*TC Series 92+ Upflow/Horizontal Two-Stage Condensing Furnace
*TL Series 90+ Downflow Two-Stage Condensing Furnace
*TC 92+ Upflow/Horizontal*TL 90+ Downflow
!
WARNING:
Improper installation, adjustment, alteration, service, or maintenance can
cause injury or property damage. Refer to this manual for assistance. For
additional information consult a qualified installer, service agency, or the
gas supplier.
These instructions are primarily intended
to assist qualified individuals experienced
in the proper installation of this appliance.
Some local codes require licensed installation/service personnel for this type of equipment. Read all instructions carefully before
starting the installation.
DO NOT DESTROY. PLEASE READ CAREFULLY AND KEEP IN A SAFE PLACE FOR
FUTURE REFERENCE.
!
FOR YOUR SAFETY:
Do not store or use gasoline or other
flammable vapors and liquids in the
vicinity of this or any other appliance.
!
FOR YOUR SAFETY:
WHAT TO DO IF YOU SMELL GAS:
• Do not try to light any appliance.
• Do not touch any electrical switch; do
not use any phone in your building.
• Immediately call your gas supplier
from a neighbor's phone. Follow the
gas supplier's instructions.
• If you cannot reach your gas supplier,
call the fire department.
Furnace Airflow Data ................................................................................................................................. 6
Safety Information ............................................................................................................................................. 7
Clearances to Combustible Materials .............................................................................................................. 7
Downflow Model Warning .................................................................................................................................. 8
Conversion of the *TC Upflow Furnace for a Horizontal Right Installation ................................................ 8
Conversion of the *TC Upflow Furnace for a Horizontal Left Installation .................................................. 9
Supply Air Plenum Installation ........................................................................................................................ 10
Installation on a Concrete Slab ................................................................................................................ 10
Installation on a Combustible Floor .......................................................................................................... 10
Circulating Air Supply ..................................................................................................................................... 10
Return Air ................................................................................................................................................. 11
Configuring the Blower .................................................................................................................................... 13
Determining Nominal AC System Capacity ............................................................................................... 13
Selecting the AC Cooling Airflow .............................................................................................................. 13
Selecting the Heating Airflow ................................................................................................................... 13
Venting and Combustion Air Requirements .................................................................................................... 13
Air Requirements for One-Pipe Installation ..............................................................................................14
Installation in An Unconfined Space ........................................................................................................ 14
Installation in A Confined Space .............................................................................................................. 14
• Air From Inside ....................................................................................................................................... 15
• Air Directly Through An Exterior Wall .....................................................................................................15
• Outdoor Air Through Vertical Openings or Ducts ...................................................................................15
• Outdoor Air Through Horizontal Openings or Ducts ............................................................................... 15
Vent Pipe Material .................................................................................................................................... 20
Vent Pipe Length and Diameter ................................................................................................................20
Drainage of Condensate From Furnace ........................................................................................................... 25
Gas Supply and Piping ..................................................................................................................................... 25
High Altitude Conversion ................................................................................................................................. 28
High Altitude Application .......................................................................................................................... 28
Pressure Switch Conversion for High Altitude Applications .....................................................................2
Natural Gas High Altitude Conversion ...................................................................................................... 28
LP/Propane Gas Sea Level and High Altitude Conversion ....................................................................... 29
Line Voltage Wiring .................................................................................................................................. 32
Low Voltage Wiring ................................................................................................................................... 32
Start-up and Adjustments ................................................................................................................................33
Verifying and Adjusting Firing Rate .......................................................................................................... 34
Configuring the Blower ............................................................................................................................. 35
Verifying Operation of the Supply Air Limit Switch ................................................................................... 37
Description of Components ..............................................................................................................................37
Location of Major Components ................................................................................................................. 39
Combustion Air and Vent System ............................................................................................................ 40
Air Filter(s) ............................................................................................................................................... 40
Heat Exchanger and Burner Maintenance ................................................................................................ 40
System Operation Information ........................................................................................................................ 40
Sequence of Operation ............................................................................................................................40
Furnace Fails to Operate ..........................................................................................................................42
1.Use only with type of gas approved for this
furnace. Refer to the furnace rating plate.
2.Install this furnace only in a location and
position as specified on Table 3 of these
instructions.
3.Provide adequate combustion and ventilation air to the furnace space as specified on
Pages 10 through 13.
4.Provisions for adequate clearances around
the vent air intake terminal(s) as specified
on Figures 19a through 22 of these instructions.
5.Combustion products must be discharged
outdoors. Connect this furnace to an approved vent system only, as specified on
Pages 16 through 23.
6.Never test for gas leaks with an open flame.
Use a commercially available soap solution
made specifically for the detection of leaks
to check all connections, as specified on
Page 27 of these instructions.
7.Always install furnace to operate within the
furnace’s intended temperature-rise range
with a duct system which has an external
static pressure within the allowable range,
as specified on Table 1a of these instructions. See furnace rating plate.
8.When a furnace is installed so that supply
ducts carry air circulated by the furnace to
areas outside the space containing the
furnace, the return air shall also be handled
by duct(s) sealed to the furnace casing and
terminating outside the space containing
the furnace.
9.A gas-fired furnace for installation in a
residential garage must be installed as
specified on Page 8 of these instructions.
10. The furnace is not to be used for temporary
heating of buildings or structures under
construction.
INSTALLATION REQUIREMENTS
Requirements and Codes
This furnace must be installed in accordance
with these instructions, all applicable local building
codes, and the current revision of the National
Fuel Gas Code (ANSI-Z223.1, NFPA-54). The
current revision of the National Fuel Gas Code
is available from:
American National Standards Institute, Inc.
1430 Broadway
New York, New York 10018
Canada installations shall comply with CAN/
CGA-B149 installation codes, local plumbing or
waste water codes and other applicable codes.
Additional helpful publications are:
• NFPA-90A - Installation of Air Conditioning
and Ventilating Systems.
• NFPA-90B - Warm Air Heating and Air
Conditioning Systems.
These publications are available from:
National Fire Protection Association, Inc.
Batterymarch Park
Quincy, Massachusetts 02269
CLEARANCES TO COMBUSTIBLE MATERIALS
This furnace is Designed Certified by CSA International for the minimum clearances to combustible
material listed in Table 4. See the furnace name plate, located inside the furnace cabinet, for specific
model number and clearance information.
36 inches is the recommended clearance for service.
Table 3. Minimum Clearances to Combustible Materials
‡
‡
‡
‡
1
7
Page 8
!
WARNING:
This furnace is not approved for installation in mobile homes. Installation in
a mobile home could cause fire, property damage, and/or personal injury.
Location
The furnace must be installed on a level surface,
and as close to the center of the air distribution
system as possible. See Table 3 for overall
dimensions to determine the required clearances in hallways, doorways, stairs, etc. to allow
the furnace to be moved to the installation point.
The furnace must be installed so that all electrical components are protected from water.
Minimum clearances to combustible materials
are listed in Table 4. Access for positioning and
servicing must be considered when locating the
unit. 24 inches is the minimum required clearance for servicing the unit. 30 inches is the
minimum required clearance for positioning the
unit. 36 inches is the recommended clearance
from the front of the unit. Please note that a
panel or door can be located such that the
minimum clearance on the rating plate is satisfied, but that panel or door must be removable
so as to allow the appropriate clearance.
This furnace is certified for use on wood flooring.
The furnace must be installed on a solid surface
and must be level front to back and side to side.
This furnace must not be installed directly on
carpeting, tile, or any combustible material other
than wood flooring.
DOWNFLOW MODEL WARNING
The design of the downflow furnace is certified
for natural or propane gas and for installation on
non-combustible flooring. A special combustible floor sub-base is required when installing on a combustible floor. Failure to install the
sub-base may result in fire, property damage
and personal injury. The special downflow subbases are factory supplied accessories, part
numbers 902974, 902677, 904108 and 904165.
904165 is an adjustable sub-base kit and it can
be used on all cabinet sizes. When the furnace
is installed on a factory or site-built cased air
conditioning coil, the sub-base is not necessary. However, the plenum attached to the coil
casing must be installed such that its surfaces
are at least 1" from combustible construction.
8
A gas-fired furnace installed in a residential
garage must be installed so that the bottom of the
furnace is located a minimum of 18" from the
floor. The furnace must be located or protected
to avoid physical damage by vehicles.
HORIZONTAL INSTALLATIONS
The upflow model furnaces are approved for
horizontal installation. Installation Kit #903568 is
available for horizontal applications. The parts
may also be field supplied. The parts that are
field supplied should conform to Figures 3 and
4. NOTE: Downflow models are NOT approved
for horizontal installation.
!
CAUTION:
Damage to the product resulting from
failure to follow instructions or use of
unauthorized parts may void the
manufacturer's product warranty coverage.
The 90+ upflow furnace can be installed horizontally in an attic, basement, crawl space or
alcove. This furnace can be installed horizontally to the clearances listed in Table 2 on a
platform or on the ceiling rafters. Note that the
platform and the ceiling rafters must be able to
support the weight of the furnace being installed.
It can also be suspended from a ceiling in a
basement or utility room in either a right to left
airflow or left to right airflow.
When installed horizontally, the furnace must be
raised above the surface to allow a drain trap to
hang vertically below the furnace. This will allow
for proper drainage of the condensate from the
furnace.
Conversion of the *TC Upflow Furnace for
a Horizontal Right Installation.
Refer to Figure 3.
1. Remove the hard “J” tube drain trap
assembly.
2. Place the 5/8" cap plug over the drain trap
in the header box from which the “J” drain
trap assembly was removed.
3. Remove the piece of soft tubing running
from the in-line drain assembly to the
header box and place a ½” vinyl cap over
the drain tap in the in-line drain assembly.
4. Remove the gray tubing from the pressure tap on the header box. Remove the
¼” cap from the pressure tap on the right
side of the header box and place it on the
Page 9
corresponding pressure tap on the opposite of the header box.
5. Place the gray tubing that was removed,
to the corresponding pressure tap on the
right side of the header box. ( Refer to
Figure 3)
6. If field supplied parts are used, disconnect both soft tubes from the hard “J” tube
drain trap after loosing 7/8" clamps.
Shorten long side of the “J” trap by 8-1/2".
7. Feed the 10" piece of soft tubing through
the round hole located in the right side of
the cabinet wrapper Note: A downward
slope must be maintained on the tube as
it is routed through the furnace (when the
furnace is in the horizontal position).
8. Assemble the 10" piece of soft tube to 5"
tall end of the hard (J) tube to the end of
the 10" soft tube located outside of the
furnace. Secure the connection using
one of the clamps that was removed, from
the “J” trap. Secure the connection with
the 7/8” hose clamp.
9. Reassemble the 30" piece of soft tubing
removed from the factory installed “J”
tube drain trap to the 2’ tall end of the
modified “J” tube drain trap.
Note: Ensure the clamps in step 7 and 8 are
securely tightened in order to avoid any condensate leakage.
Note: PVC “T” drain assembly must be installed so that condensate does not get into the
induced draft blower.( refer to Figure 3).
5/8" Vinyl Cap
1/4" Vinyl Cap
Note: To avoid condensate freezing in the
drain trap assembly and tubing, insulate around
the drain trap assembly and all tubing located
in unconditioned space.
Conversion of the *TC Upflow Furnace for
a Horizontal Left Installation.
Refer to Figure 4.
1. Remove the hard “J” tube drain trap assembly.
2. If field supplied parts are used, disconnect both soft tubes from the hard “J” tube
drain trap after loosing 7/8" clamps.
Shorten long side of the “J” trap by 8-1/2".
3. Feed the 10" piece of soft tubing through
the round hole located in the left side of the
cabinet wrapper. Note: A downward slope
must be maintained on the tube as it is
routed through the furnace (when the
furnace is in the horizontal position).
4. Assemble the 5" tall end of the hard “J”
tube to the end of the 10" soft tube located
outside of the furnace. Secure the connection using one of the 7/8" hose clamps
that were removed from the “J” trap.
5. Assemble the 30" piece of soft tubing that
was removed from the “J” trap o the 2" tall
end of the modified “J” drain trap. Secure
the connection with the 7/8" hose clamp.
NOTE: To avoid condensate freezing in the
drain trap assembly and tubing, insulate around
the drain trap assembly and all tubing located in
unconditioned space. See note in Figure 4.
Grey
Tub in g
3" to 2"
Reducer
(Optional)
Pressure Switch
Figure 3. 90+ Upflow Converted for Horizontal Installation (Horizontal Right)
Alternative
for
Horizontal
Vent
PVC Tee
Reducer
Bushing
Soft Tubing
Looped to Provide
a Drain Trap
Figure 4. 90+ Upflow Converted for Horizontal Installation (Horizontal Left)
3" to 2"
Reducer
(Optional)
Drainage Port
is Downard
Soft
Tubing
Drain Trap
Grey
Tubing
1/2" Vinyl
Cap
Pressure Switch
(Condensate)
Soft Tubing
Drain Trap
Soft
Tub in g
Vinyl Cap
1/4" Vinyl Cap
Pressure
Switch
PVC Tee
PVC Reducer
Bushing
Soft Tubing
Looped to Provide
a Drain Trap
NOTE: When converting
the furnace, to horizontal
left, ensure that the drainage port on the in-line
drain assembly is downward as shown in this figure. If the in-line drain assembly is not rotated, then
the furnace may not drain
properly.
9
Page 10
*Larger dimension
18.75"
or 13.25 or 21.50
for TL110
A
B
MODELAB
*TL 06013.25”19.25”
*TL 080/10018.75”19.25”
*TL 12021.50”19.25”
Figure 5. Opening for Concrete Slab
Concrete
Floor
Furnace
Sheet
Metal
Plenum
Figure 6. Downflow Furnace
on a Concrete Slab
A
B
MODELAB
*TL 06013.25”19.63”
*TL 080/10018.75”19.63”
*TL 12021.50”19.63”
Figure 7. Opening in Wood Floor
Downflow
Sub-base
Furnace
Sheet
Metal
Plenum
Wood
Floor
Figure 8. Furnace on a Wood Floor
10
16.75"
or *19.50"
1.50"
19.75"
or 14.25 or 22.50"*
9.25"
28.38"
1.58"
2.0"
19.63"
1 inch thick fiberglass 3 lb density
3"
Figure 9. Downflow Sub-Base Dimensions
SUPPLY AIR PLENUM
INSTALLATION FOR DOWNFLOW
MODELS
A.Installation on a concrete slab - downflow
models
1. Construct a hole in the floor per the
dimensions in Figure 5.
2. Place the plenum and the furnace as
shown in Figure 6.
B.Installation on a combustible floor - *TL
1. Cut hole and frame the hole per the
dimensions in Figure 7.
2. Place sub-base for combustible floors
over the hole with its duct collar extended
downward. Attach the supply air plenum
to the base in a manner which will assure
1” clearance to the flooring or other combustible material. Place furnace on the
combustible base as shown in Figure 8.
3. When the furnace is installed on a factory
or site-built cased air conditioning coil,
the sub-base is not necessary. However, the plenum attached to the coil
casing must be installed such that its
surfaces are at least 1” from combustible
material in Figure 9.
CIRCULATING AIR SUPPLY
Plenums and air ducts must be installed in
accordance with the Standard for the Installation of Air Conditioning and Ventilating Systems
(NFPA No. 90A) or the Standard for the Installation of Warm Air Heating and Air Conditioning
Systems (NFPA No. 90B).
Page 11
If outside air is utilized as return air to the furnace
for ventilation or to improve indoor air quality, the
system must be designed so that the return air
to the furnace is not less than 50°F (10°C) during
heating operation. If a combination of indoor and
outdoor air is used, the ducts and damper system
must be designed so that the return air supply to
the furnace is equal to the return air supply under
normal, indoor return air applications.
When a cooling system is installed which uses
the furnace blower to provide airflow over the
indoor coil, the coil must be installed downstream (on the outlet side) or in parallel with the
furnace.
If a cooling system is installed in parallel with the
furnace, a damper must be installed to prevent
chilled air from entering the furnace and condensing on the heat exchanger. If a manually
operated damper is installed, it must be designed so that operation of the furnace is prevented when the damper is in the cooling position and operation of the cooling system is
prevented when the damper is in the heating
position.
!
IMPORTANT:
The variable speed blower kit has been
designed to give the installer maximum flexibility to optimize system performance, efficiency, and comfort.
Because there are so many ways to
configure the kit it is important to read
and follow these instructions carefully.
Upflow Models
Protective Screen
Return Air
The return air ductwork may be connected to
any or all of the following: left side return, right
side return, or bottom return. Table 1 shows the
airflow data for each furnace model. Where
maximum airflow is 1800 CFM or more two
openings must be used.
!
WARNING:
Downflow Models
Figure 10. Protective Screen for One
Pipe Installations
Products of combustion must not be allowed to enter the return air ductwork or
the circulating air supply. Failure to prevent products of combustion from being
circulated into the living space can create potentially hazardous conditions
including carbon monoxide poisoning that could result in personal injury or death.
All return ductwork must be secured to the furnace with sheet metal screws. For
installations in confined spaces, all return ductwork must be adequately sealed
and joints must be taped. When return air is provided through the bottom of the
furnace, the joint between the furnace and the return air plenum must be sealed.
The floor or platform on which the furnace is mounted must provide sound physical
support of the furnace with no gaps, cracks, or sagging between the furnace and
the floor or platform.
Return air and circulating air ductwork must not be connected to any other heat
producing device such as a fireplace insert, stove, etc.
11
Page 12
,
q
Vent or
Chimney
Each opening must
be at least 100 sq. in.
or 1 sq. in. per 1000
Btuh of total input
rating, whichever is
greater. See minimum
area per table.
12" Max.
Each opening
to outside must
be at least
1 sq. in. per
4000 Btuh of
total input
rating.
10 sq. in.
15 sq. in.
20 sq. in.
25 sq. in.
30 sq. in.
35 sq. in.
40 sq. in.
Round Duct
Diameter
4"
5"
5"
6"
6"
7"
8"
Figure 12. Equipment in a Confined
Space with all Combustion Air drawn
from Outdoors through Exterior Wall
Vent or
Chimney
Air Duct must be
at least 1 sq. in.
Furnace
Water Heater
per 4,000 Btuh of
total input rating.
12" Max
Minimum
Total Input
Rating (Btuh)
40,000
60,000
80,000
100,000
120,000
140,000
160
000
Free Area
(Each Opening)
10 sq. in.
15 sq. in.
20 sq. in.
25 sq. in.
30 sq. in.
35 sq. in.
40 s
. in.
Round Duct
Diameter
4"
5"
5"
6"
6"
7"
8"
Figure 13. Equipment in a Confined
Space with all Combustion Air drawn
from Outdoors through Vertical Ducts –
from Ventilated Attic
Ventilation Louvers
(each end of attic)
---------
Furnace
Alternate
Air Inlet
Outlet
Air
Water
Heater
Inlet Air
---------
---------
Ventilation Louvers For
Unheated Crawl Space
NOTE: Air openings shall each
have a free area
of not less than
one square inch
per 4,000 Btuh of
the total input rating of all equipment
in the enclosure.
---------
Figure 14. Equipment in a Confined
Space with all Combustion Air drawn
from Outdoors through Ventilated Crawl
Space and Ventilated Attic
12
Page 13
Each opening
to outside
must be at least
1 sq. in. per 2000
Btuh of total input
rating.
-
-
-
-
-
-
-
-
-
12" Max
Air Duct
Vent or
Chimney
-
-
-
-
-
-
-
-
-
Furnace
The heating airflow is selected by setting
switches 5 and 6 on the motor control board
located in the blower control panel. Note that
switch 7 is not used for heating or cooling in
these furnaces. Therefore, switch 7 can be
either “on” or “off” without affecting the operation
of the furnace. Table 1 shows the airflow values
versus the airflow selector switch settings, and
the range of airflow settings recommended for
each heating capacity.
20 sq. in.
30 sq. in.
40 sq. in.
50 sq. in.
60 sq. in.
70 sq. in.
80 sq. in.
Water Heater
Round Duct
Diameter
5"
6"
7"
8"
9"
10"
10"
Figure 15. Equipment in a Confined Space
with all Combustion Air Drawn from the
Outside through Horizontal Ducts
Determining Nominal AC System
Capacity
In order to select the appropriate airflow for AC
operation the nominal system capacity must be
known. The nominal system capacity is
ALWAYS the nominal capacity of the outdoor
unit. In some cases the nominal system
capacity is not the same as the nominal capacity
of the indoor coil.
NOTE: The airflow values (CFM) listed in the
tables are not dependent on duct static pressure. The motor automatically compensates for
changes in duct static pressure (within the limits
of the motor).
VENTING AND COMBUSTION AIR
REQUIREMENTS
These condensing furnaces may be installed
with outdoor combustion air piped directly to the
furnace, or without such special piping. Codes
refer to the former as "direct vent" or "two pipe"
installation. Installation with air taken from
around the furnace is sometimes referred to as
"one pipe" installation - i.e. only the vent (exhaust) pipe is provided.
Provisions must be made for adequate supply of
air for combustion and ventilation. For United
States installations, the adequacy of air provisions can be determined by consulting the current version of the National Fuel Gas Code (ANSI
Z223.1/NPFA-54). For Canadian installations,
requirements are specified in the National Standard of Canada (CAN/CGA B149.1 & .2). Consult
local codes for special requirements.
NOTE: In order to change the speed settings
for heating or cooling, power to the unit
must be disconnected before the new speed
will be effective.
Selecting the AC Cooling Airflow
The cooling airflow is selected by setting switches
1 through 4 on the motor control board located in
the blower control panel. Table 1 shows the
airflow values versus the airflow selector switch
settings, and the range of airflow settings
recommended for each nominal system capacity.
An important consideration in selecting one or
two pipe installation is the quality of the combustion air. Indoor air is sometimes contaminated
with various household chemicals which can
cause severe corrosion in the furnace combustion system.
NOTE: If the furnace is operated without adequate air for combustion and ventilation, it may
not perform properly. Furnace components
may be strained by high temperature and could
fail prematurely.
13
Page 14
!
WARNING:
Furnace installation using methods
other than those described in the following sections must comply with the
National Fuel Gas Code and all applicable local codes to provide sufficient
combustion air for the furnace.
Combustion Air Quality
The recommended source of combustion air is
to use the outdoor air supply. However, the use
of indoor air in most applications is acceptable
except as follows:
1.If the furnace is installed in a confined space
it is recommended that the necessary combustion air come from the outdoors by way
of attic, crawl space, air duct, or direct
opening.
2.If outdoor combustion air is used, there
must be no exposure to the installations or
substances listed in Item 3 below.
3.The following types of installation may require Outdoor Air for combustion, due to
chemical exposures:
• Commercial buildings
• Buildings with indoor pools
• Furnaces installed in laundry rooms
• Furnaces installed in hobby or craft rooms
• Furnaces installed near chemical storage areas
Exposure to the following substances in the
combustion air supply may also require
Outdoor Air for combustion:
• Permanent wave solutions
• Chlorinated waxes and cleaners
• Chlorine based swimming pool chemicals
• Water softening chemicals
• De-icing salts or chemicals
• Carbon tetrachloride
• Halogen type refrigerants
• Cleaning solvents (such as perchloroethylene)
• Printing inks, paint removers, varnishes,
etc.
• Hydrochloric acid
• Cements and glues
• Antistatic fabric softeners for clothes dryers
• Masonry acid washing materials
14
Air Requirements For One-Pipe
Installation
When air for combustion is to be taken from
around the furnace, a protective screen must be
installed over the combustion air intake opening.
This screen is provided with the furnace installation instructions and functions to prevent debris from entering the combustion system. It
should be installed on the combustion air intake
collar or inlet PVC. If furnace location is such that
this opening might be unintentionally obstructed,
a 3" PVC elbow should be installed on the collar,
and the screen placed inside the inlet of the
elbow. See Figure 10.
Installation In An Unconfined Space
!
CAUTION:
"Tight" buildings (with weather stripping and caulk to reduce infiltration),
may require special provisions for introduction of outside air to ensure
satisfactory combustion and venting,
even though the furnace is located in
an unconfined space.
An unconfined space is an area including all
rooms not separated by doors with a volume
greater than 50 cubic feet per 1,000 Btuh of the
combined input rates of all appliances which draw
combustion air from that space. For example, a
space including a water heater rated at 45,000
Btuh and a furnace rated at 75,000 Btuh requires
a volume of 6,000 cubic feet [50 x (45 + 75) =
6,000] to be considered unconfined. If the space
has an 8 foot ceiling, the floor area of the space
must be 750 square feet (6,000 / 8 = 750). In
general, a furnace installed in an unconfined
space will not require outside air for combustion.
!
WARNING:
Furnaces installed with combustion air
drawn from a heated space which includes exhaust fans, fireplaces, or
other devices that may produce a negative pressure should be considered
confined space installations.
Installation In A Confined Space
A confined space is one which does not meet the
unconfined space volume requirements, and
Page 15
typically involves installation in a small room. All
such installations must have specific provisions
for introduction of combustion and ventilation
air.
Codes require that two openings be provided for this - one with bottom edge within 12"
of the floor and one with top edge within 12" of
the ceiling.
The size and other criteria for these
openings must be per the following sections.
Combustion air openings must not be restricted
in any manner.
Furnaces installed in a confined space which
supply circulating air to areas outside of the
space must draw return air from outside the
space and must have return air ducts tightly
sealed to the furnace.
Air From Inside
Air for combustion and ventilation may be taken
from inside the building through an interior wall
if the building is not "tight" and if the total volume
of the furnace space and the space from which
air is drawn meets the volume requirements for
an unconfined space.
In such cases, the two
openings in the wall must each have free area of
at least one square inch per 1000 Btuh of
total
appliance input, but not less than 100 square
inches of free area. See Figure 11. For example,
if the combined input rate of all appliances is less
than or equal to 100,000 Btuh,
each
opening
must have a free area of at least 100 square
inches. If the combined input rate of all appliances is 120,000 Btuh,
each
opening must have
a free area of at least 120 square inches.
Air Directly Through An Exterior Wall
If combustion air is provided directly through an
exterior wall, the two openings must
each
have
free area of at least one square inch per 4000
Btuh of
total
appliance input. (See Figure 12.)
Outdoor Air Through Vertical Openings or Ducts
If combustion air is provided through vertical
ducts or openings to attics or crawl spaces, the
two openings must each have free area of at
least one square inch per 4000 Btuh of total
appliance input. Ducts must have cross-sectional areas at least as large as the free area of
their respective openings to the furnace space.
Attics or crawl spaces must communicate freely
with the outdoors if they are the source of air for
combustion and ventilation. (See Figures 13
and 14.)
Outdoor Air Through Horizontal
Openings or Ducts
If combustion air is taken from outdoors through
horizontal ducts, the openings must
each
have
free area of at least one square inch per 2000
Btuh of total appliance input. Ducts must have
cross-sectional area at least as large as the free
area of their respective openings to the furnace
space. (See Figure 15.)
with 1 long radius elbow**with 1 long radius elbow on each pipe**
PVC,CPVC or ABSOutletOutletInlet/OutletInlet/OutletInlet/Outlet
SCH. 40 Pipe Size2"3"2"2"3"2"3"3"
Models
*T(C,L)6520040404040110110
060
Models
*T(C,L)4520035354040110110
80
Models
*T(C,L)4020025254040110110
100
Models
*T(C,L)4020020204040110110
120
**NOTES
1. Subtract 2.5 ft. for each additional 2" long radius elbow, 5 ft. for each additional 2" short radius elbow, 3.5’ for each
additional 3” long radius elbow, and 7’ for each additional 3” short radius elbow.
2.Two 45 degree elbows are equivalent to one 90 degree elbow.
3.Do not include termination elbows in calculation of vent length
4.This table is applicable for elevations from sea level to 2000 ft. For higher elevations decrease vent pipe lengths
by 8% per 1000 ft. of altitude.
5.Only the above pipe materials are approved for use with these condensing furnaces.
Table 4. Vent Table
15
Page 16
!
e
CAUTION:
Do not supply combustion air from an
attic space that is equipped with power
ventilation or any other device that
may produce a negative pressure.
Upflow Furnaces
VENTING REQUIREMENTS
This section specifies installation requirements
for vent and "2-pipe" combustion air piping. For
"one pipe" installations, install vent piping per
this section and provide air for combustion and
ventilation per the previous section. The capacity table provided in this section applies to the
total of vent and combustion air piping for either
type of installation.
5/8"
Combustion
Offset with
Exhaust Pipe
for Adequate
Dimensional
Clearance
PVC or
ABS Pipe
Straight Neoprene Coupling
with 2 Hose Clamps*
(Optional - Not Shown)
Inlet
Exhaust
Downflow Furnaces
Seal/Caulk
around Pipe
at Building
See Vent Table 4
Straps or Other Suitable
Supports at Minimum of 5 ft. Intervals
Upward Pitch - 1/4" per Foot
Outlet Exhaust Vent
First Support Placed
as Close to Furnace
Connection as Possible
Exhaust Vent
See Vent Table 4
Straps or Other Suitable
Supports at Minimum of 5 ft. Intervals
Wall
7"
Normal Snow Level
Exhaust
Inlet
Seal/Caulk
around Pip
at Building
90˚ Elbow
12" Min.
5/8"
90˚ Elbow
12" Min.
Normal Snow Level
* These neoprene couplings are field-supplied and can be used if the installation requires breakable connections
in the piping. Note that a maximum of two couplings per pipe are allowed.
16
Upward Pitch - 1/4" per Foot
Outlet Exhaust Vent
First Support Placed
Wall
as Close to Furnace
Connection as Possible
Exhaust Vent
Figure 16. Horizontal Venting
Combustion Air
Inlet
Offset with Exhaust
Pipe for Adequate
Dimensional
Clearance
PVC or
ABS Pipe
Straight Neoprene
Coupling with
2 Hose Clamps*
Page 17
Upflow Furnaces
Support System on
Vertical Rise Below Joints
Support System with
first support as close
to furnace as Possible
5'
Combustion
Air Pipe
Furnace Front
Downflow Furnaces
Exhaust
Vent
Exhaust
Vent
Straight Neoprene
Couplings with
2 Hose Clamps*
(Optional - Not
Shown)
Cabinet
Vertical Rise Below Joints
Support System with
first support as close
to furnace as Possible
Combustion
Air Pipe
Upward Pitch
1/4" per Foot
Support System on
5'
Straight Neoprene
Rubber Couplings
with 2 Hose Clamps*
Cabinet
Furnace Front
Upward Pitch
1/4" per Foot
Figure 17. Vertical Venting
* These couplings are field-supplied and can be used if the installation requires breakable connections in the piping.
Note that a maximum of two couplings per pipe are allowed.
Upflow Furnaces
Combustion Air Inlet Pipe Collar
Diameter 3" for coupling
Furnace Top
2" PVC
Exhaust Vent
Use 2" to 3" reducer
Downflow Furnaces
Combustion Air Inlet Pipe
3" PVC
Furnace Top
2" PVC
Exhaust Vent
Use 2" to 3" reducer
Figure 18. Furnace Pipe Adaptions
17
Page 18
These condensing furnaces are classified as
y
w
g
y
g
y
y
"Category IV" appliances, which require special
venting materials and installation procedures.
Category IV appliances operate with positive
vent pressure and therefore require vent systems which are thoroughly sealed. They also
produce combustion condensate, which is
slightly acidic and can cause severe corrosion
of ordinary venting materials. Furnace operation can be adversely affected by restrictive
vent and combustion air piping. Therefore,
vent
and combustion air piping lengths must conform
completely to the requirements of Table 4.
The furnace must be vented to the outdoors. It
must not be vented in common with any other
VENT TERMINAL
Clearance abov e grade, veranda, porch ,
A =
deck , or balcony
Clearance to window or door t hat m ay be
B =
opened
Clearance to permanentl
C =
Vertical clearance to ventilated soffit
D =
located above the terminal within a
horiz ontal dist ance of 2 feet (61 cm ) from
the center line of the terminal
Clearance to unventilat ed soffit
E =
Clearance to outside corner
F =
Clearance to inside corner
G =
Clearance to each side of c enter line
H =
ext ended abov e met er/re
Clearance to service regulator vent outlet3 feet (1.83 m)
I =
Clearance to nonmechanica l air s upply inlet
J =
to building or the combustion air inlet to any
other applianc e
Clearance to a mechanical air supply inlet6 feet (1.83 m)3 feet (91 cm) above if within 10 feet (3 m)
K =
Clearance abov e paved sidewalk or paved
L =
driv eway locate d on publi c property
Clearance under v eranda, porch dec k, or
M =
balc on
closed win do
ulat or ass embl
AIR SUPPLY INLET
Canadian Installations
12 inc hes (30 cm)12 inc hes (30 cm)
6 inches (15 cm) for appliances ≤ 10,000
Btuh (3 k W), 12 inches (30 cm) for
appliances > 10,000 Btuh (3 kW) and ≤
100,00 Btuh (30 kW), 36 inches (91 c m) for
appliances >100,00 Btuh (30 kW)
3 feet (91 cm) within a height 15 feet
abov e the me ter/re
6 inches (15 cm) for appliances ≤ 10,000
Btuh (3 k W), 12 inches (30 cm) for
appliances > 10,000 Btuh (3 kW) and ≤
100,00 Btuh (30 kW), 36 inches (91 c m) for
appliances >100,00 Btuh (30 kW)
7 feet (2.13 m) †
12 inc hes (30 cm) ‡
AREA WHERE TERMINAL IS NOT PERMITTED
1
**
**
**
**
**
ulat or ass embl
US Installations
6 inches (15 cm) for appliances ≤ 10,000
Btuh (3 k W), 9 inches (23 cm) for
appliances > 10, 000 Btuh (3 kW) and ≤
50,000 Btuh (15 kW), 12 inches (30 c m) for
appliances > 50, 000 Btuh (15 kW)
6 inches (15 cm) for appliances ≤ 10,000
Btuh (3 k W), 9 inches (23 cm) for
appliances > 10, 000 Btuh (3 kW) and ≤
50,000 Btuh (15 kW), 12 inches (30 c m) for
appliances > 50, 000 Btuh (15 kW)
horizontally
2
*
*
*
*
1
In accordance with the current CSA B149.1
2
In accordance with the current ANSI Z223.1 / NFPA 54
† A vent shall not terminate directly above a sidewalk or paved driveway that is located between two single family dwellings and
serves both dwellings.
‡ Permitted only if veranda, porch, deck, or balcony is fully open on a minimum of two sides beneath the floor.
* For clearances not specified in ANSI Z223.1 / NFPA 54 or CSA B149.1, the following statement shall be included:
“Clearance in accordance with local installation codes, and the requirements of the gas supplier
Figure 19a. Vent Termination Clearances for Direct Vent Furnaces
18
Natural Gas and Propane Installation Code
and the manufacturer’s installation instructions.”
National Fuel Gas Code
Page 19
appliance, even if that appliance is of the con-
y
g
y
g
y
g
densing type. Common venting can result in
severe corrosion of other appliances or their
venting and can allow combustion gases to
escape through such appliances or vents. Do
not vent the furnace to a fireplace chimney or
building chase.
!
WARNING:
FURNACE MUST NOT BE COMMON
VENTED WITH OTHER APPLIANCES.
VENT TERMINAL
Clearance above grade, veranda, porch,
A =
deck, or balcony
Clearance to window or door that may be
B =
opened
Clearance to permanentl
C =
Vertical c learance to ventilated soffit
D =
located above the terminal within a
horizonta l dis tance of 2 feet (61 c m) from
the center line of the terminal
Clearance to unvent ilat ed soffit
E =
Clearance to outside corner
F =
Clearance to inside corner
G =
Clearance to each s ide of center line
H =
extended above meter/re
Clearance to service re
I =
Clearance t o nonm echani cal air s upply inlet
J =
to building or the combustion air inlet to any
other appliance
Clearance to a mechanica l air s upply inlet6 f eet (1.83 m)3 feet (91 cm) abov e if within 10 feet (3 m)
K =
Clearance above paved sidewalk or paved
L =
driv eway l ocat ed on public property
Clearance under veranda, porch deck , or
M =
balcony
closed window
ulat or ass embl
ulat or vent outlet3 f eet (1. 83 m)
AIR SUPPLY INLET
Canadian Installations
12 inches (30 cm)12 inches (30 cm)
6 inc hes (15 cm) f or appli ances ≤ 10,000
Btuh (3 kW), 12 inches (30 cm) for
appliances > 10,000 Btuh (3 kW) and ≤
100,00 Bt uh (30 kW), 36 inches (91 cm) for
appliances >100,00 Btuh (30 kW)
3 feet (91 cm) within a height 15 feet
abov e the m eter/re
6 inc hes (15 cm) f or appli ances ≤ 10,000
Btuh (3 kW), 12 inches (30 cm) for
appliances > 10,000 Btuh (3 kW) and ≤
100,00 Bt uh (30 kW), 36 inches (91 cm) for
appliances >100,00 Btuh (30 kW)
7 feet (2.13 m) †7 feet (2.13 m)
12 inches (30 cm) ‡
AREA WHERE TERMINAL IS NOT PERMITTED
1
**
**
**
**
**
ulator assembl
US Installations
4 feet (1.2 m) below or to si de of opening;
1 foot (300 mm) above opening
4 feet (1.2 m) below or to si de of opening;
1 foot (300 mm) above opening
horizontally
2
*
*
*
1
In accordance with the current CSA B149.1 Natural Gas and Propane Installation Code
2
In accordance with the current ANSI Z223.1 / NFPA 54 National Fuel Gas Code
† A vent shall not terminate directly above a sidewalk or paved driveway that is located between two single family dwellings and
serves both dwellings.
‡ Permitted only if veranda, porch, deck, or balcony is fully open on a minimum of two sides beneath the floor.
* For clearances not specified in ANSI Z223.1 / NFPA 54 or CSA B149.1, one of the following statement shall be included:
“Clearance in accordance with local installation codes, and the requirements of the gas supplier
Figure 19b. Vent Termination Clearances for other than Direct Vent Furnaces
and the manufacturer’s installation instructions.”
19
Page 20
!
WARNING:
CARBON MONOXIDE POISONING
HAZARD
Vent Pipe Material
Vent and combustion air pipe and fittings must
be one of the following materials and must
conform to the indicated ANSI/ASTM standards:
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.
3. 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.
4. Follow the lighting instructions. Place
the appliance being inspected in
operation. Adjust thermostat so
appliance shall operate
continuously.
5. Turn on clothes dryers and any other
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.
6. Close fireplace dampers.
7. Test for spillage from draft hood
equipped appliance at the draft hood
relief opening after 5 minutes of main
burner operation. Use the flame of a
match or candle.
8. If improper venting is observed during
any of the above tests, the venting
system must be corrected in
accordance with the
Gas Code, ANSI Z223.1/NFPA 54
or
CSA B149.1, Natural Gas and
National Fuel
and/
Propane Installation Codes.
9. 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.
*In Canada, check the local codes to ensure that
SDR is approved for use. SDR is not approved
for all Canadian installations.
Cement and primer must conform to ATSM
Standard D2564 for PVC and Standard D2235
for ABS. When joining PVC piping to ABS, use
PVC solvent cement. (See procedure specified
in ASTM Standard D3138.)
Vent Pipe Length and Diameter
In order for the furnace to operate properly, the
combustion air and vent piping must not be excessively restrictive. To ensure this use Table 4,
which indicates the maximum allowable piping
length for a furnace of specified input rate, when
installed with piping of selected diameter and
number of elbows. This table applies to the length
and number of elbows for each pipe. To use the
table, the furnace input rate, the centerline length
and the number of elbows on each pipe must be
known. Choose the diameter for which the tabulated length is equal to or greater than required.
Vent Configuration to
Provide 12" Minimum
height above
Snow Level.
Outside
Wall
Figure 20. Alternate Horizontal Vent
Installation
12" Min.
19" Max.
Support
1/2"
Armaflex
Insulation or
Equivalent
(if required)
12" Above
Normally
Expected
Snow
Level
Page 21
Proper use of the table is illustrated by the
following example:
Example:
A 110,000 Btu/h furnace is to be installed in a
"one-pipe" system with 40 feet of vent piping.
There are a total of four long radius 90-degree
elbows used in the vent, including the one
exterior to the building.
Solution:
For this particular installation, the equivalent
vent length must be calculated. This equivalent
vent length will then be compared to the maximum allowable vent length given in Table 4.
Then, the diameter of the piping can be chosen
for which the equivalent vent length is less than
the maximum allowable vent length. Returning
to our example, we consult Table 4 and determine that for a 110,000 Btu/h furnace the maximum vent length for 3" diameter piping is 100
feet. Note that the maximum vent length given
in Table 4 includes one long radius elbow.
Therefore, for our example, we have three
additional long radius elbows for which we must
add to our piping. Each long radius elbow is
equivalent to 2.5 feet, so we must add 7.5 feet
to our vent length. Therefore, the equivalent
vent length for our installation is 47.5 feet. We
compare this with the maximum vent length for
3” diameter piping. Our equivalent vent length is
less than the maximum allowable vent length, so
for our “one-pipe” installation we can use 3”
diameter piping.
Condensing furnace combustion products have
very little buoyancy, so Table 4 is to be used
without consideration of any vertical rise in the
piping.
Vent Pipe Installation
Pipe Routing and Support
Route piping as directly as possible between the
furnace and the outdoors and remember that
routing affects pipe size requirements per the
preceding section. If a two pipe system is used,
locate the combustion air intake and the vent
exhaust in the same atmospheric pressure
zone - i.e. both must exit the building though the
same portion of exterior wall or roof. Vent piping
must be sloped upwards not less than 1/4” per
foot in the direction from the furnace to the
terminal. This is to ensure that any condensate
flows back to the furnace (where it can be
disposed of through the condensate disposal
system).
The quality of outdoor air must also be considered. Be sure that the combustion air intake is
not located near a source of solvent fumes or
other chemicals which can cause corrosion of
the furnace combustion system.
!
CAUTION:
Combustion air must not be drawn from
a corrosive atmosphere.
Piping must be mechanically supported so that
its weight does not bear on the furnace. Supports must be at intervals no greater than five
feet, and at smaller intervals if necessary to
ensure that there are no sagging sections to trap
water. (See Figures 16 and 17.) It is recommended to install couplings along the vent pipe,
on either side of the exterior wall. These couplings may be required by local code.
Figure 18 illustrates vent and combustion air
pipe sizes exiting the furnace. Transition to the
correct pipe size (i.e. from 2” to 3” diameter)
must be done close to the furnace so that the full
length of pipe is of proper size.
Straight neoprene couplings are supplied with
the downflow furnaces only. These couplings
are to be installed in the combustion air inlet (if
present) and exhaust vent piping at the furnace
as shown in Figure 16. For an upflow furnace
installation, if breakable connections are required in the combustion air inlet (if present) and
exhaust vent piping, then straight neoprene
couplings for 3” piping with hose clamps can be
used. These couplings can be ordered through
your local furnace distributor.
To install a coupling, slide the rubber coupling
over the end of the pipe that is attached to the
furnace and secure it with one of the hose
clamps. Then slide the other end of the rubber
coupling onto the other pipe from the vent and
secure the coupling with the second hose clamp.
For the upflow models, the combustion air pipe
can be attached to the furnace. Ensure that the
connection is tight and leak free.
21
Page 22
These condensing furnaces have been certified for installation with zero clearance between
vent piping and combustible surfaces. However, it is good practice to allow space for
convenience in installation and service.
Location of Outdoor Terminations
Horizontal Venting
Vent and combustion air intake terminations
must be as shown in Figure 21. Vent termination
clearances shall be consistent with the National
Fuel Gas Code, ANSI Z223.1/NFPA 54 and/or
the CSA B149.1, Natural Gas & Propane Installation code.
All minimum clearances specified must be maintained to protect building materials from degradation by flue gases.
Vent and combustion air intake terminations
must be located to ensure proper furnace operation and to conform to applicable codes.
Figure 19 illustrates necessary distances from
the vent termination to windows and building air
intakes. In Canada, the Canadian Fuel Gas
Code takes precedence over these instructions. Specifically, all minimum distance
requirements with respect to termination of
the vent piping listed below (items 1 through
8).
The following list is a summary of vent terminal
location requirements:
1.The termination must be 12 inches above
snow level or grade level whichever is
higher. See Figure 20 for alternate method
to achieve 12" above snow level.
2.The minimum distance for a (1-pipe installation) from any door, (openable) window,
or gravity air inlet is 4 ft. below, 4 ft. horizontally, or 1 ft. above.
3.The minimum distance for a direct vent (2pipe installation) from any door, (openable)
window, or air gravity inlet is 1 ft. below, 1
ft. horizontally, or 1 ft. above.
4.For one-pipe installations the recommended
minimum distance from an inside corner
formed by two exterior walls is 6 feet, but is
not required.
5.The vent termination for a 1-pipe installation
shall be a minimum of 3 ft. above any forced
air inlet within 10 ft.
6.The vent termination shall be located at
least 4 ft. horizontally from any electric
meter, gas meter, regulator and any relief
equipment. These distances apply ONLY
to U.S. installations. In Canada, the Canadian Fuel Gas Code takes precedence.
7.Avoid areas where condensate drainage
may cause problems by dropping on planters or patios, etc. Also ensure that exhaust
gases will not impinge on windows or building surfaces, which may be compromised
or damaged by condensation. Do not install
the vent terminal such that exhaust is
directed into window wells, stairwells, under decks or into alcoves or similar recessed areas, and do not terminate above
any public walkways.
8.Select the point of wall penetration where
the minimum 1/4 inch per foot of slope up
can be maintained.
Exhaust Vent
Mounting Kit
Faceplate Secured
to Wall with Screws
Combustion
Air Inlet
Exhaust Vent
Option C
Figure 21. Exhaust and Combustion Air Pipe Clearances
22
Option B
7" Min.
18" Min.
36" Max.
18" Min.
36" Max.
18" min.
36" max.
12" Min. to
Normal Snow Level
Inlet
Exhaust Vent
Option A
8" Min.
Grade
Level
or Normal
Snow
Exhaust
Page 23
Exhaust
Elbow
Combustion
Air
Intake
Vent
1"
18" Min.
36" Max.
A
Plumbing Vent Roof Boot
(Typ. Both Pipes)
A= 12" Above Roof or Snow
Accumulation Level
A
Exhaust
For Canadian installations please refer to the
Canadian Installation Code (CAN/CGA-B149.1
or 2) and/or local codes.
The kit consists of two face plates and an
insulating gasket to seal the exterior surface. A
hole sized closely to the pipe diameter must first
be cut through the wall. A short length of pipe is
then cut such that it can penetrate the wall and
be held in place by closely fitting standard
couplings. The face plates are retained on both
sides of the wall by the couplings, and the gasket
is retained against the wall by the outer face
plate. Face plates must be fastened to the wall
and the outside one must be flashed as appropriate to prevent entry of water.
Figure 22. Vertical Vent Termination
!
CAUTION:
For optimum performance, vent furnace through wall which experiences
the least exposure to winter winds.
!
WARNING:
Ensure that the combustion air vent
and the exhaust vent are configured as
shown in Figure 21. Improper vent
termination can cause recirculation of
the flue gases. This may result in furnace vibration. In severe cases, the
furnace will cycle due to the intermittent contact between the flame and the
flame sensor. If you note oscillations
occurring, check the vent configuration. Make sure that the exhaust vent
does not have a 90 degree termination.
When the above kits are not used the following
steps are required:
1.Check the hole size cut through the exterior
wall. Insure that the hole diameter is less than
the diameter of the couplings to be used.
2.Extend the vent pipe through the wall approximately 1" and seal the area between
the wall and pipe.
3.If required by local code, apply couplings to
the vent pipe on the interior and exterior
sides of the wall to insure the pipe can not
be pushed or pulled through the wall.
4.Insure the combustion air inlet pipe (for a 2
pipe installation) has a 90 degree termination elbow as shown in Figures 21 and 22.
Note: A combustion air intake must be provided with an elbow opening downward. The
screen provided with the furnace can be installed in the elbow to prevent entry of debris
or creatures.
When the vent pipe must exit an exterior wall
close to the grade or expected snow level, a
riser should be provided as shown in Figure 20.
Upflow Models
Left Side
Drain
8"
"HARD" J
Drain Tube
A
Collector Box
Rotate counter
clockwise (Step 2)
Clamp
(Loosen For Step 1)
(Retighten for Step 3)
Figure 23. Furnace with Condensate Drain Trap Assembly
Route to
floor drain.
...OR
Route to
condensate
pump. Keep
downward
slope.
Downflow Models
Left
Side
Drain
8"
"HARD" J
Drain Tube
Rotate clockwise
A
Collector Box
(Step 2)
Clamp
(Loosen For Step 1)
(Retighten for Step 3)
Route to
floor drain.
...OR
Route to
condensate
pump. Keep
downward
slope.
23
Page 24
Maximum Flue Pipe Length in
Unconditioned and Exterior Spaces
Winter Design
Termperature (°F)
Without Insulation
(feet)
With Insulation
(feet) ‡
204570
020 70
-201060
‡ = Insulation thickness greater than 3/8 inch, based on an R value of
3.5 (ft*°F*hr)/(BTU*in)
Table 5. Vent Protection
Table 5 describes the maximum length of flue
pipe that can travel through an unconditioned
space or an exterior space. The total vent length
must not exceed the lengths noted on Table 5.
Vertical Venting
Figure 22 shows the proper installation and clearances for vertical vent termination. The roof penetration must be properly flashed and waterproofed
with a plumbing roof boot or equivalent flashing.
Termination spacing requirements from the roof and
from each other must be per Figure 22.
Vent and combustion air piping may be installed
in an existing chimney which is not in use
provided that:
a. Both the exhaust vent and air intake run
the length of the chimney.
b. The top of the chimney is sealed and
weatherproofed.
c. The termination clearances shown in
Figure 22 are maintained.
d. No other gas fired or fuel burning
appliances are vented through the
chimney.
Vent Freezing Protection
When the vent pipe is exposed to temperatures
below freezing, i.e., when it passes through
unheated spaces, chimneys, etc., the pipe must
be insulated with 1/2 inch thick sponge rubber
insulation, Armaflex-type insulation or equivalent. Insulating pipe is important to avoid condensate icing.
For extremely cold climates or for conditions of
short furnace cycles (i.e. set back thermostat
conditions) the last three feet of vent pipe can be
reduced one nominal pipe size provided that the
total vent length is at least 15 feet in length and
the vent is sized in accordance with the venting
requirements (Table 4) before this reduction is
applied. (Example: 3” to 2-1/2”) Smaller vent
pipes are less susceptible to freezing, but must
not be excessively restrictive.
Concentric Vent Termination
A concentric vent termination is approved for
use with these furnaces. The kit part number is
904176. For proper installation of the concentric
vent termination, follow the installation instructions provided with that kit.
Upflow ModelsDownflow Models
Roll-Out Limit
Shut-Off Valve
with 1/8" NPT
Plugged Tap
Burner
Some Utilities
Require Shut-
Off Valve to
be 4 to 5 feet
Above Floor
Dripleg
Automatic Gas Valve
(with manual shut-off)
24
Assembly
Ground
Joint
Union
Figure 24a. Typical Gas Service Connection
Burner Viewport
Denotes fieldprovided and
installed
components.
Denotes fieldprovided and
installed
components.
Assembly
Burner
Automatic
Gas Valve
(with manual
shut-off)
Ground Joint
Union
Roll-Out Limit
Shut-Off Valve
with 1/8" NPT
Plugged Tap
Some Utilities
Require ShutOff Valve to
be 4 to 5 feet
Above Floor
Dripleg
Burner Viewport
Page 25
CAPACITY OF BLACK IRON GAS PIPE (CU. FT. PER HOUR)
The cubic feet per hour listed in the table above must be greater than the cubic feet per hour of gas flow required
by the furnace. To determine the cubic feet per hour of gas flow required by the furnace, divide the input rate
of the furnace by the heating value of the gas:
Cubic Feet Per Hour Required =
SPECIFIC GRAVITY - 0.60
Input To Furnace (Btu/hr)
Heating Value of Gas (Btu/Cu. Ft.)
Table 6. Capacity of Black Iron Gas Pipe (cu. ft. per hour)
for Natural Gas (specific gravity = .60)
DRAINAGE OF CONDENSATE
FROM FURNACE
The condensate drainage system is internal to
the furnace. It is not recommended to connect
additional traps to the exterior of the furnace.
Doing so will have adverse effects on the operation of the furnace. The drain may exit either the
right or left side of the furnace cabinet.
The condensate drain can be routed to a flow
drain or to a condensate pump. Ensure that the
drain maintains a downward slope from the unit
to the drain. Refer to Figure 23 for more details.
For a right side drain simply extend the tubing out
of the hole in the cabinet, see Figure 23. For a
left side drain follow the steps below:
1.Loosen the clamp on the soft exit tube (see
Figure 23.)
3.Re-tighten the clamp. MAKE SURE CLAMP
IS TIGHT TO AVOID LEAKAGE OF CONDENSATE.
4.Route the tubing out of the hole located 8
inches up from the bottom furnace.
The condensate should drain from the plastic
collector box (location A in Figure 23) as droplets
or a small stream. If you notice the furnace has
operated for more than 5 minutes without draining or the red status light on the control board is
pulsing a 2-blink code follow the steps below.
1.Remove the collector box soft tube at
location A in Figure 23 and insure the exit
from the collector box is clear of any debris
or obstructions.
2.Replace this tube and insure the fit to the
header spout is air tight. Air will be drawn
into the header if this connection is not tight.
3.Check other tube connections along the
drain system. Insure that all are air tight.
NOTE: Industry research studies indicate that
when condensate is routed to an active drain,
household detergents, etc., buffer its acidity. If
the drain is not actively used or if codes require,
obtain a neutralizer kit NORDYNE part no.
902373 (usually contains limestone). Proper
drains and connections to the condensate tubing are required as NORDYNE cannot be held
responsible for water leakage which occurs
due to loose hose connections or improperly
sealed drain line pipes.
GAS SUPPLY AND PIPING
This furnace is equipped for either left or right
side gas entry. Typical gas service hook-ups
are shown in Figure 24a. When making the gas
connection provide clearance between the gas
supply line and the entry hole in the furnace
casing to avoid unwanted noise and/or damage
to the furnace.
All gas piping must be installed in compliance
with local codes and utility regulations. Some
local regulations require the installation of a
manual main shut-off valve and ground joint
union external to the furnace. The shut-off valve
25
Page 26
should be readily accessible for service and/or
(
)
(
)
(
)
(
)
emergency use. Consult the local utility or gas
supplier for additional requirements regarding
placement of the manual main gas shut-off. In
the absence of local codes the gas line installation must comply with the latest edition of the
National Fuel Gas Code (ANSI Z223.1) or
(CAN/CGA B149) installation codes.
An 1/8" NPT plugged tap must be installed in the
gas line to the unit for use when measuring the
gas supply pressure. The plug should be readily
accessible for service use. A drip leg should be
installed in the vertical pipe run to the unit. Table
6 lists gas flow capacities for standard pipe
sizes as a function of length in typical applications based on nominal pressure drop in the line.
For a Natural Gas Sea Level Heating Value of 800 to 899 Btu/cu.ft.
Manifold Pressure Setting (in WC) Full Input
Low Input
NOTE: Gas piping must not be run in or through
air ducts, chimneys, gas vents, elevator shafts,
etc.
Compounds used on threaded joints of gas
piping must be resistant to the actions of liquefied petroleum gases.
The main manual gas valve and main power
disconnect to the furnace must be properly
labeled by the installer in case emergency
shutdown is required.
!
CAUTION:
Do not use matches, lighters, candles,
or other sources of open flame to check
for gas leaks.
Elevation
zero to
1999
3.53. 53.5
1.71. 71.7
2000 to
4999
feet above sea level
5000 to
5999
6000 to
7999
3.53.0
1.71.6
8000 to
10000
For a Natural Gas Sea Level Heating Value of 900 to 999 Btu/cu.ft.
Manifold Pressure Setting (in WC) Full Input
Low Input
For a Natural Gas Sea Level Heating Value of 1,000 to 1,100 Btu/cu.ft.
Manifold Pressure Setting (in WC) Full Input
Low Input
Table 7. Manifold Pressure (in WC) for Natural Gas at Various Altitudes
For a LP Gas Sea Level Heating Value of 2,500 Btu/hr.
Manifold Pressure Setting (in WC) Full Input
Low Input
Elevation
zero to
1999
3.53. 53.5
1.71. 71.7
zero to
1999
3.53. 53
1.71. 71.5
zero to
1999
108.510
5.55. 56.5
2000 to
4999
Elevation
2000 to
4999
Elevation
2000 to
4999
feet above sea level
feet above sea level
feet above sea level
5000 to
5999
5000 to
5999
5000 to
5999
6000 to
7999
3.22.8
1.61.5
6000 to
7999
2.82.5
1.41.3
6000 to
7999
98.5
6.56.5
8000 to
10000
8000 to
10000
8000 to
10000
Table 8. Manifold Pressure (in WC) for LP/Propane Gas at Various Altitudes
26
Page 27
FurnaceOrificeOrifice
g
High Fire Rating
Plate Input (Btu/h)NatLP
60,0004555
80,0004555
100,0004555
120,000
Drill Size Drill Size
4555
Table 9. Natural and LP Gas Orifice Sizes
for Elevations between zero and
4999 ft. Above Sea Level
Furnace Ratin
Plate Input
(Btu/h)NatLP
60,0004556
80,0004556
100,0004556
120,000
OrificeOrifice
Drill Siz e Drill Siz e
4556
Table 10. Natural and LP gas Orifice Sizes
for Elevations between 5000 and 10,000 ft.
Above Sea Level
Leak Check
After the gas piping to the furnace is complete,
all connections must be tested for gas leaks.
!
WARNING:
FIRE OR EXPLOSION HAZARD
Failure to follow the safety warnings
exactly could result in serious injury,
death or property damage.
Never test for gas leaks with an open
flame. Use a commercially available
soap solution made specifically for the
detection of leaks to check all connections. A fire or explosion may result
causing property damage, personal
injury or loss of life.
IMPORTANT NOTE: When pressure testing
gas supply lines at pressures greater than
1/2 psig (14 in. water column), the furnace
must be disconnected from the gas supply
piping system to prevent damage to the gas
control valve. If the test pressure is less than
or equal to 1/2 psig (14 in. water column), the
furnace must be isolated from the gas supply line by closing the manual shut-off
valve.
MANIFOLD PRESSURE
ADJUSTMENT
Manifold pressures for low and high stages are
independently adjustable. Adjustment tap
locations on the valve are shown in Figure 24b.
Manifold pressure would be adjusted below
procedure:
-Turn off gas shut off valve outside furnace.
-Install manometer on the gas valve at the
outlet pressure tap.
-Turn on the shut off. Run furnace at high
fire and set manifold pressure. Also set
manifold pressure while running at low fire
(refer to Tables 7 and 8.)
-Ensure plug is tight after removing
manometer.
VENT FITTING FOR 90 PLUS
HIGH STAGE ADJUSTMENT
UNDER VENT CAP
2-STAG E
OPERATOR
INLET PRESSURE TAP
1/8 NPT
(Honeywell shown)
(4) QUICK DISCONNECT TERMINALS
EFFICIENT APPLIANCES
LOW STAGE ADJUSTMENT
UNDER VENT CAP
OUTLET PRESSURE TAP
1/8 NPT
INLET PRESSURE POSTSET SCREW: 3/32” HEX HEAD
(.339 DIA. +DFT.)
ACCEPT S 5/18”
HOSE CONNECTION
!
WARNING:
This furnace was equipped at the factory for use with natural gas only. A
special kit, supplied by the manufacturer, is required to convert the furnace to operate on LP/propane gas.
Failure to use the proper conversion
kit can cause fire, explosion, property
damage, carbon monoxide poisoning,
personal injury, or death.
1ST STAG E
REGULATOR COVER
REGULATOR ADJUST
BENEATH THIS SCREW
VENT (.330 DIA.
+DFT. POST)
ACCEPT S 5/16” HOSE
CONNECTION
2ND STAG E
REGULATOR COVER
REGULATOR ADJUST
BENEATH THIS SCREW
(White Rodgers shown)
Figure 24b. Gas Valve
CONTROL
LABEL
OUTLET PRESSURE
POST SET SCREW: 3/32”
HEX HEAD (.339 DIA. +DFT.)
ACCEPT S 5/18” HOSE CONNECTION
27
Page 28
Conversion
Conversion of this furnace to use LP/propane
gas must be made by qualified service
personnel, using only approved parts.
IMPORTANT NOTE: When converting a low
NOx furnace from Natural Gas to LP/Propane
Gas, it is necessary to remove the NOx
baffles from the furnace.
HIGH ALTITUDE CONVERSION
High Altitude Application
Conversion of this furnace to replace the pressure
switch or to utilize LP/propane gas must be made
by qualified service personnel, using factory
authorized or approved parts. High altitude
applications with this furnace can be field
performed by a simple adjustment of manifold
pressure, and if necessary changing the orifices
and the vent pressure switch. The changes
required depend on the installation altitude and
the heating value of the gas. The gas heating
value based on sea level can be obtained from
your local gas utility. The heating value of gas
at high altitude is always lower than the sea level
heating value. The heating values used in Tables
7 & 8 are based on sea level values.
Pressure Switch Conversion for
High Altitude Applications
These units are factory equipped to operate
between zero and 8000 feet above sea level. For
higher altitude applications, you may need to
replace the vent pressure switch in addition to the
main gas burner orifices. The approved high
altitude pressure switch kit is 903852. The
directions to convert the furnace are given below:
1. READ ALL INSTRUCTIONS BEFORE
PROCEEDING WITH THE CONVERSION.
2. Disconnect all electrical power to the furnace.
3. Remove the access door(s) from the front
of the unit.
4. Turn the gas valve knob to the OFF position.
5. Shut off the gas to the unit.
6. The vent pressure switch will be replaced
(see Figure 30). This pressure switch is the
differential pressure switch between the
burner box and the vent assembly. If
necessary, mark the two hoses that attach
to the pressure switch.
7. Disconnect the electrical leads to the pressure switch. It is not necessary to mark the
electrical leads as polarity does not matter
across the switch.
8. Remove both hoses from the pressure
switch and remove the fasteners that secure the pressure switch to the panel.
9. Discard the old pressure switch.
10. From the kit, install the new high altitude
pressure switch using the same fasteners
that were removed earlier.
11. Reattach the hoses to the pressure switch
ports in the same manner as they were
removed.
12. Reattach the electrical leads to the pressure switch.
13. Turn on the electrical power to the furnace.
14. Turn the gas valve knob to the ON position.
15. Follow the start-up procedure outlined later
in these installation instructions. Verify that
the furnace is operating properly after the
conversion.
Natural Gas High Altitude
Conversion
All factory shipped furnaces are ready to operate
between zero and 4999 ft. above sea level. For
higher altitudes (between 5000 and 10,000 ft.
Field Supplied
Fused Service
White (Neutral)
Green or Bare
Panel
Black (Hot)
(Ground)
Ground
Field Supplied Disconnect
Within Sight of Furnace
28
Field Supplied
Panel Connector
Black
White
Black
White
Ground
Black
White
Ground
Junction Box (may be internal
or external to the furnace). These
connections can be made in the
field supplied disconnect at the
furnace.
Figure 25. Line Voltage Field Wiring
Field Line Voltage
Wiring
Factory Line
Voltage Wiring
Page 29
above sea level), conversion can be achieved
simply by adjusting the furnace manifold
pressure as shown in Table 7.
LP/Propane Gas Sea Level and
High Altitude Conversion
Conversion to LP/propane gas can be
accomplished by first replacing the natural gas
orifices with the appropriate LP/propane orifices
shown in Table 9 or 10 Note: for installations
between zero and 5000 ft. above sea level, refer
to Table 7. For installations above 5000 ft. above
sea level, refer to Table 10. After changing the
orifices, use Table 8 to determine the appropriate
manifold pressure for your installation.
Conversion to LP/propane, sea level, and high
altitude is detailed in the installation instructions
provided with the conversion kit. Approved
conversion kits are listed below.
This kit is for LP/propane conversions in Canada
at altitudes between zero and 4500 ft. above sea
level. Follow the installation instructions supplied
with the kit for proper installation.
!
CAUTION:
To avoid electric shock, personal injury, or death, turn off the power at the
disconnect or the main service panel
before making any electrical connections.
ELECTRICAL WIRING
Electrical connections must be made in accordance with all applicable local codes and ordinances, and with the current revision of the
National Electric Code (ANSI/NFPA 70).
United States LP/Propane Gas Sea Level and
High Altitude Conversion Kit - P/N 904404
This kit is for LP/propane conversion in the United
States at altitudes between zero and 10,000 ft.
above sea level. Follow the installation instructions
supplied with the kit for proper installation.
Canadian LP/Propane Gas Sea Level and High
Altitude Conversion Kit - P/N 904405
For Canadian installations electrical connections and grounding must be done in accordance with the current Canadian Electrical Code
(CSA C22.1 Part 1) and/or local codes. If any
of the original wire as supplied with the furnace
must be replaced, it must be replaced with wire
having a minimum temperature rating of 105°C.
Refer to the furnace nameplate and Table 10 for
electrical requirements.
Low Voltage Field, Five-wire Heating/Cooling Applications
TWO STAGE
ROOM THERMOSTAT
R
Y
G
W
W2
BROWN
RED
GREY
YELLOW
GREEN
YELLOW
AIR CONDITIONER
CONDENSING UNIT
YELLOW/
BLACK
C
Y
TO
VARIABLE
SPEED
BLOWER
CLOSED END
CONNECTOR
DO NOT REMOVE!
Legend
Field Wiring
Factory Wiring:
Low Voltage
High Voltage
BROWN
YELLOW
C
LO
HI
GAS VALVE
Figure 26a. Two Stage Configuration
BROWN
29
Page 30
Low Voltage Field, Five-wire Heating/Cooling Applications - continued
TWO STAGE
ROOM THERMOSTAT
R
Y
G
W
TO
VARIABLE
SPEED
BLOWER
CLOSED END
CONNECTOR
DO NOT REMOVE!
BROWN
RED
GREY
YELLOW
GREEN
YELLOW
AIR CONDITIONER
CONDENSING UNIT
YELLOW/
BLACK
C
Y
Legend
Field Wiring
Factory Wiring:
Low Voltage
High Voltage
TO
VARIABLE
SPEED
BLOWER
BROWN
YELLOW
C
LO
HI
GAS VALVE
Figure 26b. High Fire Only Configuration
TWO STAGE
ROOM THERMOSTAT
R
Y
G
W
CLOSED END
CONNECTOR
DO NOT REMOVE!
BROWN
RED
GREY
YELLOW
GREEN
YELLOW
AIR CONDITIONER
CONDENSING UNIT
YELLOW/
BLACK
C
Y
BROWN
Legend
Field Wiring
Factory Wiring:
Low Voltage
High Voltage
Figure 26c. Low Fire Only Configuration
30
BROWN
YELLOW
HI
GAS VALVE
LO
BROWN
C
Page 31
Low Voltage Field, Five-wire Heating/Cooling Applications - continued
ROOM THERMOSTAT
R
Y
G
W
CLOSED END
CONNECTOR
DO NOT REMOVE!
TO
VARIABLE
SPEED
BLOWER
Legend
Field Wiring
Factory Wiring:
Low Voltage
High Voltage
ODT: Open on rise
outdoor thermostat
BROWN
RED
GREY
YELLOW
GREEN
YELLOW
AIR CONDITIONER
CONDENSING UNIT
YELLOW/
BLACK
BROWN
YELLOW
HI
GAS VALVE
C
Y
ODT
LO
YELLOW
BROWN
C
CLOSED END
CONNECTOR
DO NOT REMOVE!
TO
VARIABLE
SPEED
BLOWER
Legend
Field Wiring
Factory Wiring:
Low Voltage
High Voltage
SDT: Two wire delay on
make timer
Figure 26d. Outdoor Ambient Dependent
ROOM THERMOSTAT
R
Y
G
W
AIR CONDITIONER
BROWN
RED
GREY
YELLOW
GREEN
YELLOW
CONDENSING UNIT
YELLOW/
BLACK
BROWN
YELLOW
HI
GAS VALVE
C
Y
SDT
LO
BROWN
C
YELLOW
Figure 26e. Timed Two Stage Configuration
31
Page 32
Line Voltage Wiring
The line voltage (115 volt) to the furnace must
be supplied from a dedicated branch circuit
containing the correct fuse or circuit breaker for
the furnace. See Table 11. An electrical switch
should be readily accessible from and within
sight of the furnace. (See the Wiring Diagram
label in the furnace and Figure 25.)
NOTE: The following procedure describes how
to connect the furnace for a two-stage application.
Low Voltage Wiring
Staging Configurations
These furnaces are factory configured to operate on high fire only, but can be field converted
to operate as two-stage furnaces.
The furnace cabinet must have an uninterrupted, unbroken ground to minimize injury
should an electrical fault condition occur. The
controls used in this furnace require an earth
ground to operate properly. Acceptable methods for grounding are electrical wire or conduit
approved for electrical ground service. Do not
use gas piping as an electrical ground.
NOTE: Proper line voltage polarity must be
maintained in order for the control system
to operate correctly. Verify that the incoming neutral line is connected to the white
wire and the incoming "hot" line is connected to the black wire in the junction box.
These furnaces will not operate unless polarity and ground are properly connected.
See Figure 25.
!
CAUTION:
Label all wires prior to disconnection
when servicing controls. Wiring errors
can cause improper and dangerous
operation. Verify proper operation after servicing.
NOTE: T
efficiency, the furnace should be operated in the
factory configuration (high fire only as described
in part 2.)
1.
2.
O achieve full rated capacity and
Two stage heating thermostat configuration
– For this installation a two stage
heating thermostat is used. CAUTION:
Disconnect yellow wire with black stripe
from low firing on the gas valve. Remove
female connector from yellow/black wire
and strip insulation from end. Connect
stripped yellow wire with black stripe to
(W2) from the thermostat. (See Figure
26a). The first stage bulb (W1) is connected
to W on the furnace control board. On a call
for first stage heat, the furnace will operate
at low fire and the blower will run at a lower
speed. On a call for second stage heat, the
furnace will operate at high fire and the
blower will run at a higher speed. The
furnace will stage between low fire, high fire,
and off depending on the thermostat signal.
High fire only configuration
from the factory, low and high terminals on
the gas valve are connected in parallel
(See Figure 26b). This defeats the staging
– As shipped
FurnaceCabinetNominalMaximum Minimum Maximum MinimumMaximum
InputWidth Electrical Operating OperatingFurna ceWireFuse or Circuit
* Time-delay fuses or HACR-type circuit breakers are required.
32
Thermostat Recommended Thermostat
Wire Wire Length
Gauge2-wire 4 or 5-wire
(heating)(cooling)
2455 ft.25 ft.
2290 ft.45 ft.
20140 ft.70 ft.
18225 ft.110 ft.
Table 11. Electrical Data
Page 33
feature and the furnace operates on high
fire only. All of the burners will operate on a
call for heat and the variable speed blower
will operate at a higher speed.
Low fire only configuration
3.
– For this installation, the high terminal is disconnected
(See Figure 26c). This defeats the staging
feature and the furnace operates on low fire
only. The furnace will run at reduced firing
rate and the variable speed blower will
operate at a lower speed.
4.
Outdoor ambient dependent configuration
– For this installation, low and high terminals
are connected in parallel with an outdoor
thermostat (open on rise style) in series
with the high terminal (See Figure 26d).
CAUTION: DO NOT CONNECT W2 from
outdoor thermostat to the furnace wiring
when using the outdoor ambient dependent
configuration. When the outdoor temperature is above the set point, the outdoor
thermostat opens keeping the high terminal
open. The furnace operates in the low fire
mode at a lower blower speed. When the
outdoor thermostat closes, the high fire on
gas valve opens and the furnace operates
in the high fire mode at higher blower speed.
5.
Timed staging configuration
– For this installation, the low and high fire on the gas
valves are connected in parallel with a delay
on make timer (two wire style) in series with
the secondary gas valve (See Figure 26e).
CAUTION: DO NOT CONNECT W2 from
thermostat to the furnace wiring when using
timed stage configuration. When the low fire
on the gas valve is energized, the furnace
operates in the low fire mode at a lower
blower speed and the timer begins its delay
function. If the room thermostat is not satisfied before the timer activates, the furnace will stage to high fire and the blower will
operate at a higher speed until the room
thermostat is satisfied.
6.
Two Stage Cooling
– The furnace is supplied with the yellow “Y1” and blue “Y2”
connections attached to the control board.
Connect a field supplied wire from the
yellow “Y1” to the thermostat and the condensing unit, and another wire connected
from “Y2” on the thermostat to “Y2” on the
condenser. (See Figure 27.)
Install the thermostat per the manufacturer's
instructions. The low voltage (24 volt) connections from the thermostat are made at the
terminal strip on the control board in the furnace. See Figures 26a-26e for the proper
connections for heating only (four wire) and
heating/cooling (five wire) applications. The
recommended minimum wire gauge for thermostat wiring is shown in Table 11.
The thermostat must not be installed on an
outside wall or any other location where its
operation may be adversely affected. Adverse
affects include radiant loading from fireplaces,
sunlight, or lighting fixtures, and convective loading from warm air registers or electrical appliances.
To check the heat anticipator setting either:
1.Add the current draw of the system components; or
2.Measure the current flow on the thermostat
R-W circuit after the circulating blower
motor has started.
Set the heat anticipator according to the thermostat manufacturer's instructions for heat anticipator settings.
START-UP AND ADJUSTMENTS
Prior to start-up, verify that:
1.The line voltage power leads are securely
connected, that the polarity of the connections is correct, and that the furnace is
properly grounded.
Two Stage Condensing Unit
CONDENSING
UNIT
Y1
Y2
YELLOW
Y1
123456789
THERMOSTAT
Y1
REMOVE BLUE
Y2
WIRE FROM
Y TERMINAL
OF
FURNACE
BOARD
BLUE
Y2
10111213141516
Figure 27. Two Stage Condensing Unit
33
Page 34
2.The thermostat wires (R, W, Y, and G) are
securely connected to the correct leads on
the terminal strip of the circuit board.
3.The gas line service pressure does not
exceed 10.0 in. water column (0.36 psig),
and is not less than 4.5 in. water column
(0.16 psig) for natural gas. For LP gas the
line service pressure must not exceed 14
in. water column (0.51 psig), and must not
be less than 11.0 in. W.C. (0.40 psig).
4.The roll-out and vent safety manual reset
switches are closed. If necessary, press
the red button to reset a switch. See Figure
30 for location. DO NOT install a jumper
wire across a switch to defeat its function.
If a switch reopens on start-up, DO NOT
reset the switch without identifying and
correcting the fault condition which caused
the switch to trip.
5.The blower door is in place, closing the door
switch in the line voltage circuit.
6.The gas line has been purged and all
connections are leak tight.
Follow the procedure below to determine the
firing rate.
1.Shut off all other gas fired appliances.
2.Start the furnace and allow it to run for at
least three minutes.
3.Measure the time (in seconds) required for
the gas meter to complete one revolution.
4.Convert the time per revolution to cubic feet
of gas per hour using Table 12.
5.Multiply the gas flow rate in cubic feet per
hour by the heating value of the gas in Btu
per cubic foot to obtain the firing rate in Btu
per hour. Example:
•Time for 1 revolution of a gas meter with
a 1 cubic foot dial = 40 seconds.
•From Table 11 read 90 cubic feet per
hour of gas.
•Heating value of the gas (obtained from
gas supplier) = 1040 Btu per cubic foot.
•Firing rate = 1040 x 90 = 93,600 Btuh.
Start-up Procedures
After all of the above checks have been made:
1.Set the thermostat to the lowest setting.
2.Close the disconnect(s) to provide line
voltage to the furnace.
3.Follow the procedures given on the operating instruction label attached to the furnace.
4.Set the thermostat above room temperature and verify the operating sequence.
(See the Sequence of Operation).
5.After the furnace has run for approximately
five minutes, set the thermostat below room
temperature and verify steps (9) through
(11) of the Sequence of Operation.
Verifying and Adjusting Firing Rate
The firing rate must be verified for each installation to prevent over-firing the furnace.
IMPORTANT NOTE:
The firing rate must not exceed the rate
shown on the furnace rating plate. At altitudes above 2000 feet it must not exceed
that on the rating plate less 4% for each 1000
feet.
6.Adjustments to the firing rate can be made
by adjusting the gas manifold pressure.
See the High Altitude Application section for
additional information of firing rate at elevations above 2000 ft.
The manifold pressure must be set to the
appropriate value for your installation. Refer to
either Table 7 for natural gas or Table 8 for LP/
propane gas to verify the manifold pressure
setting required for your particular installation.
To adjust the manifold pressure, remove the
regulator cap and turn the adjusting screw
clockwise to increase pressure or counterclockwise to reduce pressure. Replace the
regulator cap after adjustments are complete.
!
CAUTION:
Do not re-drill the burner orifices. If the
orifice size must be changed, use only
new orifices.
34
Page 35
!
WARNING:
To avoid electric shock, personal injury, or death, disconnect the electric
power before performing any maintenance.
Configuring the Blower
The variable speed blower kit is equipped with
a microprocessor-controlled variable speed
motor that is pre-programmed to deliver optimum airflow in a variety of conditions and
system configurations. Before operation, the
variable speed blower kit must be configured
to match the unit with the system, system
options, and climatic conditions. With the variable speed blower kit installed and configured
properly, the furnace will respond directly to
gradually change speed in response to changes
in system variables such as the thermostat
settings, duct static, filter, etc. The variable
speed blower kit is configured by setting the 7
switches located on the motor control board as
described below.
must be known. The nominal system capacity
is ALWAYS the nominal capacity of the outdoor
unit. In some cases the nominal system capacity is not the same as the nominal capacity of the
indoor coil.
The cooling/heat pump airflow is selected by
setting switches 1 through 4 on the motor control
board located in the blower control panel. All
airflows for other modes of operation (except
gas heat) are determined by this setting. Table
1 shows the airflow values versus the airflow
selector switch settings, and the range of airflow
settings recommended for each nominal system capacity.
NOTE: The CFM values listed on Table 2 are
not dependent on duct static pressure. The
motor automatically compensates for
changes in duct static pressure (within the
limits of the motor).
For maximum capacity and energy efficiency,
generally, a selection at or near the top of the
CFM range for that nominal capacity is best. For
maximum dehumidification, select an airflow
near the middle or bottom of the CFM range for
that nominal capacity.
!
IMPORTANT:
The variable speed blower kit has been
designed to give the installer maximum flexibility to optimize system performance, efficiency, and comfort.
Because there are so many ways to
configure the kit it is important to read
and follow these instructions carefully.
Selecting Heat Airflow
The heating airflow is selected by setting
switches 5, 6 , and 7. Refer to Table 1a and
select a nominal rise based on the furnace
nominal efficiency and input. Follow the table
column up to find the switch setting and nominal
air-flow. Be sure that the selected rise is within
the specification of the furnace as shown on the
furnace rating label. For single stage cooling,
reference the CFM in the high column.
Selecting The Cooling/Heat Pump
Airflow
In order to select the appropriate airflow for AC
and HP operation the nominal system capacity
NOTE: If coil icing is observed, the cooling/
heat pump airflow selected may be too low.
Double-check to be sure the setting selected is within the range shown in Table 1.
Also check to be sure the system is properly
charged (see outdoor unit installation instructions). If icing continues to occur,
raise the selected airflow one or two steps.
Verifying and Adjusting
Temperature Rise
Verify that the temperature rise through the
furnace is within the range specified on the
furnace rating plate. Temperature rises outside
the specified range could result in premature
heat exchanger failure.
Place thermometers in the return and supply air
stream as close to the furnace as possible. The
thermometer on the supply air side must be
shielded from direct radiation from the heat
exchanger to avoid false readings. Adjust all
registers and duct dampers to the desired
position and run the furnace for fifteen minutes
before taking any temperature readings. The
temperature rise is the difference between the
supply and return air temperatures.
35
Page 36
For Upflow and Downflow Residential Furnaces
VENT
SAFETY
SWITCH
(*TC & *TL
MODELS
ONLY)
BLACK
BLACK
WHITE
120 V
180
120
90
60
24 V
WHITE W/ BLK STRIPES
BLK W/ WHITE STRIPES
MAIN
PRESSURE SWITCH
PRESSURE
(*TC MODELS ONLY)
SWITCH
BLACK
WHITE
BLOWER DOOR
SWITCH
TRANSFORMER
GREEN
BLUE
BLUE
BLUE
BLUE
SWITCH
VENT SAFETY
(*TA & *TK MODELS ONLY)
SWITCH
(ALL MODELS)
FLAME ROLL-OUT
SUPPLY AIR
LIMIT SWITCH
(ALL MODELS)
LIMIT SWITCH
BLOWER DECK
(SELECT MODELS ONLY)
IS USED, SEE INSERT A
IF TWO STAGE CONDENSING UNIT
ORANGE
ORANGE
BLUE
BLUE
GROUND
BLACK 120V
WHITE (NEUTRAL)
R
Y
G
TWO STAGE
ROOM THERMOSTAT
FOR ALTERNATE
INSTRUCTIONS
SEE INSTALLATION
1234567
R
R
W
SECOND STAGE.
MEANS OF USING
13 11 7 5
C
SEE
AIR CONDITIONER
CONDENSING UNIT
W2
CONNECTOR
CLOSED END
DO NOT REMOVE!
W
W
RED
BLACK
BLACK
BLACK
BLACK
BLACK
C
RED
IGNITOR
BROWN
YELLOW
Y
FLAME SENSOR
INDUCER
R
C
NOTE 5
BLACK
YELLOW/
RED
BLUE
GREY
GREEN
YELLOW
BROWN
YELLOW
LO
GAS VALVE
HI
BROWN
BLACK
WHITE
VARIABLE SPEED
BLOWER CONTROL BOX
NOTES:
1. Use copper conductors only.
2. If any of the original wire assupplied with the furnace must be
replaced, it must be replaced with wiring material having a
ON
RED
LIGHT
STATU S
1 FLASH
2 FLASHES
3 FLASHES
FAULT CONDITION
Power On
Limit Circuit Open or External Load On "W"
Pressure Switch is Closed with Inducer Off
Pressure Switch is Open with Inducer On
temperature rating of at least 105° C.
3. Refer to the Installation Instructions provided with the furnace
for the appropriate heating and coolingspeed settings for
your application.
4. Ensure that wires from the blower remain connected to the board
thermostat terminals after making the field thermostat connections.
5. Wiring shown for 2-stage operation when using a multistage thermostat.
4 FLASHES
Ignition Failure (Check Ground)
5 FLASHES
115 VAC & Neutral Reversed or no Ground
Continuous
False Flame or Gas Valve Relay Shorted
OFF
Power Off
LIGHT
FLAME
YELLOW
FAULT CONDITION
Flash
Continuous
Low Flame Sensor Signal
Warning - Remove Yellow/Black wire from primary gas valve and utilize
for wiring furnace for 2-stage operation.
ON
Flame Present
GREY
123456789
123456789
Legend
Factory Wiring:
Field Wiring
Low Voltage
High Voltage
Figure 28. Upflow and Downflow Wiring Diagram
36
16
15
BLUE
YELLOW
Y2
14
13
12
11
10
9
8
7
6
5
4
3
Y1
2
1
BLUE
BROWN
YELLOW
YELLOW
VARIABLE
ORANGE
10111213141516
10111213141516
SPEED
MOTOR
BLOWER
WHITE
POWER FACTOR
CORRECTION CHOKE
12345
12345
REMOVE BLUE
THERMOSTAT
TWO STAGE CONDENSING UNIT
OF
WIRE FROM
Y TERMINAL
Y2
Y1
CONDENSING
UNIT
BOARD
FURNACE
Y2
Y1
WD# 710525A
Page 37
Common
g
Leads
Connect
Neutral
Lead of
Electronic
Air Cleaner
and/or Humidifier
Here.
R C Y G W
EAC
HUM
Humidifier Tap
(.5A@ 120 VAC)
COM
24 V
3
6
9
2
5
8
1
4
7
Neutrals
63
52
41
3 Amp Fuse
Unused Motor
Leads
M1M2M3
HUM
Flame Signal
Light (Yellow)
Status
Light (Red)
COOL
HEAT
These motor speed taps are
not used for two-sta
XFMR
EAC
L1
Electronic Air Tap
(.5A@ 120 VAC)
e models
Figure 29. Blower Speed Tap Location
Verifying Burner Operation
To verify operation of the burners, make sure
that the blower compartment door is in place and
that there is power to the furnace. Set the
thermostat above room temperature and observe the ignition sequence. The flame can be
observed through the small clear window on the
burner box. The burner flame should carry over
between all burners on high fire. Note that when
operating on low fire, the left two burners will not
operate on upflow models and the right two
burners on downflow models. The flames should
be blue, without yellow tips. Flames should
extend from each burner without lifting, curling,
or floating. After verifying ignition, set the thermostat below room temperature and verify that
the burner flame extinguishes completely.
Verifying Operation of the Supply
Air Limit Switch
To verify operation of the supply air limit switch,
make sure that the blower door is in place and that
there is power to the furnace. Completely block
the return airflow to the furnace by installing a
close-off plate in place of or upstream of the
filter(s). Set the thermostat above room tempera-
ture and verify that the Sequence of Operation is
as described in these instructions. The supply air
limit switch should function to turn off the gas
valve within approximately five minutes. The
circulating air and combustion blowers should
continue to run when the supply air limit switch
opens. Remove the close-off plate immediately
after the supply air limit switch opens. If the
furnace operates for more than five minutes with
no return air, set the thermostat below room
temperature, shut off the power to the furnace,
and replace the supply air limit switch.
DESCRIPTION OF COMPONENTS
Figure 30 shows the location of each of the
functional components described below. If
any component of the furnace must be replaced, use only factory authorized replacement parts. See the Replacement Parts List
for each component.
Flame Sensor – The flame sensor acts to prove
that flame has carried over from the igniter to the
opposite end burner. If no flame is sensed, the
furnace will be shut down automatically.
37
Page 38
Primary Gas Valve – The gas valve controls the
flow of gas to all of the burners. When the gas
valve is energized it automatically opens and
regulates the gas pressure in the manifold.
Secondary Gas Valve – The gas valve controls
the flow of gas to the high fire burners only.
MAINTENANCE
It is recommended that the furnace be checked
yearly. At a minimum, this check should include
the following items.
Pressure Switch – The pressure switch verifies that the inducer is drawing the combustion
gases through the heat exchanger. It also
senses a blocked condensate drain condition.
Vent Pressure Switch – The vent pressure
switch reacts to blockage in the vent or combustion air piping.
Supply Air Limit Switch – The supply air limit
switch prevents the air temperature leaving the
furnace from exceeding the maximum outlet air
temperature.
Vent Safety Switch – The vent safety switch
shuts the furnace down if the outlet flue gas
temperature increases above 160°F. This switch
protects the plastic flue system and the inducer
from over-temperature conditions.
Flame Roll-Out Switch – This switch provides
flame roll-out protection to the furnace and
combustion air inlet pipe.
!
WARNING:
To avoid electric shock, personal injury,
or death, disconnect the electric power
before performing any maintenance.
!
WARNING:
Holes in the vent pipe or heat exchanger
can cause products of combustion to
enter the home. Replace the vent pipe
or heat exchanger if leaks are found.
Failure to prevent products of combustion from being circulated into the
living space can create potentially hazardous conditions including carbon
monoxide poisoning that could result
in personal injury or death.
(Not Shown)
15 In-Line Drain Assembly
16 Burner View Port
17 Front Header Box
18 Combustion Air Intake
19 Exhaust Vent
20 Choke
19
18
7
10
20
6
15
13
17
9
5
11
3
1
2
4
16
Figure 30. Location of Major Components
39
Page 40
Combustion Air and Vent System
Check the combustion air and vent pipe to ensure
that it is not damaged, corroded or blocked by
debris. Any damaged section of vent pipe must
be replaced, and any obstruction or blockage
must be removed prior to operating the furnace.
Air Filter(s)
!
WARNING:
Heat Exchanger and Burner Maintenance
The furnace should operate for many years
without excessive soot buildup in the flue passageways, however, the flue passageways, the
vent system, and the burners should be inspected and cleaned (if required) by a qualified
serviceman annually to ensure continued safe
operation. Particular attention must be given to
identify deterioration from corrosion or other
sources.
Never operate the furnace without a
filter in place. Dust and lint in the return
air can build up on internal components,
resulting in loss of efficiency, equipment damage, and possible fire.
Air filter(s) are not supplied with the furnace
as shipped from the factory. Filters for side
return and bottom return applications are
available from your local distributor.
The installer should provide a filter rack for a high
velocity type filter in the return air duct adjacent
to the furnace. Filters should be changed or
cleaned monthly during the heating season.
New or newly renovated homes may require
more frequent changing until the construction
dust has been removed.
Lubrication
The bearings in the circulating air blower motors
are pre-lubricated and sealed at the factory. No
further oiling of the bearings is required for the
life of the motor.
Condensate Drain Assembly
Be sure the condensate lines are free and open
(i.e. avoid kinking hoses). Also make sure all
hose clamps are tight to avoid drawing air into
the system.
Blower Compartment
The blower compartment should be cleaned
monthly during the heating and cooling seasons
to remove any dirt and lint that may have
accumulated in the compartment or on the
blower and motor. Dirt and lint can create
excessive loads on the motor resulting in higher
than normal operating temperatures and shortened service life.
SYSTEM OPERATION
INFORMATION
Proper maintenance is most important to
achieve the best performance from a furnace.
Follow these instructions for years of safe,
trouble free operation.
• Do not place combustible materials on
or against the furnace cabinet or the
vent pipe.
• Do not store gasoline or any other flammable vapors and liquids in the vicinity of
the furnace.
• Change or replace the air filters monthly
during any period when the circulating
blower is operating regularly.
• Always replace the doors on the furnace
after servicing. Do not operate the furnace
without all doors and covers in place.
• Avoid operating the furnace when windows and doors are open.
• Be sure that the thermostat is properly
installed and is not being affected by drafts
or heat from lamps or other appliances.
Sequence of Operation
The operating sequences for the heating, cooling, and fan modes are described below. Refer
to the field and furnace wiring diagrams; Figures
25, 26a,b,c,d,e, 27, and 28.
Heating Mode:
1.On a call for heat the thermostat closes,
applying 24 VAC to the W terminal on the
control board.
2.The control board checks for continuity on
the 24 VAC limit control circuit (over-tem-
40
Page 41
perature limit switch, flame rollout switches
and blocked vent switch in series). If an
open limit is detected the control board will
energize the inducer blower. All other system functions will be inoperable until the limit
circuit closes. While the limit is open, the red
LED will pulse at a rate of 1 blink per unit time.
3.The furnace control checks for continuity
across the pressure switch (24 VAC). If the
pressure switch is closed the heat mode
sequence will not continue. If it remains
closed for 10 seconds the red LED will blink
3 times repetitively until the fault condition
clears.
4.The inducer is energized.
5.The pressure switch will close. If the pressure switch does not close after 10 seconds the fault LED will blink 2 times repetitively and the inducer will continue to run
until the switch is closed.
6.The inducer will pre-purge for 30 seconds
and then the igniter will start its warm-up as
follows:
Initial Power up: After 30 seconds of igniter
warm-up the gas valve (24 VAC) will then
open. The igniter circuit will stay energized
for 3 seconds after the gas valve opens.
After Initial Power up: The control has a
programmed adaptive ignition feature which
varies the warm-up period as follows: If
ignition is successful the warm-up is
duced
by 3-seconds on each subsequent
re-
call for heat until ignition failure occurs.
Upon ignition failure, the warm-up is
creased
by 3-seconds on the next try. If
in-
successful, the timing remains fixed at this
level. In general, whenever ignition failure
occurs the warm-up interval is increased
by 3-seconds on the next try. And if successful, it remains there. Minimum and
maximum warm-up time limits are set at 6
and 54 seconds, respectively.
7. The furnace control must prove flame via
the flame sensor 5 seconds after the gas
valve opens. If flame is sensed, all burners
are on and the igniter cools off. If no flame
is sensed, the gas valve closes immediately and the inducer continues to run. A
second trial for ignition (step 6) begins if no
flame is sensed on the fifth try for ignition,
the furnace control is locked and the red
LED will blink 4 times repetitively. The
thermostat must be opened for at least ten
seconds to reset the furnace control after
a lock out. Otherwise, the furnace will
attempt another ignition sequence in 1 hour.
8. The furnace control energizes the circulating air blower at a very low speed. After 30
seconds, the blower will ramp to the airflow
selected for heating.
9. When the thermostat has been satisfied,
gas valve is de-energized.
10. The inducer is de-energized after a 30
second postpurge.
11. The circulating air blower remains on for
120 seconds.
12. Abnormal conditions: If a limit opens during
operation, the inducer blower continues to
operate. The gas valve is de-energized
immediately. The inducer blower continues
to operate until the limit closes, then is deenergized.
Cooling Mode:
1. On a call for cooling the thermostat closes,
applying 24 VAC to the G and Y terminals
on the furnace control. This closes the
compressor contactor.
2. The furnace control energizes the circulating blower to 1/3 of the selected airflow for
approximately 30 seconds.
3. The circulating blower will then ramp to
approximately 3/4 of the selected airflow for
another 30 seconds before adjusting to full
airflow until the thermostat is satisfied.
4. When the thermostat is satisfied, the G and
Y terminals on the control board are deenergized opening the compressor
contactor.
5. The circulating air blower will operate at
1/2 of the selected speed for 60 seconds,
and de-energize.
Fan Mode:
1. On a call for fan operation, the thermostat
applies 24 VAC to the G terminal on the
furnace control board.
2. The circulating air blower ramps to 1/2 of the
selected airflow.
41
Page 42
Furnace Fails to Operate
If the furnace does not operate check the
following:
1. Is the thermostat operating properly?
2. Are the blower compartment door(s) in
place?
3. Is the furnace disconnect closed?
4. Has the circuit breaker tripped or the control board fuse burned open?
5. Is the gas turned on?
6. Are any manual reset switches open?
7. Is the filter dirty or plugged?
8. Is the flame sensor coated? (Remove and
clean with emery cloth.)
If the furnace locks out after 5 attempts for
ignition, it will try again every hour if a call for heat
remains. If the inducer and circulating air blowers are operating, and items 1 through 8 have
been checked, press the red reset button on the
vent safety switch. (See Figure 29.) If the
furnace operates after depressing the reset
button, contact a qualified serviceman to identify
and repair the problem.
If the furnace continues to not operate, depress
the red reset buttons on the flame rollout
switches. (See Figure 29.) If the furnace operates after depressing the reset buttons, contact
a qualified servicemen to identify and repair the
problem.
42
Page 43
INSTALLATION/PERFORMANCE CHECK LIST
LOCATION __________________________ CITY ____________________ STATE _____
INSTALLER _________________________ CITY ____________________ STATE _____
UNIT MODEL # ______________________ UNIT SERIAL # ________________________
Minimum Clearances per Table 3? _______
Electrical Connections tight? _____________
Line Voltage Polarity correct? ____________
Supply Voltage: ___________________ Volts
Blower Motor HP: _____________________
FUEL TYPE:
Natural Gas _______ LP/Propane ________
Gas Piping Connections leak-tested? ______
Gas Line Pressure: ____________________
(in. water column, with furnace operating)
Manifold Pressure: ____________________
(in. water column, with furnace operating)
Is there adequate fresh air supply for
combustion and ventilation? _____________
Furnace Input: __________________ (Btuh)
Supply Air Temperature: ____________ (° F)
Return Air Temperature: ____________ (° F)
Temperature Rise: ________________ (° F)
Are Flue Connections tight? _____________
Is there Proper Draft? __________________
Is Vent free from restrictions? ____________
Is the Filter(s) secured in place? __________
Is the Filter(s) clean? __________________
Has the Thermostat been calibrated? ______
Is the Thermostat level? ________________
Is the Heat Anticipator Setting correct? ____
Has the Owner's Information been reviewed
with the home-owner? __________________
Has the Literature Package been left near the
furnace? ____________________________
43
Page 44
O’Fallon, MO
¢708475E¤
708475A
708475A (Replaces 7084750)
Specifications and illustrations subject to change
without notice and without incurring obligations.
Printed in U.S.A. (11/05)
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