Daikin DM80VC Operating instructions

Daikin 80%
Communicating
Gas Furnaces
DM80VC, DD80VC
RSD6621001r6
July2016
This manual is to be used by qualified, professionally trained HVAC technicians only. Daikin does not
assume any responsibility for property damage or personal injury due to improper service procedures
or services performed by an unqualified person.
Service Instructions
TM
Copyright © 2013 - 2014, 2016

2
IMPORTANTINFORMATION
Prideandworkmanshipgointoeveryproducttoprovideourcustomerswithqualityproducts. Itispossible,however,
thatduringitslifetimeaproductmayrequireservice. Productsshouldbeservicedonlybyaqualifiedservicetechnician
whoisfamiliarwiththesafetyproceduresrequiredintherepairandwhoisequippedwiththeproper tools,parts,testing
instrumentsandtheappropriateservicemanual. REVIEW ALL SERVICE INFORMATION IN THE APPROPRIATE
SERVICE MANUAL BEFORE BEGINNING REPAIRS.
IMPORTANT NOTICES FOR CONSUMERS AND SERVICERS
RECOGNIZE SAFETY SYMBOLS, WORDS AND LABELS
WARNING
TO PREVENT THE RISK OF PROPERTY DAMAGE, PERSONAL INJURY, OR DEATH,
DO NOT STORE COMBUSTIBLE MATERIALS OR USE GASOLINE OR OTHER
FLAMMABLE LIQUIDS OR VAPORS IN THE VICINITY OF THIS APPLIANCE.
TABLE OF CONTENTS
WARNING
HIGH VOLTAGE
DISCONNECT ALL POWER BEFORE SERVICING OR
INSTALLING THIS UNIT. MULTIPLE POWER SOURCES MAY
BE PRESENT. FAILURE TO DO SO MAY CAUSE PROPERTY
DAMAGE, PERSONAL INJURY OR DEATH.
IMPORTANTINFORMATION ......................... 3 - 4
PRODUCTIDENTIFICATION ........................ 5 - 9
ACCESSORIES.................................................10
OPERATINGINSTRUCTIONS ...................11 - 13
PRODUCT DESIGN ...................................14 - 37
SYSTEMOPERATION ...............................38 - 42
TROUBLESHOOTING................................43 - 48
SYSTEM OPERATION COMFORTNET™ ...49 - 54
POLARIZATIONANDPHASING.........................55
MAINTENANCE ...........................................56 - 58
SERVICING .................................................59 - 77
SERVICING TABLE OF CONTENTS ................59
ACCESSORIESWIRINGDIAGRAMS ........78 - 79
WIRINGDIAGRAMS....................................80-82
O NLY PERSONNEL THAT HAVE BEEN TRAINED TO INSTALL , ADJUST , SERVICE OR
REPAIR ( HEREINAFTER , “ SERVICE ”) THE EQUIPMENT SPECIFIED IN THIS
MANUAL SHOULD SERVICE THE EQUIPMENT . T HE MANUFACTURER WILL NOT
BE RESPONSIBLE FOR ANY INJURY OR PROPERTY DAMAGE ARISING FROM
IMPROPER SERVICE OR SERVICE PROCEDURES . I F YOU SERVICE THIS UNIT , YOU
ASSUME RESPONSIBILITY FOR ANY INJURY OR PROPERTY DAMAGE WHICH MAY
RESULT . I N ADDITION , IN JURISDICTIONS THAT REQUIRE ONE OR MORE
LICENSES TO SERVICE THE EQUIPMENT SPECIFIED IN THIS MANUAL , ONLY
LICENSED PERSONNEL SHOULD SERVICE THE EQUIPMENT . I MPROPER
INSTALLATION , ADJUSTMENT , SERVICING OR REPAIR OF THE EQUIPMENT
SPECIFIED IN THIS MANUAL , OR ATTEMPTING TO INSTALL , ADJUST , SERVICE OR
REPAIR THE EQUIPMENT SPECIFIED IN THIS MANUAL WITHOUT PROPER
TRAINING MAY RESULT IN PRODUCT DAMAGE , PROPERTY DAMAGE , PERSONAL
INJURY OR DEATH .

3
IMPORTANT INFORMATION
To locate an authorized servicer, please consult your telephone book or the dealer from whom you purchased this
product. For further assistance, please contact:
CONSUMER INFORMATION LINE- DAIKIN BRAND PRODUCTS
TOLL FREE
1-877-254-4729 (U.S.only)
emailusat:[email protected]
fax us at: [phone]
(Not a technical assistance line for dealers.)
Outside the U.S., call 1-713-861-2500
(Nota technical assistanceline for dealers.)
Your telephone company will bill you for the call.

4
IMPORTANT INFORMATION
B10259-216
CO can cause serious illness including permanent brain
damage or death.
Advertencia especial para la instalación de calentadores ó manejadoras
de aire en áreas cerradas como estacionamientos ó cuartos de servicio.
B10259-216
El monóxido de carbono puede causar enfermedades severas
como daño cerebral permanente ó muerte.
Las emisiones de monóxido de carbono pueden circular a través
del aparato cuando se opera en cualquier modo.
B10259-216
RISQUE D'EMPOISONNEMENT AUMONOXYDE DE CARBONE
Le monoxyde de carbone peut causer des maladies graves telles que
des dommages permanents au cerveau et meme la mort.
Cette ventilation est nécessaire pour éviter le danger d'intoxication
au CO pouvant survenir si un appareil produisant du monoxyde
de carbone continue de fonctionner au sein de la zone confinée.

PRODUCT IDENTIFICATION
5
Themodelandmanufacturingnumberareusedforpositiveidentificationofcomponentpartsusedinmanufacturing.
Pleaseusethesenumberswhenrequestingserviceorpartsinformation.
DM80VC0603BNAA
1 2 3 4 5 6 7 8 9 10 11 12 13 14
Brand MinorRevision D -Daikin A- InitialRelease
B- 1stRevision
Configuration M - Upflow/Horizontal MajorRevision C - Downflow/Horizontal A- InitialRelease K-DedicatedUpflow B-1stRevision D- DedicatedDownflow Nox AFUE N- Natural Gas 97-97%AFUE X-LowNOx 80-80%AFUE CabinetWidth GasValve A-14" M - Modulating B- 17.5" V- 2Stage C-21" H - Convertible 2 Stage D- 24.5" S-SingleStage MaximumCFM Motor 3-1200CFM C- VariableSpeed/ComfortNet 4-1600CFM E-High Efficiency 5-2000CFM S-SingleSpeed MBTU/h 40-40,000 60-60,000 80-80,000 100- 100,000 120- 120,000

PRODUCT IDENTIFICATION
6
MODEL # MFG. # 80 % GAS FURNACES
MODEL # MFG. # 80 % GAS FURNACES
DD80VC DD80VC0603B* DD80VC0805C*
DD80VC1005C*
Daikin Brand 80% variable Speed Comu nicating gas Furnace - 2 stage heat gasfurnace,33 3/8"
tall,Dedicated Downflow, 2-Stage induced Draft, Two-tone graypainted cabinetand frontpanels. Left
or right gas pipe entry. Four wire serially communicaing variable speed motor, 120 volt silicon nitride
igniter. The furnace also features an integrated electronic ignition control and stainless steel tubular
heatexchan
g
er.NOx certified. Chassis sizes arenow 17.5"and 21" wide.
DM80VC DM80VC0604B* DM80VC0805C*
DM80VC1005C*
Daikin Brand 80% variable Speed Comu nicating gas Furnace - 2 stage heat gasfurnace,33 3/8"
tall,Upflow/ horizontal, 2-Stage induced Draft, Two-tone gray painted cabinet and front panels. Left or
rightgas pipe entry.Four wire serially communicaingvariable speed motor, 120voltsilicon nitride
igniter. The furnace also features an integrated electronic ignition control and stainless steel tubular
heatexchan
g
er.NOx certified. Chassis sizes arenow 17.5"and 21" wide.

PRODUCT IDENTIFICATION
7
MODEL # MFG # DESCRIPTION
AFE18-60A N/A
Fossil Fuel Kit - The AFE18-60Acontrol is designed foruse where the indoor coil is located
above/downstream of a gas or fossil fuel furnace when used with a heatpump. It will operate with
single and two stage heatpumps and single and two stage furnaces.The AFE18-60Acontrol will
turn the heat pump unit off when the furnace is turned on. As antis-short cycle feature initiates a 3
minute timed offdelaywhen the compressor goes off.
CTK01AA CTK01AA
Communicating Thermostat Kit - Digitallycommunicating touchscreen thermostat,a necessary
partofanycommunicating system.Designed for use with compatible Daikin® Air Handlers or
Furnaces and outdoor splitAC or HeatPump units.This thermostatsupports up to three stages of
heat, two stages of cooling, dual fuel applications,dehumidification, filter maintenance reminders,
outdoor temperature displayand advanced menus including diagnostics. The CTK01AAkitincludes
a communicating touchscreen thermostat and sub base,230V-24V40va transformer,terminal
blocks (2),wire jumpers,mounting screws,installation manual and homeowner guide.
CTK01BA CTK01BA
Communicating Thermostat Kit - Digitallycommunicating touchscreen thermostat,a necessary
partof anycommunicating system. Designed for use with compatible Daikin® Brand Air Handlers or
Furnaces and outdoor splitAC or HeatPump units.This thermostatsupports up to three stages of
heat, two stages of cooling, dual fuel applications,dehumidification, filter maintenance reminders,
outdoor temperature displayand advanced menus including diagnostics. The CTK01BAkitincludes
a communicating touchscreen thermostat and sub base,terminal blocks (2), installation manual
and homeowner guide.
CTK02** CTK02**
Communicating Thermostat Kit - Digitallycommunicating thermostat,a necessarypartof any
communicating system.Designed for use with compatible Daikin® Brand Air Handlers or Furnaces
and outdoor split AC or HeatPump units.The CTK02** thermostatfeatures a full color high
definition display,advanced programming options including humidification control & heat and cool
maximum temperature setting,a USB plug allowing dealers the abilityto insertpre-programmed
operating parameters and dealer information byuse of an online data entrysystem.
CTK03AA CTK03AA
Communicating Thermostat Kit - Digitallycommunicating touchscreen thermostatfrom Honeywell.
Designed for use with compatible Daikin® Brand Air Handlers or Furnaces and outdoor split AC or
Heat Pump units. The CTK03AAthermostatfeatures full color high definition displayand can be
used with RedLINK wireless accessories.
CTK03AB CTK03AB
Communicating Thermostat Kit - Digitallycommunicating touchscreen thermostatfrom Honeywell.
Designed foruse with compatible Daikin Brand AirHandlers orFurnaces and outdoorsplitAC or
Heat Pump units. The CTK04AAthermostatfeatures full color high definition displayand can be
used with RedLINK wireless accessories and added capabilityto control the HUMIN - HUMOUT
relayon the PCBKF103, PCBKF104, and PCBKF105 control board.
CTK04AA CTK04AA
Communicating Thermostat Kit - Digitallycommunicating touchscreen thermostatfrom Honeywell.
Designed foruse with compatible Daikin Brand AirHandlers orFurnaces and outdoorsplitAC or
Heat Pump units. The CTK04AAthermostatfeatures full color high definition displayand can be
used with RedLINK wireless accessories and added capabilityto control the HUMIN - HUMOUT
relayon the PCBKF103, PCBKF104, and PCBKF105 control board. Split system inverter capable.

PRODUCT IDENTIFICATION
8
MODEL # MFG # DESCRIPTION
DEH UM 1 P1227801F
Dehumidistat. For use with Daikin Brand.Wall mounted, 24 volt humidity control toreduce the
airflow in the air conditioning mode to lower the humidity in an occupied home. This control
features a moisture-sensitive nylon element and also provides positive ON-OFF settings for
manual operation. The control is a normally closed switch that opens on humidity rise causing
the blower to switch to a lower speed to control the humidity within the structure.
EFR01 P1221001
P1221002F
External Filter Rack Kit. For use with Daikin upflow gas furnace models. This kit is intended to
provide a location, external to the furnace casing, for installation of a permanent filter. The rack
is mounted over the indoor air blower compartment area of either side panel, and provide filter
retention as well as a location for attaching return air ductwork.
HA02 P1129112F
High Altitude Kit. The kit is designed to convert Daikin Brand 80% gas furnace models at
higher altitudes. This kit is required when installing these furnaces above their maximum rated
altitude. This kit contains # 43-49, 55-58 gas orifices. The orifices in the kit have been selected
as a result of testing with the American Gas Association. They will provide appropriate derating
at the altitude listed in the High Altitude Charts as shown in the installation instructions of the kit.

PRODUCT IDENTIFICATION
9
MODEL # MFG # DESCRIPTION
LPLP03 N/ A LP Gas Low Pressure Kit. For use with Daikin furnaces converted to LP gas. This kit includes
harness adaptors to work with White-Rodgers single & two stage gas valves,Honeywell single
and two-sta
g
e
g
as valves
,
as well as modulatin
g
g
as valves.
LPM-06 N/ A
LP Conversion Kit. For use with Daikin Brand 2-stage Hydrid models or 2-stage variable speed
models using a White-Rodgers 36G54 2-stage gas valve kit or a Honeywell VR9205 2-stage gas
valve kit. Includes regulator springs, #55orifices, instructions and a label to show the furnace
has been converted to L.P.
SBT17
SBT21 N/ A Dow nflow Subbase. For use with Daikin Brand 80% dedicated downflowfurnace models.
These kits are available for the following furnace widths: 17.5" wide (SBT17), and21" wide
(
SBT21
)
.

ACCESSORIES
10
EXTERNAL
FILTER RACK KIT (EFR01)
BLOWER DECK
SCREWS
SLOTS IN FILTER
CLEAR SCREWS
ON UNIT
FRONT
OF UNIT
RETURN AIR
CUTOUT AREA LOWER EDGE
SCREW
FILTER RACK ASSEMBLY
(FACE FILTER OPENING
TOWARDS FRONT
OF UNIT)
UNIT SIDE
PANEL
BASE
OF UNIT
80% UpflowModelFurnaces
EFR01 EXTERNAL FILTER RACK KIT
Used on Models
MODEL
NUMBER
AFE180-60A
EFR01 SBT17 SBT21
CTK0*
LPM06
LPLP03
HA-02
DEHUM1
Description
Dual Fuel Board
EFR External Filter
Rack
Downflow Subbase
17.5"
Downflow Subbase
21"
Communicating
Thermostat
Propane Gas
Conversion Kit
LP Low Pressure Shut
Off Kit
High Altitude Natural
Gas Orifices
Dehumidistat
DM80VC0604B** ●● ●(1) ●(2) ●
DM80VC0805C** ●● ●(1) ●(2) ●
DM80VC1005C** ●● ●(1) ●(2) ●
DD80VC0603B** ●●●(1) ●(2) ●
DD80VC0805C** ●●●(1) ●(2) ●
DD80VC1005C** ●●●(1) ●(2) ●
Not Approved for this model
●
Approved for this model
(1) W/R & HW 2 stg valve
(2) 7,000 - 11,000 ft altitude
Daikin DM80VC DD80VC Model Furnace
Accessories

11
gas. If you then smell gas, STOP!above on this label. Follow "B" in the safety information
above on this label. If you don't smell
8. Move the gas control switch or knob
9. Replace control access panel.
gas, go to the next step.
technician or gas supplier.
11. Set the thermostat to the desired
12. If the appliance will not operate,
To Appliance" and call your service
5. Replace control access panel.
to "OFF". Do not force.
follow the instructions "To Turn Off Gas
4. Move the gas control switch or knob
Do not store or use gasoline or
other flammable vapors and liquids in the vicinity of this
TO TURN OFF GAS TO APPLIANCE
10. Turn on all electric power to the
FOR YOUR SAFETY
or any other appliance.
2. Turn off all electric power to the
appliance if service is to be performed.
1. Set the thermostat to its lowest setting.
3. Remove control access panel.
automatic ignition system which
4. This appliance is equipped with an
3. Turn off all electric power to the
2. Set the thermostat to lowest setting.
5. Remove control access panel.
try to light the burners by hand.
6. Move the gas control switch or knob
automatically lights the burners. Do not
to "OFF".
appliance.
setting.
appliance.
to "ON".
0140F00001P
SWITCH SHOWN
IN "ON" POSITION
GAS CONTROL
Force or attempted repair may result in
FOR YOUR SAFETY READ BEFORE OPERATING
call the fire department.
damage, personal injury or loss of life.
If you cannot reach your gas supplier,
a fire or explosion may result causing property
If you do not follow these instructions exactly,
which has been under water.
C. Use only your hand to move the gas
control switch or knob. Never use
tools. If the gas control switch or knob
D. Do not use this appliance if any part
has been under water. Immediately call
a qualified service technician to inspect
the appliance and to replace any part of
the control system and any gas control
7. Wait five (5) minutes to clear out any
will not operate, don't try to repair it,
call a qualified service technician.
is heavier than air and will settle on the
Immediately call your supplier
the gas suppliers instructions.
WHAT TO DO IF YOU SMELL GAS
Do not try to light any appliance.
Do not touch any electric switch;
do not use any telephone in your
from a neighbor's phone. Follow
1. STOP! Read the safety information
OPERATING INSTRUCTIONS
floor.
building.
a fire or explosion.
try to light the burners by hand.
smell next to the floor because some gas
the appliance area for gas. Be sure to
B. BEFORE OPERATING smell around
automatically lights the burners. Do not
is equipped with an ignition device which
A. This appliance does not have a pilot. It
reproductive harm.
This product contains
fiberglass insulation.
cancer.
California to cause
contains a chemical
Fiberglass insulation
instructions and local
If notWARNING:
cause cancer, birth
defects or other
in fuel combustion
you to substances
death or serious
which can cause
State of California to
are known to the
illness and which
accordance with the
and maintained in
instructions, this
product could expose
manufacturer's
installed, operated
For outdoor
PGB & PGJ
For indoor installation.
of local codes, follow
codes. In the absence
Code, ANSI Z223.1.
the National Fuel Gas
installation only.
cause injury or
consult a qualified
Refer to the user's
information manual
provided with this
property damage.
This furnace must be
or the gas supplier.
alteration, service or
maintenance can
WARNING: Improper
OPERATING INSTRUCTIONS

12
OPERATING INSTRUCTIONS
CONSIGNES DE SECURITE - LIRE
AVANT D'ALLUMER L'APPAREIL
AVERTISSEMENT: Le non-respect des instructions qui suivent peut
entrainer un risque d'incendie ou d'explosion causant des dommages,
des blessures ou la mort.
A. Cet appareil comporte pas de veilleuse. Il est muni d'un mecanisme qui allume
automatiquement le bruleur. N'allumez paz le bruleur manuellement.
B. Sentir tout autour de l'apparielAVANT D'ALLUMER afin de deceler toute fuite de gaz.
Assurez-vous de sentir tout pres du plancher car certains gaz sont plus lourds que l'air
et se deposeront sur le plancher.
SI VOUS SENTEZ UNE ODEUR DE GAZ:
Ne tentez d'allumer aucun appariel.
Ne touchez pas auxinterrupteurs electriques; n'utiliser aucun telephone
dans l'edifice ou vous vous trouvez.
Appelez immediatement votre fournisseur de gaz en utilisant le telephone
d'un voisin et suivez les instructions du fournisseur.
Appelez les pompiers si vous ne parvenez pas a rejoindre votre fournisseur
de gaz.
C. N'utiliser que votre main pour pousser ou tourner le commande du gaz. N'utilisez
jamais d'outils. Si vous ne parvenez pas a pousser ou a tourner la commande, ne tentez
pas de la reparer; appelez un reparateur qualifie. Forcer la commande ou essayer de la
reparer peut entrainer un risque d'incendie ou d'explosion.
D. N'utilisez pas cet appareil si l'une de ses parties a ete dans l'eau. Si cela se produit,
demandez immediatement a un reparateur qualifie d'inspecter l'appareil et de remplacer
toute piece du systeme de controle et toute commande de gaz ayant ete dans l'eau.
0140F00002P
INSTRUCTIONS DE SERVICE
1. UN INSTANT! Lisez d'abord les consignes
2. Reglez le thermostat a son point le plus bas.
3. Coupez l'alimentation electrique de l'appareil.
4. Cet appareil est muni d'un mecanisme qui
allume automatiquement le bruleur. Ne tentez
pas d'allumer le bruleur manuellement.
5. Retirez lepanneau d'acces de la commande.
6. Mettez la commande de gaz a la position
7. Attendez cinq (5) minutes afin de permettre a
tout gaz present d'etre evacue. Si vous sentez
une odeur de gaz a ce moment, ARRETEZ! et
suivez les consignes de securite donnees au
de gaz, passez a l'etape suivante.
8. Mettez la commande de gaz a la position
en place.
10. Retablissez l'alimenation electrique de l'appareil.
11. Reglez le thermostat a le temperature desiree.
12. Si l'appareil ne fonctionne pas, suivez les
instructions intitulees "Arret du gaz" et appelez un
reparateur qualifie ou votre fournisseur de gaz.
ARRET DU GAZ
1. Reglez le thermostat a son point le plus bas.
2. Coupez l'alimentation electrique de l'appareil si vous devez effectuer un entretien.
3. Retirez le panneau d'acces de la commande.
4. Mettez la commande de gaz a la position ARRET ("OFF").
5. Remettez le panneau d'acces de la commande en place.
de securite ci-dessus.
ARRET ("OFF").
paragraphe B ci-dessus. Si vous ne sentez pas
MARCHE ("ON").
9. Remettez la panneau d'acces de la commande
^^
^
^
^
^
^
^
^
^
^
^
^
Commande de
"MARCHE"
gaz en position

13
DU GAZ
ARRIVEE
INLET
GAS
IN "ON" POS
LEVER
SHOWN
MANUAL
GAS
"ON/MARCHE"
MANUEL,
EN POS
ROBINET
A GAZ
OPERATING INSTRUCTIONS

PRODUCT DESIGN
14
Safety
Pleaseadhereto the followingwarningsand cautions when
installing,adjusting, altering, servicing,or operating thefur-
nace.
TO PREVENT PERSONAL INJURY OR DEATH DUE TO IMPROPER INSTALLATION,
ADJUSTMENT, ALTERATION, SERVICE OR MAINTENANCE, REFER TO THIS
MANUAL. FOR ADDITIONAL ASSISTANCE OR INFORMATION, CONSULT A
QUALIFIED INSTALLER, SERVICE AGENCY OR THE GAS SUPPLIER.
WARNING
WARNING
THIS PRODUCT CONTAINS OR PRODUCES A CHEMICAL OR CHEMICALS WHICH
MAY CAUSE SERIOUS ILLNESS OR DEATH AND WHICH ARE KNOWN TO THE
STATE OF CALIFORNIA TO CAUSE CANCER, BIRTH DEFECTS OR OTHER
REPRODUCTIVE HARM.
WARNING
TO PREVENT POSSIBLE PROPERTY DAMAGE, PERSONAL INJURY OR DEATH
DUE TO ELECTRICAL SHOCK, THE FURNACE MUST BE LOCATED TO PROTECT
THE ELECTRICAL COMPONENTS FROM WATER.
Charge (ESD) Precautions
NOTE: Discharge body’s static electricity before touching
unit.An electrostatic dischargecan adverselyaffect electri-
calcomponents.
Usethefollowingprecautionsduringfurnaceinstallationand
servicingtoprotectthe integrated control modulefromdam-
age. By putting the furnace, the control, and the person at
thesame electrostaticpotential, thesesteps willhelp avoid
exposingthe integratedcontrol module to electrostatic dis-
charge. This procedure is applicable to both installed and
uninstalled(ungrounded)furnaces.
1. Disconnect all power to the furnace. Do not touch the
integrated control module or any wire connected to the
control prior to discharging your body’s electrostatic
chargetoground.
2. Firmly touch a clean, unpainted, metal surface of the
furnace near the control. Any tools held in a person’s
handduringgrounding will bedischarged.
3. Service integrated control module or connecting wiring
following the discharge process in Step 2. Use caution
notto rechargeyour body with static electricity; (i.e., do
notmove or shuffle your feet, do not touch ungrounded
objects,etc.).Ifyoucomein contact with an ungrounded
object,repeat Step2 before touching control or wires.
4. Dischargeanystaticelectricityfrom your body toground
beforeremovinganew control from itscontainer.Follow
Steps 1 through 3 if installing the control on a furnace.
Returnanyoldor new controlstotheircontainers before
touchinganyungrounded object.
Product Application
This product is designed for use as a residential home gas
furnace.It is not designedorcertifiedforuseinmobile home,
trailer,orrecreational vehicleapplications.
This furnace can be used in the following non-industrial
commercial applications: Schools, Office buildings, Churches,
Retail stores, Nursing homes, Hotels/motels, Common or
office areas. In such applications, the furnace must be installed
with the installation instructions.
Daikin 80% furnaces are ETL certified appliances and are
appropriate for use with natural or propane gas. (NOTE: If
usingpropane gas, apropane conversionkit is required).
IMPORTANT NOTE: The 80% furnace cannot be installed
as a direct vent (i.e.., sealed combustion) furnace. The
burner box is present only to help reduce sound trans-
mission from the burners to the occupied space.
Toensureproper installation, operationand servicing, thor-
oughlyread the installation and service manuals for specif-
icspertainingto the installation,servicing and applicationof
this product.
WARNING
POSSIBLE PROPERTY DAMAGE, PERSONAL INJURY OR DEATH DUE TO FIRE,
EXPLOSION, SMOKE, SOOT, CONDENSTAION, ELECTRICAL SHOCK OR CARBON
MONOXIDE MAY RESULT FROM IMPROPER INSTALLATION, REPAIR, OPERATION,
OR MAINTENANCE OF THIS PRODUCT.
WARNING
TO PREVENT PROPERTY DAMAGE, PERSONAL INJURY OR DEATH DUE TO FIRE,
DO NOT INSTALL THIS FURNACE IN A MOBILE HOME, TRAILER, OR RECREATIONAL
VEHICLE.
Toensure properfurnace operation, install, operate, main-
tainand service thefurnace in accordancewith theinstalla-
tion, operation and service instructions, all local building
codes and ordinances. In their absence, follow the latest
edition of the National Fuel Gas Code (NFPA 54/ANSI
Z223.1), and/or CAN/CGA B149 Installation Codes, local
plumbingorwastewatercodes,andotherapplicable codes.
A copy of the National Fuel Gas Code (NFPA 54/ANSI
Z223.1)can be obtainedfrom any ofthe following:
AmericanNational Standards Institute
25 West 43rd Street, 4th Floor
New York, NY 10036
NationalFire ProtectionAssociation
1 Batterymarch Park
Quincy,MA 02169-7471

PRODUCT DESIGN
15
CSAInternational
8501 East Pleasant Valley
Cleveland,OH 44131
A copy of the CAN/CGA B149 Installation Codes can be
obtainedfrom:
CSAInternational
178Rexdale Boulevard
Etobicoke,Ontario, CanadaM9W, 1R3
Therated heating capacityof the furnaceshould begreater
thanor equalto the total heat loss of thearea to be heated.
The total heat loss should be calculated by an approved
methodor in accordancewith “ASHRAE Guide” or “Manual
J-LoadCalculations”publishedbytheAir Conditioning Con-
tractors of America.
Location Requirements and Considerations
WARNING
TO PREVENT POSSIBLE EQUIPMENT DAMAGE, PROPERTY DAMAGE, PERSONAL
INJURY OR DEATH, THE FOLLOWING BULLET POINTS MUST BE OBSERVED
WHEN INSTALLING THE UNIT.
Follow the instructions listed below when selecting a fur-
nace location. Refer also to the guidelines provided in the
CombustionandVentilationAirRequirementssectioninthis
manual or the installation instructions for details.
• Centrally locate the furnace with respect to the pro-
posed or existing air distribution system.
• Ensure the temperature of the return air entering the
furnaceisbetween55°F and 100°F whenthefurnace
is heating.
• If the furnace is installed in an application where the
typical operating sound level of a furnace is deemed
objectionable,anoptionalsoundreduction kit is avail-
able. Consult your local distributor for more details.
• Provide provisions for venting combustion products
outdoors through a proper venting system. Special
considerationshouldbegiventovent/fluepipe routing
andcombustion air intake pipe when applicable.
80% Furnaces: All installations must be vented in
accordance with National Fuel Gas Code, NFPA 54/
ANSIZ223.1-latesetedition. In Canada thefurnaces
mustbeventedin accordance with theNationalStan-
dardofCanada, CAN/CGA B149.
• Ensureupfloworhorizontal furnaces arenotinstalled
directlyon carpeting, or any othercombustible mate-
rial.The onlycombustible material allowed is wood.
• A special accessory subbase must be used for up-
right counterflow unit installations over any combus-
tible material (including wood). Refer to subbase in-
structions for installation details. (NOTE: A subbase
willnotberequired if anairconditioningcoil is located
beneath the furnace between the supply air opening
andthe combustible floor.
• Exposure to contaminated combustion air will result
in safety and performance-related problems. Do not
install the furnace where the combustion air is ex-
posedto thefollowing substances:
chlorinatedwaxes or cleaners
chlorine-basedswimming pool chemicals
watersoftening chemicals
deicing salts or chemicals
carbontetrachloride
halogentyperefrigerants
cleaningsolutions (such asperchloroethylene)
printinginks
paintremovers
varnishes
hydrochloricacid
cementsand glues
antistaticfabric softeners for clothes dryers
andmasonry acid washing materials
• To ensure that the enclosed non-direct vent furnace
hasan adequatesupply ofcombustion air,vent from
anearbyuncontaminatedroomor from outdoors. Re-
fer to the Combustion and Ventilation Air Require-
ments section in this manual or the installation in-
structions for details.
• If the furnace is used in connection with a cooling
unit, install the furnace upstream or in parallel with
the cooling unit coil. Premature heat exchanger fail-
urewillresult if thecooling unit coilisplaced aheadof
thefurnace.
• Ifthefurnace is installedin a residentialgarage, posi-
tionthe furnace sothattheburnersandignitionsource
are located not less than 18 inches (457 mm) above
the floor. Protect the furnace from physical damage
byvehicles.
• Ifthe furnace is installed horizontally,the furnaceac-
cess doors must be vertical so that the burners fire
horizontally into the heat exchanger. Do not install
theunitwiththeaccessdoorsonthe“up/top”or“down/
bottom”side ofthe furnace.
Clearances and Accessibility
Installations must adhere to the clearances to combustible
materials to which this furnace has been design certified.
Theminimum clearance information for this furnace is pro-
videdon the unit’sclearance label. These clearancesmust
bepermanentlymaintained.RefertoSpecification Sheet for
minimumclearances to combustible materials. Clearances
must also accommodate an installation’s gas, electrical,
anddraintrapanddrainlineconnections. NOTE: In addition
tothe required clearancesto combustible materials,a mini-
mum of 24 inches service clearance must be available in
frontof the unit.

PRODUCT DESIGN
16
A furnace installed in a confined space (i.e., a closet or
utilityroom) must have two ventilation openings with a total
minimumfree area of 0.25 squareinches per1,000 BTU/hr
offurnaceinputrating. One oftheventilation openings must
be within 12 inches of the top; the other opening must be
within 12 inches of the bottom of the confined space. In a
typical construction, the clearance between the door and
doorframe isusually adequateto satisfythis ventilation re-
quirement.
Furnace Suspension
If suspending the furnace from rafters or joist, use 3/8"
threaded rod and 2”x2”x1/8” angle iron as shown in the fol-
lowing figure. If the furnace is installed in a crawl space it
mustalso be suspendedfrom the floorjoist orsupported by
a concrete pad. Never install the furnace on the ground or
allowittobeexposedto water. The lengthofrodwilldepend
on the application and the clearances necessary.
TILT OUTWARD TO ALLOW FOR
DOOR AND CIRCULATOR BLOWER
REMOVAL.
3/8" DIAMETER
THREADED ROD
(6 PLACES)
PROVIDE 8" MINIMUM CLEARANCE BETWEEN
CENTER ROD AND FURNACE CABINET
TO ALLOW FOR CIRCULATOR BLOWER REMOVAL.
ASSURE FURNACE IS LEVEL FROM
END TO END.
ON 90% FURNACES MAKE SURE
THE UNIT HAS A SLIGHT
FORWARD TILT WITH THE FRONT
OF THE FURNACE 0"-3/4"
BELOW THE BACK OF THE FURNACE.
POSITION AS CLOSE AS POSSIBLE
TO BLOWER DECK TO ALLOW FOR
CIRCULATOR BLOWER REMOVAL.
2"X2"X1/8" ANGLE IRON
(3 PLACES)
HOLD DOWN
NUTS
SUPPORT
NUTS
CONDENSATE
DRAIN
GAS PIPING
ALTERNATE
GAS PIPING
90% Suspended Furnace Shown
(80% Furnace Similar)
EXISTING FURNACE REMOVAL
NOTE: Whenanexistingfurnace is removedfromaventing
system serving other appliances, the venting system may
be too large to properly vent the remaining attached appli-
ances.
The following vent testing procedure is reproduced from the
AmericanNationalStandard/NationalStandardofCanadafor
Gas-Fired Central Furnaces ANSI Z21.47, latest edition,
CSA-2.3b,latest editionSection 1.23.1.
The following steps shall be followed with each appliance connected to
the venting system placed in operation, while any other appliances
connected to the venting system are not in operation:
a. Seal any unused openings in the venting system;
b. Inspect the venting system for proper size and horizontal pitch,
as required by the National Fuel Gas Code, ANSI Z223.1 or the
CSA B149 Installation Codes and these instructions. Determine
thatthereisnoblockageorrestriction,leakage,corrosionandother
deficiencieswhichcould cause anunsafecondition;
c. Insofaraspractical,closeallbuildingdoorsandwindowsandall
doors between the space in which the appliance(s) connected to
the venting system are located and other spaces of the building.
Turn on clothes dryers and any appliance not connected to the
venting system. Turn on any exhaust fans, such as range hoods
andbathroomexhausts,sotheyshalloperateatmaximumspeed.
Do not operate a summer exhaust fan. Close fireplace dampers;
d. Follow the lighting instructions. Place the appliance being in-
spected in operation. Adjust thermostat so appliance shall oper-
ate continuously;
e. Test for draft hood equipped spillage at the draft hood relief
opening after 5 minutes of main burner operation. Use the flame
of a match or candle;
f. Afterithasbeendeterminedthateachapplianceconnectedtothe
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;
g. Ifimproperventingis observedduringanyoftheabovetests,the
common venting system must be corrected.
Correctionsmust be inaccordance withthe latest edition of
the National Fuel Gas Code NFPA 54/ANSI Z223.1 and/or
CSAB149 Installation Codes.
If resizing is required on any portion of the venting system,
usethe appropriate tablein AppendixG in the latest edition
oftheNationalFuelGasCodeANSIZ223.1and/orCSAB149
InstallationCodes.
Thermostat Requirements
NOTE: Asingle-stagethermostatwithonlyoneheatingstage
maybe used tocontrol ComfortNet™compatible furnaces.
The application of a single-stage thermostat does not offer
“true”thermostat-driventwo-stageoperation,but provides a
timedtransitionfromlow to highfire. Thefurnace will run on
low stage for a fixed period of time before stepping up to
high stage to satisfy the thermostat’s call for heat. The
delayperiod prior to stepping up can be set at either a fixed
5minutetimedelayor a loadbasedvariabletimebetween 1
and12 minutes(AUTOmode).IftheAUTOmodeisselected,
the control averages the cycle times of the previous three
cyclesandusesthe average todeterminethe time totransi-
tion from low stage to high stage.
To use a single-stage thermostat, turn off power to the fur-
nace,move the thermostat selection DIPswitch tothe OFF
position. Set the desired transition time by setting the tran-
sitiondelayDIPswitchtothedesiredON/OFFposition.Turn
powerback on. Referto thefollowing figure.
3
4Thermostat
Stage Delay
Move to the ON position
to select two-stage
thermostat or OFF to
select single stage
thermostat
Move to the ON position
to selectAuto transition
delay or OFF for 5 minute
transition delay
Heat OFF Delay
DIP Switches
ONOFF
S1
Dehumidistat Requirements
A dehumidistat can be used in conjunction with the two-
stage variable speed furnace to lower the humidity in the
conditionedspace.Thedehumidistatwillimprovedehumidi-
fication of the conditioned air by prompting the furnace to

PRODUCT DESIGN
17
reducethespeedofthecirculatorblower during operation in
the cooling mode. To be compatible with these furnaces, a
dehumidistat must operate on 24 VAC and utilize a switch
whichopens on humidity rise.RefertoElectricalConnec-
tions - 24 Volt Dehumidistat Wiring section in this manual
orthe installation instructions for correctinstallation proce-
dure.
Thermostat and Dehumidistat Location
Inanarea havinggoodair circulation,locatethe thermostat
anddehumidistat (ifapplicable) about five feet high on a vi-
bration-freeinside wall. Do not install the thermostat or de-
humidistat where it may be influenced by any of the follow-
ing:
• Drafts,or dead spotsbehind doors,in corners, orun-
dercabinets.
• Hot or cold air from registers.
• Radiantheat fromthe sun.
• Lightfixtures orother appliances.
• Radiantheatfrom afireplace.
• Concealed hot or cold water pipes, or chimneys.
• Unconditioned areas behind the thermostat and de-
humidistat, such as an outside wall.
HOT
COLD
DRAFTS OR DEAD SPOTS
-BEHIND DOORS
-IN CORNERS
-UNDER CABINETS
Thermostat Influences
Consult the instructions packaged with the thermostat and
dehumidistat for mounting instructions and further precau-
tions.
COMBUSTION AND VENTILATION AIR
REQUIREMENTS
WARNING
POSSIBLE PROPERTY DAMAGE, PERSONAL INJURY OR DEATH MAY OCCUR
IF THE FURNACE IS NOT PROVIDED WITH ENOUGH FRESH AIR FOR PROPER
COMBUSTION AND VENTILATION OF FLUE GASES. MOST HOMES REQUIRE
OUTSIDE AIR BE SUPPLIED TO THE FURNACE AREA.
Improvedconstructionand additional insulationin buildings
have reduced heat loss by reducing air infiltration and es-
capearounddoorsandwindows.Thesechangeshavehelped
in reducing heating/cooling costs but have created a prob-
lem supplying combustion and ventilation air for gas fired
and other fuel burning appliances. Appliances that pull air
out of the house (clothes dryers, exhaust fans, fireplaces,
etc.)increase theproblem bystarving appliancesfor air.
Ifthis furnace isto be installedin thesame space withother
gas appliances, such as a water heater, ensure there is an
adequate supply of combustion and ventilation air for the
other appliances. Refer to the latest edition of the National
FuelGasCodeNFPA54/ANSIZ223.1(Section9.3),orCAN/
CGAB149 InstallationCodes (Sections 7.2, 7.3, or 7.4), or
applicable provisions of the local building codes for deter-
miningthe combustion air requirements for the appliances.
Most homes will require outside air be supplied to the fur-
nace area by means of ventilation grilles or ducts connect-
ing directly to the outdoors or spaces open to the outdoors
such as attics or crawl spaces.
The following information on air for combustion and ventilation
isreproduced fromthe National FuelGas CodeNFPA 54/ANSI
Z223.1 Section 9.3.
9.3* Air for Combustion and Ventilation.
9.3.1 General.
9.3.1.1 Air for combustion, ventilation, and dilution of flue gases for
appliances installed in buildings shall be obtained by application of one
of the methods covered in 9.3.2 through 9.3.6. Where the requirements
of 9.3.2 are not met, outdoor air shall be introduced in accordance with
methods covered in 9.3.3 through 9.3.6.
ExceptionNo.1:This provision shall not apply todirectvent appliances.
9.3.1.2 Appliances of other than natural draft design and other than
Category 1 vented appliances shall be provided with combustion, ven-
tilation, and dilution air in accordance with the appliance manufacturer’s
instructions.
9.3.1.3 Appliances shall be located so as not to interfere with proper
circulation of combustion, ventilation, and dilution air.
9.3.1.4 Where used, a draft hood or a barometric draft regulator shall be
installed in the same room or enclosure as the appliance served so as to
prevent any difference in pressure between the hood or regulator and the
combustion air supply.
9.3.1.5Makeupair requirementsforthe operation ofexhaust fans, kitchen
ventilation systems, clothes dryers, and fireplaces shall be considered in
determining the adequacy of a space to provide combustion air require-
ments.
9.3.2 Indoor CombustionAir. The required volume of indoor air shall
be determined in accordance with the method in 9.3.2.1 or 9.3.2.2 ex-
cept that where the air infiltration rate is known to be less than 0.40
ACH, the method in 9.3.2.2 shall be used. The total required volume
shall be the sum of the required volume calculated for all appliances
located within the space. Rooms communicating directly with the space
in which the appliances are installed through openings not furnished
with doors, and through combustion air openings sized and located in
accordance with 9.3.2.3, are considered a part of the required volume.
9.3.2.1* Standard Method. The minimum required volume shall be 50
ft 3per 1,000/Btu/hour (4.8m3/kW).

PRODUCT DESIGN
18
9.3.2.2* KnownAir Infiltration Rate Method. Where the air infiltra-
tion rate of a structure is known, the minimum required volume shall be
determined as follows:
(1) For appliances other than fan-assisted, calculate using the following
equation: 21 ft3I other
Required Volume other > ________ _________
ACH 1000 Btu/hr
(2) For fan-assisted appliances, calculate using the following equation:
15 ft3I fan
Required Volume fan > ________ _________
ACH 1000 Btu/hr
where:
I other = all appliances other than fan-assisted input in Btu per
hour
I fan = fan-assisted appliances input in Btu per hour
ACH = airchangeper hour(percentof volume ofspace exchanged
per hour, expressed as a decimal)
(3) For purposes of this calculation, an infiltration rate greater than
0.60 ACH shall not be used in the equations in 9.3.2.2(1) and
9.3.2.2(2).
9.3.2.3 Indoor Opening Size and Location. Openings used to connect
indoor spaces shall be sized and located in accordance with the follow-
ing:
(1)*Combining spaces on the same story. Each opening shall have a
minimum free area of 1 in.2/1000Btu/hr (2200 mm2/kW) of the total
input rating of all appliances in the space but not less than 100 in.2
(0.60m2). One opening shall commence within 12 in. (300 mm) of
the top, and one opening shall commence within 12 in. (300 mm) of
the bottom, of the enclosure [see Figure A.9.3.2.3(1)]. The mini-
mum dimension of air openings shall be not less than 3 in. (80 mm).
Furnace Water
Heater
Opening
Chimney or Gas Vent
Opening
NOTE: Each opening must have
a free area of not less than one
square inch per 1000 BTU of
the total input rating of all equip-
ment in the enclosure, but not
less than 100 square inches.
Figure A.9.2.3.3.(1) All Combustion Air from Adjacent
Indoor Spaces through Indoor Combustion Air Openings.
(2) Combining spaces in different stories.The volumes of spaces in
differentstoriesshallbe considered as communicating spaces where
such spaces are connected by one or more openings in doors or
floors having a total minimum free area of 2 in.2/1000 Btu/hr (4400
mm2/kW) of total input rating of all appliances.
9.3.3 Outdoor Combustion Air. Outdoor combustion air shall be pro-
vided through opening(s) to the outdoors in accordance with the meth-
ods in 9.3.3.1 or 9.3.3.2. The minimum dimension of air openings shall
not be less than 3 in. (80 mm).
9.3.3.1 Two Permanent Openings Method. Two permanent open-
ings, one commencing within 12 in. (300 mm) of the top and one com-
mencing within 12 in. (300 mm) of the bottom, of the enclosure shall be
provided. The openings shall communicate directly, or by ducts, with
the outdoors or spaces that freely communicate with the outdoors, as
follows:
(1)*Where directly communicating with the outdoors or where commu-
nicating to the outdoors through vertical ducts, each opening shall
have a minimum free area of 1 in.2/4000 Btu/hr (550 min2/kW) of
total input rating of all appliances in the enclosure. [See Figure
A.9.3.3.1(1)(a) and Figure A.9.3.3.1(1)(b).]
Furnace
Water
Heater
Outlet Air
Chimney or Gas Vent
NOTE: The inlet and outlet air
openings must each have a free
area of not less than one square
inch per 4000 BTU of the
total input rating of all equipment
in the enclosure.
Inlet Air
Ventilation louvers for
unheated crawl space
A
lternate
air inlet
Ventilation louvers
(each end of attic)
Figure A.9.3.3.1(1)(a) All Combustion Air From Outdoors -
Inlet Air from Ventilated Crawl Space and Outlet Air
to Ventilated Attic.
Furnace
Water
Heater
Outlet Air
Chimney or Gas Vent
NOTE: The inlet and outlet air
openings must each have a free
area of not less than one square
inch per 4000 BTU of the
total input rating of all equipment
in the enclosure.
Inlet air duct
[ends 1 ft (300 mm)
above floor]
Ventilation louvers
(each end of attic)
Figure A.9.3.3.1(1)(b) All Combustion Air
From Outdoors through Ventilated Attic.
(2)*Where communicating with the outdoors through horizontal ducts,
each opening shall have a minimum free area of 1 in.2/2000 Btu/hr
(1100 min2/kW) of total input rating of all appliances in the enclo-
sure. [See Figure A.9.3.3.1(2).]
)
(
()

PRODUCT DESIGN
19
Furnace Water
Heater
Chimney or Gas Vent
NOTE: The air duct openings
must have a free area of not
less than one square inch per
2000 BTU of the total input
rating of all equipment in the
enclosure*.
Outlet air duct
Inlet air duct
Figure A.9.3.3.1(2) All Combustion Air From Outdoors
through Horizontal Ducts.
9.3.3.2* One Permanent Opening Method. One permanent open-
ings, commencing within 12 in. (300 mm) of the top of the enclosure,
shall be provided. The appliance shall have clearances of at least 1 in.
(25 mm) from the sides and back and 6 in. (150 mm) from the front of
the appliance. The opening shall directly communicate with the out-
doors or shall communicate through a vertical or horizontal duct to the
outdoors or spaces that freely communicate with the outdoors (see
Figure A.9.3.3.2) and shall have a minimum free area of the following:
(1) 1 in.2/3000 Btu/hr (700 mm2per kW) of the total input rating of all
appliances located in the enclosure, and
(2) Not less than the sum of the areas of all vent connectors in the
space.
Furnace
Water
Heater
Opening
Chimney or Gas Vent
NOTE: The single opening must have
a free area of not less than one
square inch per 3000 BTU of
the total input rating of all equip-
ment in the enclosure, but not less than
the sum of the areas of all vent
connectors in the confined space.
Alternate
Opening
Location
Figure A.9.3.3.2 All Combustion Air
From Outdoors through Single Combustion Air Opening.
9.3.4CombinationIndoorandOutdoorCombustionAir.The use of
a combination of indoor and outdoor combustion air shall be in accor-
dance with (1) through (3) (see example calculation in Annex J]:
(1) Indoor Openings: Where used, openings connecting the interior
spaces shall comply with 9.3.2.3.
(2) Outdoor Opening(s) Location. Outdoor opening(s) shall be located
in accordance with 9.3.3.
(3) Outdoor Opening(s) Size. The outdoor opening(s) size shall be
calculated in accordance with the following:
(a) The ratio of the interior spaces shall be the available volume
of all communicating spaces divided by the required volume.
(b) The outdoor size reduction factor shall be 1 minus the ratio of
interior spaces.
(c) The minimum size of outdoor opening(s) shall be the full size
of outdoor opening(s) calculated in accordance with 9.3.3,
multiplied by the reduction factor. The minimum dimension
of air openings shall not be less than 3 in. (80 mm).
9.3.5 Engineered Installations. Engineered combustion air installa-
tions shall provide an adequate supply of combustion, ventilation, and
dilution air and shall be approved by the authority having jurisdiction.
9.3.6 Mechanical CombustionAir Supply. Where all combustion air
is provided by a mechanical air supply system, the combustion air shall
be supplied form outdoors at the minimum rate of 0.35 ft3/min per 1000
Btu/hr (0.034 m3/min per kW) for all appliances located within the
space.
9.3.6.1Where exhaust fans are installed, additional air shall be provided
to replace the exhausted air.
9.3.6.2 Each of the appliances served shall be interlocked to the me-
chanical air supply system to prevent main burner operation where the
mechanical air supply system is not in operation.
9.3.6.3 Where combustion air is provided by the building’s mechanical
ventilation system, the system shall provide the specified combustion
air rate in addition to the required ventilation air.
9.3.7 Louvers, Grilles, and Screens.
9.3.7.1 Louvers and Grilles. The required size of openings for com-
bustion, ventilation, and dilution air shall be based on the net free area of
each opening. Where the free area through a design of louver or grille or
screen is known, it shall be used in calculating the size opening required
to provide the free area specified. Where the louver and grille design and
free area are not known, it shall be assumed that wood louvers will have
25 percent free area, and metal louvers and grilles will have 75 percent
free area. Nonmotorized louvers and grilles shall be fixed in the open
position.
9.3.7.2 Minimum Scree Mesh Size. Screens shall not be smaller than
1/4 in. mesh.
9.3.7.3 Motorized Louvers. Motorized louvers shall be interlocked
with the appliance so they are proven in the full open position prior to
main burner ignition and during main burner operation. Means shall be
provided to prevent the main burner form igniting should the louver fail
to open during burner startup and to shut down the main burner if the
louvers close during burner operation.
9.3.8 Combustion Air Ducts. Combustion air ducts shall comply with
9.3.8.1 through 9.3.8.8.
9.3.8.1 Ducts shall be constructed of galvanized steel or a material hav-
ing equivalent corrosion resistance, strength, and rigidity.
Exception: Within dwellings units, unobstructed stud and joist spaces
shall not be prohibited from conveying combustion air, provided that not
more than one fireblock is removed.
9.3.8.2 Ducts shall terminate in an unobstructed space, allowing free
movement of combustion air to the appliances.
9.3.8.3 Ducts shall serve a single space.

PRODUCT DESIGN
20
9.3.8.4 Ducts shall not serve both upper and lower combustion air
openings where both such openings are used. The separation between
ducts servicing upper and lower combustion air openings shall be main-
tained to the source of combustion air.
9.3.8.5 Ducts shall not be screened where terminating in an attic space.
9.3.8.6 Horizontal upper combustion air ducts shall not slope down-
ward toward the source of combustion air.
9.3.8.7The remaining space surrounding a chimney liner, gas vent, spe-
cial gas vent, or plastic piping installed within a masonry, metal, or
factory built chimney shall not be used to supply combustion air.
Exception: Direct vent appliances designed for installation in a solid
fuel-burning fireplace where installed in accordance with the
manufacture’s installation instructions.
9.3.8.8 Combustion air intake openings located on the exterior of the
building shall have the lowest side of the combustion air intake openings
locatedatleast12 in. (300 mm) vertically from the adjoininggradelevel.
Category I Venting (Vertical Venting)
(80% Furnaces Only)
WARNING
TO PREVENT POSSIBLE PERSONAL INJURY OR DEATH DUE TO
ASPHYXIATION, NON-CONDENSING GAS FIRED WARM AIR FURNACES MUST
BE CATEGORY IVENTED. DO NOT VENT ANY OF THESE FURNACES USING
CATEGORY III VENTING.
CategoryI Ventingis ventingat a non-positive pressure. A
furnace vented as Category I is considered a fan-assisted
applianceanddoesnothavetobe"gastight."NOTE: Single-
StageandTwo-Stagegasfurnaces with induceddraftblow-
ersdraw products ofcombustion through a heat exchanger
allowing in some instances common venting with natural
draftappliances (i.e. waterheaters).
Allinstallationsmust beventedin accordancewithNational
Fuel Gas Code NFPA 54/ANSI Z223.1 - latest edition. In
Canada, the furnaces must be vented in accordance with
the National Standard of Canada, CAN/CGA B149.1 and
CAN/CGAB149.2 - latest editions and amendments.
NOTE: Thevertical height ofthe CategoryI venting system
must be at least as great as the horizontal length of the
ventingsystem.
WARNING
TO PREVENT POSSIBLE DEATH OR PERSONAL INJURY DUE TO
ASPHYXIATION, COMMON VENTING WITH OTHER MANUFACTURER'S
INDUCED DRAFT APPLIANCES IS NOT ALLOWED.
Theminimum ventdiameter forthe CategoryI venting sys-
tem is as shown in the following chart:
UPFL OW COUNTERFLOW
060 4 Inch 4 Inch
080 4 Inch 4 Inch
100 5 Inch 5 Inch
MINIMUM VENT
MODEL
Undersomeconditions,largerventsthanthoseshownabove
maybe required orallowed.
Whenanexistingfurnaceis removed fromaventingsystem
serving other appliances, the venting system may be too
large to properly vent the remaining attached appliances.
Forcompletedetails refer to ExisitingFurnaceRemoval sec-
tion of this manual.
When resizing any portion of the common venting system,
usethe appropriate tablein AppendixG in the latest edition
ofthe National Fuel Gas Code NFPA 54/ANSI Z223.1.
Upflow or Horizontal units are shipped with the induced
draftblowerdischargingfromthe top of thefurnace("Top"is
asviewedforanupflowinstallation).Theinduceddraftblower
can be rotated 90 degrees for Category I venting. Refer to
the following figure. For horizontal installations, a four inch
single wall pipe can be used to extend the induced draft
bloweroutlet 1/2” beyond the furnace cabinet. Vent the fur-
naceinaccordance with theNational Fuel GasCode NFPA
54/ANSIZ223.1-latest edition. In Canada,ventthe furnace
inaccordance with the National Standardof Canada,CAN/
CGA B149.1 and CAN/CGA B149.2 - latest editions and
amendments.
NOTE: Thisfurnaceisnotdesigncertified to behorizontally
vented.
WARNING
TO PREVENT DEATH OR SERIOUS ILLNESS TO BUILDING OCCUPANTS DUE
TO FLUE PRODUCTS LEAKING INTO THE BUILDING, PROPER INSTALLATION OF
GASKETS AND SCREWS IS ESSENTIAL FOR PROVIDING A GAS TIGHT SEAL
BETWEEN THE PARTITION PANEL AND THE INDUCED DRAFT BLOWER.
Make sure all wires are at least one inch from flue pipe.
Relocate junction box to right side of cabinet if necessary.
Refer to Electrical Connections section of this manual for
instructions.