Sears N9MP1 User manual

International Comfort Products Corporation (USA)
Lewisburg, TN 37091 U.S.A.
FIRE OR EXPLOSION HAZARD
This furnace is not designed for use in mobile
homes, trailers or recreational vehicles.
Such use could result in death, bodily injury
and/or property damage.
!
* Denotes Brands (C, H, T)
!
Electric Shock Hazard
Turn Off All Power Before Servicing.
Failure to do so can result in death,
personal injury and/or property
damage.
INSTALLER: Affix these instructions
on or adjacent to the furnace.
CONSUMER: Retain these
instructions for future reference.
PrintedinU.S.A. 4/28/2003 440 01 1020 (02)
N9MP1 & N9MP2
*9MPD
FAN ASSISTED, DIRECT
VENT GAS FURNACE
SAFETY REQUIREMENTS
Recognizesafetyinformation. Thisisthesafety--alertsymbol !. Whenyouseethissymbolonthefurnaceandininstructionsmanualsbealertto
the potential for personal injury.
Understand the signal words DANGER, WARNING, or CAUTION. These words are used with the safety--alert symbol. DANGER identifies the
most serious hazards, those that will result in severe personal injury or death. WARNING signifies a hazard that could result in personal injury or
death. CAUTION is used to identify unsafe practices that could result in minor personal injury or product and property damage.
Installing and servicing heating equipment can be hazardous due to gas and electrical components. Only trained and qualified personnel should
install, repair, or service heating equipment.
Untrained service personnel can perform basic maintenance functions such as cleaning and replacing air filters. All other operations must be
performedbytrainedservicepersonnel. Whenworkingonheatingequipment,observeprecautionsintheliterature,ontags,andonlabelsattached
to or shipped with the unit and other safety precautions that may apply.
Follow all safety codes. In the United States, follow all safety codes including the current edition National Fuel Gas Code (NFGC) ANSI
Z223.1--2002/NFPA No.54--2002. InCanada,refertothecurrenteditionoftheNationalStandardofCanada NaturalGasandPropaneInstallation
Code (NSCNGPIC) CSA B149.1--00. Wear safety glasses and work gloves. Have fire extinguisher available during start--up and adjustment
procedures and service calls.
Theseinstructions coverminimumrequirementsandconformtoexistingnationalstandardsandsafetycodes. Insomeinstances,theseinstructions
exceedcertainlocalcodesandordinances,especiallythosethatmaynothavekeptupwithchangingresidentialconstructionpractices. Werequire
these instructions as a minimum for a safe installation.
Table of Contents
1. Safe Installation Requirements 3.................
2. Installation 4................................
3. Combustion & Ventilation Air 7..................
4. Vent & Combustion Air Piping 10................
5. Gas Supply and Piping 26......................
6. Electrical Wiring 30...........................
7. Ductwork and Filter 30........................
8. Checks and Adjustments 33....................
9. Furnace Maintenance 35.......................
10. Sequence of Operation & Diagnostics 35..........
11. Concentric Vent Termination 39.................
Tech Support and Parts 43........................

2440 01 1020 02
START--UP CHECK SHEET
For 90+ Furnace
(Keep this page for future reference)
Dealer Name:
Address:Business Card Here
City, State(Province), Zip or Postal Code:
Phone:
Owner Name:
Address:
City, State(Province), Zip or Postal Code:
Model Number:
Serial Number:
Type of Gas: Natural: LP:
Which blower speed tap is used?
(Heating) (Cooling)
Temperature of Supply Air: (°F) or(°C)
Temperature of Return Air: (°F) or(°C)
Rise (Supply Temp.--Return Temp.): (°F) or(°C)
Filter Type and Size:
Fan “Time ON” Setting:
Fan “Time OFF” Setting:
Manual Gas Shut--Off Upstream
of Furnace/Drip--Leg? YES NO
Condensate Drain Connected? YES NO
Condensate Drain Trapped? YES NO
Transition Pressure switch hose relocated for U/D/H
Application? YES NO
Blower Speed Checked? YES NO
All Electrical Connections Tight? YES NO
Gas Valve OK? YES NO
Measured Line Pressure When Firing Unit:
Calculated Firing Rate:(See Checks and Adjustments Sec-
tion).
Temperature Rise (supply--return temperature):(°F)
Measured Manifold Gas Pressure:
Static Pressure (Ducts): Supply Air Return
Date of Start--Up:
CO ?
CO2 ?
Dealer Comments:

3
440 01 1020 02
1. Safe Installation Requirements
DEATH, PERSONAL INJURY AND/OR PROPERTY
DAMAGE
Failure to carefully read and follow all instructions
in this manual can result in furnace malfunction,
death, personal injury and/or property damage.
Installation or repairs made by unqualified persons
can result in hazards to you and others. Installation
MUST conform with local codes or, in the absence
of local codes, with codes of all governmental
authorities having jurisdiction.
The information contained in this manual is
intended for use by a qualified service technician
who is experienced in such work, who is familiar
with allprecautionsandsafetyproceduresrequired
in such work, and is equipped with the proper tools
and test instruments.
!
NOTE: This furnace is design--certified by the CSA International
(formerly AGA and CGA) for installation in the United States and
Canada.Refertotheappropriatecodes,alongwiththismanual,for
proper installation.
·Use only the Type of gas approved for this furnace (see
RatingPlate onunit).Overfiringwillresultinfailure ofheat
exchanger and cause dangerous operation. (Furnaces
can be converted to L.P. gas with approved kit.)
·Install this furnaceonly in a location andposition as speci-
fied in “2. Installation” of these instructions.
·Provideadequatecombustionandventilationairtothefur-
naceas specifiedin“3.Combustionand VentilationAir” of
these instructions.
·Combustion products must be discharged outdoors. Con-
nectthisfurnaceto an approved vent systemonly, asspe-
cified in “4. Vent and Combustion Air Piping” of these
instructions.
·Never test for gas leaks with an open flame. Use a com-
mercially available soap solution made specifically for the
detection of leaks to check all connections, as specifiedin
“6. Gas Supply and Piping, Final Check” of these instruc-
tions.
·Always install furnace to operate within the furnace’s in-
tended temperature--rise range with a duct system which
hasanexternal static pressure withinthe allowablerange,
asspecifiedin“TechnicalSupportManual”oftheseinstruc-
tions.
·When a furnace is installed so that supply ducts carry air
circulated by the furnace to areas outside the space con-
tainingthefurnace,thereturnairshallalsobehandledbya
duct(s) sealed to the furnace casing and terminating out-
side the space containing the furnace.
·A gas--fired furnace for installation in a residential garage
mustbeinstalledasspecifiedin“2.Installation”ofthesein-
structions.
·This furnace is not to be used for temporary heating of
buildings or structures under construction.
·ThisfurnaceisNOTapprovedforinstallationinmobile
homes, trailers or recreation vehicles.
·Seal around supply and return air ducts.
·Install correct filter type and size.
·Unit MUST be installed so electrical components are pro-
tected from direct contact with water.
Safety Rules
Yourunitisbuilttoprovidemanyyearsofsafeanddependableser-
vice providing it is properly installed and maintained. However,
abuse and/or improper use can shorten the life of the unit and
create hazards for you, the owner.
A. The U.S. Consumer Product Safety Commission recom-
mends that users of gas--burning appliances install carbon
monoxide detectors. There can be varioussources of carbon
monoxideinabuildingordwelling.Thesourcescouldbegas--
fired clothes dryers, gas cooking stoves, water heaters, fur-
naces, gas--fired fireplaces, wood fireplaces, and several
other items.
Carbon monoxide can cause serious bodily injury and/or
death. Carbon monoxide or “CO” is a colorless and odorless
gasproducedwhenfuelisnotburnedcompletelyorwhenthe
flame does not receive sufficient oxygen.
Therefore, to help alert people of potentially dangerous car-
bon monoxide levels, you should have carbon monoxide de-
tectors that are listed by a nationally recognized agency (e.g.
UnderwritersLaboratoriesorInternationalApprovalServices)
installed and maintained in the building or dwelling (see Note
below).
B. There can benumerous sources of fireor smoke in a building
or dwelling. Fire or smoke can cause serious bodily injury,
death, and/or property damage. Therefore, in order to alert
people of potentially dangerous fire or smoke, you should
have fire extinguisher and smoke detectors listed by Under-
writersLaboratoriesinstalledandmaintainedinthebuildingor
dwelling (see Note below).
Note: The manufacturer of your furnace does not test any detec-
tors and makes no representations regarding any brand or
type of detector.
C. Toensuresafeandefficientoperationofyourunit,youshould
do the following:
1. Thoroughly read this manual and labels on the unit. This
will help you understand how your unit operates and the haz-
ards involved with gas and electricity.
2. Do not use this unit if any part has been under water. Im-
mediatelycallaqualifiedservicetechniciantoinspecttheunit
andtoreplaceanypartofthecontrolsystemandanygascon-
trol which has been under water.
3. Never obstruct the vent grilles, or any ducts that provide
air to the unit. Air must be provided for proper combustion
and ventilation of flue gases.
Frozen Water Pipe Hazard
FROZEN AND BURST WATER PIPE HAZARD
FaiIure to do so may result in burst water pipes, serious
property damage and/or personal injury.
Furnace may shut down. Do not leave your home
unattended for long periods during freezing weather
without turningoffwatersupplyanddrainingwaterpipes
or otherwise protecting against the risk of frozen pipes.
!
Your furnace is designed solely to provide a safe and comfortable
living environment. The furnace is NOT designed to ensure that
water pipes will not freeze. It is equipped with several safety de-
vices that are designed to turn the furnace off and prevent it from
restarting in the event of various potentially unsafe conditions.

4440 01 1020 02
If your furnace remains off for an extended time, the pipes in your
home could freeze and burst, resulting in serious water damage.
Watermaycreateaconditioninwhichmoldcangrowinyourhome.
Certain types of mold have been reported to cause respiratory
problemsorotherserioushealthrisks.Remedialactions,including
immediately drying all wet items, should be taken quickly to help
prevent the development of mold in your home.
If the structure will be unattended during cold weather you should
take these precautions.
1. Turnoffthewatersupplytothestructureanddrainthewater
lines if possible and add an antifreeze for potable water to
drain traps and toilet tanks. Open faucets in appropriate
areas.
-- or --
2. Have someone check the structure frequently during cold
weather to make sure it is warm enough to prevent pipes
from freezing. Instruct them on a service agency to call to
provide service, if required.
-- or --
3. Installareliableremotesensingdevicethatwillnotifysome-
body of freezing conditions within the home.
Winter Shutdown
If you go away during the wintermonths and do not leave the heat
oninyourhome,theplastictransitionboxandthecondensatetrap
on the furnace must be protected from freeze damage.(See
Figure 8 trough Figure 17)
1. Disconnect the 5/8²OD rubber hose from the vent drain fit-
tingthatislocateddownstreamofthecombustionblower.In-
sert a funnel into the hose and pour four(4) ounces of
sanitary type (RV) antifreeze into the condensate trap. Re-
connectthe5/8²ODrubberhosetothestubontheventdrain
fitting. Secure with the hose clamp.
2. Disconnect the 3/4²OD rubber hose from the condensate
trap. Insert a funnel into the hose and and pour four(4)
ouncesofsanitarytype(RV)antifreezeintotheplasticTran-
sition box. Squeeze the hose together near the end and
quicklyreconnectthe3/4²ODrubberhosetothestubonthe
condensate trap. Secure with the hose clamp.
When you return home, your furnace will be ready to start, as itis
not necessary to drain the antifreeze from the furnace.
2. Installation
CARBON MONOXIDE POISONING HAZARD
Failure to properly vent this furnace or other appliances
can result in death, personal injury and/or property
damage.
Thisfurnacecan NOTbe common ventedorconnectedto
any type B, BW or L vent or vent connector, nor to any
portion of a factory--built or masonry chimney. If this
furnace is replacing a previously common-vented
furnace, it may be necessary to resize the existing vent
andchimneyto preventoversizingproblems fortheother
remaining appliance(s). See Venting and Combustion Air
CheckinGasVentInstallationsection.ThisfurnaceMUST
be vented to the outside.
!
Location and Clearances
4. RefertoFigure 1 orFigure 2 fortypicalinstallationandba-
sic connecting parts required. Refer to Figure 4 for typical
horizontaldirectventinstallationandbasicconnectingparts
required. Supply and return air plenums and duct are also
required.
5. Iffurnaceisareplacement,itisusuallybesttoinstallthefur-
nace where the old one was. Choose the location or evalu-
atetheexistinglocationbasedupontheminimumclearance
and furnace dimensions (Figure 3).
CAUTION
Special precautions MUST be made if installing furnace in an
areawhichmaydropbelowfreezing.Thiscancauseimproper
operation or damage to equipment. If furnace environment
hasthepotentialoffreezing,thedrain trapand drainlinemust
be protected. The use of electric heat tape orRV antifreeze is
recommendedfortheseinstallations.(See“CondensateTrap
Freeze Protection Section”)
Do NOT operate furnace in a corrosive atmosphere
containing chlorine, fluorine or any other damaging
chemicals. Refer to Combustion & Ventilation Air section,
Contaminated Combustion Air.
Vent Pipes MUST be
supportedHorizontally
and Vertically
*8²Min.
20¢Max.
in same atmospheric
zone
*8²Min.
20¢Max.
in same
atmospheric
zone
Coupling on endsof
exhaust pipe. Total
pipe & coupling out-
side structure = 8²
Figure 1 Typical Upflow Installation
Aluminum or non-rusting shield recommended. (See
Vent Termination Shielding for dimensions).
*Increase minimum from 8²to 18²for cold climates (sustained temperatures below
0°F).
DISCHARGE AIR
25--23--33
Inlet Pipe (not
used on Single
Pipe model)

5
440 01 1020 02
*8²Min.
20¢Max.
in same
atmospheric zone
Figure 2 Typical Downflow Installation
Vent Pipes MUST be
supported Horizontally
and Vertically
*Increase minimum from 8²to 18²for cold climates (sustained temperatures
below 0°F).
See Vent Termination
Shielding inVentSection.
*8²Min.
20¢Max.
in same
atmosphericzone
8²Min.
Coupling on inside
and outside of wall
to restrain vent pipe
25--23--33a
Inlet Pipe
(not used on
Single Pipe
model)
DEATH, PERSONAL INJURY AND/OR PROPERTY
DAMAGE HAZARD.
Failureto properlyinstall thisfurnacecanresultindeath,
personal injury and/or property damage.
Do NOT operate furnace in a corrosive atmosphere
containing chlorine, fluorine or any other damaging
chemicals.
Refer to Combustion & Ventilation Air section,
Contaminated Combustion Air for combustion air
evaluation and remedy.
!
Installation Requirements
1. Install furnace level.
2. ThisfurnaceisNOTtobeusedfortemporaryheatofbuildings
or structures under construction.
3. Install the vent pipes as short as practical. (See Gas Vent
Installation section).
4. DoNOTinstallfurnacedirectlyoncarpeting,tileorothercom-
bustible material other than wood flooring.
5. Maintain clearance forfire safety and servicing. A front clear-
anceof30²isminimumforaccesstotheburner, controlsand
filter. See clearance requirements in Figure 3 or.
6. Use a raised base if the floor is damp or wet at times.
7. Residential garage installations require:
·Burnersandignitionsources installedat least18²(457mm)
above the floor.
·Furnace must be located or physically protected from pos-
sible damage by a vehicle.
8. Ifthefurnaceistobesuspendedfromthefloorjoistsinabase-
ment or a crawl space or the rafters in an attic, it is necessary
tousesteelpipestrapsoranangleironframetoattachthefur-
nace. These straps should be attached to the furnace with
sheet metal screws and to the rafters or joists with bolts. The
preferred method is to use an angle iron frame bolted to the
rafters or joists.
This furnace may be used for construction heat provided that:
·Thefurnaceispermanentlyinstalledwithallelectricalwiring,
piping, venting and ducting installed according to these
installationinstructions. Areturnairductisprovided,sealed
tothefurnacecasing,andterminatedoutsidethespacecon-
taining thefurnace. Thisprevents a negative pressure con-
dition as created by the circulating air blower, causing a
flame rollout and/or drawing combustion products into the
structure.
·Thefurnaceis controlledbyathermostat. Itmaynot be “hot
wired” to provide heat continuously to the structure without
thermostatic control.
·Cleanoutsideairisprovidedforcombustion. Thisistomini-
mize the corrosive effects of adhesives, sealers and other
construction materials. It also prevents the entrainment of
drywall dust into combustion air, which can cause fouling
and plugging of furnace components.
·The temperature of the return air to the furnace is no less
than55°F,withnoeveningsetbackorshutdown. Theuseof
the furnace while the structure is under construction is
deemed to be intermittent operation per our installation in-
structions.
·The airtemperature rise is within therated rise range on the
furnace rating plate, and the firing rate has been set to the
rating plate value.
·The filters used to clean the circulating air during the
construction process must be either changed or thoroughly
cleaned prior to occupancy.
·The furnace, ductwork and filters are cleaned as necessary
to remove drywall dust and construction debris from all
HVAC system components after construction is completed.
Installation Positions
This furnace can be installed in an upflow, horizontal (either left or
right) or downflow airflow position. DO NOT install this furnace on
its back. Forthe upflow position,the return air ductworkcan be at-
tached to either the left or right side panel and/or the bottom. For
horizontalanddownflowpositions,thereturnairductworkmustbe
attached to the bottom. The return air ductwork must never be at-
tached to the back of the furnace.
Furnace Installation Considerations
Theinstallationofthefurnaceforagivenapplicationwilldictatethe
positionofthefurnace,theairflow,ductworkconnections,ventand
combustion air piping.Consideration must be given to the follow-
ing:
Condensate Trap and Drain Lines
Thesuppliedcondensatetrapmustbeattachedtothefurnaceside
paneloneithertheleftorrightside.Forhorizontalinstallations,the
draintrapisverticallyattachedtothesidepanelbelowthefurnace.
A minimum clearance of 6²below the furnace is required for the
condensate trap. Downward slope of the condensate drain line
from the condensate trap to the drain location must be provided.
Adequatefreezeprotectionofthedraintrapandthedrainlinemust
be provided. See “Condensate Drain Trap” section for further de-
tails.

215/8
13/8
811/16
25--23--36b
Figure 3 Dimensions & Clearances
TOP
F
G
E
H
AIR INTAKE
VENT (*9MPD)
ELECTRICAL
11/4
TRAP (COUNTERFLOW)
LEFT SIDE
GAS
VENT
413/16
11/16
AIR INTAKE
(ALTERNATE)
TRAP
UPFLOW/HORIZONTAL
THERMOSTAT
111/16
175/16
241/16
283/4
297/8
3111/16
1311/16
1913/16
21/4
131/4
17/8215/824 47/8
7
FRONT
A
B
C
DBOTTOM
37/8
231/8
23/8
AIR INTAKE
(ALTERNATE)
RIGHT SIDE
TRAP (COUNTERFLOW)
ELECTRICAL
VENT
TRAP
UPFLOW/HORIZONTAL
THERMOSTAT
11/4
27/8
281/2181/21/2
TYP.
45/16
11/16
GAS
413/16
111/16
175/16
111/16
273/16
297/8
215/8
3311/16
17/8
913/16
13/16
47/8
21/4
24
40
191/4
7
6440 01 1020 02
Cabinet to Combustible Clearances
TOP BOT. RH LH BACK FRONT FLUE
1²0²0²0²0²3²0²
U
n
i
t
C
a
b
i
n
e
t
B
o
t
t
o
m
T
o
p
Unit Cabinet Bottom Top
U
n
i
t
Capacity A B C D E F G H
N9MP1050B12A 151/214 13/8125/8-- -- -- -- -- -- -- --
N9MP1075B12A 151/214 13/8125/8-- -- -- -- -- -- -- --
N9MP1080F16A 191/8175/821/8143/4-- -- -- -- -- -- -- --
N9MP1100F14A 191/8175/821/8143/4-- -- -- -- -- -- -- --
N9MP1100J20A 223/4211/4115/16 183/4-- -- -- -- -- -- -- --
N9MP1125J20A 223/4211/4115/16 183/4-- -- -- -- -- -- -- --
N9MP2050B12A 151/214 13/8125/8-- -- 41/2-- -- 73/4
N9MP2075B12A 151/214 13/8125/8-- -- 41/2-- -- 73/4
N9MP2080F16A 191/8175/821/8143/4-- -- 41/2-- -- 91/2
N9MP2100F14A 191/8175/821/8143/4-- -- 41/2-- -- 91/2
N9MP2100J20A 223/4211/4115/16 183/4-- -- 41/2-- -- 113/8
N9MP2125J20A 223/4211/4115/16 183/4-- -- 41/2-- -- 113/8
*9MPD050F12A 191/8175/821/8143/443/841/221/291/2
*9MPD075F12A 191/8175/821/8143/443/841/221/291/2
*9MPD080J16A 223/4211/4115/16 183/443/841/225/8113/8
*9MPD100J14A 223/4211/4115/16 183/443/841/225/8113/8
*9MPD100J20A 223/4211/4115/16 183/443/841/225/8113/8
*9MPD125L20A 241/223 7/16 23 43/841/221/4121/4

7
440 01 1020 02
Leveling
Proper leveling of the furnace must be provided to insure proper
drainageofthecondensatefromthefurnace.Thefurnacemustbe
leveltowithin1/4²fromfronttobackandfromsidetosideforupflow
and downflow installations or top to bottom forhorizontal installa-
tions.
Vent and Combustion Air Connections
On the Dual Certified furnace, the vent and combustion air pipes
attachtothefurnacethroughthetoppanelfortheupflowandhori-
zontal installations. For the downflow installation, the vent and
combustion air pipes attach to the furnace through the alternate
locations on the furnace side panels.
Note:OntheDirectVentfurnace,theventpipeattachestothefur-
nacethroughthesidepanels.Thecombustionairpipeattachesto
the top panel or to the alternate location on the side panel.
On the Single Pipe furnace, the vent pipe attaches to the furnace
through the furnace side panels.
Note: Repositioning of the combustion blower is required for the
vent pipe connection to the furnace through the “right side” panel.
See “Vent and Combustion Air Piping” section for further details.
Horizontal Furnace Installation
This furnace can be installed horizontally in an attic, basement,
crawlspace,alcove,orsuspendedfromaceiling in a basementor
utility room . See Figure 4. Do not install furnace on its back or in
thereverseairflowpositionsassafetycontroloperationwillbead-
versely affected.
Inlet Pipe (not used on Single Pipe model)
Typical Horizontal Installation
Figure 4
Vent
Pipe
Condensate
Trap
NOTE: 6²
²²
²bottom clearance required for condensate trap.
25--23--34
If the furnace is to be suspended from the floor joists in a crawl
space or the rafters in an attic, it is necessary to use steel pipe
strapsoranangleironframetorigidlyattachthefurnacetoprevent
movement. These straps should be attached to the furnace with
sheet metal screws and to the rafters or joists with bolts. The pre-
ferred method is to use an angle iron frame bolted to the rafters or
joists.(Takecautiontoallowdoorpanelstoberemovedformainte-
nance)
Ifthefurnaceistobeinstalledinacrawlspace,consultlocalcodes.
A suitable concrete pad or blocks are recommended for crawl
space installation on the ground.
NOTE: 6²bottom clearance required for condensate trap.
Thirty (30) inches between the front of the furnace and adjacent
construction or other appliances MUST be maintained for service
clearance.
Keep all insulating materials clear from louvered door. Insulating
materials may be combustible.
The horizontal furnaces may be installed directly on combustible
wood flooring or supports as long as all required furnace clear-
ances are met. See Figure 4.
Thisfurnace MUSTNOTbeinstalleddirectlyoncarpetingortileor
other combustible material other than wood flooring or supports.
Forhorizontalinstallationoverafinishedlivingspace.Afieldfabri-
catedauxiliarydrainpanwithdrainpipeisrequiredtopreventdam-
age by overflow due to blocked condensate drain.
3. Combustion & Ventilation Air
For Single Pipe Installation
CARBON MONOXIDE POISONING HAZARD
Failure to provide adequate combustion and ventilation
air can result in death and/or personal injury.
Use methods described here to provide combustion and
ventilation air.
!
Furnaces require ventilation openings to provide sufficient air for
proper combustion and ventilation of flue gases. All duct or open-
ingsforsupplyingcombustionandventilationairmustcomplywith
National Fuel Gas Code, NFPA54/ANSI Z223.1, 2002 (or current
edition) and applicable provisions of local building codes.
ThisfurnacecanNOTbecommonventedorconnectedtoanytype
B, BW or L vent or vent connector, nor to any portion of a factory--
built or masonry chimney. If this furnace is replacing a previously
common-ventedfurnace,itmaybenecessarytoresizetheexisting
vent and chimney to prevent oversizing problems for the other re-
mainingappliance(s).See“VentingandCombustionAirCheck”in
this section.This furnace MUST be vented to the outside.
Air Openings and Connecting Ducts
1. TotalinputratingforallnondirectventgasappliancesMUST
be considered when determining free area of openings.
2. Connect ducts or openings directly to outside.
3. When screens are used to cover openings, they MUST be
no less than 1/4²mesh.
4. The minimum dimension of rectangular air ducts MUST
NOT be less than 3².
5. When sizing grille or louver, use the free area of opening. If
free area is NOT stamped or marked on grill or louver, as-
sume a 20% free area for wood and 60% for metal.
Confined Space Installation
NOTE: A confined space is defined as an area with less than 50
cubic feet per 1,000 BTUH input rating for all gas appliances
installed in the area.
Requirements
1. Provide confined space with sufficient air for proper com-
bustionandventilationoffluegasesusinghorizontalorverti-
cal ducts or openings.

8440 01 1020 02
2. Figure 5 illustrate how to provide combustion and ventila-
tion air. A minimum of two permanent openings, one inlet
and one outlet, are required.
3. OneopeningMUSTbewithin12²ofthefloorandthesecond
opening within 12²of the ceiling.
Minimum One Inlet and One Outlet Air Supply is Required
May be in any Combination Shown
Inlet Air Opening Must be Within12²of floor
Outlet Air Opening Must be Within12²of ceiling
(1) 1 Square Inch per 4000 BTUH
(2) 1 Square Inch per 2000 BTUH
Outside Air (This is ONLY a guide. Subject to codes of country having jurisdiction.)
Figure 5
This installation NOT approved in Canada
Gas Vent Gable Vent
Ventilated Attic
Top Above Insulation
alternate Inlet Air (1)
Ventilated Crawl Space
Outlet Air (1) Soffit Vent Outlet
Air (1)
Inlet
Air (1)
Outlet
Air (2)
Inlet
Air (2)
Gas Vent
Inlet
Air (2)
Soffit Vent
Gas Vent Gable Vent
Ventilated Attic
Top Above Insulation
Inlet
Air (1)
OutletAir (1)
alternate Inlet Air (1)
4. Size openings and ducts per Table 1.
5. Horizontal duct openings require 1 square inch of free area
per 2,000 BTUH of combined inputfor all gas appliances in
area (see Table 1).
6. Vertical duct openings or openings directly to outside re-
quire 1 square inch of free area per 4,000 BTUH for com-
bined input of all gas appliances in area (see Table 1).
Table 1 Free Area
BTUH Minimum Free Area Required for Each Opening
B
T
U
H
Input
Rating Horizontal Duct
(2,000 BTUH) Vertical Duct or openings to outside (4,000 BTUH) Round Duct (4,000 BTUH)
50,000 25 sq. in. 12.5 sq. in. 4²
75,000 37.5 sq. in. 18.75 sq. in. 5²
100,000 50 sq. in. 25 sq. in. 6²
125,000 62.5 sq. in. 31.25 sq. in. 7²
150,000 75 sq. in. 37.5 sq. in. 7²
EXAMPLE: Determining Free Area
Appliance 1 Appliance 2 Total Input
100,000 +30,000 = (130,000 ¸4,000) = 32.5 Sq. In. Vertical
Appliance 1 Appliance 2 Total Input
100,000 +30,000 = (130,000 ¸2,000) = 65 Sq. In. Horizontal
One permanent opening, commencing within 12²of the top of the
enclosure,shallbepermittedwheretheequipmenthasclearances
of at least 1²from the sides and back and 6²from the front of the
appliance. The opening shall directly communicate with the out-
doorsorshall communicatethroughaverticalorhorizontalductto
theoutdoorsorspaces(crawlorattic)thatfreelycommunicatewith
the outdoors, and shall have a minimum free area of:
·1 sq. in per 3000 Btu per hr. of the total input rating of all
equipment located in the enclosure, and
·Notlessthanthe sum ofthe areas of all vent connectors in
the confined space.
Unconfined Space Installation
CARBON MONOXIDE POISONING HAZARD
Failure to supply additional air by means of ventilation
grilles or ducts could result in death and/or personal
injury.
An unconfined space or homes with tight construction
may not have adequate air infiltration for proper
combustion and ventilation of flue gases.
Most homes will require additional air.
!
An unconfined spaceis defined as anarea having a minimumvol-
umeof50cubicfeetper1,000Btuhtotalinputratingforallgasap-
pliances in area. Refer to Table 2 for minimum area required.
Table 2 Unconfined Space
Minimum Area in Square Feet
BTUH Input
Rating Minimum Area in Square Feet
50,000 312
78,000 490
114,000 712
155,000 968
EXAMPLE: NOTE: Square feet is based on 8 foot ceilings.
28,000 BTUH X 50CubicFt. = 1,400 = 175 Sq. Ft.
1,000 8¢Ceiling Height
NOTE: Refer to definitions in section titled Unusually Tight
Construction. If any one of the conditions apply, the space MUST
be considered confined space regardless of size.
1. Adjoining rooms can be considered part of an unconfined
area if there are openings without doors between rooms.
2. An attic or crawl space may be considered an unconfined
space provided there are adequate ventilation openingsdi-
rectly to outdoors. Openings MUST remain open and NOT
haveanymeansofbeingclosedoff.Ventilation openings to
outdoorsMUST be at least1²square of free area per 4,000
BTUH of total input rating for all gas appliances in area.

9
440 01 1020 02
3. Install air intake a minimum of 12²above maximum snow
level and clear of any obstruction. Duct or ventilation open-
ingrequiresonesquareinchof freeareaper4,000BTUHof
total input rating for all gas appliances in area.
4. Air inlet MUST be screened with not less than 1/4²mesh
screen.
Unusually Tight Construction
In unconfined spaces, infiltration may be adequate to provide air
for combustion, ventilation and dilution of flue gases. However, in
buildingswithunusuallytightconstruction,additionalairMUSTbe
provided using the methods described in section titled Confined
Space Installation:
Unusually tight construction is defined as: Construction with
1. Walls and ceilings exposed to the outside have a continu-
ous,sealedvaporbarrier.Openingsaregasketedorsealed
and
2. Doors and openable windows are weather stripped and
3. Other openings are caulked or sealed. These includejoints
around window and door frames, between sole plates and
floors, between wall--ceiling joints, between wall panels, at
penetrations for plumbing, electrical and gas lines, etc.
Ventilation Air
Some provincial codes and localmunicipalities require ventilation
or make--up air be brought into the conditioned space as replace-
mentair.Whichevermethodisused,themixedreturnairtempera-
ture across the heat exchanger MUST not fall below 60°Forflue
gaseswillcondenseintheheatexchanger.Thiswillshortenthelife
of the heat exchanger and possibly void your warranty.
Venting and Combustion Air Check
NOTE: When an existing Category I furnace is removed or re-
placed,theoriginalventingsystemmaynolongerbesizedtoprop-
erly vent the attached appliances, and to make sure there is
adequatecombustionairforallappliances,MAKETHEFOLLOW-
ING CHECK.
Vent Check
Draft HoodVent Pipe
Match
Typical Gas
Water Heater
Figure 6
Ifflame pulls towardsdrafthood,thisindicatessufficient
venting.
CARBON MONOXIDE POISONING HAZARD
Failure to follow the steps outlined below for each
applianceconnectedtotheventingsystembeingplaced
into operation, while all other appliances connected to
the venting system are not in operation could result in
carbon monoxide poisoning or death.
The followingsteps shall be followedfor each appliance
connected to the venting system being placed into
operation, while all other appliances connected to the
venting system are not in operation:
1. Seal any unused openings in the venting system.
2. Inspect the venting system for propersize and horizontal
pitch, as required in the National Fuel Gas Code, ANSI
Z223.1/NFPA 54 or CSA B149.1, Natural Gas and Pro-
pane Installation Codes and these instructions. Deter-
minethatthereisnoblockageorrestriction,leakage,cor-
rosion and other deficiencies which could cause an un-
safe condition.
3. As far as practical, close all building doors and windows
andalldoorsbetweenthespaceinwhichtheappliance(s)
connected to the venting system are located and other
spaces of the building.
4. Close fireplace dampers.
5. Turn on clothes dryers and any appliance not connected
to the venting system. Turn on any exhaust fans, such as
range hoods and bathroom exhausts, so they willoperat-
ingatmaximumspeed.Donotoperateasummerexhaust
fan.
6. Followthelightinginstructions.Placethe appliancebeing
inspected into operation. Adjust thermostat so appliance
is operating continuously.
7. Test for spillage from draft hood equipped appliances at
thedrafthoodreliefopeningafter5minutesofmainburner
operation. Usethe flame ofa match or candle. (Figure 6)
8. If improper venting is observed, during any of the above
tests, the venting system must be corrected in accor-
dance with the National Fuel Gas Code, ANSI
Z223.1/NFPA 54 and/or CSA B149.1, Natural Gas and
Propane Installation Codes.
9. After it has been determined that each appliance con-
nected to the venting system properly vents whentested
as outlined above, return doors, windows, exhaust fans,
fireplace dampers and any other gas--fired burning ap-
pliance to their previous conditions of use.
!
For Two Pipe Installation
ThisfurnacecanNOTbecommonventedorconnectedtoanytype
B, BW or L vent or vent connector, nor to any portion of a factory--
built or masonry chimney. If this furnace is replacing a previously
common-ventedfurnace,itmaybenecessarytoresizetheexisting
vent and chimney to prevent oversizing problems for the other re-
mainingappliance(s).See“VentingandCombustionAirCheck”in
this section.ThisfurnaceMUSTbeventedtotheoutside.

10 440 01 1020 02
4. Vent and Combustion Air Piping
CARBON MONOXIDE POISONING, FIRE AND EXPLOSION
HAZARD
Failure to properly vent this furnace can result in death,
personal injury and/or property damage.
Read and follow all instructions in this section.
!
SinglePipe(N9MP1Models)
This furnace is certified as a category IV appliance. This furnace
requires ventilation openings to provide air for proper combustion
and ventilation of flue gases. All duct or openings for supplying
combustion and ventilation air must comply with the gas codes or
in absence of local codes, the applicable national codes.
Whentheinstallationiscomplete,seethe“VentingandCombus-
tion Air Check” in this manual.
Direct Vent (N9MP2 Models)
This furnace is certified as a category IV appliance. This furnace
uses outside air for combustion ONLY, it MUST be taken from the
sameatmosphericpressurezoneastheventpipe. SeeConfined
SpaceInstallationintheCombustionandVentilationAir inthis
manual.
Dual Certified (*9MPD Models)
This furnace is certified as a category IV appliance. This furnace
can be installed as a direct vent furnace using outsideair for com-
bustionorthefurnacecanuseairfrominsidethestructureforcom-
bustion. The INLET air pipe is optional. If combustion air comes
frominsidethestructure,adequatemakeupairMUSTbeprovided
tocompensateforoxygenburned.SeeConfinedSpace Installa-
tion in the Combustion and Ventilation Air chapter. If combus-
tion air is drawn from outside the structure, it MUST be taken from
the same atmospheric pressure zone as the vent pipe.
Contaminated Combustion Air
Installationsincertainareasortypesofstructureswillincreasethe
exposure to chemicals or halogens that may harm the furnace.
Thefollowingareasor typesof structures may containor haveex-
posure to the substances listed below. The installation must be
evaluatedcarefullyasitmaybenecessarytoprovideoutsideairfor
combustion.
·Commercial buildings.
·Buildings with indoor pools.
·Furnaces installed in laundry rooms.
·Furnaces installed in hobby or craft rooms.
·Furnaces installed near chemical storage areas.
·Permanent wave solutions for hair.
·Chlorinated waxes and cleaners.
·Chlorine based swimming pool chemicals.
·Water softening chemicals.
·De--icing salts or chemicals.
·Carbon tetrachloride.
·Halogen type refrigerants.
·Cleaning solvents (such as perchloroethylene).
·Printing inks, paint removers, varnishes, etc.
·Hydrochloric acid.
·Sulfuric Acid.
·Solvent cements and glues.
·Antistatic fabric softeners for clothes dryers.
·Masonry acid washing materials.
Vent and Combustion Air Piping Guidelines
ThisfurnaceisapprovedforventingwithSchedule40PVC,CPVC,
ABS, Cellular Core pipe fittings and SDR--26 PVC.
NOTE: All PVC, CPVC, ABS, and Cellular Core pipe fittings, sol-
ventcement,primersandproceduresMUSTconformtoAmerican
National Standard Institute and American Society for Testing and
Materials (ANSI/ASTM) standards.
·Pipe and Fittings -- ASTM D1785, D2241, D2466, D2661,
D2665, F--891, F--628
·PVC Primer and Solvent Cement -- ASTM D2564
·Procedure for Cementing Joints -- Ref ASTM D2855
NOTE: All vent piping MUST be installed in compliance with local
codesorordinances,theseinstructions,goodtradepractices,and
codes of country having jurisdiction.
1. Determinethebestroutingandterminationforthe ventpipe
and air inlet pipe by referring to all of the instructions and
guidelines in this Section.
2. Determine the size required for the vent pipe and air inlet
pipe.
3. Loosely assemble all venting parts without adhesive (pipe
joint cement) for correct fit before final assembly.
4. Use of vertical piping is preferred because there will be
some moisture in the flue gases that may condense as it
leavestheventpipe(SeeSpecialInstructionForHorizontal
Vents).
5. TheverticalventpipeMUSTbesupportedsothatnoweight
is allowed to rest on the combustion blower.
6. Exhaust vent piping or air inlet piping diameter MUST NOT
be reduced.
7. All exhaust vent piping from the furnace to termination
MUST slope upwards. A minimum of 1/4²per foot of run is
required to properly return condensate to the furnace drain
system.
8. Use DWV type long radius elbows whenever possible, as
they provide for the minimum slope on horizontal runs and
they provide less resistance in the vent system. If DWV el-
bows cannot be used, use two, 45°elbows when possible.
On horizontal runs the elbows can be slightly misaligned to
provide the correct slope.
9. All horizontal pipe runs MUST be supported at least every
fivefeetwithgalvanized strap orotherrust resistant materi-
al. NO sags or dips are permitted.
10. All vertical pipe runs MUST be supported every six feet
where accessible.
11. The minimum pipe run length is 2¢.
12. Thepiping canberuninthesamechaseoradjacent tosup-
ply or vent pipe for water supply or waste plumbing. It can
also be run in the same chase with a vent from another 90+
furnace.
NOTE:InNO case can the piping be run in a chase where
temperatures can exceed 140°F. or where radiated heat
from adjacent surfaces would exceed 140°F.
13. The vent outlet MUST be installed to terminate in the same
atmospheric pressure zone as the combustion air inlet.
14. Theventsystemcanbeinstalledinanexistingunusedchim-
ney provided that:

11
440 01 1020 02
·Both the exhaust vent and air intake run the length of the
chimney.
·No other gas fired appliance or fireplace (solid fuel) is
vented into the chimney.
·The top of the chimney MUST be sealed flush or crowned
uptosealagainstrainormeltingsnow so ONLY thepiping
protrudes.
·The termination clearances shown in Figure 7 are main-
tained.
15. Furnaceapplicationswithverticalventsrequiringventdiam-
eter increaser fittings must have increaser fittings installed
in vertical portion of the vent. Condensate will be trappedin
the vent if the vent diameter is increased prior to having an
elbowturnedupward.Thiscouldcausenuisancetrippingof
the pressure switch.
Piping Insulation Guidelines
NOTE:Useclosedcell,neopreneinsulationorequivalent.IfFiber-
glass orequivalent insulation is used itmust havea vapor barrier.
UseRvaluesof7 upto10¢,R--11ifexposureexceeds10¢.IfFiber-
glassinsulationisused,exteriortothestructure,thepipeMUSTbe
boxed in and sealed against moisture.
1. When the vent or combustion airpipe height above the roof
exceeds 30², or if an exteriorvertical riser is used on a hori-
zontal vent to get above snow levels, the exterior portion
MUST be insulated.
2. When combustion air inlet piping is installed above a sus-
pended ceiling, the pipe MUST be insulated with moisture
resistant insulation such as Armaflex or other equivalent
type of insulation.
3. Insulatecombustionairinletpipingwhenruninwarm,humid
spaces such as basements.
Sizing Combustion Air and Vent Pipe
Consult Table 3 or Table 4 to select the proper diameter exhaust
and combustion air piping. Exhaust and combustion air piping is
sized for each furnace Btuh size based on total lineal vent length
(on inlet or outlet side), and number of 90°elbows required. Two
45°elbows can be substituted for one 90°elbow. The elbow or el-
bowsusedforventterminationoutsidethestructureAREcounted,
including elbows needed to bring termination above expected
snow levels. The elbow inside the furnace on the *9MPD IS NOT
included in the count.
Table 3 Pipe Diameter Table
N9MP1 & *9MPD Models
50,000, 75,000 & 80,000 Btuh Furnaces
40¢& (5) 90°elbows with 2²PVC pipe or
70¢& (5) 90°elbows with 3²PVC pipe
100,000 Btuh Furnace
40¢& (5) 90°elbows with 3²PVC pipe or
70¢& (5) 90°elbows with 3²PVC pipe &
Long Vent Kit (See Tech. Manual)
125,000 Btuh Furnace
40¢& (5) 90°elbows with 3²PVC pipe
Elbows are DWV Long Radius Type for 2²and 3²vents.
If more than five elbows are required, reduce the length of
both the inlet and exhaust pipes 5¢for each additional elbow
used.
NOTE: It is allowable to use larger diameter pipe and fitting than
shown in the tables but not smaller diameters than shown.
Table 4 Pipe Diameter Table
N9MP2 Models
50,000 & 80,000 Btuh Furnaces
40¢& (5) 90°elbows with 2²PVC pipe or
70¢& (5) 90°elbows with 3²PVC pipe
75,000 Btuh Furnaces
25¢& (3) 90°elbows with 2²PVC pipe or
40¢& (5) 90°elbows with 2²PVC pipe &
Long Vent Kit (See Tech. Manual) or
70¢& (5) 90°elbows with 3²PVC pipe
100,000 Btuh Furnace
40¢& (5) 90°elbows with 3²PVC pipe or
70¢& (5) 90°elbows with 3²PVC pipe &
Long Vent Kit (See Tech. Manual)
125,000 Btuh Furnace
40¢& (5) 90°elbows with 3²PVC pipe
Elbows are DWV Long Radius Type for 2²and 3²vents.
If more than five elbows are required, reduce the length of
both the inlet and exhaust pipes 5¢for each additional elbow
used.
For “Concentric Termination Kit” Venting table, see
“Section 11” in this manual.
Vent Termination Clearances
CARBON MONOXIDE POISONING, FIRE AND EXPLOSION
HAZARD
Failure to properly vent this furnace can result in death,
personal injury and/or property damage.
Inlet and outlet pipes may NOT be vented directly above
each other.
!
1. Determine termination locations based on clearancesspe-
cified in following steps and as shown in Figure 7,
Figure 19, through Figure 27.
For “Concentric Termination Kit” clearances, see Figure 45,
Figure 46, Figure 47, Figure 48 and Figure 49 in “Section 10”
in this manual.
2. The vent termination must be located at least 12²above
ground or normally expected snow accumulation levels.
3. DoNOTterminateoverpublicwalkways.Avoidareaswhere
condensate may cause problems such as above planters,
patios,oradjacenttowindowswheresteammaycausefog-
ging.
4. Theventterminationshall belocated atleast 4¢horizontally
from any electric meter, gas meter, regulator, and any relief
equipment. These distances apply ONLY to U.S. installa-
tions.
5. The vent termination is to be located at least 3¢above any
forced air inlet located within 10¢; and at least 10¢from a
combustion air intake of another appliance, except another
direct vent furnace intake.
6. InCanada,theCanadianFuelGasCodetakesprecedence
over the preceding termination instructions.

12 440 01 1020 02
Vent Termination Clearances
(United States Only)
Figure 7
In Canada See Canadian Fuel Gas Code
Direct Vent
Terminal
50,000 Btuh
or less Other Than
Direct Vent
Terminal
Direct Vent Terminal
More Than 50,000 Btuh
Other Than
Direct Vent
Terminal
Other Than
Direct Vent
Terminal
Forced Air
Inlet
10--11-- 36
9²
12²
²²
²
12²
²²
²
12²
²²
²
12²
²²
²
12²
²²
²
10¢
¢¢
¢
3¢
¢¢
¢
4¢
¢¢
¢
4¢
¢¢
¢
Condensate Drain Trap
Thisfurnaceremovesbothsensibleandlatentheatfromtheprod-
ucts of combustion. Removal of the latent heat results in con-
densationofthewatervapor.Thecondensateisremovedfromthe
furnace through the drains in the plastic transition and the vent fit-
ting. The drains connect to the externally mounted condensate
drain trap on the left or right side of the furnace.
The startup of a new furnace will involve a cycle or two of the fur-
nace to properly prime the condensate trap with water. Until the
trap is fully primed, some condensate will be pulled into the com-
bustionblower.Thefurnacemaycycleonthepressureswitchcon-
nected to the plastic transition box due to condensate buildup.
After thetrap is primed, thecondensate will start draining fromthe
furnace. The combustion blower will clear outany remaining con-
densateintheblowerhousingthrough theventfittingdownstream
ofthe blower.Notethatthe condensatetrapcanalsobeprimedby
pouring water into the 1/2²drain hose. Remove the1/2²ID drain
hosefromeitherthe gutterorthewhitePVCTeeTrap.Usingafun-
nelpoureight(8)ouncesofwaterinto1/2²IDdrain hose.Waterwill
flow through the drain hose and into the condensate drain trap.
Thiswillprimeboththeventandthetransitionsidesofthetrap.Re-
connectthe1/2²IDdrainhosetotheoriginalcomponent,eitherthe
gutter or the PVC Tee Trap.
The condensate drain trap supplied with the furnace MUST be
used. The drain connection on the condensate drain trap is sized
for3/4²PVCorCPVC pipe,howeveralternate1/2²CPVC(nominal
5/8²O.D.) or vinyl tubing with a minimum inner diameter (I.D.) of
5/8²may also be used, as allowed by local codes. Alternate drain
pipes and hoses may be used as allowed by local codes.
Thedrainlinemustmaintaina1/4²perfootdownwardslopetoward
thedrain.1/4²perfoot isrecommended.Installationofanoverflow
line is recommended when the 1/4²per foot slope to the conden-
sate drain cannot be maintained. See Figure 1 for proper routing
and installation of the overflow.
DONOTtrapthedrainlineinanyotherlocationthanattheconden-
sate drain trap supplied with the furnace.
FROZEN AND BURST WATER PIPE HAZARD
Failure to do so may result in burst water pipes, serious
property damage and/or personal injury.
If a condensate pump is installed, a plugged condensate
drainorafailedpumpmaycausethefurnacetoshutdown.
Donotleavethehomeunattendedduringfreezingweather
without turning off water supply and draining water pipes
or otherwise protecting against the risk of frozen pipes.
!
If possible DO NOT route the drain line where it may freeze. The
drain line must terminate at an inside drain to prevent freezing of
the condensate and possible property damage.
1. AcondensatesumppumpMUSTbeusedifrequiredbylocal
codes, or if no indoor floor drain is available. The conden-
sate pump must be approved for use with acidic conden-
sate.
2. A plugged condensate drain line or a failed condensate
pumpwillallowcondensatetospill.Ifthefurnaceisinstalled
where a condensate spill could cause damage, it is recom-
mended that an auxiliary safety switch be installed to pre-
ventoperationoftheequipmentin the eventof pumpfailure
or plugged drain line. If used, an auxiliary safety switch
should be installed in the R circuit (low voltage) ONLY.
3. If the auxiliary switch in the condensate pump is used, the
furnacemayshut downduetoablockedcondensatelineor
failed pump. To prevent frozen waterpipes see the “Frozen
Water Pipe Hazard” section on Page 4 of this manual.
Condensate Drain Trap Freeze Protection
SpecialprecautionsMUSTbemadeifinstallingfurnacein anarea
which may drop below freezing. This can cause improper opera-
tion or damage to the equipment. If the the furnace environment
has the potential of freezing, the drain trapand drain line mustbe
protected.Use3to6wattperfootat115volt,40°Fself--regulating
shielded and waterproof heat tape. Wrap the drain trap and drain
linewiththeheattapeandsecurewiththeties.Followtheheattape
manufacturer’s recommendations.

13
440 01 1020 02
AIR FLOW
Figure 8 Upflow Installations Top Vent
Street Elbow
1/2²
²²
²CPVC
(Loose parts bag)
Casing Grommet
Black Rubber
5/8²
²²
²ID
(Loose parts bag)
DrainTee
Drain Connector Black PVC
3/4²
²²
²PVC X 1/2²
²²
²CPVC
(Loose parts bag)
Drain Line Vent Tee 3/4²
²²
²PVC or
1/2²
²²
²CPVC (Field supplied)
1/2²
²²
²ID Drain
Hose & Clamps
5/8²
²²
²ID Hose & Clamps
3/16²
²²
²ID Rubber Tube
Coupling & Clamps
(Optional)
INLET
EXHAUST
25--24--42
Single Pressure Switch
Dual Pressure Switch Detail
Drain Tube (& Clamps)Black Rubber 5/8²
²²
²ID,
Cut length to fit (Loose parts bag)
On Some Models
ONLY
Yellow or black Plastic
Caps (2)
Vent Drain
&Clamps
Upflow Installations Top Vent (See Figure 8)
RemoveplugfromthesideofthefurnacecasingwhereDrainTube
will exit.
Install casing grommet (black rubber 5/8²ID grommet -- in loose
parts bag)
Install the 1/2²CPVC street elbow on discharge of Trap
Install the black PVC tube connector (3/4²PVC x 1/2²CPVC from
loose parts bag) as shown in the illustration above.
Cut the black Drain Tube (5/8²ID -- in loose parts bag) to length to
fit between Trap and tube connector through grommet.
Clamp both ends of the Drain Tube using clamps provided.
GluetheCPVCstreetelbowto the Trapusingappropriatecleaner
and solvent cement.
Connect the Tee trap and the main drain line exiting the casing as
shown Figure 17.
Note: It is recommended that all PVC piping and fitting connec-
tionsbefitupandinspectedbeforefinalcementing.Trap must be
primed before operation. Verify all condensate drain connec-
tions are securely clamped. A coupling and clamps (in loose part
bag)maybeinstalledasshownforfutureservicingoftheventsys-
tem.

14 440 01 1020 02
Figure 9 Upflow Installations Vent thru Left Side
Casing Grommet
Black Rubber
5/8²
²²
²ID
(Loose parts bag)
Drain Connector Black PVC
3/4²
²²
²PVC X 1/2²
²²
²CPVC
(Loose parts bag)
Drain Line Vent Tee 3/4²
²²
²PVC or 1/2²
²²
²CPVC (Field supplied)
1/2²
²²
²ID Drain Tube
Black (Move from
bottom of drain tee
if installed)
5/8²
²²
²ID Hose
&Clamps
3/16²
²²
²ID Rubber Tube
Coupling & Clamps
(Optional)
INLET
25--24--43
Single Pressure Switch
Dual Pressure Switch Detail
Tee Trap White PVC
(loose parts bag)
2²
²²
²PVC Coupling
EXHAUST
On Some Models
ONLY
Yellow or black Plastic
Cap
Vent Drain
&Clamps
Rotate downward
5°
°°
°to 10°
°°
°
NOTE: Built--in channel will
be angled 5°to 10°also.
SIDE VIEW
Either: The PVC
Drain Tee or a field
supplied 2²
²²
²PVC Tee
AIR FLOWAIR FLOW
Upflow Installations Vent thru Left Side (See Figure 9)
RemoveDrainTeefrominducerdischargeandremoveblackDrain
Tube (1/2²ID) from bottom of Drain Tee. (*9MPD models only)
Install Vent Pipe grommet in side of casing.
Cut an appropriate length of 2²PVC pipe long enough to exit the
cabinet and connect the vent drain to either:
·A standard field supplied 2²PVC tee (N9MP1 and 2 models),
or
·A2²PVC coupling fastened onto the Drain Tee (*9MPD mod-
els)
Install Tee trap into bottom of tee.
Install the 1/2²CPVC street elbow on discharge of Trap
Install the black PVC drain connector (3/4²PVC x 1/2²CPVC from
loose parts bag) as shown in the illustration above.
Cut the black Drain Tube (5/8²ID -- in loose parts bag) to length to
fit between Trap and tube connector through grommet.
Clamp both ends of the Drain Tube using clamps provided.
GluetheCPVCstreetelbowto the Trapusingappropriatecleaner
and solvent cement.
Connect the Tee trap and the main drain line exiting the casing as
shown in Figure 17.
Note: It is recommended that all PVC piping and fitting connec-
tions be fit up and inspected before final cementing. Both the in-
ternal Trap and the external Tee Trap must be primed before
operation. Verify all condensate drain connections are securely
clamped. A coupling and clamps (in loose part bag) may be
installed as shown for future servicing of the vent system.

15
440 01 1020 02
AIR FLOW
Figure 10 All Models Vent thru Right Side
Casing Grommet
Black Rubber 5/8²
²²
²CPVC
(Loose parts bag)
Drain Connector Black PVC
3/4²
²²
²PVC X 1/2²
²²
²CPVC
(Loose parts bag)
Drain Line Vent Tee 3/4²
²²
²PVC
or 1/2²
²²
²CPVC (Field supplied)
5/8²
²²
²ID Hose
&Clamps
3/16²
²²
²ID
Rubber
Tube
INLET
25--24--44
Single Pressure Switch Detain
Dual Pressure Switch
Tee Trap White PVC
(loose parts bag)
2²
²²
²PVC Coupling
Barbed Coupling, 1/2²
²²
²OD
(loose parts bag)
Elbows Tubes (2) & Clamps Black,
1/2²
²²
²ID (loose parts bag)
Rotate downward
5°
°°
°to 10°
°°
°
NOTE: Built--in channel will
be angled 5°to 10°also.
SIDE VIEW
Yellow or black Plastic
Cap
Vent Drain
&Clamps
On Some Models
ONLY
Either: The PVC
Drain Tee or a field
supplied 2²
²²
²PVC Tee
All Models Vent thru Right Side (See Figure 10)
Disconnect the black Drain Tube between the drain vent and the
Trap.
Rotate the inducer 180°for a right side vent after loosening the 4
inducer attachment screws. Reinstall and retighten the inducer
screws to 20²pounds torque.
Using the 1/2²OD barbed coupling in the loose parts bag connect
togetherwiththe2short1/2²IDelbowtubes andconnectthelower
dischargeportoftheventdraintotheTrap. Secureallconnections
with clamps.
Install the vent pipe grommet into the casing
Cut an appropriate length of 2²PVC pipe long enough to exit the
cabinet and connect the vent drain to either:
·A standard field supplied 2²PVC tee (N9MP1 and 2 mod-
els), or
·A2²PVC coupling fastened onto the Drain Tee (*9MPD
models)
Install Tee Trap into bottom section of Tee.
RemoveplugfromthesideofthefurnacecasingwhereDrainTube
will exit.
Install casing grommet (black rubber 5/8²ID grommet -- in loose
parts bag)
Install the 1/2²CPVC street elbow on discharge of Trap
Install the black PVC tube connector (3/4²PVC x 1/2²CPVC from
loose parts bag) as shown in the illustration above
Cut the black Drain Tube (5/8²ID -- in loose parts bag) to length to
fit between Trap and tube connector through grommet.
Clamp both ends of the Drain Tube using clamps provided.
GluetheCPVCstreetelbowto the Trapusingappropriatecleaner
and solvent cement.
Connect the Tee trap and the main drain line exiting the casing as
shown in Figure 17.
Note: It is recommended that all PVC piping and fitting connec-
tions be fit up and inspected before final cementing. Both the in-
ternal Trap and the external Tee Trap must be primed before
operation. Verify all condensate drain connections are securely
clamped. A coupling and clamps (in loose part bag) may be
installed as shown for future servicing of the vent system.

16 440 01 1020 02
AIR FLOW
AIR FLOW
Figure 11 Downflow Left Side Vent and Trap
3/16²
²²
²ID
Rubber Tube
25--24--45
Single Pressure Switch Detail
Dual Pressure Switch
Tee Trap White PVC
(loose parts bag)
Flexible Tubing Connector,
3/16²
²²
²OD (loose parts bag)
Drain
Elbow (1)
EXHAUST
Cut Here
Drain Tube Black, 5/8²
²²
²ID Corrugated
Cut at straight section
Leave room for clamp
WARNING
Move Caps
to top of
trap
Relief Tube,
Extension Black,
3/16²
²²
²ID Cut to fit
(loose parts bag)
1/2²
²²
²ID
Drain
Hose
INLET
On Some Models
ONLY
Either: The PVC
Drain Tee or a field
supplied 2²
²²
²PVC Tee
Yellow or black Plastic
Cap
Vent Drain
&Clamps
Rotate downward
5°
°°
°to 10°
°°
°
NOTE: Built--in channel will
be angled 5°to 10°also.
SIDE VIEW
Coupling & Clamps
(Optional)
Trap Connection “Clamp ears”
PointedOUT
Preassemble&
insert into furnace
2²
²²
²PVC Coupling
Downflow Left Side Vent and Trap (See Figure 11)
Removetheinducermountingscrews,rotatetheinducer180°and
retighten the inducer screws to 20²pounds torque.
Disconnect the hoses from the Trap assembly, and remove Trap
and Trap mounting bracket from the blower compartment. Using
cover plate and gasket provided in the loose parts bag, cover the
holefromtheburnercompartmentto theblowercompartmentand
secure with screws.
MovethecapstothetopoftheTrapandmounttheTrapexternally
to the left side of the unit using the 2 screws provided.
Cutthe5/8²IDcorrugatedhoseasshownaboveandfastenthe90°
bend end to the Trap and fasten the straight end to the transition
drain. Secure both connections with clamps.
Reconnect the 1/2²ID drain hose from the vent drain to the Trap
and secure with aclamp.. In some cases, additionallength will be
required for this hose. Use the Black plastic 1/2²OD barbed cou-
plingandasuitablesectionof1/2²IDhosetomaketheconnection.
Secure all connections with clamps
Connect the 3/16²ID relief tube from the small port on the Trap to
thetopportofthetransitionasshowninthepicture. Insomecases,
additional hose length will be needed. Use the clear plastic 3/16²
ODflexible tubingconnectorandasuitablelength ofextra 3/16²ID
hose to make this connection.
Install the vent pipe grommet into the casing
Cut an appropriate length of2²PVC pipe long , enough to exit the
cabinet and connect the vent drain to either:
·A standard field supplied 2²PVC tee (N9MP1 and 2 mod-
els), or
·A2²PVC coupling fastened onto the Drain Tee (*9MPD
models)
Install Tee Trap into bottom section of Tee.
Connect the Tee trap and the main drain line exiting the casing as
shown in Figure 17.
Note: It is recommended that all PVC piping and fitting connec-
tions be fit up and inspected before final cementing. Both the ex-
ternal Trap and the external Tee Trap must be primed before
operation. Verify all condensate drain connections are securely
clamped. A coupling and clamps (in loose part bag) may be
installed as shown for future servicing of the vent system.

17
440 01 1020 02
AIR FLOW
Figure 12 Downflow Right Side Vent and Trap
Drain Connector Black
PVC 3/4²
²²
²PVC X 1/2²
²²
²CPVC
(Loose parts bag)
3/16²
²²
²ID
Rubber Tube
Trap Connection “Clamp ears”
PointedOUT
Preassemble&
insert into furnace
25--24--46
Single Pressure Switch Detail
Dual Pressure Switch
Tee Trap White PVC
(loose parts bag)
Drain Tube Black, 5/8²
²²
²
ID Corrugated WARNING
Move Caps
to top of
trap
Drain Tube, (& Clamps)
Black, 5/8²
²²
²ID Cut to fit
(loose parts bag)
AIR FLOW
Splice Connector
Barbed 1/2²
²²
²ID
Drain Hose&
Clamps
Either: The PVC
Drain Tee or a field
supplied 2²
²²
²PVC Tee
Rotate downward
5°
°°
°to 10°
°°
°
NOTE: Built--in channel will
be angled 5°to 10°also.
SIDE VIEW
Yellow or black Plastic
Cap
Vent Drain
&Clamps
INLET
On Some
Models ONLY 2²
²²
²PVC Coupling
Coupling & Clamps
(Optional)
Downflow Right Side Vent and Trap (See Figure 12)
Remove the Drain Tee if installed.
Disconnect the hoses from the Trap assembly, and remove Trap
and Trap mounting bracket from the blower compartment. Using
cover plate and gasket provided in the loose parts bag, cover the
holefromtheburnercompartmentto theblowercompartmentand
secure with screws.
MovethecapstothetopoftheTrapandmounttheTrapexternally
to the right side of the unit using the 2 screws provided.
Connect the corrugated Drain Tube from the transition box to the
Trapasshown. Ifanextensionisrequired,usetheblackPVCtube
connectorandtheblack 5/8²ID Drain Tube in the loose partsbag.
Cut tube to length. Secure all connections with clamps.
ConnectthedrainhosefromtheVentDraintotheTrap. Ifanexten-
sion is required, use the black 1/2²OD barbed coupling, connect
ablack1/2²ID elbow tube and asuitable section of a 1/2²ID drain
tubetomakeconnection fromthe ventdraintothetrap. Secureall
connections with clamps.
Install the vent pipe grommet into the casing
Cut an appropriate length of2²PVC pipe long , enough to exit the
cabinet and connect the vent drain to either:
·A standard field supplied 2²PVC tee (N9MP1 and 2 mod-
els), or
·A2²PVC coupling fastened onto the Drain Tee (*9MPD
models)
Install Tee Trap into bottom section of Tee.
Connect the Tee trap and the main drain line exiting the casing as
shown in Figure 17.
Note: It is recommended that all PVC piping and fitting connec-
tions be fit up and inspected before final cementing. Both the ex-
ternal Trap and the external Tee Trap must be primed before
operation. Verify all condensate drain connections are securely
clamped. A coupling and clamps (in loose part bag) may be
installed as shown for future servicing of the vent system.

18 440 01 1020 02
AIR FLOW
Figure 13 Horizontal Left Thru Top
3/16²
²²
²ID
Rubber Tube
Yellow or black Plastic
Caps
Vent Drain
&Clamps Trap Connection
“Clamp ears”
PointedOUT
Preassemble&
insert into furnace
25--24--47
Single Pressure Switch Detail
Dual Pressure Switch
Tee Trap White PVC
(loose parts bag)
Cap and Clamp
Open End
3/16²
²²
²OD Flexible tubing
connector
1/2²
²²
²ID Drain
Hose &
Clamps
EXHAUST
Alternate Orienation
Field
SuppliedTee
Cut Here
Drain Tube Black, 5/8²
²²
²ID Corrugated
Cut at straight section
Leave room for clamp
Relief Tube
Relief Tube Extension
AIR FLOW
Coupling & Clamps
(Optional)
Horizontal Left--Thru Top (See Figure 13)
Disconnect the hoses from the Trap assembly, and remove Trap
and Trap mounting bracket from the blower compartment. Using
cover plate and gasket provided in the loose parts bag, cover the
holefromtheburnercompartmentto theblowercompartmentand
secure with screws.
Mount the Trap externally to the bottom side of the unit using the
2 screws provided in the location shown.
Cut the corrugated tube as shown in the illustration above. Con-
nect the corrugated hose from the transition to the Trap. Secure
connections with clamps.
Remove the black 1/2²ID Drain Tube from the Drain Tee. Install a
yellow cap and clamp over the open drain port of the Drain Tee.
Connect the black 1/2²ID Drain Tube from the Vent Drain to the
Trap. Secure connections with clamps.
Connectthe3/16²IDrelieftubeto the middleportontheTrap.Ifan
extension is required, use the 3/16²OD flexible tubing connector
and the black 3/16²ID relief tube in the loose parts bag. Cut tube
to length. Secure all connections with clamps.
Cut an appropriate length of 2²PVC pipe, long enough to exit the
cabinet and connect the vent drain to either:
·A standard field supplied 2²PVC tee (N9MP1 and 2 mod-
els), or
·A2²PVC coupling fastened onto the Drain Tee (*9MPD
models)
Install Tee Trap into bottom section of Tee.
Connect the Tee trap and the main drain line exiting the casing as
shown in Figure 17.
Note: It is recommended that all PVC piping and fitting connec-
tions be fit up and inspected before final cementing. Both the ex-
ternal Trap and the external Tee Trap must be primed before
operation. Verify all condensate drain connections are securely
clamped. A coupling and clamps (in loose part bag) may be
installed as shown for future servicing of the vent system.

19
440 01 1020 02
AIR FLOW
Figure 14 Horizontal Left--Side Vent
3/16²
²²
²ID Rubber Tube
25--24--48
Single Pressure Switch Detail
Dual Pressure Switch
Tee Trap White PVC
(loose parts bag)
WARNING
Move Caps to
top of trap
Splice Connector
1/2²
²²
²ID Drain Elbow
Drain Hose & Splice
Connector
(Cut-to-fit)
EXHAUST
Alternate Orienation
Field
SuppliedTee
Cut Here
Drain Tube Black, 5/8²
²²
²ID Corrugated
Cut at straight section
Leave room for clamp
Relief Tube
Relief Tube Extension
Yellow or black
Plastic Cap
Vent Drain
&Clamps
Drain Tube Black, 5/8²
²²
²ID
Corrugated
Level or Sloped towards Tee
INLET
On Some
Models ONLY
Horizontal Left--Side Vent (See Figure 14)
RemovetheDrainTeefromtheVentDrainifinstalled(*9MPDmod-
els only)
Rotatetheinducer180°forasideventafterlooseningthe4inducer
attachment screws. Reinstall and retighten the inducer screws to
20²pounds torque.
Disconnect the hoses from the Trap assembly, and remove Trap
and Trap mounting bracket from the blower compartment. Using
cover plate and gasket provided in the loose parts bag, cover the
holefromtheburnercompartmentto theblowercompartmentand
secure with screws.
Mount the Trap externally to the bottom side of the unit using the
2 screws provided in the location shown.
Cut the corrugated tube as shown in the illustration above. Con-
nect the corrugated hose from the transition to the Trap. Secure
connections with clamps.
Connect the black 1/2²ID Drain Tube from the Vent Drain to the
Trap. Ifanextensionisrequired,usetheblack1/2²ODflexibletub-
ing connector and the black 1/2²ID Drain Tube in the loose parts
bag. Cut tube to length. Secure connections with clamps.
Connectthe3/16²IDrelieftubeto the middleportontheTrap.Ifan
extension is required, use the 3/16²OD flexible tubing connector
and the black 3/16²ID relief tube in the loose parts bag. Cut tube
to length.
Cut an appropriate length of 2²PVC pipe, fittings and extension
pipe long enough to exit the cabinet and connect thevent drain to
either:
·A standard field supplied 2²PVC tee (N9MP1 and 2 mod-
els), or
·A2²PVC coupling fastened onto the Drain Tee (*9MPD
models)
Install Tee Trap into bottom section of Tee.
Important: The pipe to the Tee Trap must be level or sloping to-
wards the Tee Trap
Connect the Tee trap and the main drain line exiting the casing as
shown in Figure 17.
Note: It is recommended that all PVC piping and fitting connec-
tions be fit up and inspected before final cementing. Both the ex-
ternal Trap and the external Tee Trap must be primed before
operation. Verify all condensate drain connections are securely
clamped. A coupling and clamps (in loose part bag) may be
installed as shown for future servicing of the vent system.
A coupling and clamps (in loose part bag) may be installed as
shown for future servicing of the vent system.

20 440 01 1020 02
AIRFLOW
Figure 15 Horizontal Right thru Top
3/16²
²²
²ID Rubber Tube
Trap Connection “Clampears”
PointedOUT
Preassemble&
insert into furnace
25--24--49
Single Pressure Switch Detail
Dual Pressure Switch
Tee Trap
White PVC
(loose parts bag)
WARNING
Add Cap and
Clamp
Splice Connector
1/2²
²²
²ID Drain Hose & barbed
coupling (Cut-to-fit)
EXHAUST
Alternate Orienation
Field
SuppliedTee
Cut Here
Drain Tube Black, 5/8²
²²
²ID
Corrugated Cut at straight section
Leave room for clamp
Relief Tube
Relief Tube Extension
Yellow or black
Plastic Cap
Vent Drain
&Clamps
INLET
On Some Models
ONLY
Coupling & Clamps
(Optional)
Horizontal Right Thru Top(See Figure 15)
Disconnect the hoses from the Trap assembly, and remove Trap
and Trap mounting bracket from the blower compartment. Using
cover plate and gasket provided in the loose parts bag, cover the
holefromtheburnercompartmentto theblowercompartmentand
secure with screws.
Mount the Trap externally to the bottom side of the unit using the
2 screws provided in the location shown.
Cut the corrugated tube as shown in the illustration above. Con-
nect the corrugated hose from the transition to the Trap. Secure
connections with clamps.
Connect the black 1/2²ID Drain Tube from the Vent Drain to the
Trap. If an extension is required, use the black 1/2²OD barbed
coupling and the black 1/2²ID Drain Tube in the loose parts bag.
Cut tube to length. Secure connections with clamps.
Connect the 3/16²ID relief tube to the middle port on the Trap. If
anextensionisrequired,usetheclear3/16²ODflexibletubingcon-
nectorandtheblack 3/16²ID relief tubeintheloosepartsbag. Cut
tube to length.
Cut an appropriate length of 2²PVC pipe, fittings and extension
pipe long enough to exit the cabinet and connect thevent drain to
a standard field supplied 2²PVC tee
Install Tee Trap into bottom section of Tee.
Connect the Tee trap and the main drain line exiting the casing as
shown in Figure 17.
Note: It is recommended that all PVC piping and fitting connec-
tions be fit up and inspected before final cementing. Both the ex-
ternal Trap and the external Tee Trap must be primed before
operation. Verify all condensate drain connections are securely
clamped. A coupling and clamps (in loose part bag) may be
installed as shown for future servicing of the vent system.