Nordyne FG7SA-054C-23A, FG7SK-108C-35C, FG7SC-038D-23A, FG7SK-090C-24B, FG7SL-072D-24B User Manual

GAS FURNACES Single Stage, Two-Stage, and Modulating Furnaces

*SK/*TK Downflow

95.1% AFUE Condensing Furnaces
*TC Upflow/Horizontal

97%+ AFUE Modulating Furnaces

*MQ Upflow/Horizontal

FiRE OR EXPLOSION HAZARD

=Failure to follow safety warnings e×actly

could result in serious injury or property
damage.

=Installation and service must be performed

by a qualified installer, service agency or

the gas supplier.

= Do not store or use gasoline or other

flammable vapors and liquids in the
vicinity of this or any other appliance.

_SL Downflow

*TL Downfiow

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

neighbors phone. Follow the gas suppliers

instructions.

=if you cannot reach your gas supplier, call

the fire department.

_'_92.1%, 95.1% and 97%+ AFUE Models Only

Congratulations on the purchase on your new furnace! With our dedication to quality, superior reliability,
and outstanding warranty, we know you will be pleased with this new appliance. This furnace has been
designed and built to provide many years of safe and dependable home comfort, providing it is properly
installed and regular maintenance has been performed. Improper use or insufficient maintenance can

shorten the life of the furnace and result in serious personal injury or property damage. Please read
this manual thoroughly and familiarize yourself with the safety, operation and maintenance procedures

for this furnace.

TABLE OF CONTENTS

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

Air for Proper Combustion ...................... 4

Clearances to Combustibles .................. 4

Flood Damage ....................................... 4

Filters ..................................................... 4

Gas Supply and Piping .......................... 5

Inspection ............................................... 5

Venting System ...................................... 5

Shutting Down the Furnace ................... 5

COMPONENT INFORMATION ..................... 6

Venting System ...................................... 6

Category I Furnaces ......................... 6

Category IV Furnaces ...................... 6

Thermostats ........................................... 6

COMBUSTION AIR REQUIREMENTS ......... 6

Sources of Corrosion ............................. 6

Furnace in Small Room or Closet .......... 6

INSPECTION ................................................. 7

Frequency .............................................. 7

Venting System ...................................... 7

Blower and Filter ................................... 7

Air for Combustion ................................. 7

Air for Comfort ........................................ 7

Maintenance Table ................................ 8

Burner Operation .................................. 8

New Construction .................................. 8

Furnace and Air Ducts ........................... 8

TROUBLESHOOTING .................................. 8

LOCATION OF SINGLE-STAGE FURNACE

COMPONENTS ............................................. 9

LOCATION OF TWO-STAGE FURNACE

COMPONENTS ........................................... 10

LOCATION OF MODULATING FURNACE

COMPONENTS ........................................... 11

STARTUP AND SHUTDOWN ....................... 7

Starting the Furnace .............................. 7

Shutting Down the Furnace ................... 7

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.

CLEARANCES TO COMBUSTIBLES
The furnace is designed to have certain clearances to

combustible items such as wood, paper, etc. Some types
of insulation are combustible. If your furnace is installed

in an attic, near unfinished walls, or in other insulated
space, keep area surrounding the furnace free of insulating

material.

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 personal
injury, or death.

WARNING:

PROPOSITION 65 WARNING: This product contains

chemicals known to the state of California to cause
cancer, birth defects or other reproductive harm.

WARNING:

This furnace is not approved for installation in

mobile homes. Installing this furnace in a mobile
home could cause fire, property damage, and/or

personal injury.

AIR FOR PROPER COMBUSTION
For proper and safe operation, this furnace requires

unrestricted airflow for combustion and ventilation. Do
not block or obstruct air openings on the furnace, air

openings around the furnace area or the spacings around
the furnace.

WARNING:

Do not place combustible materials on or against

the furnace cabinet or within 6 inches ofthe vent

pipe. Furnace area must be kept clear and free
of combustible materials, gasoline and other

flammable vapors and liquids.A fire or explosion

may result causing property damage, personal
injury or loss of life. Failure to follow the safety

warnings exactly could result in serious injury,

death or property damage.

FLOOD DAMAGE

WARNING:

Do not use this furnace if any part has been under

water. A flood damaged furnace is extremely

dangerous. Attempts to use the furnace can
result in fire or explosion. A qualified service

agency should be contacted to inspect the

furnace and to replace all gas controls, control

system parts, electrical parts that have been

wet or the furnace if deemed necessary.

FILTERS

WARNING:

WARNING:

Do not reduce the supply of fresh air to the

furnace. This could create the production of
excessive amounts of Carbon Monoxide = a

colorless, odorless gas that is a deadly poison

that could result in serious personal injury or

death.

Do not block any openings that are supplying

fresh air to the room or closet the furnace is in.

If your furnace obtains its air through a pipe to

the outdoors, do not allow the inlet of the pipe
to become blocked.

Never operate the furnace without a filter in
place. Accumulating dust in the return air can

build up on internal components, resulting
in loss of efficiency, equipment damage, and
possible fire.

Air filter(s) are not supplied with the furnace as
shipped from the factory. The installer must provide

a high velocity filter and rack for a filter in the return air
duct adjacent to the furnace, or in a return air grill to

the furnace.
The furnace should always have a clean filter located

either at the air return on the furnace or in an air return
register in your habitable space. If the filter becomes

dirty, it should be cleaned or replaced.

Newor newlyrenovatedhomesmayrequiremore
frequentchanginguntilthe constructiondusthas
minimized.Filtersdesignedtoremovesmallerparticles
suchaspollen,mayrequireadditionalmaintenance.

GASSUPPLYANDPIPING

This furnace does not have a pilot. It is equipped with an
ignition device which automatically lights the burner. DO
NOT light the burner by hand.

IMPORTANT NOTE: Should the gas supply fail to shut
off or ifoverheating occurs,shut off the gas valvetothe
furnace before shutting off the electrical supply!

WARNING:

All gas piping and shutoff valves must be

installed in compliance with local codes and
utility regulations by licensed installers. DO

NOT attempt to modify, or tap into existing
gas lines yourself. Fire or explosion may result
causing property damage, personal injury or

loss of life. Failure to followthe safety warnings

exactly could result in serious injury, death or

property damage.

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
neighbors phone. Follow the gas suppliers

instructions.

• If you cannot reach your gas supplier, call the

fire department.

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

WARNING:

The furnace was shipped from the factory
equipped to operate on natural gas. Conversion

to LP/propane gas must be performed by a

licensed HVAC technician using a factory
supplied conversion kit. Failure to use the
proper conversion kit can cause fire, explosion,
property damage, carbon monoxide poisoning,
personal injury, or death.

INSPECTION
Your furnace and its venting system should be inspected

annually by a licensed HVAC technician. The filter should
be inspected at least once a month. See page 7 for Items
that should be inspected by the homeowner.

VENTING SYSTEM

WARNING:

it is imperative to maintain proper operation
of the venting system, including the masonry

chimney if applicable. Insufficient venting could
create the production of excessive amounts of
Carbon Monoxide - a colorless, odorless gas that
is a deadly poison that could result in serious

personal injury or death.

SHUTTING DOWN THE FURNACE
Should you ever need to shut down your furnace for service

or maintenance, shut off the gas valve to the furnace
before shutting off the electrical service. Your furnace
may be equipped with one of three types of gas valves.
Remove the door panel from the front of the furnace and
determine which valve type matches your installation in
Figure 1. Either move the switch or turn the knob to the
OFF Position. Additional instructions for shutting down the
furnace can be found on page 7. If your installation has
a manual gas shutoff valve on the gas supply pipe, shut

this off, then shut off the electric to the furnace.

SINGLE STAGE VALVE TWO - STAGE VALVE

Figure 1. Gas Valves

Thefurnacecomponentsshownonpages9- 11 will help

to identify and locate various parts of the furnace. The
component you need to familiarize yourself with is the
gas valve.You will use this to turn the furnace on and off.
There are no user serviceable parts. All repairs must be
done by a licensed HVAC technician.

VENTING SYSTEM
This furnace is designed to fulfill the requirements of being

classified as either a Category I or Category IV furnace.
These classifications are related to the furnace's Annual

Fuel Utilization Efficiency (AFUE) rating, the percentage
of fuel that is converted into usable heating energy.

Category I Furnaces
These furnaces typically have an AFUE rating of about
80% and may be vented through a properly designed metal
vent or masonry chimney. This venting system needs to
be primarily vertical, so that the hot combustion products
will develop a natural upwards draft action.

Category IV Furnaces
Category IV furnaces typically have an AFUE rating over
90% and are mainly vented through plastic PVC pipe.
These furnaces also produce liquid condensate which is
slightly acidic. The vent piping must be sloped upwards
away from the furnace to properly drain the condensate
back to the condensate disposal system.

THERMOSTATS
This family offurnaces includes single stage, two-stage and

modulating capabilities.These different capabilities require
different thermostats to reach their best performance.
Single stage furnaces (SA, SK, SC & SL models) should
be controlled by a conventional single stage thermostat.
Two stage furnaces (TA, TK, TC & TL models) will perform
best with a conventional two - stage thermostat. However,
it is possible to also control two stage furnaces with a
single stage thermostat. Both thermostats are commonly
available at your local building supply store. Consult
with your installer about which type is best for your
installation. The modulating MQ furnaces will not work
with a conventional thermostat and must be controlled by
an iQ thermostat, available through your dealer.

CAUTION'.

Do not reduce the supply of fresh air to the
furnace, it is extremely important that the
furnace receives an unobstructed flow of clean,

fresh air to properly burn the fuel gas. If this
flow of air is restricted, the partially burned

combustion gases may create dangerous

amounts of carbon monoxide = a colorless,

odorless gas that is a deadly poison that can

cause personal injury or death.

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 flame
roll-out switch will open, turning off the gas supply to the
burners. This indicates that a serious problem with the
burners has occurred and must be corrected immediately.
Only a licensed HVAC technician can reset this switch.

Before remodeling near the furnace, consult with a local
code official or the National Fuel Gas Code to make sure

you will be in compliance with supplying adequate air for
combustion. By erecting new walls, itissometimes possible
to inadvertently restrict the furnace's air supply. You can
find more information about supplying combustion air in
the NFGC, which is available at many libraries.

SOURCES OF CORROSION
It is known that certain common household chemicals can

cause heat exchanger corrosion ifthevapors are pulled into
the furnace's burners The following is a list of chemicals

that should not be used or stored near the furnace.
Do not store these chemicals near the furnace:

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

FURNACE IN A SMALL ROOM OR CLOSET
If a furnace is installed in relatively small utility room or

closet, the installation needs openings inthe walls or door
to let combustion air in. Make sure that these openings
remain unobstructed. Do not modify these openings in any
way without consulting a licensed HVAC technician.

STARTINGTHEFURNACE:

1. Makesurethefilteriscleanandinplace.

2. Makesuretheventsystemisproperlyinstalled.

3. Setthethermostattothelowestsetting.

4. Closethemanualgasvalveoutsidethefurnace.

5. Turnoffallelectrictothefurnace.

6. Removethedoorfromtheburnercompartment.

7. SetthegasvalveswitchorknobtotheOFFposition.
SeeFigure2forgasvalveswitchorknoblocation.

8. Wait5minutes.Ifthereisanysmellofgas,see"WHAT
TODOIFYOUSMELLGAS"onpage5.

9. SetthegasvalveswitchorknobtotheONposition.

10.Turnonallelectrictothefurnace.

11.Openthemanualgasvalve.

12.Turnthethermostatbackuptoforceignition.

13.Observeoperation,includingburners.Ifburnersfail
toignite,calla licensedHVACtechnician.

14.Replacethedoorontheburnercompartment.

SHUTTINGDOWNTHEFURNACE:
Shouldyoueverneedtoshutdownyourfurnacefor

serviceormaintenance,followthesesteps:

1. Setthethermostattothelowestsetting.

2. Closethemanualgasvalveoutsidethefurnace.

3. Turnelectrictothefurnaceoff.

4. Openthedoortotheburnercompartment.

5. Set the gas valve switchor knob to the OFF
position.

6. ReplacethedoorontheburnerCompartment.

SINGLE STAGE VALVE TWO - STAGE VALVE

Figure 2. Gas Valves

FREQUENCY
The furnace should be inspected annually by a licensed

HVAC technician. Table 1 (page 8) contains suggested
inspections and frequency of maintenance.

VENTING SYSTEM

Existing masonry chimneys should be inspected and
relined if necessary. Vent pipe must slope upwards
and be physically sound without holes or corrosion.
Any corroded section of vent pipe must be replaced,
and any obstruction or blockage must be removed by

a licensed HVAC technician.

Flue passageways, the vent system, and the burners
should be inspected and cleaned (if required) by a
licensed HVAC technician annually to ensure continued
safe operation.

BLOWER AND FILTER
It is recommended that the blower compartment be

cleaned of dirt or lint that may have accumulated in the
compartment or on the blower and motor as part of the
annual inspection.

MODULATING VALVE

AiR FOR COMBUSTION

For proper and safe operation, the furnace needs air for
combustion and ventilation. Do Not block or obstruct

air openings on the furnace, or any air openings where
the furnace may be installed, including any surrounding

spaces.
Direct vent furnaces pull combustion air from the

outdoors and vent combustion products back outside.
Combustion air coming from the outside needs to be

clean of chemicals that can cause corrosion, such as
pool chlorinating products.

AIR FOR COMFORT

• Keep air filters cleaned. It is recommended that the
furnace air filter be checked at least once a month.

Clean or replace filter to maintain proper airflow and
achieve maximum efficiency.

• Furniture and drapery should be arranged so that
the supply air registers and return grilles are not

obstructed.

Verifyfurnaceareaisfreeofcombustible
materials.

Verifycombustionandventilationairis
notrestricted.

X X X
X X X

Verifynosignsofphysicaldeterioration X X X
ofthefurnace.

Verifynoobstructionsorrestrictionsin

X X

ventorchimney.
Verifynoholesorcracksinventpipe. X X

Verifynocorrosioninventpipe. X X
Verifythehorizontalventpipesslope X X

upwardsawayfromfurnace.
Verifyburnerflame. X
Cleanorreplacefilter(s). X

Cleanblowercompartment. X
Cleanburnerassembly. X

Cleancondensatecollectionand

X

disposalsystem(ifapplicable).

Table 1. Maintenance Table

BURNER OPERATION
Perform the startup instructions on page 7. The igniter

should ignite the closest burner and the flames should
quickly carryover to the other burners. The flames should
be bright blue, with occasional yellow streaks.

NEW CONSTRUCTION
The operation of gasfurnaces ina construction environment

can cause a variety of problems with the furnace. Before
occupying the residence, homeowners should have these
safety inspections performed by a licensed technician:

The filter must be replaced or cleaned and the furnace
must be inspected by a licensed HVAC technician. The
furnace must be cleaned and/or repaired if found to be
dirty, damaged, or malfunctioning in any way. Before
occupancy, the furnace shall be inspected and ap-
proved by applicable local authority even if this results
in redundant inspections.
The duct work must be inspected and cleaned if found
to contain any construction debris.

If the furnace fails to operate check the following:

1. Is the thermostat setting correct?

2. Are the blower compartment door(s) in place?

3. Has the circuit breaker tripped or the control board

fuse burned open?

4. Is the gas turned on at the manual shutoff?

5. Is the filter dirty or clogged?

If the furnace still doesn't operate, contact a licensed
HVAC technician

FURNACE AND AIR DUCTS
Homeowners should perform frequent visual inspections

of the furnace for obvious signs of deterioration. The
furnace should be sound without sagging, cracks gaps,
etc around the base. The return air duct connection(s) is

secured and sealed to the furnace cabinet and terminates
outside the area containing the furnace. Any signs of

damage or loose connections should be repaired by a
qualified HVAC technician.

LOCATION OF SINGLE-STAGE FURNACE COMPONENTS

*SA 80+ Upflow/Horizontal Gas Furnace *SK 80+ Downflow Gas Furnace

1 Blower Assembly 5 Flame Rollout Switch 9 Gas Valve 13 Pressure Switch
2 Blower Door Switch 6 Flame Sensor 10 Igniter 14 Transformer

3 Burner Assembly 7 Furnace Control Board 11 Inducer Assembly
4 Combustion Tube 8 Gas Manifold 12 Limit Switch

*SC 92.1% Upflow/Horizontal Gas Furnace *SL 92.1% Downflow Gas Furnace

.................._ i!-'

LOCATION OF TWO-STAGE FURNACE COMPONENTS

J

1i

*TA 80+ Upflow/Horizontal Gas Furnace *TK 80+ Downflow Gas Furnace

1 Blower Assembly 5 Flame Rollout Switch 9 Gas VaNe 13 Motor Choke

2 . Blower Door Switch _ 6 _ Flame Sensor . 10 . Igniter _ 14 _M°t°r Control Board
3 Burner Assembly 7 Furnace Control Board 11 Inducer Assembly 15 Pressure Switch

4 Combustion Tube 8 Gas Manifold 12 Limit Switch 16 Transformer

*TC 95.1% Upflow/Horizontal Gas Furnace

10

*TL 95.1% Downflow Gas Furnace

LOCATION OF MODULATING FURNACE COMPONENTS

1. Blower Assembly

2. Blower Door Switch

3. Burner Assembly

4. Finish Flange

5. Flame Roll-Out Switch

6. Flame Sensor

7. Furnace Control Board

8. Gas Manifold

9. Gas Valve

®
©

10. Igniter

11. Inducer Assembly

12. Inducer Limit Switch

13. Motor Choke (candDcabinetsonly)

14. Motor Control Board

15. Motor Control Box

16. Pressure Switches

17. Transformer
*MQ 97%+ Upflow/Horizontal Gas Furnace

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11

NORD_E

O'Fallon, MO

RATING

!1I!1IIIlllIEIIIillIllll

708967

7089670

Specifications and illustrations subject to change

without notice or incurring obligations.

Printed in U.S.A. (10/08)