6
GeneralInformation
WARNING:
This furnace must be installed by a qualied
installingagencyandinaccordancewithapplicable
localcodesandordinancesthatgovernthistypeof
equipment.Failuretoproperlyinstallthefurnace,
baseassembly,andventingsystemasdescribed
hereinmaydamagetheequipmentand/orthehome,
cancreateareorasphyxiationhazard,violates
U.S.listingrequirements,andwillvoidthewarranty.
ThisfurnaceisNOTapprovedforinstallationwith
split system air conditioning. Use a NORDYNE
packagedairconditioningsystem.
• Instructionsfordeterminingtheadequacyofcombustion
airforaninstallationcanbefoundinthecurrentrevisionof
theNFGC(ANSIZ223.1/NFPA54).Theserequirements
areforUSinstallationsasfoundintheNFGC.Consult
localcodesforspecialrequirements.
• The requirements in Canada (B149.1) are structured
differently. Consult with B149.1 and local code ofcials
forCanadianinstallations.
The CMF3 Series furnace can draw combustion air from
outside the home (direct vent) or from the space being
conditioned.Thishighquality,directventfurnaceisusedfor
manufacturedhousingapplications.ItiscertiedtotheUL307
standards(UL307-Aforoilmodels;UL307-Bforgasmodels).
TheCMF3furnaceisavailableinpowergas(PGmodels)
orpoweroil(POmodels)andcanbeconvertedfrompower
oil to power gas, and vice versa. The power gas models
aredesignedfor operation with either natural or propane
(LP) gas. The ring rate of the CMF3 Convertible Series
canbeeld-installed(usingacertiedconversionkit)bya
qualiedservicetechnician.Refertopage14forconversion
information.
CAUTION:
Exhaustfans,clothesdryers,replacesandother
appliances that force air from the house to the
outdoors can create a negative pressure inside
thehouse,resultinginimproperfurnaceoperation
orunsafeconditionssuchasamerollout.Itis
imperative that sufcient air exchange with the
outdoorsisprovidedtopreventdepressurization.
Additional information about how to test for
negativepressureproblemscanbefoundinthe
NFGC.
CombustionAirQuality
CAUTION:
Combustionairmustnotbedrawnfromacorrosive
atmosphere.
Provisionsforadequatecombustionairandventilationair
must be in accordance with the ANSI Z223.1/NFPA 54,
(NationalFuelGasCode),ANSI/NFPA31(InstallationofOil
BurningEquipment),andallapplicablelocalcodes.
The installation of the furnace must allow for adequate
supplyoffreshairforcombustion.Airopeningsontopofthe
furnaceandopeningsinclosetdoorsorwallsmustnever
be restricted. The combustion air opening of the furnace
mustbedesignedandlocatedtopreventblockagebysnow.
Ifthefurnaceisoperatedwithoutadequateairforcombustion,
theameroll-outswitchwillopenandshutoffthegassupply
totheburners.
IMPORTANT NOTE
Thissafetydeviceisamanuallyresetswitch.DONOT
install jumper wires across these switches to defeat
their function or reset a switch without identifying
andcorrectingthefaultcondition.Ifaswitchmustbe
replaced,useonlythecorrectsizedpartspeciedinthe
ReplacementPartsListprovidedonline.
Thecombustionairfromtheoutsideneedstobeclearof
chemicals that can cause corrosion. Excessive exposure
to contaminated combustion air will result in safety and
performancerelatedproblems.Thelistbelowareexamples
ofchemicalcontaminantsfoundinawidevarietyofsome
commoncommercialandhouseholdproducts:
Permanentwavesolutions
Chlorinatedwaxesandcleaners
Chlorinebasedswimmingpoolchemicals
Watersofteningchemicals
De-icingsaltsorchemicals
CarbonTetrachloride
Cleaningsolvents(perchloroethylene)
Printinginks,paintremovers,varnishes,etc.
HydrochloricAcid
Cementsandglues
Antistaticfabricsofteners
Masonryacidwashingmaterials
Whendrawingcombustionairfromunderneaththehome,a
ventorductofatleast18in
2
offreeareashouldbeinstalled
outside and completely unobstructed. When using the
combustionairduct,makesureitextendsthroughtheoor.
DirectVentFurnaces
Direct Vent furnaces draw combustion air directly from
theoutdoorsandthenventthecombustionproductsback
outside,isolatingtheentiresystemfromtheindoorspace.
Itisimportanttomakesurethatthewholesystemissealed
andclearancestocombustiblesaremaintainedregardless
oftheinstallationbeinginaconnedorunconnedspace.
Thecombustionairhoseisprovidedandmustbeusedfor
directventapplications.
OnlyforspecialCB-200Acottagebaseinstallationscanthe
CMF3furnacedrawscombustionairfromtheconditioned
space. The CB-200A cottage base is an accessory item
thatcanbepurchasedseparately.Refertothereplacement
partslistingprovidedwiththefurnacetoorderthecottage
basekit.Followthe instructionsprovidedwiththe kitsfor
properinstallation.
When unsure about combustion air supply availability, a
directventsystemshouldbeused.Forsmallrooms,conned
spaces,tightconstructionorsimilarsituationsinwhichthe
combustion air requirements of the furnace might not be
met,adirectventsystemmustbeused.
Forallmanufacturedhousingapplications,theCMF3furnace
mustbeventedusingtheSRJseriesroofjackasshownin
Figure1.Theinstructionsforselectingtheproperroofjack
foryourinstallationaredetailedlaterintheseinstructions.