION OF MANUFACTURING SITE
AIRFLOW
UPFLOW
HORIZONTAL
LEFT
HORIZONTAL
RIGHT
DOWNFLOW
AIRFLOW
AIRFLOW
AIRFLOW
Fig. 1—Multipoise Orientations
A93041
SEQUENCE OF OPERATION..............................................30-31
Heating Mode..........................................................................30
Cooling Mode .........................................................................30
Continuous Blower Mode.......................................................30
Heat Pump Mode...............................................................30-31
Component Test ......................................................................31
START-UP PROCEDURES ..................................................31-37
General ....................................................................................31
Prime Condensate Trap With Water ......................................32
Purge Gas Lines......................................................................32
Adjustments .......................................................................32-37
Set Gas Input Rate ............................................................32-36
Set Temperature Rise ........................................................36-37
Blower Off Delay (Heat Mode) .............................................37
Set Thermostat Heat Anticipator............................................37
CHECK SAFETY CONTROLS..................................................37
Check Primary Limit Control.................................................37
Check Pressure Switch ...........................................................37
CHECKLIST...........................................................................37-38
—1—
—2—
11⁄4"
1"
14 1⁄2"
TYP
24 1⁄2"
5⁄16"
1⁄2-IN.
26 15⁄16" TYP
23 1⁄4" TYP
SIDE INLET
SIDE INLET
DIA THERMOSTAT
ENTRY
22 11⁄16"
2-IN. VENT CONN
DIA
GAS CONN
1⁄2-IN.
2-IN. COMBUSTIONAIR CONN
22
26 15⁄16"
26 1⁄4"
UNIT SIZE
024040
036040
024060
036060
048060
036080
048080
060080
048100
060100
060120
CONDENSATE
DRAIN LOCATION
(UPFLOW)
9 7⁄16"
TYP
E
INLET
OUTLET
D
11/16"
D
15-7/8
15-7/8
15-7/8
15-7/8
15-7/8
15-7/8
15-7/8
19-3/8
19-3/8
19-3/8
22-7/8
Fig. 2—Dimensional Drawing
A
17-1/2
17-1/2
17-1/2
17-1/2
17-1/2
17-1/2
17-1/2
21
21
21
24-1/2
DIMENSIONS (IN.)
18 1⁄4"
TYP
9⁄16"
DIMPLE LOCATORS
FOR HORIZONTAL
HANGING
CONDENSATE
DRAIN LOCATION
(UPFLOW)
30
1⁄2"
CONDENSATE DRAIN
TRAP LOCATION
(DOWNFLOW &
HORIZONTAL RIGHT)
OR ALTERNATE
1⁄2-IN. DIA GAS CONN
13/16"
NOTES: Minimum return-air opening at furnace:
1. For 800 CFM--16-In. round or 14 1/2 x 12-In. rectangle.
2. For 1200 CFM--20-In. round or 14 1/2 x 19 1/2-In. rectangle.
3. For 1600 CFM--22-In. round or 14 1/2 x 23 1/4-In. rectangle.
4. For airflow requirements above 1800 CFM, use both side inlets, a
combination of 1 side inlet and the bottom, or the bottom only.
11/16"
33 1⁄4"
TYP
5
32 ⁄8"
TYP
30 13⁄16"
29 11⁄16"
TYP
27 5⁄8"
27 9⁄16"
TYP
24 1⁄2"
17 5⁄16"
CONDENSATE
DRAIN TRAP
LOCATION
(ALTERNATE
UPFLOW)
DIA
ACCESSORY
POWER ENTRY
7⁄8-IN.
DIA
POWER CONN
7⁄8-IN.
CONDENSATE DRAIN
TRAP LOCATION
(DOWNFLOW &
HORIZONTAL LEFT)
13/16"
A
AIRFLOW
E
16
16
16
16
16
16
16
19-1/2
19-1/2
19-1/2
23
24 3⁄16"
BOTTOM INLET
22 1⁄4" TYP
SIDE INLET
22 11⁄16"
2-IN. VENT CONN
DIA
THERMOSTAT ENTRY
1⁄2-IN.
DIA
POWER CONN
7⁄8-IN.
DIA
GAS CONN
1⁄2-IN.
2-IN. COMBUSTIONAIR CONN
OUTLET
19"
22 5⁄16"
26 1⁄4"
28 1⁄2"
26 15⁄16"
A93023
11⁄16"
7⁄16"
1"
39 7⁄8"
5⁄16"
5⁄8"
13⁄16"
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. Untrained
personnel can perform basic maintenance functions such as cleaning and replacing air filters. All other operations must be performed by trained service personnel. When working on heating
equipment, observe precautions in literature, on tags, and on labels
attached to or shipped with unit and other safety precautions that
may apply.
→ Follow all safety codes. In the United States, follow all safety
codes including the National Fuel Gas Code (NFGC) NFPA No.
54-1992/ANSI Z223.1-1992 and the Installation Standards, Warm
Air Heating and Air Conditioning Systems (NFPA 90B)
ANSI/NFPA 90B. In Canada, refer to the current edition of the
National Standard of Canada CAN/CGA-B149.1- and .2-M95
Natural Gas and Propane Installation Codes (NSCNGPIC). Wear
safety glasses and work gloves. Have fire extinguisher available
during start-up and adjustment procedures and service calls.
Recognize safety information. This is the safety-alert symbol .
When you see this symbol on unit or in instructions and manuals,
be alert to potential for personal injury.
Understand the signal words DANGER, WARNING, and CAUTION. These words are used with the safety-alert symbol. DANGER identifies 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.
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 electrostatic 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.
This appliance is equipped for use with natural gas at altitudes 0 - 10,000 ft (0-3,050 m).
A conversion kit, supplied by the manufacturer, shall be used to convert to propane or
elevation.
This direct-vent, forced-air furnace is for indoor installation in a building constructed
on site or in a manufactured (mobile) home when using factory authorized kit, see
rating plate. For installation in alcove or closet at minimum clearances from combustible
material as shown below.
This appliance requires a special venting system. Refer to the installation instructions for
parts list and method of installation. This furnace is for use with schedule-40 PVC, PVCDWV, or ABS-DWV pipe, and must not be vented in common with other gas-fired appliances.
Construction through which vent/air intake pipes may be installed is maximum 24 inches
(600 mm), minimum 3/4 inches (19 mm) thickness (including roofing materials).
MINIMUM CLEARANCE TO COMBUSTIBLE MATERIAL
TOP / PLENUM BOTTOM SIDES
BACK
FRONT
VENT
INCHES
1
0
0
0
3 Ø
0
UPFLOW
1
#
0
0
3 Ø
0
DOWNFLOW
1
0†
1
0
3 Ø
0
HORIZONTAL
*
#
For Installation on combustible floors only when installed on special base
No. KGASB0201ALL.
shown is for air inlet and air outlet end.
* Clearance
Horizontal position: Line contact is permissible only between lines formed by intersections
of top and two sides of furnace jacket, and building joists, studs, or framing.
† 120,000 BTU Input Furnaces require 1 inch bottom clearance to combustible materials.
Ø Minimum front clearance for service is 30 inches. (762mm).
320611-101 REV. H
A96229
→ Fig. 3—Clearances to Combustibles
—3—
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.
These instructions cover minimum requirements for a safe installation and conform to existing national standards and safety codes.
In some instances, these instructions exceed certain local codes
and ordinances, especially those that may not have kept pace with
changing residential construction practices. We require these
instructions as a minimum for a safe installation.
CAUTION: Application of this furnace should be indoors with special attention given to vent sizing and
material, gas input rate, air temperature rise, unit leveling,
and unit sizing. Improper installation or misapplication of
furnace can require excessive servicing or cause premature component failure.
7. An ESD service kit (available from commercial sources)
may also be used to prevent ESD damage.
INTRODUCTION
340MAV Multipoise Condensing Gas-Fired Furnaces are
A.G.A./C.G.A. certified for natural and propane gases and for
installation in alcoves, attics, basements, closets, utility rooms,
crawlspaces, and garages. The furnace is factory-shipped for use
with natural gas. An A.G.A/C.G.A certified gas conversion kit is
required to convert furnace for use with propane gas. The
340MAV Furnaces are A.G.A./C.G.A. approved for use in manufactured (mobile) homes when factory accessory conversion kit is
used. These furnaces are suitable for installation in a residence
built on site or a manufactured residence completed at final site.
The design of this furnace line is NOT A.G.A./C.G.A. certified for
installation in recreation vehicles or outdoors.
These furnaces SHALL NOT be installed directly on carpeting,
tile, or any other combustible material other than wood flooring. In
downflow installations, factory accessory floor base MUST be
used when installed on combustible materials and wood flooring.
These furnaces are shipped with the drain and pressure tubes
connected for UPFLOW applications. Minor modifications are
required when used in DOWNFLOW, HORIZONTAL RIGHT, or
HORIZONTAL LEFT (supply-air discharge direction) applications as shown in Fig. 1. See details in Applications section.
These furnaces are shipped with the following materials to assist in
proper furnace installation. These materials are shipped in the main
blower compartment.
Installer Packet includes:
Installation, Start-Up, and Operating Instructions
Service and Maintenance Procedures
User’s Information Manual
Warranty Certificate
Loose Parts Bag includes:
Quantity
Pressure tube extension
1
Collector box or condensate trap extension tube
1
Inducer housing drain tube
1
1/2-in. CPVC street elbow
2
Drain tube coupling
1
Drain tube coupling grommet
1
Vent and combustion-air pipe support
2
Combustion-air pipe perforated disk assembly
1
Vent Pipe Extension
1*
* ONLY supplied with some furnaces.
→ Before installing the furnace in the United States, refer to the
current edition of the NFGC and the NFPA 90B. For further
information, the NFGC and the NFPA 90B are available from
National Fire Protection Association Inc., Batterymarch Park,
Quincy, MA 02269; American Gas Association, 1515 Wilson
Boulevard, Arlington, VA 22209; or from Literature Distribution.
Before installing the furnace in Canada, refer to the current edition
of the NSCNGPIC. Contact Standards Department of Canadian
Gas Association, 55 Scarsdale Road, Don Mills, Ontario, Canada
M3B 2R3.
Installations must comply with regulations of serving gas supplier
and local building, heating, plumbing, or other codes in effect in
area in which installation is made. In absence of local codes,
installation must conform with NFGC.
Canadian installations must be made in accordance with NSCNGPIC and all authorities having jurisdiction.
→ The
WARNING: Improper installation, adjustment, alteration, service, maintenance, or use can cause carbon
monoxide poisoning, explosion, fire, electrical shock, or
other conditions which may cause personal injury or
property damage. Consult a qualified installer, service
agency, local gas supplier, or your distributor or branch
for information or assistance. The qualified installer or
agency must use only factory-authorized and listed kits or
accessories when modifying this product. Failure to
follow this warning could result in electrical shock, fire,
personal injury, or death.
For accessory installation details, refer to applicable installation
literature.
APPLICATIONS
I. GENERAL
Some assembly and modifications are required for furnaces
installed in any of the 4 applications shown in Fig. 1. All drain and
pressure tubes are connected as shown in Fig. 5. See appropriate
application instructions for these procedures.
II. UPFLOW APPLICATIONS
An upflow furnace application is where furnace blower is located
below combustion and controls section of furnace, and conditioned
air is discharged upwards.
A. Condensate Trap Location (Factory-Shipped
Orientation)
The condensate trap is factory installed in the blower shelf and
factory connected for UPFLOW applications. A factory-supplied
tube is used to extend the condensate trap drain connection to the
desired furnace side for field drain attachment. See Condensate
Trap Tubing (Factory-Shipped Orientation) section for drain tube
extension details.
B. Condensate Trap Tubing (Factory-Shipped
Orientation)
NOTE: See Fig. 5 or tube routing label on main furnace door to
confirm location of these tubes.
1. Collector Box Drain, Inducer Housing Drain, Relief Port,
and Pressure Switch Tubes
These tubes should be factory attached to condensate trap
and pressure switch ready for use in UPFLOW applications.
These tubes can be identified by their connection location
and also by a color label on each tube. These tubes are
identified as follows: collector box drain tube (blue label),
inducer housing drain tube (violet label or molded), relief
port tube (green label), and pressure switch tube (pink
label).
—4—
FURNACE
DOOR
BLOWER SHELF
CONDENSATE
TRAP
CONDENSATE
TRAP (INSIDE)
FURNACE
DOOR
FURNACE
SIDE
4 78
FURNACE
SIDE
4
534
534
4
FIELD
DRAIN
CONN
ALTERNATE DRAIN
TUBE LOCATION
26 1 4
26 1 4
11 2
SIDE VIEW
CONDENSATE TRAP
DRAIN TUBE LOCATION
FIELD
DRAIN
CONN
FRONT VIEW
END VIEW
SLOT FOR SCREW
HORIZONTAL
APPLICATION
(OPTIONAL)
FRONT VIEW
HORIZONTAL
APPLICATIONS
DOWNFLOW AND ALTERNATE
EXTERNAL UPFLOW APPLICATIONS
UPFLOW APPLICATIONS
34
1⁄4
OD
COLLECTOR BOX TO
TRAP RELIEF PORT
11 2
1⁄2
OD
INDUCER HOUSING
DRAIN CONNECTION
34
5⁄8
OD
COLLECTOR BOX
DRAIN CONNECTION
71 8
SCREW HOLE FOR
UPFLOW OR DOWNFLOW APPLICATIONS
(OPTIONAL)
13 4
78
WIRE TIE
GUIDES
(WHEN USED)
21 4
FRONT VIEW
1⁄2-IN.
PVC OR CPVC
SIDE VIEW
A93026
Fig. 4—Condensate Trap
2. Condensate Trap Drain Tube
h. Attach tube to coupling and clamp securely.
The condensate trap drain connection must be extended for
field attachment by doing the following:
a. Determine location of field drain connection. (See Fig. 2
or 5.)
C. Condensate Trap Location (Alternate Upflow
Orientation)
An alternate location for the condensate trap is the left-hand side
of casing. (See Fig. 2 and 6.)
NOTE: If the alternate left-hand side of casing location is used,
the factory-connected drain and relief port tubes must be disconnected and modified for attachment. See Condensate Trap Tubing
(Alternate Upflow Orientation) section for tubing attachment.
To relocate condensate trap to the left-hand side, perform the
following:
NOTE: If internal filter is used, drain tube should be located to
opposite side of casing of return duct attachment to assist in filter
removal.
b. Remove and discard casing drain hole plug button from
desired side.
c. Install drain tube coupling grommet (factory-supplied in
loose parts bag) in selected casing hole.
1. Remove 3 tubes connected to condensate trap.
2. Remove trap from blower shelf by gently pushing tabs
inward and rotating trap.
d. Slide drain tube coupling (factory-supplied in loose parts
bag) through grommet ensuring long end of coupling
faces blower.
3. Remove casing hole filler cap from casing hole. (See Fig. 2
or 6.)
e. Cement 2 factory-supplied 1/2-in. street CPVC elbows to
the rigid drain tube connection on the condensate trap.
(See Fig. 5.) These elbows must be cemented together
and cemented to condensate trap drain connection.
4. Install casing hole filler cap into blower shelf hole where
trap was removed.
5. Install condensate trap into left-hand side casing hole by
inserting tube connection stubs through casing hole and
rotating until tabs snap into locking position.
NOTE: Failure to use CPVC elbows may allow drain to kink and
prevent draining.
f. Connect larger diameter drain tube and clamp (factorysupplied in loose parts bag) to condensate trap and clamp
securely.
D. Condensate Trap Tubing (Alternate Upflow
Orientation)
NOTE: See Fig. 6 or tube routing label on main furnace door to
confirm location of these tubes.
g. Route tube to coupling and cut to appropriate length.
—5—
PLUG
PLUG
CAP
CAP
COLLECTOR BOX
DRAIN TUBE (BLUE
& WHITE STRIPED)
COLLECTOR BOX
DRAIN TUBE (BLUE
& WHITE STRIPED)
COLLECTOR BOX
TUBE (PINK)
COLLECTOR BOX
TUBE (PINK)
COLLECTOR BOX
TUBE (GREEN)
COLLECTOR BOX
TUBE (GREEN)
COLLECTOR BOX
DRAIN TUBE (BLUE)
INDUCER HOUSING
(MOLDED) DRAIN
TUBE (BEHIND
COLLECTOR BOX
DRAIN TUBE)
COLLECTOR BOX
DRAIN TUBE (BLUE)
CONDENSATE
TRAP
CONDENSATE
TRAP
INDUCER
HOUSING
DRAIN TUBE
(VIOLET)
FIELD-INSTALLED
FACTORY-SUPPLIED
DRAIN TUBE
COUPLING (LEFT
DRAIN OPTION)
FIELD-INSTALLED
FACTORY-SUPPLIED
DRAIN TUBE
FIELD-INSTALLED
FACTORY-SUPPLIED
1⁄2-IN. CPVC STREET
ELBOWS (2) FOR
LEFT DRAIN OPTION
FIELD-INSTALLED
FACTORY-SUPPLIED
DRAIN TUBE
COUPLING (RIGHT
DRAIN OPTION)
A96194
A96195
→ Fig. 6—Alternate Upflow Tube Configuration and
Trap Location
→ Fig. 5—Factory-Shipped Upflow Tube Configuration
(Shown With Blower Access Panel Removed)
F. Pressure Switch Tubing
The LOWER collector box pressure tube (pink label) is factory
connected to the pressure switch and should not require any
modification.
NOTE: See Fig. 5 or 6 or tube routing label on main furnace door
to check for proper connections.
1. Collector Box Drain Tube
Connect collector box drain tube (blue label) to condensate
trap.
NOTE: On 17-1/2-in. wide furnaces ONLY, cut tube between
corrugated sections to prevent kinks from occurring.
2. Inducer Housing Drain Tube
a. Remove and discard LOWER (molded) inducer housing
drain tube which was previously connected to condensate trap.
G. Upper Collector Box and Inducer Housing (Unused)
Drain Connections
UPPER COLLECTOR BOX DRAIN CONNECTION
Attached to the UPPER collector box drain connection is a
factory-installed corrugated, plugged tube (blue and white striped
label). This tube is plugged to prevent condensate leakage in this
application. Ensure this tube is plugged.
NOTE: See Fig. 5 or 6 or tube routing label on main furnace door
to check for proper connections.
b. Use inducer housing drain extension tube (violet label
and factory-supplied in loose parts bag) to connect
LOWER inducer housing drain connection to the condensate trap.
c. Determine appropriate length, cut, and connect tube.
d. Clamp tube to prevent any condensate leakage.
UPPER INDUCER HOUSING DRAIN CONNECTION
Attached to the UPPER (unused) inducer housing drain connection
is a cap and clamp. This cap is used to prevent condensate leakage
in this application. Ensure this connection is capped.
NOTE: See Fig. 5 or 6 or tube routing label on main furnace door
to check for proper connections.
3. Relief Port Tube
a. Connect relief port tube (green label) to condensate trap.
b. Use smaller diameter tube (factory-supplied in loose
parts bag) to extend this tube if required.
c. Determine appropriate length, cut, and connect tube.
E. Condensate Trap Field Drain Attachment
Refer to Condensate Drain section for recommendations and
procedures.
H. Condensate Trap Freeze Protection
Refer to Condensate Drain Protection section for recommendations and procedures.
—6—
III.
DOWNFLOW APPLICATIONS
(1.) Condensate Trap Located on Left Side of Casing
A downflow furnace application is where furnace blower is located
above combustion and controls section of furnace, and conditioned
air is discharged downwards.
(a.) Connect LOWER collector box drain tube
(blue and white striped label) to condensate
trap. Tube does not need to be cut.
A.
(b.) Clamp tube to prevent any condensate leakage.
Condensate Trap Location
The condensate trap must be removed from the factory-installed
blower shelf location and relocated in selected application location
as shown in Fig. 2, 7, or 8.
To relocate condensate trap from the blower shelf to desired
location, perform the following:
(2.) Condensate Trap Located on Right Side of Casing
(a.) Install drain tube coupling (factory-supplied in
loose parts bag) into collector box drain tube
(blue and white striped label) which was previously plugged.
1. Remove 3 tubes connected to condensate trap.
(b.) Connect larger diameter drain tube (factorysupplied in loose parts bag) to drain tube
coupling, extending collector box drain tube
for connection to condensate trap.
2. Remove trap from blower shelf by gently pushing tabs
inward and rotating trap.
3. Remove casing hole filler cap from casing hole. (See Fig. 2,
7, or 8.)
(c.) Route extended collector box drain tube between gas valve and inlet housing as shown in
Fig. 8.
4. Install casing hole filler cap into blower shelf hole where
trap was removed.
5. Install condensate trap into desired casing hole by inserting
tube connection stubs through casing hole and rotating until
tabs snap into locking position.
(d.) Determine appropriate length and cut.
(e.) Connect to condensate trap.
(f.) Clamp tube to prevent any condensate leakage.
B. Condensate Trap Tubing
NOTE: See Fig. 7 or 8 or tube routing label on main furnace door
to check for proper connections.
2. Inducer Housing Drain Tube
a. Remove factory-installed cap and clamp from LOWER
inducer housing drain connection.
1. Collector Box Drain Tube
a. Remove factory-installed plug from LOWER collector
box drain tube (blue and white striped label).
b. Remove and discard UPPER (molded) inducer housing
drain tube which was previously connected to condensate trap.
b. Install removed clamp and plug into UPPER collector
box drain tube (blue label) which was connected to
condensate trap.
c. Install cap and clamp on UPPER inducer housing drain
connection where molded drain tube was removed.
c. Connect LOWER collector box drain connection to
condensate trap.
COLLECTOR BOX
DRAIN TUBE (BLUE)
CAP
PLUG
PLUG
CAP
COLLECTOR BOX
TUBE (GREEN)
COLLECTOR BOX
DRAIN TUBE (BLUE)
COLLECTOR BOX
EXTENSION TUBE
COLLECTOR BOX
TUBE (PINK)
COLLECTOR BOX
TUBE (PINK)
COLLECTOR BOX
TUBE (GREEN)
COLLECTOR BOX
EXTENSION TUBE
COLLECTOR BOX
DRAIN TUBE (BLUE
& WHITE STRIPED)
COLLECTOR BOX
DRAIN TUBE (BLUE
& WHITE STRIPED)
COLLECTOR BOX
EXTENSION TUBE
COLLECTOR BOX
EXTENSION TUBE
INDUCER HOUSING
DRAIN TUBE
(VIOLET)
CONDENSATE
TRAP
CONDENSATE
TRAP
COLLECTOR BOX
EXTENSION
DRAIN TUBE
INDUCER HOUSING
DRAIN TUBE (VIOLET)
DRAIN TUBE
COUPLING
A96196
A96197
→ Fig. 8—Downflow Tube Configuration
(Right-Hand Trap Installation)
→ Fig. 7—Downflow Tube Configuration
(Left-Hand Trap Installation)
—7—
NOTE: See Fig. 7 or 8 or tube routing label on main furnace door
to check for proper connections.
d. Use inducer housing drain tube (violet label and factorysupplied in loose parts bag) to connect LOWER inducer
housing drain connection to the condensate trap.
Relocate tubes as described below.
e. Connect inducer housing drain connection to condensate
trap.
1. Disconnect collector box pressure tube (pink label) attached
to pressure switch.
(1.) Condensate Trap Located on Left Side of Casing
2. Use smaller diameter tube (factory-supplied in loose parts
bag) to extend collector box pressure tube (green label)
which was previously connected to condensate trap relief
port connection.
(a.) Determine appropriate length and cut.
(b.) Connect tube to condensate trap.
(c.) Clamp tube to prevent any condensate leakage.
(2.) Condensate Trap Located on Right Side of Casing
3. Connect collector box pressure tube (green label) to pressure switch connection labeled COLLECTOR BOX.
(a.) Route inducer housing drain tube (violet label)
between gas valve and inlet housing behind
collector box drain tube.
4. Use remaining smaller diameter tube (factory-supplied in
loose parts bag) to extend collector box pressure tube (pink
label) which was previously connected to pressure switch.
(b.) Determine appropriate length and cut.
(c.) Connect tube to condensate trap.
5. Route this extended tube (pink label) to condensate trap
relief port connection.
(d.) Clamp tube to prevent any condensate leakage.
3. Relief Port Tube
Refer to Pressure Switch Tubing section for connection
procedure.
6. Determine appropriate length, cut, and connect tube.
7. Clamp tube to relief port connection.
C. Condensate Trap Field Drain Attachment
Refer to Condensate Drain section for recommendations and
procedures.
D. Pressure Switch Tubing
→ One collector box pressure tube (pink label) is factory connected to
the pressure switch for use when furnace is installed in UPFLOW
applications. This tube MUST be disconnected and used for the
condensate trap relief port tube. The other collector box pressure
tube (green label) which was factory connected to the condensate
trap relief port connection MUST be connected to the pressure
switch in DOWNFLOW or HORIZONTAL RIGHT applications.
E.
Condensate Trap Freeze Protection
Refer to Condensate Drain Protection section for recommendations and procedures.
IV. HORIZONTAL LEFT (SUPPLY-AIR DISCHARGE)
APPLICATIONS
A horizontal left furnace application is where furnace blower is
located to the right of combustion and controls section of furnace,
and conditioned air is discharged to the left.
PLUG
CAP
AUXILIARY "J" BOX
RELOCATED HERE
COLLECTOR BOX EXTENSION TUBE
COLLECTOR BOX
DRAIN TUBE
(BLUE AND WHITE STRIPED)
CONDENSATE
TRAP
COLLECTOR BOX
TUBE (GREEN)
COLLECTOR
BOX EXTENSION
DRAIN TUBE
COLLECTOR BOX
EXTENSION TUBE
INDUCER HOUSING
DRAIN TUBE (VIOLET)
COLLECTOR BOX
DRAIN TUBE (BLUE)
DRAIN TUBE COUPLING
COLLECTOR BOX TUBE (PINK)
A96198
→ Fig. 9—Horizontal Left Tube Configuration
—8—
C.
CAUTION: Local codes may require a drain pan under
entire furnace and condensate trap when a condensing
furnace is used in an attic application or over a finished
ceiling.
→ D.
Pressure Switch Tubing
The LOWER collector box pressure tube (pink label) is factory
connected to the pressure switch for use when furnace is installed
in UPFLOW applications. This tube MUST be disconnected,
extended, rerouted, and then reconnected to the pressure switch in
HORIZONTAL LEFT applications.
NOTE: See Fig. 9 or tube routing label on main furnace door to
check for proper connections.
Modify tube as described below.
NOTE: In Canada, installations shall be in accordance with
current NSCNGPIC and/or local codes.
NOTE: The auxiliary junction box (J-Box) MUST be relocated to
opposite side of furnace casing. (See Fig. 9.) See Electrical
Connection section for J-Box relocation.
A.
Condensate Trap Field Drain Attachment
Refer to Condensate Drain section for recommendations and
procedures.
Condensate Trap Location
The condensate trap must be removed from the factory-installed
blower shelf location and relocated in selected application location
as shown in Fig. 2 or 9.
1. Disconnect collector box pressure tube (pink label) attached
to pressure switch.
2. Use smaller diameter tube (factory-supplied in loose parts
bag) to extend tube disconnected in item 1.
To relocate condensate trap from the blower shelf to desired
location, perform the following:
3. Route extended tube:
a. Behind inducer housing.
1. Remove 3 tubes connected to condensate trap.
2. Remove trap from blower shelf by gently pushing tabs
inward and rotating trap.
b. Between blower shelf and inducer housing.
3. Remove casing hole filler cap from casing hole. (See Fig. 2
or 9.)
d. Between inducer motor and pressure switch.
c. Behind inducer motor bracket.
4. Determine appropriate length, cut, and reconnect tube to
pressure switch connection labeled COLLECTOR BOX.
4. Install casing hole filler cap into blower shelf hole where
trap was removed.
E. Condensate Trap Freeze Protection
Refer to Condensate Drain Protection section for recommendations and procedures.
5. Install condensate trap into casing hole by inserting tube
connection stubs through casing hole and rotating until tabs
snap into locking position.
F. Construct a Working Platform
Construct working platform where all required furnace clearances
are met. (See Fig. 3 and 10.)
B. Condensate Trap Tubing
NOTE: See Fig. 9 or tube routing label on main furnace door to
check for proper connections.
CAUTION: The condensate trap MUST be installed
below furnace. See Fig. 4 for dimensions. The drain
connection to condensate trap must also be properly
sloped to an open drain.
1. Collector Box Drain Tube
a. Install drain tube coupling (factory-supplied in loose
parts bag) into collector box drain tube (blue label)
which was previously connected to condensate trap.
b. Connect large diameter drain tube and clamp (factorysupplied in loose parts bag) to drain tube coupling,
extending collector box drain tube.
NOTE: Combustion-air and vent pipes are restricted to a minimum length of 5 ft. (See Table 5.)
→ NOTE: A 12-in. minimum offset pipe section is recommended
with short (5 to 8 ft) vent systems. This recommendation is to
reduce excessive condensate droplets from exiting the vent pipe.
(See Fig. 10 or 28.)
c. Route extended tube (blue label) to condensate trap and
cut to appropriate length.
d. Clamp tube to prevent any condensate leakage.
2. Inducer Housing Drain Tube
a. Remove and discard LOWER (molded) inducer housing
drain tube which was previously connected to condensate trap.
V. HORIZONTAL RIGHT (SUPPLY-AIR DISCHARGE)
APPLICATIONS
A horizontal right furnace application is where furnace blower is
located to the left of combustion and controls section of furnace,
and conditioned air is discharged to the right.
b. Use inducer housing drain extension tube (violet label
and factory-supplied in loose parts bag) to connect
LOWER inducer housing drain connection to the condensate trap.
CAUTION: Local codes may require a drain pan under
entire furnace and condensate trap when a condensing
furnace is used in attic application or over a finished
ceiling.
c. Determine appropriate length, cut, and connect tube.
d. Clamp tube to prevent any condensate leakage.
3. Relief Port Tube
a. Use smaller diameter tube (factory-supplied in loose
parts bag) to extend collector box tube (green label)
which was previously connected to the condensate trap.
NOTE: In Canada, installations shall be in accordance with
current NSCNGPIC Installation Codes and/or local codes.
A. Condensate Trap Location
The condensate trap must be removed from the factory-installed
blower shelf location and relocated in selected application location
as shown in Fig. 2 or 11.
To relocate condensate trap from the blower shelf to desired
location, perform the following:
b. Route extended collector box pressure tube to relief port
connection on the condensate trap.
c. Determine appropriate length, cut, and connect tube.
d. Clamp tube to prevent any condensate leakage.
—9—
COMBUSTION – AIR
INTAKE
VENT
30″ MIN
WORK AREA
5 3⁄4″
MANUAL
SHUTOFF
GAS VALVE
A 12-IN. MIN HORIZONTAL PIPE
SECTION IS RECOMMENDED WITH
SHORT (5 TO 8 FT) VENT SYSTEMS
TO REDUCE EXCESSIVE
CONDENSATE DROPLETS FROM
EXITING THE VENT PIPE.
ACCESS OPENING
FOR TRAP
SEDIMENT
TRAP
DRAIN
CONDENSATE
TRAP
NOTE: LOCAL CODES MAY REQUIRE A DRAIN PAN UNDER THE
FURNACE AND CONDENSATE TRAP WHEN A CONDENSING
FURNACE IS INSTALLED ABOVE FINISHED CEILINGS.
A93031
1.
2.
3.
4.
5.
Fig. 10—Attic Location and Working Platform
Remove 3 tubes connected to condensate trap.
c. Install cap and clamp on UPPER inducer housing drain
connection where molded drain tube was removed.
Remove trap from blower shelf by gently pushing tabs
inward and rotating trap.
d. Use inducer housing drain extension tube (violet label
and factory-supplied in loose parts bag) to connect
Remove casing hole filler cap from casing hole. (See Fig. 2
LOWER inducer housing drain connection to condenor 11.)
sate trap.
Install casing hole filler cap into blower shelf hole where
e. Determine appropriate length, cut, and connect tube to
trap was removed.
condensate trap.
Install condensate trap into casing hole by inserting tube
f. Clamp tube to prevent any condensate leakage.
connection stubs through casing hole and rotating until tabs
snap into locking position.
3. Relief Port Tube
B. Condensate Trap Tubing
NOTE: See Fig. 11 or tube routing label on main furnace door to
check for proper connections.
1. Collector Box Drain Tube
a. Remove factory-installed plug from LOWER collector
box drain tube (blue and white striped label).
C. Condensate Trap Field Drain Attachment
Refer to Condensate Drain section for recommendations and
procedures.
b. Install removed clamp and plug into UPPER collector
box drain tube (blue label) which was previously connected to condensate trap.
→ One collector box pressure tube (pink label) is factory connected to
Refer to Pressure Switch Tubing section for connection
procedure.
D.
Pressure Switch Tubing
the pressure switch for use when furnace is installed in UPFLOW
applications. This tube MUST be disconnected and used for the
condensate trap relief port tube. The other collector box pressure
tube (green label) which was factory connected to the condensate
trap relief port connection MUST be connected to the pressure
switch in DOWNFLOW or HORIZONTAL RIGHT applications.
c. Connect LOWER collector box drain tube (blue and
white striped label) to condensate trap. Tube does not
need to be cut.
d. Clamp tube to prevent any condensate leakage.
2. Inducer Housing Drain Tube
a. Remove factory-installed cap and clamp from LOWER
inducer housing drain connection.
NOTE: See Fig. 11 or tube routing label on main furnace door to
check for proper connections.
Relocate tubes as described below.
b. Remove and discard UPPER (molded) inducer housing
drain tube which was previously connected to condensate trap.
1. Disconnect collector box pressure tube (pink label) attached
to pressure switch.
—10—
CAP
COLLECTOR BOX DRAIN TUBE (BLUE)
COLLECTOR BOX TUBE (GREEN)
COLLECTOR BOX EXTENSION TUBE
COLLECTOR BOX TUBE (PINK)
PLUG
CONDENSATE
TRAP
COLLECTOR BOX DRAIN TUBE
(BLUE AND WHITE STRIPED)
INDUCER HOUSING
DRAIN TUBE (VIOLET)
COLLECTOR BOX
EXTENSION TUBE
A96199
→ Fig. 11—Horizontal Right Tube Configuration
2. Use smaller diameter tube (factory-supplied in loose parts
LOCATION
bag) to extend collector box pressure tube (green label)
which was previously connected to condensate trap relief
I. GENERAL
port connection.
When a furnace is installed so that supply ducts carry air to areas
→ 3. Route extended collector box pressure tube behind inducer
outside the space containing the furnace, return air must also be
motor bracket then between inducer motor and pressure
handled by ducts sealed to furnace casing. The ducts terminate
switch.
outside the space containing the furnace to ensure there will not be
4. Connect collector box pressure tube (green label) to presa negative pressure condition within equipment room or space.
sure switch connection labeled COLLECTOR BOX.
Furnace may be located in a confined space without special
5. Use remaining smaller diameter tube (factory-supplied in
provisions for dilution or ventilation air. This furnace must be
loose parts bag) to extend collector box pressure tube (pink
installed so electrical components are protected from water.
label) which was previously connected to pressure switch.
6. Route this extended tube (pink label) to condensate trap
relief port connection.
7. Determine appropriate length, cut, and connect tube.
8. Clamp tube to relief port connection.
E. Condensate Trap Freeze Protection
Refer to Condensate Drain Protection section for recommendaLEVEL (0″) FRONT
tions and procedures.
FRONT
TO
LEVEL (0″)
1⁄2″ MAX
F. Construct a Working Platform
TO
1⁄2″ MAX
Construct working platform where all required furnace clearances
are met. (See Fig. 3 and 10.)
UPFLOW OR DOWNFLOW
CAUTION: The condensate trap MUST be installed
below furnace. See Fig. 4 for dimensions. The drain
connection to condensate trap must also be properly
sloped to an open drain.
HORIZONTAL
A93025
NOTE: For proper furnace operation, install furnace so that it is
level or pitched forward within 1/2 in. to ensure proper condensate
drainage from secondary heat exchangers.
NOTE: Combustion-air and vent pipes are restricted to a minimum length of 5 ft. (See Table 5.)
→ NOTE: A 12-in. minimum offset pipe section is recommended
with short (5 to 8 ft) vent systems. This recommendation is to
reduce excessive condensate droplets from exiting the vent pipe.
(See Fig. 10 or 28.)
Locate furnace as close to center of air distribution system as
possible.
Locate furnace so combustion-air pipe maximum lengths are not
exceeded. Refer to Table 5—Maximum Allowable Pipe Length.
—11—
FRONT
°F
32°F MINIMUM INSTALLED
AMBIENT OR FREEZE
PROTECTION REQUIRED
°F
RETURN
AIR
MAX 85°F
MIN 55°F
A93058
A93042
NOTE: These furnaces are designed for a minimum continuous
return-air temperature of 60°F or intermittent operation down to 55°F
such as when used with a night setback thermostat. Return-air
temperature must not exceed a maximum of 85°F. Failure to follow
these return-air temperature limits may affect reliability of heat
exchangers, motors, and controls.
FRONT
CAUTION: If these furnaces are installed in an unconditioned space where ambient temperatures may be 32°F
or lower, freeze protection measures must be taken.
Provide ample space for servicing and cleaning. Always comply
with minimum fire protection clearances shown on unit’s clearance to combustibles label. (See Fig. 3.) Locate furnace where
available electric power and gas supplies meet specifications on
furnace rating plate.
II. FURNACE LOCATION RELATIVE TO COOLING
EQUIPMENT
The cooling coil must be installed parallel with or on downstream
side of furnace to avoid condensation in heat exchanger. When
installed parallel with a furnace, dampers or other means used to
control flow of air must prevent chilled air from entering furnace.
If dampers are manually operated, they must be equipped with a
means to prevent operation of either unit unless damper is in
full-heat or full-cool position.
B
A
C
K
BACK
III.
HAZARDOUS LOCATIONS
FRONT
A93043
WARNING: Do not install furnace on its back. Safety
control operation will be adversely affected. Never connect return-air ducts to back of furnace. Failure to follow
this warning could result in fire, personal injury, or death.
CAUTION: If these furnaces are used during construction when adhesives, sealers, and/or new carpets are
being installed, make sure all combustion and circulating
air requirements are followed. If operation of furnace is
required during construction, use clean outside air for
combustion and ventilation. Compounds of chlorine and
fluorine, when burned with combustion air, form acids
which will cause corrosion of heat exchangers. Some of
these compounds are found in paneling, dry wall adhesives, paints, thinners, masonry cleaning materials, and
many other solvents commonly used in construction
process.
Excessive exposure to contaminated combustion air will
result in safety and performance related problems.
18-IN. MINIMUM
TO BURNERS
A93044
WARNING: When furnace is installed in a residential
garage, it must be installed so that burners and ignition
sources are located a minimum of 18 in. above floor. The
furnace must be located or protected to avoid physical
damage by vehicles. When furnace is installed in a public
garage, airplane hangar, or other building having a
hazardous atmosphere, unit must be installed in accordance with requirements of National Fire Protection
Association, Inc.
—12—
INSTALLATION
I.
LEVELING LEGS (IF DESIRED)
When furnace is used in upflow position with side inlet(s), leveling
legs may be desired. (See Fig. 12.) Install field-supplied,
corrosion-resistant 5/16-in. machine bolts and nuts.
A
B
HOLE IN
FLOOR
5⁄16″
5⁄16″
1 3⁄4″
1 3⁄4″
A73382
OPENING DIMENSIONS (IN.)
5⁄16″
FURNACE
CASING WIDTH
A
17-1/2
21
24-1/2
16-7/16
19-7/8
23-7/16
B
Heat Only
19-5/8
19-5/8
19-5/8
Heat/Cool*
19-7/16
19-7/16
19-7/16
* These dimensions apply when a model CB or CD Evaporator Coil casing is
to be installed.
5⁄16″
Fig. 13—Floor Opening in Concrete Slab
1 3⁄4″
1 3⁄4″
FURNACE
A89014
Fig. 12—Leveling Legs
NOTE: The maximum length of bolt should not exceed 1-1/2 in.
1. Position furnace on its back. Locate and drill a 5/16-in.
diameter hole in each bottom corner of furnace. (See Fig.
12.) Holes in bottom closure panel may be used as guide
locations.
PLENUM
A73383
2. For each hole, install nut on bolt and then install bolt and
nut in hole. (Install flat washer if desired.)
Fig. 14—Furnace on a Concrete Slab
(Non-Garage Installation)
3. Install another nut on other side of furnace base. (Install flat
washer if desired.)
PERFORATED
DISCHARGE DUCT
FLANGE
4. Adjust outside nut to provide desired height, and tighten
inside nut to secure arrangement.
NO
NOTE: Bottom closure must be used when leveling legs are used.
See Bottom Closure Panel section.
II.
INSTALLATION ON A CONCRETE SLAB
1. Construct hole in floor per dimensions in Fig. 13.
2. Place plenum and furnace as shown in Fig. 14.
III. INSTALLATION ON A COMBUSTIBLE
(DOWNFLOW APPLICATIONS)
YES
FLOOR
210°
MIN
1. Cut and frame hole in floor per dimensions in Installation
Instructions packaged with downflow subbase kit.
YES
NOTE: Remove furnace perforated, discharge duct flanges when
they interfere with mating flanges on coil on downflow subbase.
To remove furnace perforated, discharge duct flange, use wide
duct pliers or duct flange tool to bend flange back-and-forth until
it breaks off. Be careful of sharp edges. (See Fig. 15.)
Fig. 15—Duct Flanges
—13—
A93029
WARNING: Do not bend duct flanges inward as shown
in Fig. 15. This will affect airflow across heat exchangers
and may cause limited cycling or premature heat exchanger failure. Remove duct flange completely or bend
it inward a minimum of 210° as shown in Fig. 15.
FURNACE
(OR COIL CASING
WHEN USED)
2. When complete, downflow subbase, plenum, and furnace
(or coil casing when used) should be installed as shown in
Fig. 16.
IV.
DOWNFLOW
SUBBASE
INSTALLATION IN HORIZONTAL APPLICATIONS
→ These
furnaces can be installed horizontally in either horizontal
left or right discharge position. In a crawlspace, furnace can either
be hung from floor joist or installed on suitable blocks or pad.
Furnace can be suspended from each corner by hanger bolts and
angle iron supports. (See Fig. 17.) Cut hanger bolts (4 each 3/8-in.
all-thread rod) to desired length. Use 1 X 3/8-in. flat washers,
3/8-in. lockwashers, and 3/8-in. nuts on hanger rods as shown in
Fig. 17. Dimples are provided for hole locations. (See Fig. 2.)
SHEET METAL
PLENUM
CAUTION: The entire length of furnace MUST be
supported when furnace is used in a horizontal position to
ensure proper draining.
A78651
Fig. 16—Furnace, Plenum, and Subbase Installed on a
Combustible Floor
3⁄8-IN.
ANGLE
IRON OR
EQUIVALENT
ROD
5 3⁄4″
ALTERNATE SUPPORT
LOCATION 4-IN. MIN
8-IN. MAX
(B)
(A)
DRAIN
(B)
(A)
(A) ROD LOCATION
USING DIMPLE
LOCATORS
(SEE DIMENSIONAL
DWG FOR
LOCATIONS)
(B)
3/8-IN.
HEX NUT
& WASHER (4)
REQD PER ROD
(A) PREFERRED ROD LOCATION
(B) ALTERNATE ROD LOCATION
(A)
(B)
13/16-IN.
MAX
ALTERNATE SUPPORT
LOCATION FROM BACK
NOTES: 1. A 1 In. clearance minimum between top of
furnace and combustible material.
2. The entire length of furnace must be
supported when furnace is used in horizontal
position to ensure proper drainage.
A93304
Fig. 17—Crawlspace Horizontal Application
—14—
V.
FILTER ARRANGEMENT
171⁄2-IN. WIDE
CASINGS ONLY:
INSTALL FIELD-SUPPLIED
FILTER FILLER STRIP
UNDER FILTER.
CAUTION: Never operate unit without a filter or with
blower access panel removed.
Factory-supplied washable framed filters are shipped in blower
compartment. Determine location for filter and relocate filter
retaining wire if necessary. See Table 1 to determine correct filter
size for desired filter location. Table 1 indicates filter size,
location, and quantity shipped with this furnace. See Fig. 2 for
location and size of bottom and side return-air openings.
241⁄2-IN. WIDE
CASINGS ONLY:
CUT AND FOLD
FACTORY-PROVIDED
FILTERS AS SHOWN
TO DESIRED SIZE.
3″
24 1/2″
1″
TABLE 1—FILTER INFORMATION
FURNACE
FILTER SIZE (IN.)*
FILTER TYPE
CASING
FRAMED
Side Return
Bottom Return
WIDTH (IN.)
17-1/2
(1) 16 X 25 X 1† (1) 16 X 25 X 1
Cleanable
21
(1) 16 X 25 X 1 (1) 20 X 25 X 1†
Cleanable
24-1/2
(2) 16 X 25 X 1† (1) 24 X 25 X 1
Cleanable
* Filters can be field modified by cutting frame as marked and folding to desired
size. Alternate sizes can be ordered from your distributor or dealer.
† Factory-provided with furnace.
CAUTION: Air delivery above 1800 CFM requires that
both sides, a combination of 1 side and bottom, or bottom
only of furnace be used for return air.
NOTE: Side return-air openings can ONLY be used in UPFLOW
configurations. Install filter(s) as shown in Fig. 18.
WASHABLE
FILTER
WASHABLE
FILTER
FILTER
RETAINER
FILTER
SUPPORT
FILTER
RETAINER
A96030
Fig. 19—Bottom Filter Arrangement
A93045
Fig. 18—Filter Installed for Side Inlet
Bottom return-air opening may be used with all 4 orientations.
Filter may need to be cut to fit some furnace widths. Install filter
as shown in Fig. 19.
NOTE: Remove and discard bottom closure panel when bottom
inlet is used.
VI. BOTTOM CLOSURE PANEL
These furnaces are shipped with bottom enclosure panel installed
in bottom return-air opening. This panel MUST be in place when
side return air is used.
To remove bottom closure panel, perform following:
BOTTOM
CLOSURE
PANEL
FRONT FILLER
PANEL
1. Tilt or raise furnace and remove 2 screws holding front
filler panel. (See Fig. 20.)
A93047
Fig. 20—Removing Bottom Closure Panel
2. Rotate front filler panel downward to release holding tabs.
3. Remove bottom closure panel.
4. Reinstall front filler panel and screws.
—15—
VII.
GAS PIPING
GAS
SUPPLY
Gas piping must be installed in accordance with national and local
codes. Refer to current edition of NFGC. Canadian installations
must be made in accordance with NSCNGPIC and all authorities
having jurisdiction. Gas supply line should be a separate line
running directly from meter to furnace, if possible. Refer to Table
2 for recommended gas pipe sizing. Risers must be used to connect
to furnace and to meter. Support all gas piping with appropriate
straps, hangers, etc. Use a minimum of 1 hanger every 6 ft. Joint
compound (pipe dope) should be applied sparingly and only to
male threads of joints. Pipe dope must be resistant to propane gas.
MANUAL
SHUTOFF
VALVE
(REQUIRED)
SEDIMENT
TRAP
UNION
CAUTION: Connect gas pipe to furnace using a backup
wrench to avoid damaging gas controls.
WARNING: Gas valve shutoff switch MUST be facing
forward or tilted upward. Failure to follow this warning
could result in property damage or death.
A93324
Fig. 21—Typical Gas Pipe Arrangement
plugged tapping, accessible for test gage connection, MUST be
installed immediately upstream of gas supply connection to
furnace and downstream of manual shutoff valve.
NOTE: The gas valve inlet press tap connection is suitable to use
as test gage connection providing test pressure DOES NOT exceed
maximum 0.5 psig (14-in. wc) stated on gas valve. (See Fig. 44.)
Piping should be pressure tested in accordance with local and
national plumbing and gas codes before furnace is attached. In
Canada, refer to current edition of NSCNGPIC. If pressure
exceeds 0.5 psig (14-in. wc), gas supply pipe must be disconnected
from furnace and capped before pressure test. If test pressure is
equal to or less than 0.5 psig (14-in. wc), turn off electric shutoff
switch located on gas valve before test. It is recommended that
ground joint union be loosened before pressure testing. After all
connections have been made, purge lines and check for leakage.
WARNING: Never purge a gas line into a combustion
chamber. Never use matches, candles, flame, or other
sources of ignition for purpose of checking leakage. Use
a soap-and-water solution to check for leakage. A failure
to follow this warning could result in fire, explosion,
personal injury, or death.
WARNING: Use proper length of pipe to avoid stress on
gas control manifold. Failure to follow this warning could
result in a gas leak resulting in fire, explosion, personal
injury, or death.
ELECTRICAL CONNECTIONS
See Fig. 22 for field wiring diagram showing typical field 115-v
and 24-v wiring. Check all factory and field electrical connections
for tightness.
TABLE 2—MAXIMUM CAPACITY OF PIPE*
NOMINAL
IRON
PIPE
SIZE
(IN.)
1/2
3/4
1
1-1/4
1-1/2
WARNING: Blower access panel door switch opens
115-v power to control center. No component operation
can occur. Do not bypass or close switch with panel
removed. Failure to follow this warning could result in
personal injury or death.
LENGTH OF PIPE (FT)
INTERNAL
DIAMETER
(IN.)
10
20
30
40
50
0.622
0.824
1.049
1.380
1.610
175
360
680
1400
2100
120
250
465
950
1460
97
200
375
770
1180
82
170
320
660
990
73
151
285
580
900
CAUTION: Furnace control must be grounded for
proper operation or control will lock out. Control is
grounded through green wire routed to gas valve and
burner box screw.
* Cubic ft of gas per hr for gas pressures of 0.5 psig (14-in. wc) or less, and a
pressure drop of 0.5-in. wc (based on a 0.60 specific gravity gas). Ref: Table
10-2 NFPA 54-1992.
I. 115-V WIRING
Before proceeding with electrical connections, make certain that
voltage, frequency, and phase correspond to that specified on unit
rating plate. Also, check to be sure that service provided by utility
is sufficient to handle load imposed by this equipment. Refer to
rating plate or Table 3 for equipment electrical specifications.
Make all electrical connections in accordance with National
Electrical Code (NEC) ANSI/NFPA 70-1996 and any local codes
or ordinances that might apply. For Canadian installations, all
electrical connections must be made in accordance with Canadian
Electrical Code CSA C22.1 or subauthorities having jurisdiction.
Use a separate, fused branch electrical circuit containing a properly
sized fuse or circuit breaker for this furnace. See Table 3 for wire
size and fuse specifications. A disconnecting means must be
located within sight from and readily accessible to furnace.
Install a sediment trap in riser leading to furnace. Trap can be
installed by connecting a tee to riser leading to furnace so
straight-through section of tee is vertical. Then connect a capped
nipple into lower end of tee. Capped nipple should extend below
level of gas controls. Place a ground joint union between gas
control manifold and manual gas shutoff valve. (See Fig. 21.)
CAUTION: If a flexible connector is required or allowed by authority having jurisdiction, black iron pipe
shall be installed at gas valve and extend a minimum of
2 in. outside furnace casing.
An accessible manual shutoff valve MUST be installed upstream
of furnace gas controls and within 6 ft of furnace. A 1/8-in. NPT
—16—
FIELD 24-VOLT WIRING
FIELD 115-, 208/230-, 460-VOLT WIRING
FACTORY 24-VOLT WIRING
FACTORY 115-VOLT WIRING
NOTE 2
W
FIVE
WIRE
C
R
G
Y
THERMOSTAT
TERMINALS
FIELD-SUPPLIED
FUSED DISCONNECT
THREE-WIRE
HEATINGONLY
BLK
BLK
W
WHT
WHT
R
GND
GND
115-VOLT FIELD- AUXILIARY
J-BOX
SUPPLIED
CONTROL
FUSED
BOX
DISCONNECT
208/230- OR
460-VOLT
THREE
PHASE
G
C
NOTE 1
Y
24-VOLT
TERMINAL
BLOCK
FURNACE
GND
208/230VOLT
SINGLE
PHASE
CONDENSING
UNIT
TWO
WIRE
NOTES: 1. Connect Y-terminal as shown for proper operation.
2. Some thermostats require a "C" terminal connection as shown.
3. If any of the original wire, as supplied, must be replaced, use
same type or equivalent wire.
A95241
Fig. 22—Heating and Cooling Application Wiring Diagram
FACTORY
INSTALLED
LOCATION
ELECTRIC
DISCONNECT
SWITCH
COPPER
WIRE ONLY
ALTERNATE
FIELD
LOCATION
ALUMINUM
WIRE
A93033
CAUTION: Do not connect aluminum wire between
disconnect switch and furnace. Use only copper wire.
NOTE: Proper polarity must be maintained for 115-v wiring. If
polarity is incorrect, control center fault code indicator light will
flash rapidly and furnace will NOT operate.
A93051
Fig. 23—Relocating J-Box
CAUTION: If manual disconnect switch is to be
mounted on furnace, select a location where a drill or
fastener will not contact electrical or gas components.
WARNING: The cabinet MUST have an uninterrupted
or unbroken ground according to NEC ANSI/NFPA
70-1996 and Canadian Electrical Code CSA C22.1 or
local codes to minimize personal injury if an electrical
fault should occur. This may consist of electrical wire or
conduit approved for electrical ground when installed in
accordance with existing electrical codes. Do not use gas
piping as an electrical ground. Failure to follow this
warning could result in electrical shock, fire, or death.
II. 24-V WIRING
Make field 24-v thermostat connections at 24-v terminal block on
control center. For proper cooling operation, Y wire from thermostat MUST be connected to Y terminal on control center, as shown
in Fig. 22. The 24-v terminal board is marked for easy connection
of field wiring. (See Fig. 24.) The 24-v circuit contains a 3-amp,
automotive-type fuse located on control center. (See Fig. 25.) Any
electrical shorts of 24-v wiring during installation, service, or
maintenance may cause fuse to blow. If fuse replacement is
required, use only a fuse of identical size (3 amp).
NOTE: Use AWG No. 18 color-coded copper thermostat wire for
lengths up to 100 ft. For wire lengths over 100 ft, use AWG No.
16 wire.
J-BOX RELOCATION
1. Remove 2 screws holding auxiliary J-box. (See Fig. 23.)
2. Rotate J-box 180° and attach box to right side, using holes
provided.
—17—
—18—
120 VAC
L1 PR1
GV
GVR
HI/LO
HSI
HSIR
HUM
IDM
IDR
ILK
JB
LED
LGPS
LS
OL
PCB
BLWR
BLWM
CAP
CPU
EAC-1
EAC-2
FRS
FSE
FU1
FU2
1
HSI
2
1
2
PL3
1
2
3
BLK
GRN
WHT
1 2 3 PL4
M
OL
IDM
BRN
AUX
CAP -2
EAC-2
C OM
HEAT SPARE-2
EAC-1
COOL SPARE-1
24 VAC-3A
FUSE
BRN
PR2
L2
BLOWER
SPEED
SELECT
FU1
LED
SEC-2
6 5 4
9 8 7
3 2 1
SEC-1
PL1
WHT
HI/LO
RELAY
BLWR
PL5
PL2
IDR
GVR
225 SEC
180 SEC
135 SEC
TEST/TWIN
RED
WHT (COM)
RED (LO)
BLU (MED LO)
NOTE #8
YEL (MED HI)
BLK (HI)
WHT
ORN
BLOWER MOTOR RELAY, SPST-(N.O.)
BLOWER MOTOR
CAPACITOR
MICROPROCESSOR AND CIRCUITRY
ELECTRONIC AIR CLEANER CONNECTION (115 VAC 1.5 AMP MAX.)
ELECTRONIC AIR CLEANER CONNECTION (COMMON)
FLAME ROLLOUT SW. -MANUAL RESET, SPST-(N.C.)
FLAME PROVING ELECTRODE
FUSE, 3 AMP, AUTOMOTIVE BLADE TYPE, FACTORY INSTALLED
FUSE OR CIRCUIT BREAKER CURRENT INTERRUPT DEVICE
(FIELD INSTALLED & SUPPLIED)
GAS VALVE-REDUNDANT OPERATORS
GAS VALVE RELAY, DPST-(N.O.)
BLOWER MOTOR SPEED CHANGE RELAY, SPDT
HOT SURFACE IGNITOR (115 VAC)
HOT SURFACE IGNITOR RELAY, SPST-(N.O.)
24VAC HUMIDIFIER CONNECTION (.5 AMP. MAX.)
INDUCED DRAFT MOTOR
INDUCED DRAFT RELAY, SPST-(N.O.)
BLOWER ACCESS PANEL INTERLOCK SWITCH, SPST-(N.O.)
JUNCTION BOX
LIGHT-EMITTING DIODE FOR STATUS CODES
LOW GAS PRESSURE SWITCH, SPST-(N.O.)
LIMIT SWITCH, AUTO RESET, SPST(N.C.)
AUTO-RESET INTERNAL MOTOR OVERLOAD TEMP. SW.
PRINTED CIRCUIT BOARD
LEGEND
BLK
90 SEC
BLOWER OFF DELAY
SELECTION CHART
(NOT ON ALL MODELS)
BLK
HSIR
BLK
SEE NOTE #10
BLK
G
R
Y
W
C OM
HUM
1.5 AMP
PCB
WHT
SW2
BLOWER
OFF
DELAY
SW1
GRN
WHT
WHT
ILK
BLK
OL
RED
BLU
PL1
PL2
PL3
PL4
PL5
PRS
SW1 & 2
TEST/TWIN
TRAN
WHT
LS
RED
PRS
JB
BRN
NOTE #5
2-C
GV
3-P
GRN
BLK
WHT
FU2
L1
NEUTRAL
FUSED DISCONNECT
SWITCH (WHEN REQ’D)
NOTE #4
CAP -1
WHT (COM)
GRN
WHT
YEL
Fig. 24—Wiring Diagram
PLUG RECEPTACLE
FIELD SPLICE
EQUIPMENT GROUND
FIELD GROUND
FIELD WIRING TERMINAL
CONDUCTOR ON PCB
FIELD WIRING (24VAC)
FIELD WIRING (115VAC)
FACTORY WIRING (24VAC)
FACTORY WIRING (115VAC)
PCB TERMINAL
UNMARKED TERMINAL
JUNCTION
9-CIRCUIT CONNECTOR
2-CIRCUIT PCB CONNECTOR
3-CIRCUIT IDM CONNECTOR
3-CIRCUIT IDM EXTENSION CONNECTOR
2-CIRCUIT HSI/PCB CONNECTOR
PRESSURE SWITCH, SPST-(N.O.)
BLOWER OFF DELAY
COMPONENT TEST & TWIN TERMINAL
TRANSFORMER-115VAC/24VAC
GRN
BLWM
START
BRN
GRN
1-M
BLU
BLK
FSE
RED
FRS
NOTE #6
(WHEN USED)
LGPS
TRAN
L1
IDR
HSIR
COM
HSIR
IDR
CPU
BLWR
GVR-2
SEC-1
TRAN
PR1
EAC-2
2
1
HI/LO
PR2
PL5
GVR-1
GVR
SEC-2
24VAC
115VAC
PL2
2
1
9
6
5
8
2
3
4
1
7
FRS
PL1
M
1-M
3-P
NOTE #6
PRS
LS
FSE
NOTE #5
2-C
GV
(WHEN USED)
CAP -2
BRN
IDM
CAP-1
AUX
OL
BLWM
START
BRN
PL4
LGPS
2
3
3
2
1
PL3
HSI
OL
1
SPARE-1
NOTE #8
COOL
COM
COM
LO
MED LO
MED HI
HI
SCHEMATIC DIAGRAM
(NATURAL GAS & PROPANE)
L2
A95087
322854-101 REV. C
1. IF ANY OF THE ORIGINAL EQUIPMENT WIRE IS REPLACED USE WIRE RATED FOR 105°C.
2. INDUCER (IDM) AND BLOWER (BLWM) MOTORS CONTAIN INTERNAL
AUTO-RESET THERMAL OVERLOAD SWITCHES (OL).
3. BLOWER MOTOR SPEED SELECTIONS ARE FOR AVERAGE CONDITIONS, SEE INSTALLATION
INSTRUCTIONS FOR DETAILS ON OPTIMUM SPEED SELECTION.
4. USE ONLY COPPER WIRE BETWEEN THE DISCONNECT SWITCH AND THE
FURNACE JUNCTION BOX (JB).
5. THIS WIRE MUST BE CONNECTED TO FURNACE SHEETMETAL FOR CONTROL TO PROVE
FLAME.
6. FACTORY CONNECTED WHEN LGPS NOT USED.
7. REPLACE ONLY WITH A 3 AMP FUSE.
8. YELLOW LEAD NOT ON ALL MOTORS.
9. BLOWER-ON DELAY, GAS HEATING 60 SECONDS, COOLING OR HEAT PUMP 2 SECONDS.
10. BLOWER-OFF DELAY, GAS HEATING 90, 135, 180 OR 225 SECONDS, COOLING OR
HEAT PUMP 90 SECONDS. (135 SECONDS ONLY ON SOME MODELS)
11. IGNITION-LOCKOUT WILL OCCUR AFTER FOUR CONSECUTIVE UNSUCCESSFUL
TRIALS-FOR-IGNITION. CONTROL WILL AUTO-RESET AFTER THREE HOURS.
12. SOME MODELS MAY HAVE SPADE QUICK CONNECT TERMINALS.
NOTES:
G
Y
W
R
NOTE #12
HUM
HI/LO
SPARE-2
HEAT
EQUIPMENT GROUND
EAC-1
NOTE #7
BLWR
NEUTRAL
TEST/TWIN FU1
ILK
L1
TO 115VAC FIELD DISCONNECT
NOTE #4
TABLE 3—ELECTRICAL DATA
UNIT
SIZE
VOLTS—
HERTZ—
PHASE
024040
036040
024060
036060
048060
036080
048080
060080
048100
060100
060120
115—60—1
115—60—1
115—60—1
115—60—1
115—60—1
115—60—1
115—60—1
115—60—1
115—60—1
115—60—1
115—60—1
OPERATING
VOLTAGE RANGE
Max*
Min*
127
104
127
104
127
104
127
104
127
104
127
104
127
104
127
104
127
104
127
104
127
104
MAX
UNIT
AMPS
UNIT
AMPACITY†
MIN
WIRE
SIZE
MAX WIRE
LENGTH (FT)‡
MAX FUSE OR
CKT BKR AMPS**
6.1
7.3
6.1
7.1
9.5
7.6
10.0
14.1
10.2
14.8
14.6
8.4
10.0
8.4
9.8
12.8
10.4
13.4
18.4
13.5
19.3
19.1
14
14
14
14
14
14
14
12
14
12
12
44
37
44
38
29
36
28
31
27
30
30
15
15
15
15
15
15
15
20
15
20
20
* Permissible limits of voltage range at which unit will operate satisfactorily.
† Unit ampacity = 125 percent of largest operating component’s full load amps plus 100 percent of all other potential operating components’ (EAC, humidifier, etc.) full load
amps.
‡ Length shown is as measured 1 way along wire path between unit and service panel for maximum 2 percent voltage drop.
** Time-delay fuse is recommended.
ACCESSORIES
2. Humidifier (HUM)
1. Electronic Air Cleaner (EAC)
A quick-connect terminal (HUM) and screw terminal (COM)
are provided for 24-v humidifier connection. (See Fig. 24.)
HUM terminal is energized with 24v (0.5-amp maximum)
after inducer motor prepurge period.
NOTE: A field-supplied, 115-v controlled relay connected to
EAC terminals may be added if humidifier operation is desired
during blower operation.
Two quick-connect terminals marked EAC-1 and EAC-2
are provided for EAC connection. (See Fig. 25.) These
terminals are energized with 115v (1.5-amp maximum)
during blower motor operation.
24V
TEST/TWIN
COM W Y R G
III.
HUM
24-V THERMOSTAT
TERMINALS
HUMIDIFIER TERMINAL
(24-VAC 0.5 AMP MAX)
LED OPERATION &
DIAGNOSTIC LIGHT
HARNESS CONNECTOR
SEC-1
24-V TRANSFORMER SEC-2
3-AMP FUSE
SPARE-1
COOL
HEAT
BLOWER SPEED
SELECTION TERMINALS
SPARE-2
EAC-1
EAC-ELECTRONIC AIR CLEANER
TERMINALS (115-VAC 1.5 AMP MAX)
115-VAC (L1)
POWER SUPPLY
HOT SURFACE
IGNITOR CONNECTOR
EAC-2
115-VAC (L2) NEUTRAL
CONNECTION
INDUCER MOTOR
CONNECTOR
A95086
Fig. 25—Control Center
—19—
DIRECT VENTING
The 340MAV Furnaces require a dedicated (one 340MAV furnace
only) direct-vent system. In a direct-vent system, all air for
combustion is taken directly from outside atmosphere, and all flue
products are discharged to outside atmosphere.
FURNACE
I. REMOVAL OF EXISTING FURNACES FROM
COMMON VENT SYSTEMS
If furnace being replaced was connected to a common vent system
with other appliances, the following steps shall be followed with
each appliance connected to the venting system placed in operation, while any other appliances connected to the venting system
are not in operation:
NOT IN
HORIZONTAL
SECTION
PIPE DIAMETER
TRANSITION IN
VERTICAL SECTION
1. Seal any unused openings in the venting system.
2. Inspect the venting system for proper size and horizontal
pitch as required in the National Fuel Gas Code, ANSI
Z223.1 or the CAN/CGA B149 Installation Codes and these
instructions. Determine that there is no blockage or restriction, leakage, corrosion, and other deficiencies which could
cause an unsafe condition.
A93034
Fig. 26—Combustion-Air and Vent Pipe Diameter
Transition Location and Elbow Configuration
Combustion-air and vent pipes must terminate together in same
atmosphere pressure zone, either through roof or sidewall (roof
termination preferred), using accessory termination kit. See Table
4 for required clearances.
3. In so far as is practical, close all building doors and
windows and all doors between the space in which the
appliance(s) connected to the venting system are located
and other spaces of the building. Turn on clothes dryers and
any appliance not connected to the venting system. Turn on
any exhaust fans, such as range hoods and bathroom
exhausts, so they shall operate at maximum speed. Do not
operate a summer exhaust fan. Close fireplace dampers.
TABLE 4—COMBUSTION-AIR AND VENT PIPE
TERMINATION CLEARANCES
4. Follow the lighting instructions. Place the appliance being
inspected in operation. Adjust thermostat so appliance shall
operate continuously.
LOCATION
Above grade level or above anticipated snow depth
Dryer vent
From plumbing vent stack
From any mechanical fresh air
intake
For furnaces with an input capacity less than 100,000 Btuh—from
any non-mechanical air supply
(windows or doors which can be
opened) or combustion-air opening
For furnaces with an input capacity greater than 100,000
Btuh—from any non-mechanical
air supply (windows or doors
which can be opened) or
combustion-air opening
From service regulator vent, electric and gas meters, and relief
equipment
Above grade when adjacent to
public walkway
5. Test for draft hood equipped appliance spillage at the draft
hood relief opening after 5 minutes of main burner operation. Use the flame of a match or candle.
6. After it has been determined that each appliance connected
to the venting system properly vents when tested as outlined
above, return doors, windows, exhaust fans, fireplace dampers, and any other gas-burning appliance to their previous
conditions of use.
7. If improper venting is observed during any of above tests,
the venting system must be corrected.
Vent system or vent connectors may need to be resized. For any
other appliances when resizing vent systems or vent connectors,
system or connector must be sized to approach minimum size as
determined using appropriate table found in the NFGC or NSCNGPIC.
II.
COMBUSTION-AIR AND VENT PIPING
A. General
Combustion-air and vent pipe fittings must conform to American
National Standards Institute (ANSI) standards and American
Society for Testing and Materials (ASTM) standards D1785
(schedule-40 PVC), D2665 (PVC-DWV), D2241 (SDR-21 and
SDR-26 PVC), D2661 (ABS-DWV), F628 (schedule-40 ABS), or
F891 (PVC-DWV cellular core). Pipe cement and primer must
conform to ASTM standards D2564 (PVC) or D2235 (ABS). See
Table 5 for maximum pipe lengths and Fig. 30, 31, 32, 33, and 34
for exterior piping arrangements.
In Canada construct all combustion-air and vent pipes for this unit
of CSA or ULC certified schedule-40 PVC, PVC-DWV or
ABS-DWV pipe and pipe cement. SDR pipe is NOT approved in
Canada.
NOTE: Furnace combustion-air and vent pipe connections are
sized for 2-in. pipe. Any pipe size change should be made outside
furnace casing in vertical pipe. (See Fig. 26.) This allows proper
drainage of vent condensate.
CLEARANCE (FT)
U.S.A.
Canada
1
1†
3
3
3
3
1
6
1
1
1
3
4*
6‡
7
7
* Horizontal distance.
† 18 in. above roof surface in Canada.
‡ 36 in. to electric meter in Canada only.
NOTES:
1. If installing 2 adjacent 340MAV Furnaces, refer to Multiventing and Vent
Terminations section for proper vent configurations.
2. When locating combustion-air and vent terminations, consideration must be
given to prevailing winds, location, and other conditions which may cause
recirculation of the appliance’s own flue products or the flue products of
adjacent vents. Recirculation can cause poor combustion, inlet condensate
problems, and accelerated corrosion of heat exchangers.
Furnace combustion-air and vent pipe connections must be attached as shown in Fig. 27. Combustion-air intake plug fitting and
inducer housing alternate vent cap may need to be relocated in
some applications.
NOTE: Slope combustion-air and vent pipes a minimum of 1/4
in. per linear ft with no sags between hangers.
—20—
NOTE: Select 1 vent pipe connection and NOTE: Select 1 vent pipe connection and
1 combustion-air pipe connection.
1 combustion-air pipe connection.
COMBUSTIONAIR
AIR
FLOW
COMBUSTIONAIR
WARNING: All combustion-air and vent pipes must be
airtight and watertight. Pipes must also terminate exactly
as shown in Fig. 30, 31, 32, 33, or 34. Failure to follow
this warning could result in property damage, personal
injury, or death.
VENT
VENT
VENT
VENT
→ NOTE:
COMBUSTIONAIR
UPFLOW
COMBUSTIONAIR
AIR
FLOW
The minimum combustion-air and vent pipe length (each)
for these furnaces is 5 ft. Short pipe lengths (5-8 ft) may discharge
water droplets. These droplets may be undesirable, and a 12-in.
minimum offset pipe section is recommended, as shown in Fig. 28,
to reduce excessive droplets from exiting vent pipe outlet.
COMBUSTIONAIR
B.
1. Using Table 5, individually determine the combustion-air
and vent pipe diameters. Pick the larger of these 2 pipe
diameters and use this diameter for both combustion-air and
vent pipes.
2. When installing vent systems of short pipe length, use the
smallest allowable pipe diameter. Do not use pipe size
greater than required or incomplete combustion, flame
disturbance, or flame sense lockout may occur.
NOTE: Do not count elbows or pipe sections in terminations or
within furnace. See shaded areas in Fig. 30, 31, 32, 33, and 34.
COMBUSTIONAIR
VENT
AIR
FLOW
VENT
AIR
FLOW
HORIZONTAL-LEFT DISCHARGE
Combustion-Air and Vent Pipe Diameter
→ Determine combustion-air and vent pipe diameter.
DOWNFLOW
EXAMPLE:
An 036080 size furnace located in Indianapolis, elevation
650 ft above sea level, could be installed in an application
requiring 3 elbows and 32 ft of vent pipe, along with 5
elbows and 34 ft of combustion-air pipe. Table 5 indicates
this application would allow a 2-in. diameter vent pipe, but
require a 2-1/2 in. diameter combustion air pipe (2-in. pipe
is good for 35 ft with 3 elbows, but only 30 ft with 5
elbows). Therefore, 2-1/2 in. diameter pipe must be used
for both vent and combustion-air pipes since larger required
diameter must always be used for both pipes. If same
installation were in Albuquerque, elevation 5250 ft above
sea level, installation would require 2-1/2 in. vent pipe and
combustion-air pipe. At 5001- to 6000-ft elevation, 2-in.
pipe is only good for 17 ft with 5 elbows, and 2-1/2 in. pipe
is good for 70 ft with 5 elbows.
HORIZONTAL-RIGHT DISCHARGE
A96187
Fig. 27—Combustion-Air and Vent Pipe Connections
CAUTION: When combustion-air pipe is installed
above a suspended ceiling, pipe must be insulated with
3/8-in. thick Armaflex-type insulation. Combustion-air
pipe should also be insulated when it passes through
warm, humid space.
CAUTION: When vent pipe is exposed to temperatures
below freezing, such as when it passes through an
unheated space or when a chimney is used as a raceway,
pipe must be insulated as shown in Table 6 with
Armaflex-type insulation.
C. Combustion-Air and Vent Pipe Attachment
NOTE: All pipe joints must be watertight except attachment of
combustion-air pipe to inlet housing connection, since it may be
necessary to remove pipe for servicing.
1. Attach combustion-air pipe as follows:
a. Determine location of combustion-air intake pipe connection to combustion-air intake housing as shown in
Fig. 27 for application.
CAUTION: Combustion air must not be taken from
inside structure because inside air is frequently contaminated by halogens, which include fluorides, chlorides,
bromides, and iodides. These elements are found in
aerosols, detergents, bleaches, cleaning solvents, salts, air
fresheners, adhesives, paint, and other household products. Locate combustion-air inlet as far as possible from
swimming pool and swimming pool pump house.
Excessive exposure to contaminated combustion air will
result in safety and performance related problems.
b. Reposition combustion-air intake housing plug fitting in
appropriate unused intake housing connection.
c. Insert perforated disk assembly (factory-supplied in
loose parts bag) in intake housing where combustion-air
intake pipe will be connected.
d. Install pipe support (factory-supplied in loose parts bag)
into selected furnace casing combustion-air pipe hole.
Pipe support should be positioned at bottom of casing
hole.
WARNING: Solvent cements are combustible. Keep
away from heat, sparks, and open flame. Use only in
well-ventilated areas. Avoid breathing in vapor or allowing contact with skin or eyes. Failure to follow this
warning could result in fire, property damage, personal
injury, or death.
e. Insert 2-in. diameter pipe into intake housing.
NOTE: A 2-in. diameter pipe must be used within the furnace
casing. Make all pipe diameter transitions outside furnace casing.
f. Drill a 1/8-in. hole in 2-in. combustion-air pipe using
hole in intake housing as a guide.
—21—
12″ MIN
12″ MIN
VENT PIPE
VENT PIPE
COMBUSTION-AIR PIPE
HORIZONTAL TO ROOF
COMBUSTION-AIR PIPE
HORIZONTAL TO SIDEWALL
COMBUSTION-AIR PIPE
VENT PIPE
COMBUSTION-AIR PIPE
12″ MIN
12″ MIN
VENT PIPE
VERTICAL TO ROOF
VERTICAL TO SIDEWALL
NOTE: A 12 In. minimum offset pipe section is recommended with
short (5 to 8 ft) vent systems. This recommendation is to reduce
excessive condensate droplets from exiting the vent pipe.
A96230
→ Fig. 28—Short Vent (5 to 8 Ft) System
g. Install a field-supplied No. 6 or No. 8 sheet metal screw
into combustion-air pipe.
If use of this drain connection is desired, drill out fitting’s
tap plug with a 3/16-in. drill and connect a field-supplied
3/8-in. tube. This tube should be routed to open condensate
drain for furnace and A/C (if used), and should be trapped.
(See Fig. 29.)
NOTE: DO NOT OVERTIGHTEN SCREW. Breakage to intake
housing or fitting may cause air leakage to occur.
NOTE: Do not attach combustion-air intake pipe permanently to
combustion-air intake housing since it may be necessary to remove
pipe for service of ignitor or flame sensor.
2. Attach vent pipe as follows:
a. Determine location of vent pipe connection to inducer
housing as shown in Fig. 27 for application.
COMBUSTION-AIR INTAKE HOUSING PLUG
FITTING
b. Reposition neoprene inducer housing outlet cap and
clamp to appropriate unused inducer housing connection. Tighten clamp.
The combustion-air intake plug fitting must be installed in
unused combustion-air intake housing. This fitting must be
attached by using RTV sealant, or by drilling a 1/8-in. hole
in fitting, using hole in intake housing as a guide. Install a
field-supplied No. 6 or No. 8 sheet metal screw.
WARNING: Inducer housing outlet cap must be installed and fully seated against inducer housing. Clamp
must be tightened to prevent any condensate leakage.
Failure to follow this warning could result in electrical
shock, fire, personal injury, or death.
NOTE: DO NOT OVERTIGHTEN SCREW. Breakage to intake
housing or fitting may cause air leakage to occur.
A plugged drain connection has been provided on this
fitting for use when moisture is found in combustion-air
intake pipe and combustion box.
c. Install pipe support (factory-supplied in loose parts bag)
into selected furnace casing vent pipe hole. Pipe support
should be positioned at bottom of casing hole.
NOTE: Moisture in combustion-air intake may be result of
improper termination. Ensure combustion-air intake pipe is similar
to that shown in Fig. 30, 31, 32, 33, or 34 so it will not be
susceptible to areas where light snow or other sources of moisture
could be pulled in.
d. Insert 2-in. diameter pipe into inducer housing through
neoprene coupling and clamp in inducer housing.
Tighten clamp.
—22—
TABLE 5—MAXIMUM ALLOWABLE PIPE LENGTH (FT)
ALTITUDE
0 to 2000
ALTITUDE
2001 to 3000
ALTITUDE
TERMINATION
TYPE
PIPE DIA
(IN.)*
024040
036040
2 Pipe or 2-In.
Concentric
024060
036060
048060
2 Pipe or 2-In.
Concentric
UNIT SIZE
ALTITUDE
4001 to 5000‡
2
NA
70
70
1-1/2
20
15
5
NA
NA
70
70
70
70
70
70
10
55
70
5
40
70
10
35
35
70
NA
50
70
NA
30
70
NA
30
35
70
NA
35
70
NA
20
70
NA
15
35
70
NA
30
70
NA
20
70
NA
NA
30
70
NA
30
70
NA
10
70
NA
NA
30
70
NA
20
70
NA
NA
70
NA
NA
30
70
1-1/2
2
1
67
70
2
62
70
NUMBER OF 90° ELBOWS
3
4
5
57
52
52
70
70
70
6
47
70
2 Pipe or 2-In.
Concentric
1-1/2
17
12
2
70
67
66
61
61
61
2 Pipe or 2-In.
Concentric
2
49
44
30
25
25
15
048100
060100
2 Pipe or 3-In.
Concentric
060120
2 Pipe or 3-In.
Concentric
UNIT SIZE
TERMINATION
TYPE
PIPE DIA
(IN.)*
024040
036040
2 Pipe or 2-In.
Concentric
7
NA
NA
NA
2-1/2
70
70
70
70
70
70
2-1/2
3
3 one disk
3† one disk
3† no disk
35
70
31
31
63
26
70
26
30
62
16
70
12
30
62
16
70
NA
25
61
6
66
NA
25
61
NA
61
NA
24
61
2 Pipe or 2-In.
Concentric
1-1/2
2
1
64
70
2
59
70
NUMBER OF 90° ELBOWS
3
4
5
54
49
48
70
70
70
6
43
70
2 Pipe or 2-In.
Concentric
1-1/2
16
11
6
NA
NA
NA
2
68
63
62
57
57
56
13
048100
060100
2 Pipe or 3-In.
Concentric
060120
2 Pipe or 3-In.
Concentric
UNIT SIZE
TERMINATION
TYPE
PIPE DIA
(IN.)*
024060
036060
048060
036080
048080
060080
10
6
NA
55
70
2
2 Pipe or 2-In.
Concentric
024060
036060
048060
036080
048080
060080
NUMBER OF 90° ELBOWS
3
4
5
NA
NA
NA
65
60
60
70
70
70
1-1/2
2
2-1/2
2
2-1/2
3
2-1/2 one disk
3 one disk
3† one disk
3† no disk
036080
048080
060080
024040
036040
3001 to 4000
1
1-1/2
2
1
5
70
70
2 Pipe or 2-In.
Concentric
2
46
41
28
23
22
2-1/2
70
70
70
70
70
70
2-1/2
3
3 one disk
3† one disk
3† no disk
33
70
29
29
59
24
70
24
28
59
15
70
10
28
58
14
66
NA
23
57
5
61
NA
22
57
NA
56
NA
21
56
2
55
70
NUMBER OF 90° ELBOWS
3
4
5
50
45
44
70
70
70
6
39
70
048100
060100
2 Pipe or 3-In.
Concentric
060120
2 Pipe or 3-In.
Concentric
UNIT SIZE
TERMINATION
TYPE
PIPE DIA
(IN.)*
024040
036040
2 Pipe or 2-In.
Concentric
1-1/2
2
1
60
70
2 Pipe or 2-In.
Concentric
1-1/2
15
10
5
NA
NA
NA
2
64
59
58
53
52
52
2 Pipe or 2-In.
Concentric
2
44
39
26
21
20
11
024060
036060
048060
036080
048080
060080
048100
060100
2 Pipe or 3-In.
Concentric
060120
2 Pipe or 3-In.
Concentric
2-1/2
70
70
70
70
70
70
2-1/2
3
3† one disk
3† no disk
31
70
27
56
22
70
26
55
13
67
26
54
12
62
21
53
NA
57
20
52
NA
52
19
52
See notes on page 25.
—23—
TABLE 5—MAXIMUM ALLOWABLE PIPE LENGTH (FT)
ALTITUDE
5001 to 6000‡
ALTITUDE
6001 to 7000‡
ALTITUDE
7001 to 8000‡
ALTITUDE
8001 to 9000‡
UNIT SIZE
TERMINATION
TYPE
PIPE DIA
(IN.)*
024040
036040
2 Pipe or 2-In.
Concentric
024060
036060
048060
036080
048080
060080
Continued
NUMBER OF 90° ELBOWS
3
4
5
47
42
40
70
70
70
1-1/2
2
1
57
70
2
52
70
2 Pipe or 2-In.
Concentric
1-1/2
14
9
2
60
55
54
2 Pipe or 2-In.
Concentric
2
41
36
23
NA
NA
6
35
70
NA
NA
49
48
47
18
17
8
2-1/2
70
70
70
70
70
70
2 Pipe or 3-In.
Concentric
2-1/2
3
3† one disk
3† no disk
29
70
26
53
21
67
24
52
12
62
23
50
11
57
18
49
NA
52
17
48
NA
47
16
47
UNIT SIZE
TERMINATION
TYPE
PIPE DIA
(IN.)*
024040
036040
2 Pipe or 2-In.
Concentric
1-1/2
2
1
53
70
2
48
70
NUMBER OF 90° ELBOWS
3
4
5
43
38
37
68
67
66
6
32
64
2 Pipe or 2-In.
Concentric
1-1/2
13
8
NA
NA
NA
NA
2
57
52
50
45
44
43
2 Pipe or 2-In.
Concentric
2
38
33
21
16
15
6
048100
060100
2 Pipe or 3-In.
Concentric
060120
024060
036060
048060
036080
048080
060080
2-1/2
70
70
68
67
66
64
2 Pipe or 3-In.
Concentric
2-1/2
3
3† one disk
3† no disk
27
68
24
49
19
63
22
48
10
58
21
47
9
53
16
45
NA
48
15
44
NA
43
13
43
UNIT SIZE
TERMINATION
TYPE
PIPE DIA
(IN.)*
024040
036040
2 Pipe or 2-In.
Concentric
1-1/2
2
1
49
66
2
44
65
NUMBER OF 90° ELBOWS
3
4
5
39
34
33
63
62
60
6
28
59
2 Pipe or 2-In.
Concentric
1-1/2
12
7
2
53
48
46
41
40
38
2 Pipe or 2-In.
Concentric
2
36
31
19
14
12
NA
048100
060100
2 Pipe or 3-In.
Concentric
060120
024060
036060
048060
036080
048080
060080
NA
NA
NA
NA
2-1/2
66
65
63
62
60
59
25
63
22
46
17
58
20
44
8
53
19
43
7
48
14
41
NA
43
12
40
NA
38
11
38
2
41
60
NUMBER OF 90° ELBOWS
3
4
5
36
31
29
58
56
55
6
24
53
048100
060100
2 Pipe or 3 In.
Concentric
060120
2 Pipe or 3-In.
Concentric
2-1/2
3
3† one disk
3† no disk
UNIT SIZE
TERMINATION
TYPE
PIPE DIA
(IN.)*
024040
036040
2 Pipe or 2-In.
Concentric
1-1/2
2
1
46
62
2 Pipe or 2-In.
Concentric
1-1/2
11
6
NA
NA
NA
NA
2
49
44
42
37
35
34
2 Pipe or 2-In.
Concentric
2
33
28
17
12
10
NA
024060
036060
048060
036080
048080
060080
048100
060100
2 Pipe or 3-In.
Concentric
060120
2 Pipe or 3-In.
Concentric
2-1/2
62
60
58
56
55
53
2-1/2
3
3† one disk
3† no disk
23
59
20
43
15
54
18
41
7
49
17
39
5
44
12
37
NA
39
10
35
NA
34
8
34
See notes on page 25.
—24—
TABLE 5—MAXIMUM ALLOWABLE PIPE LENGTH (FT)
ALTITUDE
9001 to 10,000‡
UNIT SIZE
TERMINATION
TYPE
PIPE DIA
(IN.)*
024040
036040
2 Pipe or 2-In.
Concentric
2 Pipe or 2-In.
Concentric
024060
036060
048060
036080
048080
060080
2 Pipe or 2-In.
Concentric
048100
060100
2 Pipe or 3-In.
Concentric
060120
2 Pipe or 3-In.
Concentric
Continued
NUMBER OF 90° ELBOWS
3
4
5
32
27
25
53
51
49
1-1/2
2
1
42
57
2
37
55
6
20
47
2
45
40
38
33
31
29
2
30
25
14
9
7
NA
2-1/2
57
55
53
51
49
47
2-1/2
3
3† one disk
3† no disk
21
54
18
39
13
49
16
37
5
44
14
35
NA
39
9
33
NA
34
7
31
NA
29
5
29
* Disk usage—Unless otherwise specified, use perforated disk assembly (factory-supplied in loose parts bag). If stated, separate 2 halves of perforated disk assembly and
use shouldered disk half or no disk assembly.
† Wide radius elbow.
‡ Vent sizing for Canadian installations over 4500 ft (1370 m) above sea level are subject to acceptance by the local authorities having jurisdiction.
NA—Not Allowed; pressure switch will not make.
NOTES:
1. Do not use pipe size greater than those specified in table or incomplete combustion, flame disturbance, or flame sense lockout may occur.
2. Size both the combustion-air and vent pipe independently, then use the larger diameter for both pipes.
3. Assume two 45° elbows equal one 90° elbow. Long radius elbows are desirable and may be required in some cases.
4. Elbows and pipe sections within the furnace casing and at the vent termination should not be included in vent length or elbow count.
5. The minimum pipe length is 5 ft for all applications.
6. Clean and dry all surfaces to be joined.
COMBUSTION – AIR
INTAKE HOUSING
3/8" ID TUBE
7. Check dry fit of pipe and mark insertion depth on pipe.
NOTE: It is recommended that all pipes be cut, prepared, and
preassembled before permanently cementing any joint.
BURNER
BOX
3/16"
DRILL
COMBUSTION –
AIR PIPE
4″
MIN
TRAP
8. After pipes have been cut and preassembled, apply generous layer of cement primer to pipe fitting socket and end of
pipe to insertion mark. Quickly apply approved cement to
end of pipe and fitting socket (over primer). Apply cement
in a light, uniform coat on inside of socket to prevent
buildup of excess cement. Apply second coat.
9. While cement is still wet, twist pipe into socket with 1/4
turn. Be sure pipe is fully inserted into fitting socket.
TO OPEN
DRAIN
10. Wipe excess cement from joint. A continuous bead of
cement will be visible around perimeter of a properly made
joint.
A93035
Fig. 29—Intake Housing Plug Fitting Drain
11. Handle pipe joints carefully until cement sets.
12. Support combustion-air and vent piping a minimum of
every 5 ft (3 ft for SDR-21 or -26 PVC) using perforated
metal hanging strap.
WARNING: Vent pipe must be installed and fully
seated against inducer housing. Clamp must be tightened
to prevent any condensate leakage. Failure to follow this
warning could result in electrical shock, fire, personal
injury, or death.
13. Slope combustion-air and vent pipes toward furnace a
minimum of 1/4 in. per linear ft with no sags between
hangers.
14. Use appropriate methods to seal openings where vent and
combustion-air pipes pass through roof or side wall.
NOTE: A 2-in. diameter pipe must be used within the furnace
casing. Make all pipe diameter transitions outside furnace casing.
III. CONCENTRIC VENT AND COMBUSTION-AIR
TERMINATION KIT INSTALLATION
NOTE: If these instructions differ from those packaged with
termination kit, follow kit instructions.
Combustion-air and vent pipes must terminate outside structure. A
factory accessory termination kit must be installed in 1 of the
installations shown in Fig. 30, 31, 32, 33, or 34. Four termination
kits are available.
VENT EXTENSION PIPE
Some furnaces are supplied with a PVC vent extension pipe
(2-in. diameter by 12-in. long). This pipe has a built-in
channel to assist vent condensate disposal. When this vent
extension pipe is supplied, it must be used to connect the
field vent pipe to furnace inducer housing on ALL upflow
and downflow applications.
NOTE: See label on vent extension pipe for proper installation.
This pipe may be shortened if an elbow is used to connect vent
extension tube to field-installed vent pipe.
1. The 2-in. termination bracket kit is for 1-in., 1-1/2 in., and
2-in. diameter 2-pipe termination systems.
3. Working from furnace to outside, cut pipe to required
length(s).
2. The 3-in. termination bracket kit is for 2-1/2 in. and 3-in.
diameter 2-pipe termination systems.
4. Deburr inside and outside of pipe.
3. The 2-in. concentric vent/air termination kit is for 1-in.,
1-1/2 in., 2-in., and 2-1/2 in. diameter pipe systems when
single penetration of wall or roof is desired.
5. Chamfer outside edge of pipe for better distribution of
primer and cement.
—25—
4. The 3-in. concentric vent/air termination kit is for 2-1/2 in.
and 3-in. diameter pipe systems when single penetration of
wall or roof is desired.
NOTE: Shaded parts in Fig. 30, 31, 32, 33, and 34 are considered
to be termination. These components should NOT be counted
when determining pipe diameter. Roof termination is preferred
since it is less susceptible to damage, has reduced chances to intake
contaminants, and has less visible vent vapors. (See Fig. 30 or 31.)
Sidewall termination may require sealing or shielding of building
surfaces with a corrosive resistance material due to corrosive
combustion products of vent system.
A.
e. Termination kit should be positioned where vent vapors
are not objectionable.
2. Cut 2 holes, 1 for each pipe, of appropriate size for pipe size
being used.
3. Loosely install elbow in bracket and place assembly on
combustion-air pipe.
Roof terminations—Loosely install pipe coupling on properly cut vent pipe. Coupling must be positioned so bracket
will mount as shown in Fig. 30.
For applications using combustion-air pipe option, indicated by dashed lines in Fig. 30, install 90° street elbow into
90° elbow, making U-fitting. A 180° U-fitting may be used.
Extended Exposed Sidewall Pipes
Sidewall combustion-air and vent pipe terminations may be
extended beyond area shown in Fig. 33 or 34 in outside ambient by
insulating pipes as indicated in Table 6.
Sidewall terminations—Install bracket as shown in Fig. 33
or 34.
1. Determine combustion-air and vent pipe diameters, as
stated above, using total pipe length and number of elbows.
For applications using vent pipe option indicated by dashed
lines in Fig. 33, rotate vent elbow 90° from position shown
in Fig. 33.
2. Using winter design temperature (used in load calculations),
find appropriate temperature for your application and furnace model.
3. Determine required insulation thickness for exposed pipe
lengths.
NOTE: Pipe length (ft) specified for maximum pipe lengths
located in unconditioned spaces cannot exceed total allowable pipe
length as specified in Table 5.
B. Two-Pipe Termination Kit
4. Disassemble loose pipe fittings. Clean and cement using
same procedures as used for system piping.
5. Check required dimensions as shown in Fig. 30, 33, or 34.
C.
Concentric Vent/Air Termination Kit
1. Determine location for termination.
Consideration of the following should be made when
determining an appropriate location for termination kit.
a. Comply with all clearance requirements as stated in
Table 4.
1. Determine location for termination.
Consideration of the following should be made when
determining an appropriate location for termination kit.
a. Comply with all clearance requirements as stated in
Table 4.
b. Termination kit should be positioned where vent vapors
will not damage plants/shrubs or air conditioning equipment.
b. Termination kit should be positioned where vent vapors
will not damage plants/shrubs or air conditioning equipment.
c. Termination kit should be positioned so it will not be
affected by wind eddy (such as inside building corners)
or that may allow recirculation of flue gases, airborne
leaves, or light snow.
c. Termination kit should be positioned so that it will not be
affected by wind eddy (such as inside building corners)
or allow recirculation of flue gases, airborne leaves, or
light snow.
d. Termination kit should be positioned where it will not be
damaged by or subjected to foreign objects, such as
stones, balls, etc.
d. Termination kit should be positioned where it will not be
damaged by or subjected to foreign objects, such as
e. Termination kit should be positioned where vent vapors
stones, balls, etc.
are not objectionable.
TABLE 6—MAXIMUM ALLOWABLE EXPOSED VENT PIPE LENGTH (FT) WITH INSULATION IN WINTER DESIGN
TEMPERATURE AMBIENT*
UNIT
SIZE
040
060
080
100
120
WINTER
DESIGN
TEMPERATURE(°F)
20
0
-20
20
0
-20
20
0
-20
20
0
-20
20
0
-20
INSULATION THICKNESS (IN.)†
MAX PIPE
DIAMETER
0
3/8
1/2
3/4
1
1-1/2
1-1/2
1-1/2
2
2
2
2-1/2
2-1/2
2-1/2
3
3
3
3
3
3
31
16
9
45
25
16
55
31
20
61
33
20
70
40
26
56
34
23
70
51
36
70
61
43
70
65
45
70
70
55
63
39
27
70
58
42
70
69
49
70
70
52
70
70
64
70
47
34
70
70
51
70
70
61
70
70
65
70
70
70
70
54
39
70
70
60
70
70
70
70
70
70
70
70
70
* Pipe length (ft) specified for maximum pipe lengths located in unconditioned spaces. Pipes located in unconditioned space cannot exceed total allowable pipe length as
specified in Table 5.
† Insulation thickness based on R value of 3.5 per in.
—26—
ROOF
18″ MAXIMUM
BRACKET
COUPLING
COMBUSTION
AIR
VERTICAL SEPARATION
BETWEEN COMBUSTION
AIR AND VENT
8 3/4″ FOR 3″ KIT
6 3/4″ FOR 2″ KIT
VENT
MAINTAIN 12 IN. MINIMUM
CLEARANCE ABOVE HIGHEST
ANTICIPATED SNOW LEVEL.
MAXIMUM OF 24 IN. ABOVE ROOF.
A87224
Fig. 30—Roof Termination (Preferred)
OVERHANG OR ROOF
12″ MINIMUM
1″ MAXIMUM
VENT
COMBUSTION-AIR
VENT
COMBUSTION
AIR
MAINTAIN 12 IN.
CLEARANCE
ABOVE HIGHEST
ANTICIPATED SNOW
LEVEL OR GRADE,
WHICHEVER IS
GREATER.
MAINTAIN 12 IN.
(18 IN. FOR CANADA)
MINIMUM CLEARANCE
ABOVE HIGHEST
ANTICIPATED SNOW
LEVEL. MAXIMUM OF
24 IN. ABOVE ROOF.
A93055
A93054
Fig. 32—Concentric Vent and Combustion-Air Side
Termination
Fig. 31—Concentric Vent and Combustion-Air Roof
Termination (Preferred)
OVERHANG OR ROOF
OVERHANG OR ROOF
12″ MINIMUM
12″ MINIMUM
VENT
VENT
90°
90°
BRACKET
COUPLING
BRACKET
12 IN. SEPARATION
BETWEEN BOTTOM OF
COMBUSTION AIR AND
BOTTOM OF VENT
MAINTAIN 12 IN.
CLEARANCE
ABOVE HIGHEST
ANTICIPATED SNOW
LEVEL OR GRADE,
COMBUSTION-AIR WHICHEVER IS
GREATER.
COMBUSTION-AIR
(ELBOW PARALLEL
TO WALL)
A87225
Fig. 33—Sidewall Termination of 12 in. or More
12 IN. SEPARATION
BETWEEN BOTTOM OF
COMBUSTION AIR AND
BOTTOM OF VENT
MAINTAIN 12 IN.
CLEARANCE
ABOVE HIGHEST
ANTICIPATED SNOW
LEVEL OR GRADE,
WHICHEVER IS
GREATER.
A87226
Fig. 34—Sidewall Termination of Less than 12 in.
—27—
2. Cut one 4-in. diameter hole for 2-in. kit, or one 5-in.
diameter hole for 3-in. kit.
3. Loosely assemble concentric vent/air termination components together using instructions in kit.
4. Slide assembled kit with rain shield REMOVED through
hole.
NOTE: Do not allow insulation or other materials to accumulate
inside of pipe assembly when installing it through hole.
Roof terminations—Locate assembly through roof to appropriate height as shown in Fig. 31.
32°F MINIMUM INSTALLED
AMBIENT OR FREEZE
PROTECTION REQUIRED
Sidewall terminations—Locate assembly through sidewall
with rain shield positioned no more than 1-in. from wall as
shown in Fig. 32.
5. Disassemble loose pipe fittings. Clean and cement using
same procedures as used for system piping.
6. Check required dimensions as shown in Fig. 31 or 32.
IV. MULTIVENTING AND VENT TERMINATIONS
When 2 or more 340MAV Furnaces are vented near each other,
each furnace must be individually vented. NEVER common vent
or breach vent 340MAV furnaces. When 2 or more 340MAV
furnaces are vented near each other, 2 vent terminations may be
installed as shown in Fig. 35, 36, 37, 38, or 39, but next vent
termination must be at least 36 in. away from first 2 terminations.
It is important that vent terminations be made as shown to avoid
recirculation of flue gases. Dimension "A" in Fig. 35, 36, 37, 38,
and 39 represents distance between pipes or rain shields, as
touching or 2-in. maximum separation.
A93058
CAUTION: Unit must not be installed, operated, and
then turned off and left in an unoccupied structure during
cold weather when temperature drops to 32°F and below
unless drain trap and drain line have adequate freeze
protection. See Service and Maintenance Instructions for
winterizing procedure.
CONDENSATE DRAIN
I. GENERAL
Condensate trap is shipped installed in the blower shelf and factory
connected for UPFLOW applications. Condensate trap must be
RELOCATED for use in DOWNFLOW and HORIZONTAL
applications.
Condensate trap MUST be used for all applications.
An external trap is not required when connecting the field drain to
this condensate trap.
The field drain connection (condensate trap or drain tube coupling)
is sized for 1/2-in. CPVC, 1/2-in. PVC, or 5/8-in. ID tube
connection.
Drain pipe and fittings must conform to ANSI standards and
ASTM D1785 or D2846. CPVC or PVC cement and primer must
conform to ASTM D2564 or F493. In Canada, use CSA or ULC
certified schedule 40 CPVC or PVC drain pipe, fittings, and
cement.
When a condensate pump is required, select a pump which is
approved for condensing furnace applications. To avoid condensate spillage, select a pump with an overflow switch.
→ Furnace condensate is mildly acidic, typically in the pH range of
3.2 to 4.5. Due to corrosive nature of this condensate, a condensate
pH neutralizing filter may be desired. Check with local authorities
to determine if a pH neutralizer is required.
Outdoor draining of the furnace is permissible if allowed by local
codes. Caution should be taken when freezing ambient may freeze
drain pipe and prohibit draining.
WARNING: Caution should be taken to prevent draining where slippery conditions may cause personal injuries. Excessive condensate draining may cause saturated
soil conditions which may result in damage to plants.
III.
CONDENSATE DRAIN PROTECTION
Freezing condensate left in condensate trap and drain line may
cause cracks, and possible water damage may occur. If freeze
protection is required, use condensate freeze protection accessory
or equivalent 3 to 6 watt per ft at 120v and 40°F self-regulating,
shielded, and waterproof heat tape. See Installation Instructions
supplied with accessory or heat tape manufacturer’s recommendations.
1. Fold heat tape in half and wrap on itself 3 times.
2. Locate heat tape between sides of condensate trap back.
(See Fig. 41.)
II. APPLICATION
The furnace, A/C, and humidifier drains may be combined and
drained together. The A/C drain must have an external, fieldsupplied trap prior to the furnace drain connection. All drain
connections (furnace, A/C, or humidifier) must be terminated into
an open or vented drain as close to the respective equipment as
possible to prevent siphoning of the equipment’s drain.
See Fig. 40 for example of possible field drain attachment using
1/2-in. CPVC or PVC tee for vent and A/C or humidifier drain
connection.
3. Use wire ties to secure heat tape in place. Wire ties can be
positioned in notches of condensate trap sides. (See Fig.
41.)
4. Wrap field drain pipe with remaining heat tape, approximately 1 wrap per ft.
5. When using field-supplied heat tape, follow heat tape
manufacturer’s instructions for all other installation guidelines.
—28—
A
A96128
→ Fig. 35—Rooftop Termination (Dimension "A" is Touching or 2-In. Maximum Separation)
1″ MAXIMUM
(TYP)
VENT
VENT
A
COMBUSTION AIR
VENT
COMBUSTION
AIR
A
VENT
A93056
A93057
Fig. 36—Concentric Vent and Combustion-Air
Roof Termination
(Dimension "A" is Touching or 2-In. Maximum Separation)
Fig. 37—Concentric Vent and Combustion-Air
Side Termination
(Dimension "A" is Touching or 2-In. Maximum Separation)
VENT
VENT
COMBUSTION AIR
COMBUSTION AIR
COMBUSTION AIR
COMBUSTION AIR
A
A
A96129
A96130
→ Fig. 38—Sidewall Termination of 12 in. or Less
(Dimension "A" is Touching or 2-In. Maximum Separation)
→ Fig. 39—Sidewall Termination of More Than 12 in.
(Dimension "A" is Touching or 2-In. Maximum Separation)
—29—
1. Prepurge period—As inducer motor comes up to speed,
pressure switch contacts close to begin a 15-sec prepurge
period.
2. Ignitor warm up—At end of prepurge period, ignitor is
energized for a 17-sec ignitor warm-up period.
3. Ignition sequence—When ignitor warm-up period is completed, gas valve opens, permitting gas flow to burners
where it is ignited. After 5 sec, ignitor is de-energized and
a 2-sec flame-sensing period begins.
OPEN STAND
PIPE FOR
A/C OR
HUMIDIFIER
DRAIN
HUM terminal on control center is energized with gas
valve. See Accessories — Humidifier section.
4. Flame sensing—When burner flame is sensed, control
begins blower on delay period and continues holding gas
valve open.
TEE
If burner flame is not sensed, control center de-energizes
gas valve and ignition sequence is repeated.
NOTE: Ignition sequence repeats 3 additional times before a
lockout occurs. Lockout automatically resets after 3 hr or can be
manually reset by turning off 115v (not at thermostat) for 3 sec
minimum, then turning it on again.
TO OPEN
DRAIN
5. Blower on delay—Sixty sec after burner flame is proven,
blower motor is energized on heating speed. Simultaneously, electronic air cleaner terminal EAC-1 is energized.
A94054
6. Blower off delay—When thermostat is satisfied, circuit
between R-W is opened, de-energizing gas valve (stopping
gas flow to burners) and humidifier. Blower motor and
electronic air cleaner remain energized for 135 sec.
Fig. 40—Example of Field Drain Attachment
CONDENSATE TRAP
7. Post purge—Inducer motor remains energized 15 sec after
burners are extinguished.
II. COOLING MODE
When thermostat "calls for cooling," R-G and R-Y circuits close.
R-Y circuit starts outdoor condensing unit, and combined R-Y and
R-G circuit starts furnace blower motor on cooling speed. Electronic air cleaner EAC-1 terminal is energized with 115v whenever
blower is operating.
When thermostat is satisfied, R-G and R-Y circuits are opened,
furnace blower continues operating on cooling speed for an
additional 90 sec.
WIRE TIE(S)
III. CONTINUOUS BLOWER MODE
When R-G circuit is made, blower motor operates on heating
speed.
NOTE: Electronic air cleaner EAC-1 terminal is energized with
115v whenever blower is operating.
If a "call for heat" (R-W) occurs while thermostat is in continuous
blower mode, blower stops to allow furnace heat exchangers to
heat up more quickly, then restarts at end of blower on delay
period of 60 sec.
Blower reverts to continuous operation after heating cycle is
completed.
If a "call for cooling" (R-Y) occurs while thermostat is in
continuous blower mode, blower changes from continuous blower
speed (heating speed) to cooling speed.
When thermostat cooling call is satisfied, R-Y opens and blower
operates an additional 90 sec at cooling speed before reverting
back to continuous operation (heating speed).
HEAT TAPE
(3 WRAPS MINIMUM)
Fig. 41—Condensate Trap Heat Tape
SEQUENCE OF OPERATION
A93036
CAUTION: Furnace control must be grounded for
proper operation, or control will lock out. Control is
grounded through green wire routed to gas valve and
burner box screw.
Using schematic diagram, follow sequence of operation through
different modes. (See Fig. 24.) This furnace has a new control
system. Read and follow wiring diagram carefully.
NOTE: If 115-v power supply to furnace or blower access panel
switch is interrupted during a call for heat, blower operates for 90
sec when power is restored before heating cycle is resumed.
IV. HEAT PUMP MODE
When installed with a heat pump, furnace control automatically
changes blower on delay timing sequence to avoid no blower
operation time during demand defrost cycles. When R-W and R-Y
or R-W, R-Y, and R-G thermostat inputs are received at the same
time at furnace control center, control starts blower in heating
I. HEATING MODE
When wall thermostat "calls for heat," R-W circuit closes. Furnace
control performs a self-check, verifies pressure switch contacts are
open, and starts inducer motor.
—30—
speed. Then a gas heat mode begins. Blower remains operating at
heating speed for 15 sec or until end of prepurge period, then
blower shuts off until end of ignitor warm up and trial for ignition
periods (a total of 24 sec). Blower restarts at heating speed.
5. When above items have been completed, the component
test sequence will occur as described in the Component Test
Sequence section above.
NOTE: Be sure to record the fault code which is flashed 4 times
at start of component test for further troubleshooting.
When R-W thermostat call disappears, control completes inducer
post-purge period (15 sec) and changes to cooling speed after a
2-sec delay.
6. After component test is completed and LED is ON continuously indicating the furnace is ready to operate when a
signal from the thermostat is received, replace main furnace
door.
If R-W, R-Y, and R-G thermostat signals should disappear
simultaneously, blower remains on for heating blower off delay
period of 135, and the inducer goes through 15 sec post-purge
period. If R-W and R-Y thermostat signals should disappear,
leaving R-G thermostat signal, blower remains on in heating speed
and inducer remains on for 15 sec to complete post-purge period.
C. Initiating Component Test By Jumpering Control
TEST Terminal
1. Remove main furnace door.
Control initiates a 90-sec blower only on period before starting
another heat pump cycle if there is a power interruption. Anytime
control senses false flame, control locks out of heating mode. This
reaction occurs because control ignores W input due to false flame
signal and, as a result, sees only Y input and goes into cooling
mode blower off delay. All other control functions remain in
standard format.
NOTE: EAC-1 terminal is energized whenever blower operates.
HUM terminal is only energized when gas valve is energized.
→ V.
2. Remove blower access panel.
3. Manually close blower access panel door switch. Use a
piece of tape to hold switch closed.
WARNING: Blower access panel door switch opens
115-v power to control center. 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 electrical shock, personal injury,
or death.
COMPONENT TEST
A. Component Test Sequence
NOTE: All components are functionally operated except the gas
valve.
When component test is initiated, the following sequence of events
occurs:
4. BRIEFLY short (jumper) TEST, 1/4-in. quick-connect
terminal on control center (adjacent to the LED diagnostic
light) and the COM terminal on thermostat connection block.
(See Fig. 25.)
NOTE: If TEST to COM terminals are jumpered longer than 2 sec,
LED will flash rapidly, and retrieval request will be ignored.
1. LED flashes a fault code 4 times.
2. Inducer motor starts and continues to run for remainder of
component test.
5. When above items have been completed, the component
test sequence will occur as described in the Component Test
Sequence section above.
NOTE: Be sure to record the fault code which is flashed 4 times
at start of component test for further troubleshooting.
3. Hot surface ignitor is energized for 15 sec, then deenergized.
4. Main blower operates at cooling speed for 10 sec, then turns
off.
6. After component test is completed and furnace is operating
properly, release blower access panel door switch, replace
blower access panel, and replace main furnace door.
5. Main blower operates at heating speed for 10 sec, then turns
off.
START-UP PROCEDURES
6. Inducer motor stops.
Component test can be initiated by one of the following procedures.
I.
GENERAL
1. Furnace must have a 115-v power supply properly connected and grounded. Proper polarity must be maintained
for correct operation.
NOTE: Proper polarity must be maintained for 115-v wiring. If
polarity is incorrect, control center fault indicator light will flash
rapidly and furnace will not operate.
B. Initiating Component Test By Removing Main Limit
Switch Wire
NOTE: NO thermostat signal may be present at control center
and all blower time delay off periods must be completed.
1. Leave 115-v power to furnace turned on.
2. Thermostat wire connections at terminals R, W, G, and Y
must be made at 24-v terminal block on control center.
2. Remove main furnace door.
3. Look into blower access panel sight glass for current LED
status.
NOTE: Leave blower access panel installed to maintain power to
control center to view current LED status.
3. Natural gas service pressure must not exceed 0.5 psig
(14-in. wc), but must be no less than 0.16 psig (4.5-in. wc).
4. Blower access panel must be in place to complete 24-v
electrical circuit to furnace.
4. BRIEFLY remove either wire from the main limit switch
until the LED goes out, then reconnect it.
CAUTION: These furnaces are equipped with a manual
reset limit switch in burner box. This switch will open if
an overheat condition (rollout) occurs in burner enclosure. Correct inadequate combustion-air supply or improper venting condition and reset switch. DO NOT
jumper this switch.
CAUTION: Make sure limit switch wire does not contact any metallic component such as the gas valve. If wire
is shorted, 3-amp fuse on control center will blow.
NOTE: If wire to main limit is disconnected longer than 4 sec, the
control senses limit circuit is open. Main blower will start and fault
retrieval request will be ignored.
Before operating furnace, check each manual reset switch for
continuity. If necessary, press button to reset switch.
—31—
A94208
A94209
Fig. 42—Inducer Housing Drain Tube
II.
Fig. 43—Filling Condensate Trap
PRIME CONDENSATE TRAP WITH WATER
IV.
→ A.
CAUTION: Condensate trap must be PRIMED or
proper draining may not occur. The condensate trap has 2
internal chambers which can ONLY be primed by pouring water into the inducer drain side of condensate trap.
ADJUSTMENTS
Set Gas Input Rate
Furnace gas input rate on rating plate is for installations at altitudes
up to 2000 ft. Furnace input rate must be within ±2 percent of input
on furnace rating plate.
1. Determine natural gas orifice size and manifold pressure for
correct input.
1. Remove upper inducer housing drain connection cap. (See
Fig. 42.)
a. Obtain average yearly heat value (at installed altitude)
from local gas supplier.
2. Connect field-supplied 1/2-in. ID tube to upper inducer
housing drain connection.
3. Insert field-supplied funnel into tube.
b. Obtain average yearly specific gravity from local gas
supplier.
4. Pour 1 quart of water into funnel/tube. Water should run
through inducer housing, overfill condensate trap, and flow
into open field drain. (See Fig. 43.)
c. Verify furnace model. Table 7 can only be used for
model 340MAV furnaces.
d. Find installation altitude in Table 7.
5. Remove funnel and tube from inducer housing and replace
drain connection cap and clamp.
NOTE: For Canada altitudes of 2000 to 4500 ft, use U.S.A.
altitudes of 2001 to 3000 ft in Table 7.
III. PURGE GAS LINES
If not previously done, purge lines after all connections have been
made and check for leaks.
e. Find closest natural gas heat value and specific gravity in
Table 7.
f. Follow heat value and specific gravity lines to point of
intersection to find orifice size and manifold pressure
settings for proper operation.
WARNING: Never purge a gas line into a combustion
chamber. Never use matches, candles, flame, or other
sources of ignition for purpose of checking leakage. Use
a soap-and-water solution to check for leakage. Failure to
follow this warning could result in fire, explosion, personal injury, or death.
—32—
TABLE 7—MODEL 340MAV ORIFICE SIZE AND MANIFOLD PRESSURE FOR CORRECT INPUT
(TABULATED DATA BASED ON 20,000 BTUH PER BURNER, DERATED 2% FOR EACH 1000 FT ABOVE SEA LEVEL)
U.S.A. and Canada
ALTITUDE
RANGE
(FT)
0
to
2000
U.S.A. and Canada
ALTITUDE
RANGE
(FT)
U.S.A.
Altitudes
2001
to
3000
or
Canada
Altitudes
2000
to
4500
U.S.A. Only
ALTITUDE
RANGE
(FT)
3001
to
4000
U.S.A. Only
ALTITUDE
RANGE
(FT)
4001
to
5000
AVG GAS
HEAT VALUE
AT ALTITUDE
(BTU/CU FT)
850
875
900
925
950
975
1000
1025
1050
1075
1100
AVG GAS
HEAT VALUE
AT ALTITUDE
(BTU/CU FT)
775
800
825
850
875
900
925
950
975
1000
1025
AVG GAS
HEAT VALUE
AT ALTITUDE
(BTU/CU FT)
750
775
800
825
850
875
900
925
950
975
1000
AVG GAS
HEAT VALUE
AT ALTITUDE
(BTU/CU FT)
725
750
775
800
825
850
875
900
925
950
0.58
Orifice
Manifold
No.
Pressure
43
3.7
43
3.5
44
3.7
44
3.5
44
3.4
44
3.2
45
3.7
45
3.5
45
3.3
45
3.2
47
3.6
SPECIFIC GRAVITY OF NATURAL GAS
0.60
0.62
0.64
Orifice
Manifold
Orifice
Manifold
Orifice
Manifold
No.
Pressure
No.
Pressure
No.
Pressure
43
3.8
42
3.2
42
3.3
43
3.6
43
3.7
43
3.8
43
3.4
43
3.5
43
3.6
44
3.7
44
3.8
43
3.4
44
3.5
44
3.6
44
3.7
44
3.3
44
3.4
44
3.5
45
3.8
44
3.2
44
3.4
45
3.6
45
3.7
44
3.2
45
3.4
45
3.6
45
3.7
45
3.3
45
3.4
45
3.5
47
3.7
45
3.2
45
3.4
Orifice
No.
42
42
43
43
44
44
44
44
45
45
45
0.66
Manifold
Pressure
3.4
3.2
3.7
3.5
3.8
3.6
3.5
3.3
3.8
3.6
3.5
0.58
Orifice
Manifold
No.
Pressure
43
3.8
43
3.5
44
3.8
44
3.6
44
3.4
44
3.2
45
3.7
45
3.5
45
3.3
45
3.1
45
3.0
SPECIFIC GRAVITY OF NATURAL GAS
0.60
0.62
0.64
Orifice
Manifold
Orifice
Manifold
Orifice
Manifold
No.
Pressure
No.
Pressure
No.
Pressure
42
3.2
42
3.3
42
3.4
43
3.7
43
3.8
42
3.2
43
3.4
43
3.6
43
3.7
44
3.7
44
3.8
43
3.5
44
3.5
44
3.6
44
3.7
44
3.3
44
3.4
44
3.5
45
3.8
44
3.2
44
3.3
45
3.6
45
3.7
45
3.8
45
3.4
45
3.5
45
3.6
45
3.2
45
3.4
45
3.5
45
3.1
45
3.2
45
3.3
Orifice
No.
42
42
43
43
43
44
44
44
45
45
45
0.66
Manifold
Pressure
3.5
3.3
3.8
3.6
3.4
3.6
3.4
3.3
3.8
3.6
3.4
0.58
Orifice
Manifold
No.
Pressure
43
3.7
43
3.5
44
3.7
44
3.5
44
3.3
45
3.8
45
3.6
45
3.4
45
3.2
45
3.0
45
2.9
SPECIFIC GRAVITY OF NATURAL GAS
0.60
0.62
0.64
Orifice
Manifold
Orifice
Manifold
Orifice
Manifold
No.
Pressure
No.
Pressure
No.
Pressure
43
3.8
42
3.3
42
3.4
43
3.6
43
3.7
43
3.8
43
3.4
43
3.5
43
3.6
44
3.6
44
3.8
43
3.4
44
3.4
44
3.5
44
3.7
44
3.2
44
3.3
44
3.5
45
3.7
45
3.8
44
3.3
45
3.5
45
3.6
45
3.7
45
3.3
45
3.4
45
3.5
45
3.2
45
3.3
45
3.4
45
3.0
45
3.1
45
3.2
Orifice
No.
42
42
43
43
44
44
44
44
45
45
45
0.66
Manifold
Pressure
3.5
3.2
3.7
3.5
3.8
3.6
3.4
3.2
3.7
3.5
3.3
0.58
Orifice
Manifold
No.
Pressure
43
3.7
43
3.4
44
3.7
44
3.5
44
3.2
45
3.7
45
3.5
45
3.3
45
3.1
45
3.0
SPECIFIC GRAVITY OF NATURAL GAS
0.60
0.62
0.64
Orifice
Manifold
Orifice
Manifold
Orifice
Manifold
No.
Pressure
No.
Pressure
No.
Pressure
43
3.8
42
3.2
42
3.3
43
3.5
43
3.7
43
3.8
44
3.8
43
3.4
43
3.5
44
3.6
44
3.7
44
3.8
44
3.4
44
3.5
44
3.6
45
3.8
44
3.3
44
3.4
45
3.6
45
3.7
44
3.2
45
3.4
45
3.5
45
3.6
45
3.2
45
3.3
45
3.4
45
3.1
45
3.2
45
3.3
Orifice
No.
42
42
43
43
44
44
44
45
45
45
0.66
Manifold
Pressure
3.4
3.2
3.7
3.4
3.7
3.5
3.3
3.8
3.6
3.4
—33—
TABLE 7—MODEL 340MAV ORIFICE SIZE AND MANIFOLD PRESSURE FOR CORRECT INPUT Continued
(TABULATED DATA BASED ON 20,000 BTUH PER BURNER, DERATED 2% FOR EACH 1000 FT ABOVE SEA LEVEL)
U.S.A. Only
ALTITUDE
RANGE
(FT)
5001
to
6000
U.S.A. Only
ALTITUDE
RANGE
(FT)
6001
to
7000
U.S.A. Only
ALTITUDE
RANGE
(FT)
7001
to
8000
U.S.A. Only
ALTITUDE
RANGE
(FT)
8001
to
9000
AVG GAS
HEAT VALUE
AT ALTITUDE
(BTU/CU FT)
700
725
750
775
800
825
850
875
900
925
950
975
1000
AVG GAS
HEAT VALUE
AT ALTITUDE
(BTU/CU FT)
650
675
700
725
750
775
800
825
850
875
AVG GAS
HEAT VALUE
AT ALTITUDE
(BTU/CU FT)
625
650
675
700
725
750
775
800
825
850
AVG GAS
HEAT VALUE
AT ALTITUDE
(BTU/CU FT)
600
625
650
675
700
725
750
775
800
0.58
Orifice
Manifold
No.
Pressure
43
3.6
43
3.4
44
3.6
44
3.4
44
3.2
45
3.6
45
3.4
45
3.2
45
3.0
45
2.9
45
2.7
45
2.6
45
2.5
SPECIFIC GRAVITY OF NATURAL GAS
0.60
0.62
0.64
Orifice
Manifold
Orifice
Manifold
Orifice
Manifold
No.
Pressure
No.
Pressure
No.
Pressure
43
3.7
42
3.2
42
3.3
43
3.5
43
3.6
43
3.7
44
3.7
43
3.4
43
3.5
44
3.5
44
3.6
44
3.7
44
3.3
44
3.4
44
3.5
45
3.7
44
3.2
44
3.3
45
3.5
45
3.6
45
3.8
45
3.3
45
3.4
45
3.6
45
3.1
45
3.3
45
3.4
45
3.0
45
3.1
45
3.2
45
2.8
45
2.9
45
3.0
45
2.7
45
2.8
45
2.9
45
2.5
45
2.6
45
2.7
Orifice
No.
42
43
43
43
44
44
44
45
45
45
45
45
45
0.66
Manifold
Pressure
3.4
3.8
3.6
3.4
3.6
3.4
3.2
3.7
3.5
3.3
3.1
2.9
2.8
0.58
Orifice
Manifold
No.
Pressure
42
3.2
43
3.6
44
3.8
44
3.6
44
3.3
45
3.8
45
3.5
45
3.3
45
3.1
45
3.0
SPECIFIC GRAVITY OF NATURAL GAS
0.60
0.62
0.64
Orifice
Manifold
Orifice
Manifold
Orifice
Manifold
No.
Pressure
No.
Pressure
No.
Pressure
42
3.3
42
3.4
42
3.5
43
3.7
43
3.8
42
3.2
43
3.4
43
3.6
43
3.7
44
3.7
44
3.8
43
3.4
44
3.4
44
3.6
44
3.7
44
3.2
44
3.3
44
3.4
45
3.7
45
3.8
44
3.2
45
3.4
45
3.6
45
3.7
45
3.2
45
3.4
45
3.5
45
3.1
45
3.2
45
3.3
Orifice
No.
42
42
43
43
44
44
44
45
45
45
0.66
Manifold
Pressure
3.6
3.3
3.8
3.5
3.8
3.5
3.3
3.8
3.6
3.4
0.58
Orifice
Manifold
No.
Pressure
43
3.8
43
3.5
44
3.8
44
3.5
44
3.3
45
3.7
45
3.5
45
3.3
45
3.1
45
2.9
SPECIFIC GRAVITY OF NATURAL GAS
0.60
0.62
0.64
Orifice
Manifold
Orifice
Manifold
Orifice
Manifold
No.
Pressure
No.
Pressure
No.
Pressure
42
3.3
42
3.4
42
3.5
43
3.7
43
3.8
42
3.2
43
3.4
43
3.5
43
3.6
44
3.6
44
3.8
43
3.4
44
3.4
44
3.5
44
3.6
45
3.8
44
3.3
44
3.4
45
3.6
45
3.7
45
3.8
45
3.4
45
3.5
45
3.6
45
3.2
45
3.3
45
3.4
45
3.0
45
3.1
45
3.2
Orifice
No.
42
42
43
43
44
44
44
45
45
45
0.66
Manifold
Pressure
3.6
3.3
3.7
3.5
3.7
3.5
3.3
3.7
3.5
3.3
0.58
Orifice
Manifold
No.
Pressure
43
3.8
43
3.5
44
3.7
44
3.5
44
3.2
45
3.6
45
3.4
45
3.2
45
3.0
SPECIFIC GRAVITY OF NATURAL GAS
0.60
0.62
0.64
Orifice
Manifold
Orifice
Manifold
Orifice
Manifold
No.
Pressure
No.
Pressure
No.
Pressure
42
3.3
42
3.4
42
3.5
43
3.6
43
3.8
42
3.2
43
3.4
43
3.5
43
3.6
44
3.6
44
3.7
44
3.8
44
3.3
44
3.4
44
3.6
45
3.8
44
3.2
44
3.3
45
3.5
45
3.6
45
3.8
45
3.3
45
3.4
45
3.5
45
3.1
45
3.2
45
3.3
Orifice
No.
42
42
43
43
44
44
44
45
45
0.66
Manifold
Pressure
3.6
3.3
3.7
3.4
3.7
3.4
3.2
3.6
3.4
—34—
TABLE 7—MODEL 340MAV ORIFICE SIZE AND MANIFOLD PRESSURE FOR CORRECT INPUT Continued
(TABULATED DATA BASED ON 20,000 BTUH PER BURNER, DERATED 2% FOR EACH 1000 FT ABOVE SEA LEVEL)
U.S.A. Only
ALTITUDE
RANGE
(FT)
AVG GAS
HEAT VALUE
AT ALTITUDE
(BTU/CU FT)
9001
to
10,000
575
600
625
650
675
700
725
750
775
0.58
Orifice
Manifold
No.
Pressure
43
3.8
43
3.5
44
3.7
44
3.4
45
3.8
45
3.6
45
3.3
45
3.1
45
2.9
SPECIFIC GRAVITY OF NATURAL GAS
0.60
0.62
0.64
Orifice
Manifold
Orifice
Manifold
Orifice
Manifold
No.
Pressure
No.
Pressure
No.
Pressure
42
3.2
42
3.3
42
3.5
43
3.6
43
3.7
42
3.2
44
3.8
43
3.5
43
3.6
44
3.5
44
3.7
44
3.8
44
3.3
44
3.4
44
3.5
45
3.7
45
3.8
44
3.3
45
3.4
45
3.6
45
3.7
45
3.2
45
3.3
45
3.4
45
3.0
45
3.1
45
3.2
Orifice
No.
42
42
43
43
44
44
45
45
45
0.66
Manifold
Pressure
3.6
3.3
3.7
3.4
3.6
3.4
3.8
3.5
3.3
CAUTION: DO NOT bottom out gas valve regulator
adjusting screw. This can result in unregulated manifold
pressure and result in excess overfire and heat exchanger
failures.
EXAMPLE: (0—2000 ft altitude)
Heating value = 1050 Btu/cu ft
Specific gravity = 0.62
Therefore: Orifice No. 45
Manifold pressure 3.6-in. wc
* Furnace is shipped with No. 45 orifices. In this example
all main burner orifices are the correct size and do not need
to be changed to obtain the proper input rate.
NOTE: If orifice hole appears damaged or it is suspected to have
been redrilled, check orifice hole with a numbered drill bit of
correct size. Never redrill an orifice. A burr-free and squarely
aligned orifice hole is essential for proper flame characteristics.
Check and verify burner orifice size in furnace. NEVER ASSUME
ORIFICE SIZE; ALWAYS CHECK AND VERIFY.
2. Adjust manifold pressure to obtain input rate.
NOTE: Manifold pressure must always be measured with burner
enclosure front REMOVED. Gas meter must always be clocked
with burner enclosure front INSTALLED.
a. Remove burner enclosure front.
b. Remove cap that conceals adjustment screw for gas
valve regulator. (See Fig. 44.)
ON AND
OFF SWITCH
BURNER
ORIFICE
GAS
PRESSURE
REGULATOR
ADJUSTMENT
A93059
CAUTION: DO NOT redrill orifices. Improper drilling
(burrs, out-of-round holes, etc.) can cause excessive
burner noise and misdirection of burner flames. This can
result in flame impingement of burners and heat exchangers causing failures.
BURNER
ENCLOSURE
REFERENCE
PRESSURE
TAP
INLET
PRESSURE TAP
d. Replace gas valve regulator adjustment screw cap.
MANIFOLD
PRESSURE TAP
e. Replace burner enclosure front and verify adjusted gas
input rate using method outlined in item 3.
A95622
f. Look through sight glass in burner enclosure and check
burner flame. Burner flame should be clear blue, almost
transparent. (See Fig. 45.)
Fig. 44—Redundant Automatic Gas Valve
c. Turn adjusting screw, counterclockwise (out) to decrease
manifold pressure or clockwise (in) to increase manifold
pressure.
NOTE: This furnace has been approved for a manifold pressure
of 3.2 in. wc to 3.8 in. wc when installed at altitudes up to 2000 ft.
For altitudes above 2000 ft, the manifold pressure can be adjusted
from 2.0 in. wc to 3.8 in. wc.
—35—
TABLE 9—GAS RATE (CU FT/HR)
BURNER FLAME
SECONDS
FOR 1
REVOLUTION
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
BURNER
MANIFOLD
A89020
Fig. 45—Burner Flame
3. Verify natural gas input rate by clocking gas meter.
NOTE: Be sure all pressure tubing, combustion-air and vent
pipes, and burner enclosure front are in place when checking input
by clocking gas meter.
a. Calculate high-altitude adjustment (if required).
UNITED STATES
At altitudes above 2000 ft, this furnace has been approved for a 2% derate for each 1000 ft above sea level.
See Table 8 for derate multiplier factor.
TABLE 8—ALTITUDE DERATE MULTIPLIER FOR U.S.A.
ALTITUDE
(FT)
0—2000
2001—3000
3001—4000
4001—5000
5001—6000
6001—7000
7001—8000
8001—9000
9001—10,000
% OF
DERATE
0
4—6
6—8
8—10
10—12
12—14
14—16
16—18
18—20
DERATE MULTIPLIER
FACTOR FOR U.S.A*
1.00
0.95
0.93
0.91
0.89
0.87
0.85
0.83
0.81
EXAMPLE: (0—2000 ft altitude)
Btu heating input = Btu/cu ft X cu ft/hr
Heating value of gas = 975 Btu/cu ft
Time for 1 revolution of 2-cu ft dial = 70 sec
Gas rate = 103 cu ft/hr (from Table 9)
Btu heating input = 103 X 975 = 100,425 Btuh
In this example, the orifice size and manifold pressure
adjustment is within ±2 percent of the furnace input rate.
* Derate multiplier factor is based on midpoint altitude for altitude range.
EXAMPLE:
100,000 Btuh input furnace installed at 4300 ft.
Furnace Input
Rate at
Sea Level
100,000
X
X
0.91
Derate
Multiplier
Factor
=
=
SIZE OF TEST DIAL SECONDS SIZE OF TEST DIAL
1
2
5
1
2
5
FOR 1
cu ft cu ft cu ft REVOLUTION cu ft cu ft cu ft
360
720 1800
50
72
144
360
327
655 1636
51
71
141
355
300
600 1500
52
69
138
346
277
555 1385
53
68
136
340
257
514 1286
54
67
133
333
240
480 1200
55
65
131
327
225
450 1125
56
64
129
321
212
424 1059
57
63
126
316
200
400 1000
58
62
124
310
189
379
947
59
61
122
305
180
360
900
60
60
120
300
171
343
857
62
58
116
290
164
327
818
64
56
112
281
157
313
783
66
54
109
273
150
300
750
68
53
106
265
144
288
720
70
51
103
257
138
277
692
72
50
100
250
133
267
667
74
48
97
243
129
257
643
76
47
95
237
124
248
621
78
46
92
231
120
240
600
80
45
90
225
116
232
581
82
44
88
220
113
225
563
84
43
86
214
109
218
545
86
42
84
209
106
212
529
88
41
82
205
103
206
514
90
40
80
200
100
200
500
92
39
78
196
97
195
486
94
38
76
192
95
189
474
96
38
75
188
92
185
462
98
37
74
184
90
180
450
100
36
72
180
88
176
439
102
35
71
178
86
172
429
104
35
69
173
84
167
419
106
34
68
170
82
164
409
108
33
67
167
80
160
400
110
33
65
164
78
157
391
112
32
64
161
76
153
383
116
31
62
155
75
150
375
120
30
60
150
73
147
367
B.
Furnace Input Rate
at Installation
Altitude
Set Temperature Rise
CAUTION: Temperature rise must be within limits
specified on unit rating plate. Recommended operation is
at midpoint of rise or above. Failure to follow this caution
may result in condensing or overheating the heat exchangers.
91,000
CANADA
At installation altitudes from 2000 to 4500 ft, this
furnace must be derated 5% by an authorized Gas
Conversion Station. To determine correct input rate for
altitude, see example above and use 0.95 as derate
multiplier factor.
b. Turn off all other gas appliances and pilots.
Determine and adjust air temperature rise as follows:
1. Place thermometers in return and supply ducts as close to
furnace as possible. Be sure thermometers do not see heat
exchanger so that radiant heat does not affect readings. This
practice is particularly important with straight-run ducts.
c. Start furnace and let operate for 3 minutes.
d. Measure time (in sec) for gas meter test dial to complete
1 revolution.
e. Refer to Table 9 for cu ft of gas per hr.
2. When thermometer readings stabilize, subtract return-air
temperature from supply-air temperature to determine air
temperature rise.
f. Multiply gas rate (cu ft/hr) X heating value (Btu/cu ft)
using natural gas heating value from local gas
utility/supplier.
3. Adjust temperature rise by adjusting blower speed. Increase
blower speed to reduce temperature rise. Decrease blower
speed to increase temperature rise.
—36—
THERMOSTAT SUBBASE
TERMINALS WITH
THERMOSTAT REMOVED
WARNING: Disconnect 115-v electrical power before
changing speed tap. Failure to follow this warning could
result in personal injury.
HOOK-AROUND
VOLT/AMMETER
4. To change blower motor speed selections for heating mode,
remove blower motor lead from control center HEAT
terminal. (See Fig. 25.) Select desired blower motor speed
lead from 1 of the other terminals and relocate it to HEAT
terminal. See Table 10 for lead color identification. Reconnect original lead on SPARE terminal.
R Y W G
Follow this same procedure for proper selection of COOL
speed selection.
TABLE 10—SPEED SELECTOR
COLOR
SPEED
Black
Yellow (When Present)
Blue
Red
White
High
Medium High
Medium Low
Low
Common
10 TURNS
FACTORYSHIPPED
CONNECTION
Cool
Spare
Heat
Spare
Com
FROM UNIT 24-VOLT
TERMINAL BLOCK
EXAMPLE: 5.0 AMPS ON AMMETER
10 TURNS AROUND JAWS
= 0.5 AMPS FOR THERMOSTAT SETTING
A80201
Fig. 46—Amp Draw Check with Ammeter
C. Blower Off Delay (Heat Mode)
The main blower off time delay period is factory-set at 135 sec and
is not field-adjustable.
2. Remove main furnace door and disconnect inducer motor
lead wires from wire harness.
3. Turn on 115-v power to furnace.
D. Set Thermostat Heat Anticipator
Thermostat heat anticipator must be set to match amp draw of
components in R-W circuit. Accurate amp draw measurements can
be obtained at thermostat subbase terminals R and W.
Fig. 46 illustrates an easy method of obtaining these measurements. Amp reading should be taken after blower motor has
started. See thermostat manufacturer’s instructions for adjusting
heat anticipator and for varying heating cycle length.
4. Set thermostat to "call for heat" and wait 1 minute. When
pressure switch is functioning properly, hot surface ignitor
should NOT glow, and control center diagnostic light
flashes a 31 fault. If hot surface ignitor glows when inducer
motor is disconnected, shut furnace down immediately.
Determine reason pressure switch did not function properly
and correct condition.
5. Turn off 115-v power to furnace.
CHECK SAFETY CONTROLS
I. CHECK PRIMARY LIMIT CONTROL
This control shuts off combustion control system and energizes
air-circulating blower motor if furnace overheats. Recommended
method of checking this limit control is to gradually block off
return air after furnace has been operating for a period of at least
5 minutes. As soon as limit control has shut off burners, return-air
opening should be unblocked to permit normal air circulation. By
using this method to check limit control, it can be established that
limit is functioning properly and operates if there is a restricted
return-air supply or motor failure. If limit control does not function
during this test, cause must be determined and corrected.
6. Reconnect inducer motor leads, reinstall main furnace door,
and turn on 115-v power supply.
CHECKLIST
1. Put away tools and instruments. Clean up debris.
2. Verify manual reset switch has continuity.
3. Verify that blower and control access doors are properly
installed.
4. Cycle test furnace with room thermostat.
5. Check operation of accessories per manufacturer’s instructions.
II. CHECK PRESSURE SWITCH
This control proves operation of draft inducer. Check switch
operation as follows:
6. Review User’s Guide with owner.
7. Leave literature packet near furnace.
1. Turn off 115-v power to furnace.
—37—
CHECKLIST—INSTALLATION
LOAD CALCULATION
Condensate Drain
____________
Heating Load (Btuh)
____________
Cooling Load (Btuh)
____________
Furnace Model Selection
COMBUSTION AND VENT PIPING
Termination Location
________
Roof or Sidewall
________
Termination Kit — 2 Pipe or Concentric
________
Combustion-Air Pipe Length
________
Combustion-Air Pipe Elbow Quantity
________
Vent Pipe Length
________
Vent Pipe Elbow Quantity
________
Pipe Diameter Determined from Sizing Table
________
Pipe Sloped To Furnace
________
Unit Level or Pitched Forward
________
Internal Tubing Connections Free of Kinks
and Traps
________
External Drain Connection Leak Tight and
Sloped
________
Condensate Trap Primed before Start-Up
________
Heat Tape Installed if Required
CHECKLIST—START-UP
________
Gas Input Rate
(Set Within 2 percent of Rating Plate)
________
Temperature Rise Adjusted
Thermostat Anticipator
________
Anticipator Setting Adjusted or
________
Cycle Rate (3 Cycles per Hr) Selected
Safety Controls Check Operation
Pipe Insulation
________
Over Ceilings
________
Low-Ambient Exposed Pipes
—38—
________
Primary Limit
________
Pressure Switch
SERVICE TRAINING
Packaged Service Training programs are an excellent way to increase your
knowledge of the equipment discussed in this manual, including:
• Unit Familiarization
• Maintenance
• Installation Overview
• Operating Sequence
A large selection of product, theory, and skills programs is available, using popular
video-based formats and materials. All include video and/or slides, plus companion
book.
Classroom Service Training plus "hands-on" the products in our labs can mean
increased confidence that really pays dividends in faster troubleshooting, fewer
callbacks. Course descriptions and schedules are in our catalog.
CALL FOR FREE CATALOG 1-800-962-9212
[ ] Packaged Service Training
[ ] Classroom Service Training
A94328
—39—
© 1996 BDP Co. • P.O. Box 70 • Indianapolis, IN 46206
Printed in U.S.A.
—40—
340m403
Catalog No. BDP-3334-008
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