M7RL Series 95.1 AFUE
Downflow, Single Stage Condensing Gas Furnace
USER’S MANUAL
DO NOT DESTROY THIS MANUAL. KEEP IN A SAFE PLACE FOR FUTURE REFERENCE.
FIRE OR EXPLOSION HAZARD
•Failure to follow safety warnings exactly
could result in serious injury or property
damage.
•Installationandservicemustbeperformed
byaqualiedinstaller,serviceagencyorthe
gassupplier.
•Do not store or use gasoline or other
ammablevaporsandliquidsinthevicinity
ofthisoranyotherappliance.
WHAT TO DO IF YOU SMELL GAS
•Donottrytolightanyappliance.
•Donottouchanyelectricalswitch;donot
useanyphoneinyourbuilding.
•Leavethebuildingimmediately.
•Immediatelycall yourgassupplierfroma
neighbor’sphone.Followthegassupplier’s
instructions.
•Ifyoucannotreachyourgassupplier,call
theredepartment.
WARNING:
RISQUE D’INCENDIE OU D’ EXPLOSION
•Le non-respect des avertissements de
sécurité pourrait entraîner des blessures
graves,lamortoudesdommagesmatériels.
•L’installation et l’entretien doivent être
effectués par un installateur qualié, un
organismedeserviceoulefournisseur de
gazstaller,serviceagencyorthegassupplier.
•Nepasentreposerniutiliserdel’essenceni
d’autres vapeurs ou liquides inammables
danslevoisinagedecetappareil,nidetout
autreappareil.
QUE FAIRE S’IL Y A UNE ODEUR DE GAZ
•Nepastenterd’allumeraucunappareil.
•Netoucheràaucuninterrupteurélectrique;
n’utiliseraucuntéléphonedanslebâtiment.
•Évacuerl’immeubleimmédiatement.
•Appeler immédiatement le fournisseur de
gazenemployantletéléphoned’unvoisin.
Respecter à la lettre les instructions du
fournisseurdegaz.
•Sipersonnenerépond,appelerleservicedes
incendies.
AVERTISSEMENT
IMPORTANT! Please read all information in this manual thoroughly and become familiar
with the capabilities and use of your appliance before attempting to operate or maintain
this unit. 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.
Keep this literature where you have easy access to it in the future. If a problem occurs, check
the instructions and follow recommendations given. If these suggestions don’t eliminate
your problem, call your servicing contractor. Do not attempt to service this unit yourself!
Under no circumstances should the appliance owner attempt to install and/or service
this equipment. Some local codes require licensed installation / service personnel for this
type of equipment. Improper service, adjustment, or maintenance may cause explosion,
fire, electrical shock or other hazardous conditions which may result in personal injury or
property damage.
2
IMPORTANT SAFETY INFORMATION ........ 3
Gas Supply & Piping .................................. 3
Combustion Air & Venting System .............. 4
Clearances to Combustibles ...................... 4
Shutting Down the Furnace ........................ 4
GENERAL INFORMATION ........................... 5
About the Furnace ...................................... 5
Air Filters .................................................... 5
Furnace in Small Room or Closet .............. 5
Sources of Corrosion ................................. 5
Thermostat ................................................. 5
Warranty Information .................................. 5
MAINTENANCE ............................................ 6
Blower and Filter ....................................... 6
Condensate Drainage ............................... 6
Furnace & Air Ducts ................................... 6
Venting System .......................................... 6
TROUBLESHOOTING .................................. 6
STARTUP & SHUTDOWN ............................ 7
Starting the Furnace .................................. 7
Shutting Down the Furnace ........................ 7
FURNACE COMPONENTS .......................... 8
TABLE OF CONTENTS
FOR FURNACES INSTALLED IN:
• ManufacturedHomes
• RecreationalVehicles,ParkModels,&ManufacturedBuildings
• ModularHomes/Buildings
3
GAS SUPPLY & PIPING
IMPORTANT SAFETY INFORMATION
WARNING:
Toavoidpossibleequipmentdamage,re,or
personalinjury,thefollowinginstructionsmust
beobservedregardingunitmaintenanceand
operationalprocedures.
WARNING:
PROPOSITION65WARNING:Thisproductcontains
chemicalsknowntothestateofCaliforniatocause
cancer,birthdefectsorotherreproductiveharm.
• To achieve optimum performance and minimize
equipment failure, it is recommended that periodic
maintenance be performed on this unit. The ability
to properly perform maintenance on this equipment
requires certain mechanical skills and tools. Please
consult your dealer for maintenance information and
availability of maintenance contracts.
• Thearea aroundthegas furnace(Figure1,page4)
and the vicinity of any other gas appliances must be
kept clear and free of combustible materials, gasoline,
and other flammable vapors and liquids. Do not store
or use flammable items such as paint, varnish, or
strippers in the vicinity of the unit.
• Donotusetheareaaroundtheunitasastoragearea.
This area must be kept clean and clear of loose or
exposed insulation materials. Examine the unit’s area
when it is installed or when insulation is added, since
some insulation materials may be combustible.
• 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.
• Familiarizeyourselfwiththecontrolsthatshutoffthe
gas and electrical power to the unit.
IMPORTANT NOTE: If the unit needs to be shut
down for an extended period of time, turn off
boththegasandelectricalpower.Foryoursafety
alwaysturnoffboththegasandelectricalpower
beforeperformingserviceormaintenanceonthe
furnace.Ifthegassupplytotheunitmustbeshut
off,refertotheshutdowninstructionsonpage7.
WHAT TO DO IF YOU SMELL GAS
•Donottrytolightanyappliance.
•Donottouchanyelectricalswitch;donot
useanyphoneinyourbuilding.
•Leavethebuildingimmediately.
•Immediately call your gas supplier froma
neighbor’sphone.Followthegassupplier’s
instructions.
•Ifyoucannotreachyourgassupplier,call
theredepartment.
QUE FAIRE S’IL Y A UNE ODEUR DE GAZ
•Nepastenterd’allumeraucunappareil.
•Netoucheràaucuninterrupteurélectrique;
n’utiliseraucuntéléphonedanslebâtiment.
•Évacuerl’immeubleimmédiatement.
•Appeler immédiatement le fournisseur de
gazenemployantletéléphoned’unvoisin.
Respecter à la lettre les instructions du
fournisseurdegaz.
•Sipersonnene répond, appeler le service
des incendies.
WARNING:
All gas piping and shutoff valves must be
installedincompliancewithlocalcodesand
utility regulations by licensed installers. DO
NOT attempt to modify, or tap into existing
gaslinesyourself.Fireorexplosionmayresult
causingpropertydamage,personalinjuryor
lossoflife.Failuretofollowthesafetywarnings
exactlycouldresultinseriousinjury,deathor
propertydamage.
WARNING:
The furnace was shipped from the factory
equippedtooperateonnaturalgas.Conversion
to LP/propane gas must be performed by a
licensed HVAC technician using a factory
supplied conversion kit. Failure to use the
properconversionkitcancausere,explosion,
propertydamage,carbonmonoxidepoisoning,
personalinjury,ordeath.
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.
4
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:
Donotplacecombustiblematerialsonoragainst
the furnace cabinet or vent pipe. The area
aroundthefurnacemustbekeptclearandfree
ofcombustiblematerials,gasolineandother
ammablevaporsandliquids.Areorexplosion
mayresultcausingpropertydamage,personal
injuryorlossoflife.Failuretofollowthesafety
warningsexactlycouldresultinseriousinjury,
deathorpropertydamage.
IMPORTANT NOTE: Shouldthegassupplyfailtoshut
offorifoverheatingoccurs,shutoffthegasvalveto
thefurnacebeforeshuttingofftheelectricalsupply!
COMBUSTION AIR & VENTING SYSTEM
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:
It is extremely important that the furnace
receivesanunobstructedowofclean,fresh
airtoproperlyburnthefuelgas.Ifthisowof
airisrestricted,thepartiallyburnedcombustion
gasesmaycreatedangerousamountsofcarbon
monoxide-acolorless,odorlessgasthatisa
deadlypoisonthatcancausepersonalinjury
ordeathThiscouldcreatetheproductionof
excessive amounts of Carbon Monoxide - a
colorless,odorlessgasthatisadeadlypoison
thatcouldresultinseriouspersonalinjuryor
death.
Donotblockanyopeningsthataresupplying
freshairtotheroomorclosetthefurnaceisin.
Ifyourfurnaceobtainsitsairthroughapipeto
theoutdoors,donotallowtheinletofthepipe
tobecomeblocked.
• 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
mustbecorrectedimmediately.OnlyalicensedHVAC
technician can reset this switch.
• 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.
SeealsotheMaintenanceInstructionsonpages6-7.
• Before you remodel a room 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,
it is sometimes 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.
IMPORTANT SAFETY INFORMATION
Figure 1. Minimum Clearances
FURNACE CLEARANCES
CLOSET ALCOVE
Front 1" 1"
Rear 0” 0”
Sides 0” 0”
Top 6” 6”
Vent 0” 0”
LEFT
SIDE
FRONT
RIGHT
SIDE
REAR
RIGHT
SIDE
SHORT A-SIZE CABINET & TALL B-SIZE CABINET TALL B-SIZE CABINET WITH TOP AIR RETURN
REAR
LEFT
SIDE
FRONT
VENT
VENT
SHUTTING DOWN THE FURNACE
If you need to shut down your furnace for service or
maintenance, shut off the gas valve to the furnace before
shutting off the electrical service. Remove the door panel
from the front of the furnace and 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.
5
GENERAL INFORMATION
ABOUT THE FURNACE
• This furnace has been tested for capacity and
efciencyinaccordancewithAHRIStandardsandwill
provide many years of safe and dependable comfort,
providing it is properly installed and maintained. With
regular maintenance, this unit will operate satisfactorily
year after year. Abuse, improper use, and/or improper
maintenance can shorten the life of the appliance and
create unsafe hazards.
• This furnace is designed to fulll the requirements
of being classified as a Category IV furnace. This
classification is related to the furnace’s Annual Fuel
UtilizationEfciency(AFUE)rating,thepercentageof
fuel that is converted into usable heating energy.
• Category IVfurnaces typicallyhave anAFUE rating
over 90% and are mainly vented through plastic PVC
pipe.
AIR FILTERS
WARNING:
Never operate the furnace without a lter in
place.Accumulatingdustinthereturnaircan
build up on internal components, resulting
inlossofefciency,equipmentdamage,and
possiblere.
• An air lter is supplied with the furnace as shipped
from the factory.
• The furnace should alwayshavea clean lter. If the
filter becomes dirty, it should be cleaned or replaced.
The filter is installed over the return air grille of the
door inside the furnace cabinet.
• New or newly renovated homes may require more
frequent changing or cleaning until the construction
dust has minimized. Filters designed to remove
smaller particles such as pollen, may require additional
maintenance.
FURNACE IN A SMALL ROOM OR CLOSET
If a furnace is installed in relatively small utility room or
closet, the installation needs openings in the walls or door
toletreturnairin.Makesurethattheseopeningsremain
unobstructed. Do not modify these openings in any way
withoutconsultingalicensedHVACtechnician.
SOURCES OF CORROSION
It is known that certain common household chemicals can
cause heat exchanger corrosion if the vapors 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:
• Gasoline/Kerosene
• Permanentwavesolutions
• Chlorinatedwaxesandcleaners
• Chlorinebasedswimmingpoolchemicals
• Watersofteningchemicals
• De-icingsaltsorchemicals
• Carbontetrachloride
• Halogentyperefrigerants
• Cleaningsolvents(perchloroethylene)
• Printinginks,paintremovers,varnishes,etc.
• Hydrochloricacid
• Cementsandglues
• Antistaticfabricsofteners
• Masonryacidwashingmaterials
THERMOSTAT
• This single stage gas furnace is designed to be
controlled by a conventional single stage thermostat.
The thermostat’s wiring must comply with the current
provisions of the NEC (ANSI/NFPA 70) and with
applicable local codes having jurisdiction. Thermostat
connections should be made in accordance with the
instructions supplied with the thermostat and the
indoor equipment.
• Thethermostatshouldbemountedabout5feetabove
the floor on an inside wall and not on an outside wall
or other location where its operation may be adversely
affected by radiant heat from fireplaces, sunlight, or
lighting fixtures, and convective heat from warm air
registers or electrical appliances.
• Thermostatstylesvary.Pleaserefertothethermostat
manufacturer’sUserManualfordetailedprogramming
instructions.
WARRANTY INFORMATION
A warranty certificate with full details is included with the
equipment. Carefully review these responsibilities with
your dealer or service company. The manufacturer will not
be responsible for any costs found necessary to correct
problems due to improper setup, improper installation,
adjustments, improper operating procedure on the part of
the user, Some specific examples of service calls which
are not included in the limited warranty are:
• Correcting wiring problems in the electrical circuit
supplying the equipment.
• Resettingcircuitbreakersorotherswitches.
• Adjustingorcalibratingofthermostat.
6
MAINTENANCE INFORMATION
Proper maintenance is important to achieve optimum performance from the furnace. This equipment should be
inspectedannuallybyalicensedHVACtechnician.Table1(page8)containssuggestedinspectionsandfrequency
of maintenance. Routine maintenance should include the following:
BLOWER & FILTER
• Neveroperatethefurnacewithoutalterinplace.Dust
and lint can build up on internal components, resulting
in loss of efficiency, equipment damage, and possible
fire.
• Keep air lters cleaned. Filters should be changed
or cleaned monthly during the heating season.
Clean or replace filter to maintain proper airflow and
achieve maximum efficiency. Newly built or renovated
homes may require more frequent changing until the
construction dust has minimized. Filters designed to
remove smaller particles such as pollen, may require
additional maintenance.
• 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.
CONDENSATE DRAINAGE
• This furnace produces liquid condensate which is
slightly acidic. The vent pipe must be sloped upwards
away from the furnace to properly drain the water back
into the condensate disposal system.
• Condensate drain tubes must maintain a downward
slope to ensure proper drainage. Periodically inspect
the condensate drain tube for proper drainage and
remove any possible blockages. Also, do not place
heavy objects on the tubing that restricts the flow of
condensate.
FURNACE & 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
connectionsshould berepairedbyaqualiedHVAC
technician.
• Furniture and drapery should be arranged so that
the supply air registers and return grilles are not
obstructed.
• Ifhouseisnewlybuilt,theoperationofagasfurnace
in a 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:
– Theltermustbereplaced(orcleaned)andthe
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 approved 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.
VENTING SYSTEM
• Forproperandsafeoperation,thefurnaceneedsairfor
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.
• Existingmasonrychimneysshouldbeinspectedand
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
alicensedHVACtechnician.
• Fluepassageways,theventsystem,andtheburners
should be inspected and cleaned (if required) by
a licensed HVAC technician annually to ensure
continued safe operation.
TROUBLESHOOTING
Ifthefurnacefailstooperatecheckthefollowing:
1.Isthethermostatsettingcorrect?
2.Aretheblowercompartmentdoor(s)inplace?
3.Hasthecircuitbreakertrippedorthecontrolboardfuse
burnedopen?
4.Isthegasturnedonatthemanualshutoff?
5.Isthelterdirtyorclogged?
If the furnace still doesn’t operate, contact a licensed
HVACtechnician
7
STARTUP & SHUTDOWN
STARTING THE FURNACE
1.Makesurethelteriscleanandinplace.
2.Makesuretheventsystemisproperlyinstalled.
3. Set the thermostat to the lowest setting.
4. Close the manual gas valve outside the furnace.
5. Turn off all electric to the furnace.
6. Remove the door from the burner compartment.
7. Set the gas valve On/Off knob to the OFF position.
See Figure 2 for gas valve knob location.
8.Wait5minutes.Ifthereisanysmellofgas,see“WHAT
TODOIFYOUSMELLGAS”onpage3.
9. Set the gas valve On/Off knob to the ON position.
10.Turnonallelectrictothefurnace.
11.Openthemanualgasvalve.
12.Turnthethermostatbackuptoforceignition.
13.Observeoperation,includingburners.Ifburnersfail
toignite,callalicensedHVACtechnician.
14.Replacethedoorontheburnercompartment.
SHUTTING DOWN THE FURNACE
IFYOUNEEDTOSHUTDOWN
YOUR FURNACE FOR SERVICE OR
MAINTENANCE,FOLLOWTHESESTEPS:
1.Setthethermostattothelowestsetting.
2. Close the manual gas valve outside the furnace.
3. Turn electric to the furnace off.
4. Open the door to the burner compartment.
5. Set the gas valve On/Off knob to the OFF position.
6. Replace the door on the burner Compartment.
Figure2.GasValve
ON / OFF Knob
OFF Position
ON Position
MAINTENANCE ITEM
FREQUENCY OF MAINTENANCE
BEGINNING OF EACH
HEATING SEASON
END OF EACH
HEATING SEASON
MONTHLY
Verify furnace area is free of combustible
materials.
X X X
Verify combustion and ventilation air is
not restricted.
X X X
Verify no signs of physical deterioration
of the furnace.
X X X
Verify no obstructions or restrictions in
vent or chimney.
X X
Verify no holes or cracks in vent pipe.
X X
Verify no corrosion in vent pipe.
X X
Verify the horizontal vent pipes slope
upwards away from furnace.
X X
Verify burner flame.
X
Cleanorreplacelter(s).
X
Clean blower compartment.
X
Clean burner assembly.
X
Clean condensate collection and
disposalsystem(ifapplicable).
X
Table1.MaintenanceTable
The furnace components shown in Figure 3 will help 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
userserviceableparts.AllrepairsmustbedonebyalicensedHVACtechnician.
FURNACE COMPONENTS
Figure3.M7RLFurnaceComponents
Blower Assembly
Inducer Assembly
Gas Valve
Gas Manifold &
Burner Assembly
Blower Switch
Control Board
Limit Switch
Inline Drain
Assembly
Igniter
Flame Sensor
Roll-Out Switch
Combustion Air Pipe
Exhaust Vent Pipe
Main Air Limit Switch
24V Transformer
M7RL B Cabinet Shown
Specifications & illustrations subject to change without notice or incurring obligations.
O’Fallon,MO|PrintedinU.S.A.(09/11)
709266A (Replaces7092660)
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