Maytag TC UPFLOW/HORIZONTAL, TL DOWNFLOW Installation Manual

TWO-STAGE CONDENSING GAS FURNACES WITH FIXED & VARIABLE SPEED BLOWERS - 95.1 % AFUE

Installation Instructions

*TC UPFLOW/HORIZONTAL MODEL

WARNING:

FIRE OR EXPLOSION HAZARD

• Failure to follow safety warnings exactly
could result in serious injury or property
damage.

• Installation and service must be performed
by a qualifi ed installer, service agency or the
gas supplier.

• Do not store or use gasoline or other
fl ammable vapors and liquids in the vicinity
of this or any other appliance.

WHAT TO DO IF YOU SMELL GAS

• Do not try to light any appliance.

• Do not touch any electrical switch; do not
use any phone in your building.

• Leave the building immediately.

• 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 fi re department.

*TL DOWNFLOW MODEL

AVERTISSEMENT

RISQUE D’INCENDIE OU D’ EXPLOSION

• Le non-respect des avertissements de
sécurité pourrait entraîner des blessures
graves, la mort ou des dommages matériels.

• L’installation et l’entretien doivent être
effectués par un installateur qualifié, un
organisme de service ou le fournisseur de
gazstaller, service agency or the gas supplier.

• Ne pas entreposer ni utiliser de l’essence ni
d’autres vapeurs ou liquides infl ammables
dans le voisinage de cet appareil, ni de tout

autre appareil.

QUE FAIRE S’IL Y A UNE ODEUR DE GAZ

• Ne pas tenter d’allumer aucun appareil.

• Ne toucher à aucun interrupteur électrique;
n’utiliser aucun téléphone dans le bâtiment.

• Évacuer l’immeuble immédiatement.

• Appeler immédiatement le fournisseur de
gaz en employant le téléphone d’un voisin.
Respecter à la lettre les instructions du
fournisseur de gaz.

• Si personne ne répond, appeler le service des
incendies.

DO NOT DESTROY THIS MANUAL. KEEP IN A SAFE PLACE FOR FUTURE REFERENCE.

TABLE OF CONTENTS

IMPORTANT SAFETY INFORMATION .......................4

Upfl ow/Horizontal Furnaces ..............................15

REQUIREMENTS & CODES .......................................4

Combustion Air Quality ............................................. 5

Operation of Furnace During Construction ............... 5

Heating Load ............................................................5

Clearances to Combustible Materials ....................... 6

Installation in a Garage ............................................6

COMBUSTION AIR & VENTING REQUIREMENTS ....7

General Information .................................................8

Direct Vent Furnaces ................................................8

Conventional Furnaces - Confi ned Spaces ..............8

Air From Inside .....................................................8

Outdoor Air from a Crawl Space or

Vented Attic...........................................................9

Outdoor Air Using Vertical Ducts .......................... 9

Outdoor Air Using Horizontal Ducts ......................9

Air Directly Through an Exterior Wall .................. 10

Alternate Method of Providing Air from

Outside ............................................................... 10

Conventional Furnaces - Unconfi ned Spaces ........ 10

Category IV Venting ...............................................10

Vent Pipe Material .............................................11

Vent Pipe Length & Diameter ............................11

Vent Pipe Installation .........................................12

Outdoor Terminations - Horizontal Venting ........12

Outdoor Terminations - Vertical Venting ............13

Vent Freezing Protection ...................................13

Side Return Installations ..............................15

Bottom Return Installations ..........................15

Downfl ow Furnaces ............................................15

Acoustical Treatments ............................................15

FURNACE INSTALLATION .......................................16

General Requirements ...........................................16

Upfl ow Installation ..................................................16

Side Return Air Inlet ...........................................16

Bottom Return Air Inlet .......................................16

Downfl ow Installation ..............................................16

Installation on a Concrete Slab ..........................16

Horizontal Installation .............................................16

Inducer & Venting Options ......................................17

Inducer Assembly Rotation ................................17

Pressure Switch Tubing......................................18

Accessories ............................................................19

Finish Flange ......................................................19

Rubber Grommets ..............................................19

PVC Tee, Reducer, & Hose Barb ........................19

Condensate Drain Lines .....................................20

Bottom Panel Removal ...........................................20

Alternate Bottom Panel Removal .......................20

GAS SUPPLY & PIPING ............................................21

Leak Check ...........................................................21

High-Altitude Application ........................................22

Conversion to LP / Propane ...................................24

Existing Installations ..........................................14

Condensate Disposal ............................................14

CIRCULATING AIR REQUIREMENTS ...................... 14

Plenums & Air Ducts ............................................... 14

Supply Air Connections .......................................... 15

Upfl ow/Horizontal Furnaces ............................... 15

Downfl ow Furnaces ............................................ 15

Return Air Connections ..........................................15

2

ELECTRICAL WIRING ...............................................24

Line Voltage Wiring .................................................24

Grounding ...............................................................25

Thermostat / Low Voltage Connections .................25

Single Stage AC & Single Stage Heat

Thermostat .........................................................26

Single Stage AC & Two - Stage Heat

Thermostat .........................................................26

Two - Stage AC & Two - Stage Heat

Thermostat .........................................................26

Autostaging for Single Stage Thermostats .............26

Autostaging for Two-Stage Thermostats .................27

Heat Anticipator ......................................................27

Dehumidifi cation Options .......................................27

Table 10 -

Nominal Cooling / Heat Pump CFM -

Variable Speed .....................................36

Gas Information .....................................................37

Table 11 - Gas Flow Rates .................................37

Blower Speed Confi guration ...................................27

Fixed Speed Blower Applications .......................27

Variable Speed Blower Applications ...................27

START-UP & ADJUSTMENTS ...................................28

Pre-Start Checklist..................................................28

Start-Up Procedures ...............................................28

Verifying & Adjusting Input Rate .............................28

Verifying & Adjusting Temperature Rise .................28

Verifying Burner Operation .....................................29

Verifying Operation of the Supply Air

Limit Switch ............................................................29

OPERATING SEQUENCE .........................................29

Heating Cycle .........................................................29

Cooling Cycle .........................................................30

Fan Mode ................................................................30

DESCRIPTION OF COMPONENTS ..........................30

MAINTENANCE .........................................................30

Air Filters ................................................................31

Blower Compartment ..............................................31

Cleaning of Burners ................................................31

Heat Exchanger & Burner Maintenance .................31

Lubrication ..............................................................31

Vent System ...........................................................31

TROUBLESHOOTING ...............................................32

FIGURES & TABLES .................................................33

Figure 28 - Furnace Dimensions ........................33

Airfl ow Data ...........................................................34

Table 8 - Heating / Cooling Airfl ows &

Temperature Rises - Fixed

Table 9 -

Nominal CFM & Temperature Rises -

Speed .......34

Variable Speed .....................................35

Table 12 - Gas Pipe Capacities ..........................37

Table 13 - High Altitude Deration Chart for

Propane Gas .....................................38

Table 14 - Natural Gas Heating Values ..............38

Table 15 - High Altitude Deration Chart for

Nat. Gas - High Heating Value ...........39

Table 16 - High Altitude Deration Chart for

Nat. Gas - Low Heating Value ...........39

Electrical Information .............................................40

Figure 29 - Two-Stage Fixed Speed Motor

Control Board ....................................40

Figure 30 - Two-Stage Variable Speed

Motor Control Board ..........................40

Figure 31 - Two-Stage Furnace Control Board ....40

Figure 32 - Wiring Diagram - Two Stage Fixed

Speed Upfl ow / Horiz. Furnaces .......41

Figure 33 - Wiring Diagram - Two Stage Fixed

Speed Downfl ow Furnaces ...............42

Figure 34 - Wiring Diagram - Two Stage Variable

Speed Upfl ow / Horiz. Furnaces .......43

Figure 35 - Wiring Diagram - Two Stage Variable

Speed Downfl ow Furnaces ...............44

Venting Information .................................................45

Table 17 -

Vent Termination Clearances .............45

Figure 36 - Horizontal & Vertical Venting ............46

Figure 37 - Upfl ow Options .................................47

Figure 38 - Horizontal Options ..........................48

Figure 39 - Downfl ow Options ............................49

Location of Furnace Components .........................50

Figure 40 - Furnace Components ....................50

INSTALLATION / PERFORMANCE CHECKLIST .....52

3

IMPORTANT SAFETY INFORMATION

Please read all instructions before servicing this equipment.
Pay attention to all safety warnings and any other special
notes highlighted in the manual. Safety markings are
used frequently throughout this manual to designate a
degree or level of seriousness and should not be ignored.
WARNING indicates a potentially hazardous situation that
if not avoided, could result in personal injury or death.
CAUTION indicates a potentially hazardous situation that
if not avoided, may result in minor or moderate injury or
property damage.

REQUIREMENTS & CODES

WARNING:

The safety information listed below must be
followed during the installation, service, and
operation of this furnace. Failure to follow safety
recommendations could result in possible
damage to the equipment, serious per

injury or death

• 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
(NFPA54/ANSI Z223.1) or the Natural Gas and Propane
Installation Code, CAN/CGA B149.1.

• Use only with type of gas approved for this furnace.
Refer to the furnace rating plate.

• Install this furnace only in a location and position as
specifi ed in Table 1 (page 6).

• Provide adequate combustion and ventilation air to the
furnace space as specifi ed on pages 7 - 14.

• Provide adequate clearances around the vent air intake
terminal as specifi ed in Figures 6 - 9 (pages 12 - 13).

• Combustion products must be discharged outdoors.
Connect this furnace to an approved vent system only,
as specifi ed on pages 10 - 14.

• Never test for gas leaks with an open fl ame. Use a
commercially available soap solution to check all
connections. See page 21.

• This furnace is designed to operate with a maximum
external pressure rise of 0.5 inches of water column.
Consult Tables 8 - 10 (pages 34 - 36), and the rating
plate for the proper circulating air fl ow and temperature
rise. It is important that the duct system be designed
to provide the correct fl ow rates and external pressure
rise. An improperly designed duct system can result in
nuisance shutdowns, and comfort or noise issues.

• When 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 in the conditioned
space. See pages 14 - 15.

• A gas-fi red furnace for installation in a residential garage
must be installed as specifi ed on page 6.

.

sonal

• This furnace may be used for temporary heating of
buildings or structures under construction. See the
guidelines listed on pages 5.

• This furnace is not approved for installation in mobile
homes. Installing this furnace in a mobile home could
cause fi re, property damage, and/or personal injury.

• The Commonwealth of Massachusetts requires
compliance with regulation 248 CMR 4.00 and 5.00 for
installation of through – the – wall vented gas appliances

as follows:

1. For direct-vent appliances, mechanical-vent heating

appliances or domestic hot water equipment, where
the bottom of the vent terminal and the air intake is
installed below four feet above grade the following
requirements must be satisfi ed:

a.) A carbon monoxide (CO) detector and alarm shall be

placed on each fl oor level where there are bedrooms.
The detector shall comply with NFPA 720 (2005
Edition) and be mounted in the living area outside the
bedroom(s).

b.) A (CO) detector shall be located in the room that

houses the appliance or equipment and shall:

• Be powered by the same electrical circuit as the

appliance or equipment. Only one service switch shall
power the appliance and the (CO) detector;

• Have battery back-up power;

• Meet ANSI/UL 2034 Standards and comply with

NFPA 720 (2005 Edition); and Approved and listed
by a Nationally Recognized Testing Laboratory as
recognized under 527 CMR.

c.) A Product-approved vent terminal must be used,

and if applicable, a product-approved air intake must
be used. Installation shall be in strict compliance
with the manufacturer’s instructions. A copy of the
installation instructions shall remain with the appliance
or equipment at the completion of the installation.

d.) A metal or plastic identifi cation plate shall be mounted

at the exterior of the building, four feet directly above
the location of vent terminal. The plate shall be of
suffi cient size, easily read from a distance of eight
feet away, and read “Gas Vent Directly Below”.

2. For direct-vent appliances, mechanical-vent heating

appliances or domestic hot water equipment where
the bottom of the vent terminal and the air intake is
installed above four feet above grade the following
requirements must be satisfi ed:

a.) A (CO) detector and alarm shall be placed on each

fl oor level where there are bedrooms. The detector
shall comply with NFPA 720 (2005 Edition) and be
mounted in the living area outside the bedroom(s).

b.) The (CO) detector shall:

• Be located in the room that houses the appliance or

equipment;

• Be hard-wired or battery powered or both.

• Shall comply with NFPA 720 (2005 Edition).

c.) A product-approved vent terminal must be used,

and if applicable, a product-approved air intake must
be used. Installation shall be in strict compliance

4

with the manufacturer’s instructions. A copy of the
installation instructions shall remain with the appliance
or equipment at the completion of the installation.

Combustion Air Quality

CAUTION:

Combustion air must not be drawn from a
corrosive atmosphere.

To maximize heat exchanger life, the combustion air
must be free of chemicals that can form corrosive acidic
compounds in the combustion gases. The recommended
source of combustion air is to use outdoor air. However,
the use of indoor air in most applications is acceptable
except as listed:

• If the furnace is installed as a single pipe installation
in a confi ned space, it is required that the necessary
combustion air come from the outdoors by way of attic,
crawl space, air duct, or direct opening. For Installations
in confi ned spaces, see pages 7 - 10 for combustion

air requirements.

• Installations in these locations 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 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 (perchloroethylene)
Printing inks, paint removers, varnishes, etc.
Hydrochloric Acid
Cements and glues
Antistatic fabric softeners
Masonry acid washing materials

Operating gas furnaces in construction environments can
cause a variety of problems with the furnace. Proper use
of commercial portable space heating equipment during
construction is recommended. This gas furnace may be
used during construction if it is not in violation of any
applicable codes and the following criteria are met:

• The installation must meet all applicable codes. The
furnace must be permanently installed according to
the instructions supplied with the furnace including
electrical supply, gas supply, duct work and venting. The
furnace must be controlled by a thermostat properly
installed according to the instructions supplied with the
furnace and thermostat. The installation must include
a properly installed fi lter in the return air system with
no by-pass air. The fi lter must be inspected frequently
and replaced when necessary.

• Combustion air must be supplied from outside the
structure and located such that dust and gases
from construction activity are not introduced into the
combustion system.

• Provisions must be made to insure that condensate
does not freeze in the furnace or condensate drain lines
during operation and during idle times; for example,
overnight if turned off. (Condensing furnaces only)

• Before occupying the structure: The filter must be
replaced or cleaned, the duct work must be inspected
and cleaned of any construction debris, and the furnace
must be cleaned and/or repaired if found to be dirty,
damaged, or malfunctioning in any way by a qualifi ed
HVAC technician. The furnace shall be inspected and
approved by applicable local authority even if this
requires redundant inspections.

• Serial numbers for furnaces used during construction
must be submitted in writing (fax and email also
acceptable). This information will be used to track the
long-term affects of the use during construction on
furnaces. Proof of this submittal shall be available for
the fi nal inspection of the furnace prior to occupancy.

• This furnace is designed to operate with return air
temperatures in ranges normally found in occupied
residences, including setbacks. Minimum continuous
return temperature must not be below 60° F (15° C).
Occasionally a temporary return temperature of 55° F
(12° C) is acceptable. However, operation with a return
temperature below 55° F (12° C) is not allowed.

Operation of Furnace During Construction

CAUTION:

Failure to follow these instructions will void the
factory warranty and may signifi cantly reduce
the life or the performance of the furnace, and/
or result in other unsafe conditions. It is the
responsibility of the installing contractor to
insure these provisions are met.

Heating Load

This furnace should be sized to provide the design heating
load requirement. Heating load estimates can be made
using approved methods available from Air Conditioning
Contractors of America (Manual J); American Society of
Heating, Refrigerating, and Air Conditioning Engineers;
or other approved engineering methods. Excessive

oversizing of the furnace could cause the furnace
and/or vent to fail prematurely. The ductwork should

be appropriately sized to the capacity of the furnace to
ensure its proper airfl ow rating.

5

For installations above 2,000 ft., the furnace should have
a sea level input rating large enough that it will meet the
heating load after deration for altitude.

Two-stage furnaces operate at two input rates to better
meet heating loads. The lower heating rate (low fi re) is
65% of the high fi re rate. The greatest degree of control
over the furnace can be gained by controlling it with a two
stage thermostat. This allows the thermostat to directly
request either high or low fi re. However, it is possible to
operate the furnace using a single stage thermostat. In
this application the furnace control can be set to increase
from low to high fi re, based on a timer. See Autostaging
for Single Stage Thermostats (page 26).

Furnaces are properly sized to meet the expected
maximum heating load. But this load occurs infrequently.
So, during more moderate weather, the furnace is likely to
use low fi re a considerable part of the time. This is normal
and has the benefi t of quieter and more effi cient operation.

Clearances to Combustible Materials

This furnace is Design Certifi ed in the U.S. and Canada
by CSA International for the minimum clearances to
combustible materials. NOTE: The furnace is listed for
installation on combustible or non-combustible fl ooring.
However, wood is the only combustible fl ooring allowed
for installation. Downfl ow models must use the appropriate
subase kit when installing over a wood fl oor. To obtain model
number and specifi c clearance information, refer to the
furnace rating plate, located inside of the furnace cabinet.

Access for positioning and servicing the unit must be
considered when locating unit. The need to provide
clearance for access to panels or doors may require
clearance distances over and above the requirements.

Allow 24 inches minimum clearance from the front of
the unit. However 36 inches is strongly recommended.

See Table 1 for minimum clearance requirements.

Installation in a Garage

This Gas-fi red furnace may be installed in a residential
garage with the provision that the burners and igniter
are located no less than 18 inches (457mm) above the
fl oor. The furnace must be located or protected to prevent
physical damage by vehicles.

WARNING:

Do not place combustible material on or against
the furnace cabinet or within 6 inches of the
vent pipe. Do not place combustible materials,
including gasoline or any other fl ammable
vapors and liquids, in the vicinity of the furnace.

CLEARANCES TO COMBUSTIBLE MATERIALS

Left Side..................0 Inches Top ..........................0 Inches

Right Side ...............0 Inches Front ......................

†

4 Inches

Vent ......................... 0 Inches Back ........................ 0 Inches

†

Allow 24 in. minimum clearance for servicing. Recommended

clearance is 36 in.

BOTTOM

DOWNFLOW

APPLICATIONS

BACK

TOP

LEFT SIDE

FRONT

RIGHT SIDE

UPFLOW

APPLICATIONS

BACK

TOP

LEFT SIDE

FRONT

TOP

RIGHT SIDE

VENT

VENT

HORIZONTAL

APPLICATIONS

SIDE

FRONT

SIDE

Table 1. Minimum Clearances to

Combustible Materials

The information listed below is for reference purposes only
and does not necessarily have jurisdiction over local or state
codes. Always consult with local authorities before installing

any gas appliance.

Combustion and Ventilation Air

• US: National Fuel Gas Code (NFGC), Air for Combustion
and Ventilation

• CANADA: Natural Gas and Propane Installation Codes
(NSCNGPIC), Venting Systems and Air Supply for
Appliances

Duct Systems

• US and CANADA: Air Conditioning Contractors Association
(ACCA) Manual D, Sheet Metal and Air Conditioning
Contractors National Association (SMACNA), or American
Society of Heating, Refrigeration, and Air Conditioning
Engineers (ASHRAE) Fundamentals Handbook

Electrical Connections

• US: National Electrical Code (NEC) ANSI/NFPA 70

• CANADA: Canadian Electrical Code CSA C22.1

Gas Piping and Gas Pipe Pressure Testing

• US: NFGC and National Plumbing Codes

• CANADA: NSCNGPIC

General Installation

• US: Current edition of the NFGC and the NFPA 90B. For
copies, contact the National Fire Protection Association
Inc., Batterymarch Park, Quincy, MA 02269; or American
Gas Association, 400 N. Capitol, N.W., Washington DC
20001 or www.NFPA.org

• CANADA: NSCNGPIC. For a copy, contact Standard Sales,
CSA International, 178 Rexdale Boulevard, Etobicoke
(Toronto), Ontario, M9W 1R3 Canada

Safety

• US: (NFGC) NFPA 54–1999/ANSI Z223.1 and the Installation
Standards, Warm Air Heating and Air Conditioning Systems
ANSI/NFPA 90B.

• CANADA: CAN/CGA-B149.1 and .2–M00 National Standard
of Canada. (NSCNGPIC)

VENT

6

COMBUSTION AIR & VENTING REQUIREMENTS

WARNING:

CARBON MONOXIDE POISONING HAZARD

Failure to follow the steps outlined below
for each appliance connected to the venting
system being placed into operation could
result in carbon monoxide poisoning or death.

The following steps shall be followed with
each individual appliance connected to the
venting system being placed in operation,
while all other appliances connected to the
venting system are not in operation:

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/NFPA 54 or
the CSA B149.1, Natural Gas and Propane
Installation Codes and these instructions.

Determine that there is no blockage or
restriction, leakage, corrosion and other
defi ciencies which could cause an unsafe
condition.

3. As far as 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. Close fi replace dampers.

5. Turn on clothes dryers and any appliance not
connected to the venting system. Turn on
any exhaust fans, such as range hoods and
bathroom exhausts, so they are operating at
maximum speed. Do not operate a summer
exhaust fan.

6. Follow the lighting instructions. Place the
appliance being inspected into operation.
Adjust the thermostat so appliance is
operating continuously.

7. Test for spillage from draft hood equipped
appliances at the draft hood relief opening
after 5 minutes of main burner operation. Use
the fl ame 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 National Fuel

Gas Code, ANSI Z223.1/NFPA 54 and/or CSA
B149.1, Natural Gas 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, fi replace
dampers and any other gas-fi red burning
appliance to their previous conditions of use.

AVERTISSEMENT:

RISQUE D’EMPOISONNEMENT AU

MONOXYDE DE CARBONED

Le non-respect des consignes suivantes portant

sur chacun des appareils raccordés au système
d’évacuation mis en service pourrait entraîner
l’empoisennement au monoxyde de carbone ou
la mort. Les consignes suivantes doivent être
observées pour chaque appareil raccordé au
système d’évacuation mis en service si les autres
appareils raccordés au système ne sont pas en
service:

1. Sceller toute ouverture non utilisée de la systéme
d’évacuation;

2. S’assurer que la systéme d’évacuation présente des
dimensions et une pente horizontale conformes à la
norme ANSI Z223.1/NFPA 54, intitulée National Fuel
Gas Code ou aux codes d’installation CSA-B149.1,
ainsi qu’aux présentes instructions. S’assurer que la
systéme d’évacuation n’est pas bloquée, restreinte,
corrodée, qu’elle ne fuit pas et qu’elle ne présente
aucun autre défaut potentiellement dangereux;

3. Dans la mesure du possible, fermer toutes les portes
et fenêtres du bâtiment, et toutes les portes entre la
pièce où se trouve l’appareil raccordé à la systéme
d’évacuation et les autres pièces du bâtiment.

4. Fermer les registres des foyers;

5. Mettre en service les sécheuses et tout autre appareil
qui n’est pas raccordé à la systéme d’évacuation.
Faire fonctionner à régime maximal tout ventilateur
d’évacuation, tel que les hottes de cuisinière et les
ventilateurs de salles de bains. Ne pas mettre en
service les ventilateurs d’été.

6. Respecter les instructions d’allumage. Mettre en
service l’appareil à l’essai. Régler le thermostat
de manière à ce que l’appareil fonctionne sans
interruption;

7. Vérifi er s’il y a débordement à l’orifi ce d’évacuation
du coupe tirage des appareils dotés d’un coupe
tirage 5 minutes après l’allumage du brûleur
principal. Utiliser la fl amme d’une allumette ou
d’une chandelle.

8. Si l’on constate, au cours de l’un des essais qui
précèdent, que l’évacuation est défi ciente, corriger
le système d’évacuation conformément à la norm
ANSI Z223.1/NFPA 54, National Fuel Gas Code, et
(ou) aux codes d’installation CSA B149.1.

9. Après avoir déterminé que tous les appareils
raccordés à la systéme d’évacuation évacuent
correctement tel que prescrit ci-dessus, rouvrir les
portes et les fenêtres et remettre les ventilateurs
d’évacuation, les registres de foyers et tout
autre appareil fonctionnant au gaz à leur état de
fonctionnement initial.

7

General Information

WARNING:

Furnace installation using methods other than
those described in the following sections must
comply with the National Fuel Gas Code (NFGC)
and all applicable local codes.

• Instructions for determining the adequacy of combustion
air for an installation can be found in the current revision
of the NFGC (ANSI Z223.1 / NFPA54). Consult local
codes for special requirements. These requirements
are for US installations as found in the NFGC.

• The requirements in Canada (B149.1) are structured
differently. Consult with B149.1 and local code offi cials
for Canadian installations.

This condensing furnace is certifi ed for installation either as
a Direct Vent (2-pipe) or Conventional (1-pipe) appliance.
Direct Vent appliances draw combustion air from the
outdoors and vent combustion products back outside.
Installation with air taken from around the furnace is often
referred to as Conventional installation - i.e. only the vent
(exhaust) pipe is provided.

Provisions must be made during the installation of
this furnace that provide an adequate supply of air for
combustion. The combustion air from the outside needs
to be clear of chemicals that can cause corrosion. The
inlet pipe should not be placed near corrosive chemicals
such as those listed on page 5.

Another important consideration when selecting one or
two pipe installation is the quality of the Indoor air which
can sometimes be contaminated with various household
chemicals . These chemicals can cause severe corrosion
in the furnace combustion system. A 2-pipe installation
has the additional advantage that it isolates the system
from the effects of negative pressure in the house.

CAUTION:

Exhaust fans, clothes dryers, fi replaces and
other appliances that force air from the house
to the outdoors can create a negative pressure
inside the house, resulting in improper furnace
operation or unsafe conditions such as fl ame roll
out. It is imperative that suffi cient air exchange
with the outdoors is provided to prevent
depressurization. Additional information about
testing negative pressure problems can be
found in the National Fuel Gas Code.

burners. NOTE: This safety device is a manually reset
switch. DO NOT install jumper wires across these
switches to defeat their function or reset a switch
without identifying and correcting the fault condition. If

a switch must be replaced, use only the correct sized part
specifi ed in the Replacement Parts List provided online.

Direct Vent Furnaces

Direct Vent (2-pipe) furnaces draw combustion air directly
from the outdoors and then vent the combustion products
back outside, isolating the entire system from the indoor
space. It is important to make sure that the whole system
is sealed and clearances to combustibles are maintained
regardless of the installation being in a confi ned or
unconfi ned space.

Conventional Furnaces - Confi ned Spaces

A confi ned space is an area with volume less than 50
cubic feet per 1,000 Btuh of the combined input rates of
all appliances drawing combustion air from that space.
Furnace closets, small equipment rooms and garages are
confi ned spaces. Furnaces installed in a confi ned space
which supply heated air to areas outside the space must
draw return air from outside the space and must have the
return air ducts tightly sealed to the furnace. Ducts must
have cross - sectional area at least as large as the free area
of their respective openings to the furnace space. Attics
or crawl spaces must connect freely with the outdoors if
they are the source of air for combustion and ventilation.

The required sizing of these openings is determined by
whether inside or outside air is used to support combustion,
the method by which the air is brought to the space, and
by the total input rate of all appliances in the space. In
all cases, the minimum dimension of any combustion air
opening is 3 inches.

Air From Inside

If combustion air is taken from the heated space, the two
openings must each have a free area of at least one square
inch per 1,000 Btuh of total input of all appliances in the
confi ned space, but not less than 100 square inches of
free area (Figure 1, page 9).

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 openings on top of the furnace and openings in closet
doors or walls must never be restricted. If the furnace is
operated without adequate air for combustion, the fl ame
roll-out switch will open, turning off the gas supply to the

8

Vent or

Chimney

Vent or

Chimney

Ventilation Louvers
at each end of attic

Attic

Insulation

Air Duct must be
at least 1 sq. in.
per 4,000 Btuh of
total input rating.

NOTES:
Each opening must be
at least 100 sq. in. or
1 sq. in. per 1,000 Btuh
of total input rating,
whichever is greater.

Openings must start at
no more than 12 inches
from the top and bottom
of the enclosure.

Total Input Rating

(Btuh)

Water
Heater

Minimum Free Area

(Each Opening)

12” Max.

Furnace

See

Notes

See

Notes

12” Max.

Round Duct

Diameter

40,000 100 sq. In 12 inches
60,000 100 sq. In 12 inches

80,000 100 sq. In 12 inches
100,000 100 sq. In 12 inches
120,000 120 sq. In 13 inches
140,000 140 sq. In 14 inches
160,000 160 sq. In 15 inches

Figure 1. Combustion Air Drawn from Inside

Outdoor Air from a Crawl Space or Vented Attic

When the openings can freely exchange air with the
outdoors, each opening shall have a minimum free area
of 1 square inch per 4,000 Btuh of total appliance input.
The openings shall exchange directly, or by ducts, with
the outdoor spaces (crawl or attic) that freely exchange
with the outdoors (Figure 2).

Ducts must
extend above

Water

Furnace

Heater

Total Input Rating

(Btuh)

40,000 10 sq. In 4 inches

60,000 15 sq. In 5 inches

80,000 20 sq. In 5 inches

100,000 25 sq. In 6 inches

120,000 30 sq. In 6 inches

140,000 35 sq. In 7 inches

160,000 40 sq. In 8 inches

Minimum Free Area

(Each Opening)

attic insulation.

Air Duct must be
at least 1 sq. in.
per 4,000 Btuh of
total input rating.

12" Max

Round Duct

Diameter

Figure 3. Combustion Air Drawn from Outside

Through Vertical Ducts

Outdoor Air Using Horizontal Ducts

If combustion air is taken from outdoors through horizontal
ducts, the openings and ducts must have a minimum free
area of one square inch per 2,000 Btuh of total appliance
input (Figure 4). Ducts must have cross - sectional area at
least as large as the free area of their respective openings
to the furnace space.

Outdoor Air Using Vertical Ducts

If combustion air is taken from outdoors through vertical
ducts, the openings and ducts must have a minimum free
area of one square inch per 4,000 Btuh of total appliance
input (Figure 3).

Vent or

Chimney

Ventilation Louvers
(each end of attic)

---------

Outlet
Air

Water

Furnace

Alternate

Air Inlet

---------

Ventilation Louvers For
Unheated Crawl Space

Heater

Inlet Air

---------

Figure 2. Combustion Air Drawn from a Crawl

Space or Vented Attic

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.

---------

Vent or

Chimney

Water
Heater

Air Duct

Furnace

Air Ducts must be
at least 1 sq. in.
per 2,000 Btuh of
total input rating.

Air Duct

Total Input Rating

(Btuh)

Minimum Free Area

(Each Opening)

Round Duct

Diameter

40,000 20 sq. In 5 inches
60,000 30 sq. In 6 inches

80,000 40 sq. In 7 inches
100,000 50 sq. In 8 inches
120,000 60 sq. In 9 inches
140,000 70 sq. In 10 inches
160,000 80 sq. In 10 inches

Figure 4. Combustion Air Drawn from Outside

Through Horizontal Ducts

9

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 4,000 Btuh of total appliance
input (Figure 5).

Vent or

Chimney

-

-

-

-

-

See

-

-

-

-

Note

Note

12" Max.

Total Input Rating

12"

Max

See

-

-

-

-

-

-

-

-

-

(Btuh)

40,000 10 sq. In 4 inches
60,000 15 sq. In 5 inches

80,000 20 sq. In 5 inches
100,000 25 sq. In 6 inches
120,000 30 sq. In 6 inches
140,000 35 sq. In 7 inches
160,000 40 sq. In 8 inches

Water
Heater

Minimum Free Area

(Each Opening)

NOTE: Each opening to outside

must be at least 1 sq. in. per
4,000 Btuh of total input rating.

Furnace

Round Duct

Diameter

Figure 5. Combustion Air Drawn from Outside

Through an Exterior Wall

Alternate Method of Providing

Air from Outside:

If acceptable under local Codes, it is permitted to provide
outside air using one opening (See NFGC). Generally,
confi ned spaces must have two openings in the space
for combustion air. One opening must be within 12
inches of the ceiling, and the other must be within 12
inches of the fl oor. However, an alternative method
recently adopted by the NFGC uses one opening within
12 inches of the top of the space. This method may be
used if it is acceptable to the local codes.

Conventional Furnaces - Unconfi ned Spaces

An unconfi ned 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.

In general, a furnace installed in an unconfi ned space will
not require outside air for combustion. However, in homes
built for energy effi ciency (low air change rates), it may
be necessary to provide outside air to ensure adequate
combustion and venting, even though the furnace is located
in an unconfi ned space. See example.

Example:

A space with a water heater rated at 45,000 Btuh
input 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 unconfi ned. If the space has an 8 foot
ceiling, the fl oor area of the space must be 750 square
feet (6,000 / 8 = 750).

Category IV Venting

This furnace is classifi ed as a “Category IV” appliance,
which requires special venting materials and installation
procedures. This section specifi es installation requirements
for Conventional (1-pipe) and Direct Vent (2-pipe) piping.

WARNING:

Upon completion of the furnace installation,
carefully inspect the entire fl ue system both
inside and outside the furnace to assure it is
properly sealed. Leaks in the fl ue system can
result in serious personal injury or death due
to exposure of fl ue products, including carbon
monoxide.

• This furnace must be vented in compliance with
the current revision of the National Fuel Gas Code
(ANSI-Z223.1/NFPA54) and the instructions provided
below. Consult local codes for special requirements.

• In Canada, venting shall conform to the requirements of
the current (CAN/CGA B149.1 or .2) installation codes.

Consult local codes for special requirements.

The following conditions must be met:

1. The opening must start within 12” of the top of the
structure and connect with the out of doors through
vertical or horizontal ducts or be ducted to a crawl
or attic space that connects with the out of doors.

2. The opening must have a minimum free area of 1 sq.
in. per 3,000 Btu per hour of the total input rating of
all equipment located in the enclosure.

3. The free area must not be less than the sum of all
the areas of the vent connectors in the enclosure.

10

WARNING:

This furnace must not be vented with other
appliances, even if that appliance is of the
condensing type. This includes water heaters
of any effi ciency. 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 fi replace chimney or
building chase.

For 1- pipe installations, install vent piping as described in
this section and provide air for combustion and ventilation
according to pages 7 - 10. Table 2 contains the maximum
length of vent and combustion air piping for either type
of installation.

Category IV appliances operate with positive vent pressure
and therefore require vent systems which are thoroughly
sealed. They also produce liquid 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.

The inducer assembly on this furnace can be rotated to
vent the fl ue products out of the left or right side of the
furnace. This increases the fl exibility of which direction
the vent pipe can exit the furnace.

In Canada, all plastic vent pipes and fi ttings including
any cement, cleaners, or primers must be certifi ed as a
system to ULC S636. However this requirement does not
apply to the fi nish fl anges or piping internal to the furnace.

Vent Pipe Length & Diameter

In order for the furnace to operate properly, the combustion
air and vent piping must not be excessively restrictive.

• The venting system should be designed to have the
minimum number of elbows or turns.

• All horizontal runs must slope upwards from the furnace
at 1/4 inch minimum per running foot of vent.

• Transition to the fi nal vent diameter should be done as
close to the furnace outlet as practical.

• Always use the same size or a larger pipe for combustion
air that is used for the exhaust vent.

Vent Pipe Material

Vent and combustion air pipe and fi ttings must be one of
the following materials in the list and must conform to the
indicated ANSI/ASTM standards. Cement must conform
to ASTM Standard D2564 for PVC and Standard D2235
for ABS. PVC primer must meet standard ASTM F656.
When joining PVC piping to ABS, use PVC solvent cement.
(See procedure specifi ed in ASTM Standard D3138)

Materials Standards

Schedule 40PVC .............................. D1785

PVC-DWV ..........................................D2665

SDR-21 & SDR-26 .............................D2241

Table 2 indicates the maximum allowable pipe length for
a furnace of known input rate, when installed with piping
of selected diameter and number of elbows. To use the
table, the furnace input rate, the centerline length and the
number of elbows on each pipe must be known.

When estimating the length of vent runs, consideration
must be made to the effect of elbows and other fi ttings.
This is conveniently handled using the idea of “equivalent
length”. This means the fi ttings are assigned a linear
length that accounts for the pressure drop they will cause.
For example: a 2” diameter, long radius elbow is worth
the equivalent of 2.5 feet of linear run. A 90 degree tee
is worth 7 ft.

ABS-DWV ..........................................D2661

Schedule 40 ABS ...............................F628

Foam/Cellular Core PVC ....................F891

FURNACE

MODELS

(BTU)

60,000

80,000

100,000

120,000

1. Subtract 2.5 ft. for each additional 2 inch long radius elbow, 5 ft. for each additional 2 inch short radius elbow, 3.5 ft. for each additional 3
inch long radius elbow, and 7 ft. for each additional 3 inch short radius elbow. Subtract 5 ft for each 2” tee and 8 ft for each 3” tee. Two 45
degree elbows are equivalent to one 90 degree elbow.

FURNACE

INSTALLATION

Upfl ow 90 90 90 90

Horizontal 50 90 50 90

Downfl ow 30 90 30 90

Upfl ow 90 90 90 90

Horizontal 30 90 30 90

Downfl ow 30 90 30 90

Upfl ow 60 90 60 90

Horizontal 30 90 30 90

Downfl ow 30 90 25 90

Upfl ow N/A 90 N/A 90

Horizontal N/A 90 N/A 90

Downfl ow N/A 90 N/A 90

SINGLE VENT PIPE LENGTH (FT.)

with 1 long radius elbow**

OUTLET

2” Diameter

The equivalent lengths of tees and various elbows are
listed in Table 2. Measure the linear length of the vent run

DUAL VENT PIPE LENGTH (ft.)

with 1 long radius elbow on each pipe**

OUTLET

3” Diameter

*NOTES:

INLET / OUTLET

2” Diameter

INLET / OUTLET

3” Diameter

2. This table applies for elevations from sea level to 2,000 ft. For higher elevations, decrease pipe lengths by 8% per 1,000 ft of altitude.

Table 2. Vent Pipe Lengths

11

and then add in the equivalent length of each fi tting. The

18” Min.

36” Max.

total length, including the equivalent fi tting lengths, must
be less than the maximum length specifi ed in Table 2.

Condensing furnace combustion products have very little
buoyancy, so Table 2 is to be used without consideration
of any vertical rise in the piping.

Vent Pipe Installation

CAUTION:

Combustion air must not be drawn from a
corrosive atmosphere.

This furnace has been certifi ed 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.

• 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. (See
list of substances on page 5).

• Route piping as direct as possible between the furnace
and the outdoors. Longer vent runs require larger
diameters. Vent piping must be sloped upwards 1/4”
per foot in the direction from the furnace to the terminal.
This is to ensure that any condensate fl ows back to the
condensate disposal system.

• If a Direct Vent (2-pipe) system is used, the combustion
air intake and the vent exhaust must be located in the
same atmospheric pressure zone. This means both
pipes must exit the building through the same portion
of exterior wall or roof as shown in Figures 6 - 9 (pages
12 - 13) and Figure 37 (page 46).

• Piping must be mechanically supported so that its weight
does not bear on the furnace. Pipe supports must be
installed a minimum of every 5 feet along the vent run to
ensure no displacement after installation. Supports may
be at shorter intervals if necessary to ensure that there
are no sagging sections that can trap condensate. It is
recommended to install couplings along the vent pipe,
on either side of the exterior wall (Figure 37). These
couplings may be required by local code.

• If breakable connections are required in the combustion
air inlet pipe (if present) and exhaust vent piping, then
straight neoprene couplings for 2” or 3” piping with
hose clamps can be used. These couplings can be
ordered through your local furnace distributor. To install
a coupling:

1. 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.

2. Slide the other end of the rubber coupling onto the

other pipe from the vent.

3. Secure the coupling with the second hose clamp,

ensuring that the connection is tight and leak free.

Outdoor Terminations - Horizontal Venting

Vent and combustion air intake terminations shall be
installed as depicted in Figures 6 & 7 (page 13) and in
accordance with these instructions:

• Vent termination clearances must be consistent with the
NFGC, ANSI 2223.1/NFPA 54 and/or the CSA B149.1,
Natural Gas and Propane Installation Code. Table 17
(page 45) lists the necessary distances from the vent
termination to windows and building air intakes.

• All minimum clearances must be maintained to protect
building materials from degradation by fl ue gases as
shown in Figure 7.

• Vent and combustion air intake terminations must
be located to ensure proper furnace operation and
conformance to applicable codes. A vent terminal
must be located at least 3 feet above any forced air
inlet located within 10 feet. This does not apply to the
combustion air inlet of a direct vent (two pipe) appliance.
In Canada, CSA B149.1, takes precedence over these
instructions. See Table 17 (page 45).

• For optimal performance, vent the furnace through a wall
that experiences the least exposure to winter winds.

• The vent termination shall be located at least 3 ft.
horizontally from any electric meter, gas meter, regulator
and any relief equipment. These distances apply ONLY
to U.S. installations. In Canada, CSA B149.1, takes
precedence over these instructions.

• 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.

• If venting horizontally, a side wall vent kit is available
according to the pipe diameter size of the installation.
For 2 inch pipe use side wall vent kit #904617, and
for 3 inch pipe use kit #904347. Please follow the

instructions provided with the kit.

18” Min.

36” Max.

Exhaust vent

option C

Mounting kit faceplate

secured to wall with screws

(both pipes)

Exhaust vent

option B

Combustion

air inlet

12’ min. to maximum

expected snow level

(both pipes)

Figure 6. Inlet and Exhaust Pipe Clearances

90° Elbow

(all positions)

Exhaust vent

option A

8” Min.

36” Max.

12

• Concentric vent termination kits are available for use
with these furnaces. For 2 Inch pipe use kit #904177
and for 3 inch pipe use kit # 904176. Please follow the

instructions provided with the kit.

• When the vent pipe must exit an exterior wall close to
the grade or expected snow level where it is not possible
to obtain clearances shown in Figure 6, a riser may be
provided as shown in Figure 8. Insulation is required
to prevent freezing of this section of pipe. See Table 3
for vent freezing protection.

Outdoor Terminations - Vertical Venting

Termination spacing requirements from the roof and from
each other are shown in Figure 9. The roof penetration
must be properly fl ashed and waterproofed with a plumbing
roof boot or equivalent fl ashing. Vent and combustion air
piping may be installed in an existing chimney which is
not in use provided that:

• Both the exhaust vent and air intake run the length of
the chimney.

Direct vent
terminal

50,000 Btuh

or less

Mechanical

9 in.

Note 2

Mechanical draft
vent terminal

NOTES:

1. All dimensions shown are
minimum requirements.

2. Exterior vent terminations must
be located at least 12” above the
maximum expected snow level.

4 ft

Note 2

Figure 7. Vent Locations

19" Max.

(See Note)

Support

Outside

Wall

4 ft

draft vent

terminal

12 in.

Note 2

12" Above

Maximum

Expected

Snow Level

1/2"
Armaflex
Insulation or
Equivalent
(if required)

Mechanical

draft vent

12 in.

than 50,000 Btuh

3 ft.

Forced air inlet

Direct vent

terminal - more

terminal

Less

10 ft.

than

• The top of the chimney is sealed and weatherproofed.

• The termination clearances shown in Figure 9 are
maintained.

• No other gas fi red or fuel-burning equipment is vented
through the chimney.

Vent Freezing Protection

CAUTION:

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, Armafl ex-type insulation or
equivalent. Insulating pipe is important to avoid
condensate icing.

• Table 3 lists the maximum length of fl ue pipe that can
travel through an unconditioned space or an exterior
space. The total vent length must not exceed the lengths
noted in Table 2 (page 11). For Canadian installations,
please refer to the Canadian Installation Code (CAN/
CGA-B149.1 or 2) and/or local codes.

• For extremely cold climates or for conditions of short
furnace cycles (i.e. set back thermostat conditions)
the last 18 inches of vent pipe can be reduced. It is
acceptable to reduce from 3” to 2-1/2”, 3” to 2”, or 2”
to 1-1/2” if the total vent length is at least 15 feet in
length and the vent length is within the parameters
specifi ed in Table 2 (page 11). The restriction should
be counted as 3 equivalent feet. Smaller vent pipes are

Winter Design

Temperature

20 45 70

020 70

-20 10 60

*NOTE: Insulation thickness greater than 3/8 inch, based on an

R value of 3.5 (ft x F x hr) / (BTU x in.)

Table 3. Vent Protection

Elbows on the combustion air

inlet must be positioned pointing

away from the exhaust vent.

Maximum Flue Pipe Length (FEET)

in Unconditioned & Exterior Spaces

Without Insulation With Insulation*

Plumbing Vent Roof Boot

(Both Pipes)

12” Above Maximum

Expected Snow Level

(Both pipes)

Combustion Air

Exhaust Vent

NOTE: Vent Configuration to Provide
12" Minimum height above Snow Level.

Figure 8. Alternate Horizontal Vent Installation

8" Min.
36" Max.

Figure 9. Vertical Vent Termination

13

less susceptible to freezing, but must not be excessively
restrictive. The length of the 2 inch pipe must not be
longer than 18 inches.

• If furnace is installed horizontally, make sure the
drainage port on the in-line drain assembly is pointed
downward to ensure proper drainage of condensate.
See Figure 39 on page 48.

• To prevent debris or creatures from entering the
combustion system, a protective screen may be
installed over the combustion air intake opening. The
screens hole size must be large enough to prevent air
restriction.

Existing Installations

When an existing furnace is removed from a vent system
serving other appliances, the existing vent system may
not be sized properly to vent the remaining appliances
(For example: water heater). An improperly sized venting
system can result in the formation of condensate, leakage,
or spillage. The existing vent system should be checked
to make sure it is in compliance with NFGC and must
be brought into compliance before installing the furnace.

NOTE: If replacing an existing furnace, it is possible you
will encounter an existing plastic venting system that is
subject to a Consumer Product Safety Commission recall.
The pipes involved in the recall are High Temperature
Plastic Vent (HTPV). If your venting system contains
these pipes DO NOT reuse this venting system! This
recall does not apply to other plastic vent pipes, such
as white PVC or CPVC. Check for details on the CPSC
website or call their toll-free number [phone].

CIRCULATING AIR REQUIREMENTS

WARNING:

Do not allow combustion products to enter the
circulating air supply. Failure to prevent the
circulation of combustion products 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 confi ned spaces, all return
ductwork must be adequately sealed. When
return air is provided through the bottom of the
furnace, the joint between the furnace and the
return air plenum must be air tight.

The surface that the furnace is mounted on must
provide sound physical support of the furnace
with no gaps, cracks or sagging between the
furnace and the fl oor or platform.

Return air and circulating air ductwork must
not be connected to any other heat producing
device such as a fi replace insert, stove, etc. This
may result in fi re, explosion, carbon monoxide
poisoning, personal injury, or property damage.

Condensate Disposal

The method for disposing of condensate varies according
to local codes. Consult your local code or authority having
jurisdiction.

Each of the condensate drain lines must be J-trapped
using fi eld supplied parts. After the condensate lines are
J-trapped, they may be combined together into a single
run to the drain. The drain lines must be routed downward
to ensure proper drainage from furnace.

Neutralizer kit P/N 902377 is available for use with this
furnace. Please follow the instructions provided with

the kit.

Plenums & Air Ducts

• 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).

• Tables 8 - 10 (pages 34 - 36) contain the maximum
airfl ow and temperature rise data for fi xed and variable
speed motors. If the maximum airfl ow is 1,600 CFM or
more, it is recommended that two openings be used for
return air on upfl ow furnaces. Downfl ow furnaces can
only use one return opening.

• It is recommended that the outlet duct contain a
removable access panel. The opening should be
accessible when the furnace is installed in service and
shall be of a size that smoke or refl ected light may be
observed inside the casing to indicate the presence of
leaks in the heat exchanger. The cover for the opening
shall be attached in such a way as to prevent leaks.

• If outside air is used as return air to the furnace for
ventilation or to improve indoor air quality, the system
must be designed so that the return air is not less than
60° F (15° C) during 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

14

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 airfl ow over the indoor coil,
the coil must be installed downstream (on the outlet
side) of the furnace 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.

• It is good practice to seal all connections and joints
with industrial grade sealing tape or liquid sealant.
Requirements for sealing ductwork vary from region
to region. Consult with local codes for requirements
specifi c to your area.

Supply Air Connections

The supply air must be delivered to the heated space by
duct(s) secured to the furnace casing, running full size
and without interruption.

Upfl ow and Horizontal Furnaces

To attach the supply air duct to the furnace, bend the
furnace fl anges (Figure 29, page 33) upward 90° with a
pair of wide duct pliers. Position the duct on top of the
furnace and secure together with sheet metal screws. The
screws must penetrate the sheet metal casing and furnace
fl ange. Tape or seal all seams if required by local code.

Downfl ow Furnaces

To attach the supply air duct to the downfl ow furnace,
position the furnace over the duct and secure together
with sheet metal screws. The screws must penetrate the
duct and furnace cabinet.

Return Air Connections

In applications where the supply ducts carry heated air
to areas outside the space where the furnace is installed,
the return air must be delivered to the furnace by duct(s)
secured to the furnace casing, running full size and without
interruption.

Upfl ow Horizontal Furnaces

For upfl ow installations, the return air ductwork may
be connected to the left side, right side, or bottom. The
bottom panel (Figure 29) must be installed for left or right
return air. NOTE: Do not use the back of the furnace

for return air.

the opening in the side and secure together with sheet
metal screws. The screws must penetrate the duct and
furnace cabinet.

WARNING:

The solid base of the furnace must be in
position when the furnace is installed with side
return air ducts. Removal of all or part of the
base could cause circulation of combustible
products into the living space and create
potentially hazardous conditions, including
carbon monoxide poisoning that could result
in personal injury or death.

Bottom Return Installations

The bottom panel (Figure 29) must be removed from the
bottom of the furnace for bottom return air. If bottom panel
is installed, go to page 15 for removal instructions. Position
the furnace over the return air duct and secure together
with sheet metal screws. The screws must penetrate the
duct and furnace cabinet.

Downfl ow Furnaces

To attach the return air duct to the furnace, bend the
furnace fl anges (Figure 29, page 33) upward 90° with a
pair of wide duct pliers. Position the duct on top of the
furnace and secure together with sheet metal screws. The
screws must penetrate the sheet metal cabinet and furnace
fl ange. Tape or seal all seams if required by local code.

Acoustical Treatments

Damping ducts, fl exible vibration isolators, or pleated
media-style fi lters on the return air inlet of the furnace
may be used to reduce the transmission of equipment
noise eminating from the furnace. These treatments can
produce a quieter installation, particularly in the heated
space. However, they can increase the pressure drop in
the duct system. Care must be taken to maintain the proper
maximum pressure rise across the furnace, temperature
rise and fl ow rate. This may mean increasing the duct size
and/or reducing the blower speed. These treatments must
be constructed and installed in accordance with NFPA and
SMACNA construction standards. Consult with local codes
for special requirements. For best sound performance, be
sure to install all the needed gaskets and grommets around
penetrations into the furnace, such as for electrical wiring

Side Return Installations

To attach the return air duct to the left or right side of the
furnace, punch out the four knockouts (Figure 29) from the
preferred side of the furnace. Using sharp metal cutters,
cut an opening between all four knockouts to expose
the blower assembly. Position the return air duct over

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FURNACE INSTALLATION

*TC series gas furnaces offer a wide range of installation
options, including installation in the upfl ow or horizontal
positions with either right, left, or upfl ow return air. The
*TL series gas furnaces may only be installed as a down
fl ow application.

General Requirements

• The furnace must be leveled at installation and attached
to a properly installed duct system. See Table 1 (page 6)
for the required clearances needed to move the furnace
to its installation point (hallways, doorways, stairs, etc).

• The furnace must be installed so that all electrical
components are protected from water.

• The furnace must be installed upstream from a
refrigeration system. (If applicable)

• The cabinet plug must always be used to close the hole
in the side of the furnace when rotating the inducer.

• The furnace requires special venting materials and
installation procedures. See pages 10 -14 for venting
guidelines and specifi cations.

Upfl ow Installation

letter of the furnace. For ‘B’, ‘C’, and ‘D’ size cabinets use
Kit #904911. Please follow the instructions provided

with the kit.

A downfl ow sub-base kit is not necessary if the furnace
is installed on a factory or site-built cased air conditioning
coil. However, the plenum attached to the coil casing
must be installed so that its surfaces are at least 1” from
combustible construction.

Installation on a concrete slab

1. Create an opening in the fl oor according to the
dimensions in Figure 10.

2. Position the plenum and the furnace as shown in
Figure 11.

Opening in concrete floor

“A”

“B”

WARNING:

The furnace must not be installed directly on
carpeting, tile, or any combustible material other
than wood fl ooring.

Side Return Air Inlet

*TC series gas furnaces are shipped with the bottom panel
installed (Figure 29). If the upfl ow furnace is installed using
both side return air inlets, the bottom panel must not be
removed. The bottom panel must be in place if the bottom
of the furnace is not being used as a return.

Bottom Return Air Inlet

If the *TC series gas furnace is installed using the bottom
as a return air inlet and 1 side return, the bottom panel
(Figure 29) must be removed.

Downfl ow Installation

WARNING:

The furnace must not be installed directly on
carpeting, tile, or any combustible material other
than wood fl ooring.

WARNING:

Failure to install the downfl ow sub-base kit may
result in fi re, property damage or personal injury.

To install the furnace on combustible fl ooring, a special
sub-base is required. Downfl ow sub-base kits are factory
supplied accessories and are listed according to the cabinet

Cabinet Size Dim. “A” Dim. “B”

B 16 5/8 19 1/4
C 20 1/8 19 1/4
D 23 5/8 19 1/4

NOTE: Dimensions shown in Inches.

Figure 10. Cutout Dimensions

Concrete

Floor

Figure 11. Furnace on a Concrete Slab

Furnace

Sheet

Metal

Plenum

Horizontal Installation

WARNING:

The furnace must not be installed directly on
carpeting, tile, or any combustible material other
than wood fl ooring.

The *TC series gas furnace can be installed horizontally
(Figure 12, page 17) in an attic, basement, crawl space
or alcove. It can also be suspended from a ceiling in a
basement or utility room in either a right to left airfl ow or
left to right airfl ow as shown in Figure 13.

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