Tempstar HUH5 Series User manual

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.
Manufactured by:
International Comfort Products Corporation (USA)
Lewisburg, TN USA 37091
!
Electric Shock Hazard
Turn Off All Power
Before Servicing.
Failure to do so can result
in death, personal injury
and/or property damage.
!
Printed in U.S.A. LP1 2/17/2003 441 01 5001 00
HUH5
SAFETY REQUIREMENTS
Recognizesafety information. This isthesafety--alertsymbol !. Whenyouseethissymbolonthefurnaceandininstructionsmanualsbe
alert to the potential for personal injury.
UnderstandthesignalwordsDANGER,WARNING,orCAUTION. Thesewordsareusedwiththesafety--alertsymbol. DANGERidentifiesthe
mostserioushazards,thosethatwillresultinseverepersonalinjuryordeath. WARNINGsignifiesahazardthatcouldresultinpersonalinjury
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.
Untrainedservicepersonnelcanperformbasic maintenancefunctionssuch as cleaningandreplacing airfilters. Allotheroperations must be
performed by trained service personnel. When working on heating equipment, observe precautions in the literature, on tags, and on labels
attached 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) NFPA No.
54/ANSIZ223.1. In Canada, refer to the current edition of the National Standard Canada CAN/CGA--B149.1-- and .2--M91 Natural Gas and
PropaneInstallationCodes(NSCNGPIC). Wearsafetyglassesandworkgloves. Havefireextinguisheravailableduringstart--upandadjust-
ment procedures and service calls.
These instructions cover minimum requirements and conform to existing national standards and safety codes. In some instances, these
instructions exceed certain local codes and ordinances, especially those that may not have kept up with changing residential construction
practices. We require 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. Gas Vent Installation 9.......................
5. Horizontal Venting 10.........................
6. Gas Supply and Piping 10.....................
7. Electrical Wiring 10..........................
8. Ductwork and Filter (Upflow/Horizontal) 13.......
9. Checks and Adjustments 14...................
10. Furnace Maintenance 15.....................
11. Sequence of Operation & Diagnostics 17.........

244101261000
START--UP CHECK SHEET
(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:
Blower Motor H.P.:
Supply Voltage:
Limit Opens at...(°F) or(°C)
Limit Closes at...(°F) or(°C)
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
Drip--Leg Upstream of Gas Valve? 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).
Measured Manifold Pressure:
Thermostat OK? YES NO
Subbase Level? YES NO
Anticipator Set? YES NO Set At?:
Breaker On? YES NO
Date of Installation:
Date of Start--Up:
Dealer Comments:

3
44101500100
1. Safe Installation Requirements
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 allprecautionsandsafety proceduresrequired
in such work, and is equipped with the proper tools
and test instruments.
Failure to carefully read and follow all instructions
in this manual can result in furnace malfunction,
death, personal injury and/or property damage.
!
NOTE: This furnace is design certified by the American Gas
Association and the Canadian Gas Association for installationin
the United States and Canada. Refer to the appropriate codes,
along with this manual, for proper installation.
·Use only the Type of gas approved for this furnace (see
RatingPlateonunit).Overfiringwillresultinfailureofheat
exchanger and cause dangerous operation. (Furnaces
can be converted to L.P. gas with approved kit.)
·Installthisfurnaceonlyinalocationandpositionasspeci-
fied in “Installation” of these instructions.
·Provide adequate combustion and ventilation air to the
furnaceasspecifiedin“CombustionandVentilationAir” of
these instructions.
·Combustionproductsmustbedischargedoutdoors.Con-
nectthisfurnacetoanapprovedventsystemonly,asspe-
cified in “Combustion and Ventilation Air” of these
instructions.
·Never test for gas leaks with an open flame. Use a com-
merciallyavailablesoapsolutionmadespecificallyforthe
detectionofleakstocheckallconnections,asspecifiedin
“Gas Supply and Piping” of these instructions.
·Always install furnace to operate within the furnace’s in-
tended temperature--rise range with a duct system which
has an external static pressure within the allowable rat-
ings,as specifiedin“TechnicalSupport Specifications”of
these instructions.
·When a furnace is installed so that supply ducts carry air
circulated by the furnace to areas outside the space con-
tainingthe furnace, thereturnair shallalsobe handledby
duct(s) sealed to the furnace casing and terminating out-
side the space containing the furnace.
·A gas--fired furnace for installation ina residential garage
must be installed as specified in “Installation Require-
ments” of these instructions.
·This furnace is not to be used for temporary heating of
buildings or structures under construction.
·This furnace is NOT approved for installation in mo-
bile 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
Your unit is built to provide many years of safe and dependable
serviceprovidingitisproperlyinstalledandmaintained.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
monoxidedetectors.Therecanbevarioussourcesofcarbon
monoxide in a building or dwelling. The sources could be
gas--firedclothes dryers,gascookingstoves, waterheaters,
furnaces, gas--fired fireplaces, wood fireplaces, and several
otheritems.Carbonmonoxidecancauseseriousbodilyinju-
ry and/or death. Therefore, to help alert people of potentially
dangerouscarbonmonoxidelevels,youshouldhavecarbon
monoxidedetectorslistedbyanationallyrecognizedagency
(e.g. Underwriters Laboratories or International Approval
Services)installedandmaintainedinthebuildingordwelling
(see Note below).
B. Therecanbenumeroussourcesoffireorsmokeinabuilding
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 byUnder-
writers Laboratories installed and maintained in the building
or 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 the following:
1. Thoroughly read this manual and labels on the unit. This
willhelpyouunderstandhowyourunitoperatesand thehaz-
ards involved with gas and electricity.
2. Do not use this unit if any part has been under water. Im-
mediatelycallaqualifiedservicetechniciantoinspecttheunit
and to replace any part of the control system and any gas
control which has been under water.
3. Never obstruct thevent grilles, or anyducts that provide
air to the unit. Air must be provided for proper combustion
and ventilation of flue gases.
Carbon monoxide or “CO” is a colorless and odorless gas
produced when fuel is not burned completely or when the
flame does not receive sufficient oxygen.
Frozen Water Pipe Hazard
FROZEN AND BURST WATER PIPE HAZARD
FaiIure to do so may result in burst waterpipes, serious
property damage and/or personal injury.
Furnace may shut down. Do not leave your home
unattended for long periods during freezing weather
without turning off water supply and draining water
pipes or otherwise protecting against the risk of frozen
pipes.
!
Yourfurnaceisdesignedsolelytoprovide asafeandcomfortable
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 furnaceoff and prevent itfrom
restarting in the event of various potentially unsafe conditions.
If yourfurnace remains off for an extendedtime, thepipes in your
home could freeze and burst, resulting in serious water damage.

444101261000
Water may create a condition in which mold can grow in your
home.Certaintypesof moldhavebeenreportedtocauserespira-
tory problems orother serious health risks. Remedial actions,in-
cluding immediately drying all wet items, should be taken quickly
to help prevent the development of mold in your home.
Ifthestructurewillbe unattendedduring coldweatheryoushould
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. Install a reliable remote sensing device that will notify
somebody of freezing conditions within the home.
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.
If this furnace is replacing a previously common-
vented furnace, it may be necessary to resize the
existing vent line and chimney to prevent
oversizing problems for the other remaining
appliances(s). See applicable codes and Venting
and Combustion Air Check and Gas Vent
Installation section.
!
Location and Clearances
If furnace is a replacement, it is usually best to install the furnace
wheretheoldonewas.Choose thelocation orevaluatetheexist-
ing location based upon the minimum clearance and furnace di-
mensions (Figure 1).
CAUTION
Do NOT operate furnace in a corrosive atmosphere contain-
ingchlorine,fluorineoranyotherdamagingchemicals.Refer
toCombustion&VentilationAirsection,ContaminatedCom-
bustion Air.
Installation Requirements
1. Install furnace level.
2. This furnace is NOT to be used for temporary heat of build-
ings 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. Maintainclearanceforfiresafetyandservicing.Afrontclear-
anceof30²isminimumforaccesstotheburner,controlsand
filter.
6. Use a raised base if the floor is damp or wet at times.
7. Residential garage installations require:
·Burnersandignitionsourcesinstalledatleast18²abovethe
floor.
·Furnace must be located or physically protected from pos-
sible damage by a vehicle.

11/2
51/3
47/8
21/4
5
7
175/16
7
47/8
33/4
21/4
303/4
291/2
175/16
RIGHT SIDE
Dimensions and Clearances (H8UH5 Models)
Figure 1
30²min.
Drawing is representative some models may vary
DIMENSIONS IN INCHES
TOP
LEFT SIDE
BOTTOM
FRONT
25--23--44a
40
37
131/4
181/2
281/2
17/8
1
265/8
213/4
A
B
11/2
265/8
271/2
277/8
321/2
213/4
33/4
131/4
1
17/8
D
C
F
231/841/16
NOTE: Evaporator “A” coil drain pan dimensions
may vary from furnace duct opening size. Always
consult evaporator specifications for duct size
requirements.
Unit is designed for bottom return or side return.
Return air through back of unit is NOT allowed.
3/4
5
44101500100
MINIMUM CLEARANCES TO COMBUSTIBLE
MATERIALS FOR ALL UNITS
REAR 0
FRONT 3²
Recommended For Service 30²
ALL SIDES Of SUPPLY PLENUM 1²
SIDES 0
VENT
Single Wall Vent 6²
Type B--1 Double Wall Vent 1²
TOP OF FURNACE 1²
Horizontal position: Line contact ispermissible onlybetween lines
formed byintersectionsof top and two sides offurnace jacket,and
building joists, studs or framing.
DIMENSIONAL INFORMATION
Unit Cabinet Top Bottom
U
n
i
t
Capacity A B F C D
H8UH5050B12
H8UH5075B12 151/214 6 13/8125/8
H8UH5100F14 191/8175/873/421/8143/4
H8UH5125J20
H8UH5140J20 223/4211/491/2115/16 183/4
Furnace Installation
Inspecttheratingplatetobecertainthemodelnumberbeginswith
“H8UH5”. This identifies the unit as a dual--position furnace and
can be Installed in a Upflow, Horizontal Right or Horizontal Left
position.
Upflow
No modifications are required for upflow installation. (See
Figure 2)
Typical Upflow Installation
Figure 2
25--23--17
VENT
SUPPLY
AIR
GAS SUPPLY
RETURN
AIR

644101261000
Horizontal
If you purchased a dual--position furnace, it can be installed hori-
zontallyinanattic,basement,crawlspace,alcove,orsuspended
from a ceiling in a basement or utility room in either a right or left
airflow position. (see Figure 3)
The minimum clearances to combustibles MUST be maintained
between the furnace and adjacent construction, as shown in
Figure 1.ONLYthecornerofthecabinetisallowedtocontactthe
rafters Figure 3. All other clearances MUST be observed as
shown in Figure 1.
Typical Horizontal Installation
Figure 3
VENT
GAS SUPPLY
SUPPLY
AIR
RETURN
AIR
25-23-18a
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
straps or an angle iron frame to attach the furnace. These straps
should be attached to thefurnace withsheet 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.
If thefurnace is tobe installed ground level in acrawl space,con-
sult local codes. A concrete pad 1²to 2²thick is recommended.
Thirty inches (30²) is recommended between the front of the fur-
nace and adjacent construction or other appliances. This should
be maintained for service clearance.
Keep all insulating materialsclear from louvered door. Insulating
materials may be combustible.
The horizontal furnaces may be installed directly on combustible
woodflooringorsupports,however,itisrecommendedforfurther
fireprotectioncementboardorsheetmetalisplacedbetweenthe
furnace and the combustible wood floor and extend 12²beyond
the front of the furnace louver door. (This is a recommendation
only, not a requirement).
Thisfurnace MUST NOT be installeddirectly on carpeting, tile or
other combustible material other than wood flooring or supports.
3. Combustion & Ventilation Air
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 combus-
tion and ventilation air.
!
Furnaces require ventilation openings to provide sufficient air for
propercombustionand ventilationoffluegases. Allduct oropen-
ingsforsupplyingcombustionandventilationairmustcomplywith
thegascodes,orintheabsenceoflocalcodes,theapplicablena-
tional codes.
When the installation is complete, check that all appliances have
adequate combustion air and are venting properly. See Venting
And Combustion Air Check in “Gas Vent Installation” Section in
this manual.
Contaminated Combustion Air
Installationsincertainareasortypesofstructureswillincreasethe
exposure to chemicals or halogens that may harm the furnace.
These instances must use only outside air for combustion.
Thefollowingareasortypesofstructuresmaycontainorhaveex-
posure to the substances listed below. The installation must be
evaluated carefully as it may be necessary toprovide outside air
for 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.
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.
Air Openings and Connecting Ducts
1. Total input rating for allgas appliances MUST beconsidered
when determining free area of openings.
2. Connect ducts or openings directly to outside.
3. When screens are used to cover openings, the openings
MUST be no smaller than 1/4²mesh.
4. TheminimumdimensionofrectangularairductsMUSTNOT
be less than 3².

7
44101500100
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.
Requirements
1. Provideconfinedspacewithsufficientairforpropercombus-
tion and ventilation of flue gases using horizontal or vertical
ducts or openings.
2. Figure 4 illustrates how to provide combustion and ventila-
tionair.Aminimumoftwopermanentopenings,oneinletand
one outlet, are required.
3. OneopeningMUST bewithin12²ofthefloorandthesecond
opening within 12²of the ceiling.
4. Size openings and ducts per Table 1.
Furnace
Furnace
Minimum One Inlet and One Outlet Air Supply is Required
May be in and Combination Shown
Inlet Air Opening Must be Within12²(300mm) of floor
Outlet Air Opening Must be Within12²(300mm) of ceiling
(1) 1 Square Inch (6cm2) per 4000 BTUH
(2) 1 Square Inch (6cm2) per 2000 BTUH
Outside Air (This is ONLY a guide. Subject to codes of country having jurisdiction.)
Figure 4
This installation NOT approved in Canada
Gas Vent
Gas Vent
Gas Vent
Gable Vent Gable Vent
Outlet
Air (1)
Outlet Air (1)
Outlet Air (1)
Furnace
Outlet
Air (2)
Optional Inlet Air (1)
Ventilated Attic Ventilated Attic
Ventilated Crawl Space
Inlet
Air (1) Inlet
Air (1)
Inlet
Air (1)
Inlet
Air (2)
Inlet
Air (2)
Top Above Insulation
Top Above Insulation
Soffit Vent
Soffit Vent
5. Horizontal duct openings require 1 square inch of free area
per 2,000 BTUH of combined input for all gas appliances in
area (see Table 1).
6. Vertical duct openings oropeningsdirectly tooutsiderequire
1squareinchoffreeareaper4,000BTUHforcombinedinput
of all gas appliances in area (see Table 1).
Onepermanentopening,commencingwithin12²of thetop ofthe
enclosure, shall be permitted where the equipment has clear-
ancesofatleast1²fromthesidesandbackand6²fromthefrontof
the appliance. The opening shall directly communicate with the
outdoors or shall communicate through a vertical or horizontal
ducttotheoutdoorsorspaces(crawlorattic)thatfreelycommuni-
cate with the outdoors, and shall have a minimum free area of:
·1sq.inper3000Btuperhr.ofthetotalinputratingofallequip-
ment located in the enclosure, and
·Notlessthanthesumoftheareasofallventconnectorsinthe
confined space.
Table 1 Free Area
B
T
U
H
Minimum Free Area Required for Each Opening
BTUH
Input
Rating Horizontal Duct
(sq. in./2,000 BTUH)
Vertical Duct or
openings to outside
(sq. in./4,000 BTUH)
Rd Duct
(sq. in. /4,000
BTUH)
50,000 25 sq. in. 12.5 sq. in. 4²
75,000 35.5 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
EXAMPLE: Determining Free Area
Furnace Water Heater Total Input
100,000 +30,000 = (130,000 ¸4,000) = 32.5 Sq. In. Vertical
Furnace Water Heater Total Input
100,000 +30,000 = (130,000 ¸2,000) = 65 Sq. In. Horizontal
Unconfined Space Installation
!
CARBON MONOXIDE POISONING HAZARD.
Most homes will require additional air.
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.
Anunconfinedspaceisdefinedasanareahavingaminimumvol-
umeof50cubicfeetper1,000Btuhtotalinputratingforallgasap-
pliances in area.

844101261000
Adjoining rooms can be considered part of an unconfined area if
there are no doors between rooms.
An attic or crawl space may be considered an unconfined space
provided there are adequate ventilation openings directly to out-
doors.OpeningsMUSTremainopenandNOThaveanymeansof
being closed off. Ventilation openings to outdoors MUST be at
least1squareinchoffreeareaper4,000BTUHoftotalinputrating
for all gas appliances in area.
In unconfined spaces, infiltration should be adequate to provide
airforcombustion,ventilationanddilutionoffluegases.However,
inbuildingswithunusuallytightconstruction,additionalairMUST
be provided using the methods described in section titled Con-
fined Space Installation:
Unusually tight construction is defined as: Construction with
1 Wallsandceilingsexposedtotheoutsidehaveacontinuous,
sealed vapor barrier. Openings are gasketed or sealed and
2 Doors and openable windows are weather stripped and
3. Other openings are caulked or sealed. These include joints
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
Someprovincialcodesandlocalmunicipalitiesrequireventilation
ormake--upair bebrought intotheconditionedspaceas replace-
mentair.Whichevermethodisused,themixedreturnairtempera-
ture across the heat exchanger MUST not fall below 60°for flue
gases will condense in the heat exchanger. This will shorten the
life of the heat exchanger and possibly void your warranty.
4. Gas Vent Installation
CARBON MONOXIDE POISONING, FIRE AND
EXPLOSION HAZARD.
Read and follow all instructions in this section.
Failure to properly vent this furnace can result in
death, personal injury and/or property damage.
!
Install thevent incompliance with codes of the country havingju-
risdiction, local codes or ordinances and these instructions.
These fanassisted combustionfurnaces havebeen classified as
CategoryIapplianceswhich meansthat theyMUST operatewith
a negative vent pressure.
Category ISafe Venting Requirements
NOTE: The following instructions comply with the United States
National Fuel Gas Code. Based on the highest input rate on the
furnace rating plate.
1. If a Category Ivent passes through an attic, any concealed
space or floor, use ONLY Type B or Type L double wall vent
pipe.Ifventpipepassesthroughinteriorwall,usetypeBvent
pipe with ventilated thimble ONLY.
2. Do NOT vent furnace into any chimney serving an open fire-
place or solid fuel burning appliance.
3. Use the same diameter Category Iconnector or pipe as per-
mitted by the United States National Fuel Gas Code vent-
ing tables.
4. Keep vertical Category Ivent pipe or vent connector runsas
short and direct as possible.
5. Vertical outdoor runs of type B or ANY single wall vent pipe
below the roof line are NOT permitted.
6. Slopeall horizontalrunsup awayfromfurnacea minimumof
1/4²per foot.
7. Supportallhorizontalventpipeevery6¢usingproperclamps
and metal straps.
8. Check existing gas vent or chimney to ensure they meet
clearances and local codes.
9. ThefurnaceMUSTbeconnectedtoafactorybuiltchimneyor
vent complying with a recognized standard. Venting into a
masonry or concrete chimney is only permitted as out-
linedintheUnitedStatesNationalFuelGasCodeventing
tables or Masonry Chimney section in these instruc-
tions.
Venting and Combustion Air Check
NOTE:Ifthisinstallationremovesanexistingfurnacefromavent-
ing system serving one or more other appliances, and to make
sure there is adequate combustion air for all appliances, MAKE
THE FOLLOWING CHECK.(SeeFigure 5)

9
44101500100
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:
1.Seal any unused openings in the venting system.
2.Inspect the venting system for proper size 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.Turnonclothesdryersandanyappliancenotconnectedto
the venting system. Turn on any exhaust fans, such as
rangehoodsandbathroomexhausts,sotheywilloperate
at maximum speed. Do not operate a summer exhaust
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 5)
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 or CSA B149.1, Natural Gas and Pro-
pane 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.
!Vent Check
Draft HoodVent Pipe
Match
Typical Gas
Water Heater
Figure 5
NOTE: If flame pulls towards draft hood, this indicates
sufficient infiltration air.
Venting to Existing Masonry Chimney
NOTE: The tables and notes referred to below are found in the
most recent printing of the United States National Fuel Gas
Code venting tables.
UsetheUnitedStatesNationalFuelGasCodeorNFGCTablesto
sizethechimneyorvent.Dedicatedventingofonefanassisted
furnace into any masonrychimney is restricted.Thechimney
mustfirstbe linedwitheithertypeBventsizedinaccordancewith
tables 1 or 2 or a listed single wall, metal lining system, sized in
accordance with the vent tables: or (Venting as outlined with
useofoptionalmasonrychimneykitasapplicable.)(SeeSec-
tion 7)
Listed, corrugated metallic chimney liner systems in masonry
chimneys shall be sized by using United States National Fuel
Gas Code tables for dedicated venting and United States Na-
tional Fuel Gas Code tables for common venting with the maxi-
mum capacity reduced by 20% (0.80 X maximum capacity) and
the minimum capacity as shown in the applicable table. Corru-
gated metal vent systems installed with bends or offsets require
additional reduction of 10% of the vent capacity for each 90°el-
bow.
NOTE:Two(2)45°elbows are equivalent to one (1) 90°elbow.
Combined Venting into a Masonry Chimney
Venting into a masonry or concrete chimney is only per-
mitted as outlined in the United States National Fuel Gas
Code venting tables. Follow all safe venting requirements.
Note: See section “Masonry Chimney Venting with optional kit”.
5. Horizontal Venting
Category IFurnaces With External Power
Venters
Inorder to maintainaCategory Iclassificationoffan assistedfur-
naceswhenventedhorizontallywithsidewalltermination,apower
venteris REQUIREDto maintain a negative pressurein the vent-
ing system. Please consult the Fields Controls Co. or Tjernlund
Products,Inc.forpowerventerscertifiedforusewithourfurnaces.
Vent Termination
Venting Through a Non--Combustible and
Combustible Wall
Consult External Power Venter manufacturer instructions.
CAUTION
It is the responsibility of the installer to properly termi-
nate the vent and provide adequate shielding. This is
essential in order to avoid water/ice damage to build-
ing, shrubs and walk--ways.
6. Gas Supply and Piping

10 44101261000
CARBON MONOXIDE POISONING, FIRE AND
EXPLOSION HAZARD.
Failure to follow these instructions can result in
death, personal injury and/or property damage.
Models designated for Natural Gas are to be used
with Natural Gas ONLY, unless properly converted
to use with LP gas.
!
Gas Supply Requirements
·UseonlytheTypeofgasapprovedforthisfurnace.Seerating
plate for approved gas type.
·Gasinputmustnotexceedtheratedinputshownontherating
plate. Overfiring will result in failure of heat exchanger and
cause dangerous operation.
·Do not allow minimum supply pressure to vary downward.
Doing so will decrease input to furnace. Refer to Table 2 for
Gas supply and manifold pressures.
Table 2 Gas Pressures
Gas
T
Supply Pressure Manifold
P
Type Recommended Max. Min. Pressure
Natural 7²14²4.5²3.5²
Propane 11²14²11²10²
Natural Gas Input Rating Check
Thegasmetercanbeusedtomeasureinputtofurnace. Ratingis
basedonanaturalgasBTUcontentof1,000BTU’spercubicfoot.
Check with gas supplier for actual BTU content.
1. TurnOFFgassupplytoallappliancesotherthanfurnaceand
start furnace.
2. Time how manyseconds ittakes thesmallest dialon the gas
meter to make one complete revolution. Refer to Example.
Note: If meter uses a 2 cubic foot dial, divide results (se-
conds) by two.
Example
Natural Gas
BTU Content No. of Seconds Per Hour Time Per Cubic Foot in Seconds BTU Per Hour
1,000 3,600 48 75,000
1,000 x 3,600 ¸48 = 75,000 BTUH
3. Relight all appliances and ensure all pilots are operating.
Orifice Sizing
NOTE: Factory sized orifices for natural and LP gas are listed in
the furnace Technical Support manual.
Ensure furnace is equipped with the correct main burner orifices.
Refer to Table 3 for correct orifice size for a given heating value
and specific gravity for natural and propane gas. Note that this
chart is ONLY for installations below 2000¢in altitude.
Table 3 Orifice Sizes (below 2000¢)
Gas
Type Manifold Pressure Specific Gravity
Heating Value
(BTU per
Cubic Ft.)
Orifice Size
(Drill #)
Natural
3
5
²
w
c
800 40
3.5²w.c.
0
9
k
P
0
6
900 41
0.9kPa
w
c
0.6 1000 42
w.c. 1100 43
Propane 10²w.c.
2.5kPa
w.c. 1.53 2500 54
Operation Above 2000¢Altitude
FIRE, EXPLOSION, CARBON MONOXIDE POISON-
ING HAZARD.
This conversion shall be done by a qualified ser-
vice agency in accordance with the Manufactur-
er’s instructions and all applicable codes and re-
quirements, or in the absence of local codes, the
applicable national codes.
Failure to follow these instructions exactly can re-
sult in death, personal injury and/or property dam-
age.
!
These units may beused at full input rating wheninstalled at alti-
tudesup to2000¢. When installed above 2000¢,theinputmustbe
decreased2%(natural)or4%(LP)foreach1000¢abovesealevel.
This may be accomplished by a simple adjustment of manifold
pressure or an orifice change, or a combination of a pressuread-
justmentandanorificechange.Thechangesrequireddependon
theinstallationaltitudeandtheheatingvalueofthefuel.Table 4 &
Table 5 show the proper furnace manifold pressure and gas ori-
ficesizetoachieveproperperformancebasedonelevationabove
sea level for both natural gas and propane.
To use the natural gas table, first consult your local gas utility for
theheatingvalueofthegassupply.Selecttheheatingvalueonthe
vertical border and follow across the table until the appropriate
elevationfortheinstallationisreached.Thefirstvalueintheboxat
theintersectionoftheheatingvalueandelevationwillbetheman-
ifoldpressurerequired.Ifagasorificechangeisalsorequired,the
box is shaded. The required orifice size is shown at the bottomof
the table. Sea Level
High Altitude Input Rate = Nameplate x (Multiplier)
Input Rate
E
l
e
v
a
t
i
o
n
High Altitude Multiplier
Ele
v
ation Natural LP Gas
2000¢- 2999¢0.96 0.92
3000¢- 3999¢0.94 0.88
4000¢- 4999¢0.92 0.84
5000¢- 5999¢0.90 0.80
6000¢- 6999¢0.88 0.76
7000¢- 7999¢0.86 0.72

11
44101500100
MANIFOLD PRESSURE AND ORIFICE SIZE FOR HIGH ALTITUDE APPLICATIONS
Table 4 NATURAL GAS
MEAN ELEVATION FEET ABOVE SEA LEVEL
HEATING VALUE
BTU/CU. FT. 0to 1999 2000 to 2999 3000 to 3999 4000 to 4999 5000 to 5999 6000 to 6999 7000 to 8000
800 3.5²wc 3.5²wc 3.5²wc 3.5²wc 3.5²wc 3.5²wc 3.5²wc
850 3.5²wc 3.5²wc 3.5²wc 3.5²wc 3.5²wc 3.5²wc 3.5²wc
900 3.5²wc 3.5²wc 3.5²wc 3.5²wc 3.5²wc 3.5²wc 3.4²wc
950 3.5²wc 3.5²wc 3.5²wc 3.5²wc 3.3²wc 3.2²wc 3.1²wc
1000 3.5²wc 3.4²wc 3.3²wc 3.2²wc 3.0²wc 2.9²wc 2.8²wc
1050 3.2²wc 3.1²wc 3.0²wc 2.9²wc 2.7²wc 2.6²wc 2.5²wc
1100 2.9²wc 2.8²wc 2.7²wc 2.6²wc 2.5²wc 2.4²wc 2.3²wc
Orifice Size #42 #42 #42 #42 #42 #42 #42
Table 5 PROPANE MEAN ELEVATION FEET ABOVE SEA LEVEL
HEATING VALUE
BTU/CU. FT. 0to 1999 2000 to 2999 3000 to 3999 4000 to 4999 5000 to 5999 6000 to 6999 7000 to 8000
2500 10.0²wc 10.0²wc 9.4²wc 10.0²wc 9.8²wc 8.8²wc 7.9²wc
Orifice Size #54 #54 #54 #55 #55 #55 #55
NOTE: NATURALGASDATABASEDON0.60SPECIFICGRAVITY.PROPANEDATABASEDON1.53SPECIFICGRAVITY.FOR
FUELS WITH DIFFERENT SPECIFIC GRAVITY CONSULT THE LATEST EDITION OF THE NATIONAL FUEL GAS CODE ANSI
Z223.1 and CAN B149.
NOTE: The derating of these units at 2% (Natural) and 4%(L.P.)
has been tested and approved by AGA.
High Altitude Air Pressure Switch
Altitudes over 4,000¢require a different air pressure switch than
theoneinstalledatthefactory.Checkpartslistforpressureswitch
and consult your distributor for part number and availability. In
Canada,provincialcodesmaygoverninstallationofswitch.Check
with governing authorities.
Changing Orifices
1. Afterdisconnecting powerand gas supply tothe furnace, re-
move the burner compartment door, exposing the burner
compartment.
2. Disconnect gas line and pilot tubing fromgas valve so man-
ifold can be removed.
3. Disconnect wiring at gas valve. Be sure to note the proper
location of any and all electrical wiring disconnected.
4. Remove the four (4) screws holding the manifold and gas
valve to the manifold supports. Do not discard any screws.
See Figure 6.
Figure 6 Manifold
25--23--51z
Some Models may vary
5. Carefully remove the manifold assembly.
6. Removethe orifices fromthemanifoldandreplacethemwith
proper sized orifices. See Figure 7.
7. Tighten orifices so it is seated and gas tight. See Figure 7.

12 44101261000
Figure 7 Clearances
Measure from face of orifice to the
back side of the manifold.
11/8²
13/16²
29.3 mm
+1.5
-- 1.1
8. Reassembleallpartsinreverseorderasremoved.Besureto
engage the main burner orifices in the proper opening in the
burners.
9. After reassembling, turn gas on and check all joints for gas
leaks using a soapy solution. All leaks must be repaired im-
mediately.
Gas Piping Requirements
NOTE:Thegassupplylinemustbeinstalledbyaqualifiedservice
technician in accordance with all building codes, (In the state of
Massachusetts,gassupplyconnectionsMUSTbeperformedbya
licensed plumber or gas fitter).
1. Installgaspipinginaccordancewithlocalcodes,orintheab-
sence of local codes, the applicable national codes.
2. Itis recommendedthata manualshutoffvalvebeinstalledin
the gas supply line outside the unit. Locate valve as close to
thefurnaceaspossiblewhereitisreadilyaccessible.Referto
Figure 8.
3. Useblackironorsteelpipeandfittingsorotherpipeapproved
by local code.
4. Use pipe thread compound which is resistant to natural and
LP gases.
NOTE: The use of copper tubing for gas piping is NOT approved
by the state of Massachusetts.
5. Use ground joint unions and install a drip leg no less than 3²
long to trap dirt and moisture before it can enter gas valve.
6. Providea1/8²inchplugfortestgaugeconnectionimmediate-
ly up stream of gas supply connection to furnace.
7. Usetwopipewrencheswhenmakingconnections toprevent
gas valve from turning.
Typical Gas Piping
Figure 8
25--24--35a
Union
Manual
Valve
Drip leg & pipe cap
left side entry
8. Flexible corrugated metal gas connector may NOT be used
insidethe furnaceorbesecured orsupportedby thefurnace
or ductwork.
9. Properlysize gaspipeto handlecombinedapplianceloador
run gas pipe directly from gas meter or LP gas regulator.
10. Install correct pipe size for run length and furnace rating.
11. Measurepipelengthfromgas meterorLPsecond stagereg-
ulator to determine gas pipe size.
CAUTION
Usewrenchtohold gasvalvewhen turningelbowsand
gas line to prevent damage to the gas valve and fur-
nace.
Left Side Gas Entry
Pipe can be ran directly to gas valve.
Right Side Gas Entry
Requires two(2) 90°elbows and nipples.
FIRE OR EXPLOSION HAZARD.
Failure to properly install metal gas connector can
result in death, bodily injury and/or property
damage.
The flexible corrugated metal gas connector must
beproperlyinstalled,cannotgothroughthesideof
the furnace, and can not be used inside the
furnace.
!
Additional LP Piping Requirements
·Have a licensed LP gas dealer make all connections atstor-
age tank and check all connections from tank to furnace.
·Ifcoppertubing isused,it MUST complywithlimitationset in
LocalCodes,orintheabsenceoflocalcodes,the gascodes
of the country having jurisdiction.

13
44101500100
·Two--stage regulation of LP gas is recommended.
Final Check
·Test all pipe for leaks.
·If orifices where changed, make sure they are checked for
leaks.
·Duringpressuretestingofgaspipingsystem,observethefol-
lowing:
a. Iftestpressure doesnotexceed 1/2²PSIG,isolatethefur-
nace by closing its individual manual shutoff valve.
b.Iftestpressureexceeds1/2²PSIG,thefurnaceanditsindi-
vidual shutoff valve must be disconnected from the gas sup-
ply system.
·To check for leaks apply soap suds or a liquid detergent to
each joint. Bubbles forming indicate a leak.
·Do not use an open flame to test forgas leaks. Fire or explo-
sion could occur.
·Correct even the smallest leak at once.
FIRE OR EXPLOSION HAZARD.
Liquid petroleum (LP) gas is heavier than air and
will settle and remain in low areas and open
depressions.
Anopenflameorsparkcanresultindeath,personal
injury and/or property damage.
Thoroughly ventilate area and dissipate gas. Do
NOT use a match or open flame to test for leaks, or
attempt to start up furnace before thoroughly
ventilating area.
!
7. Electrical Wiring
Electrical shock hazard.
Turn OFF electrical power at fuse box or service
panel before making any electrical connections
and ensure a proper ground connection is made
before connecting line voltage.
Failure to do so can result in death, personal injury
and/or property damage.
!
Power Supply Wiring
The furnace MUST be electrically wired and grounded in accor-
dancewithlocalcodes,orintheabsenceoflocalcodes,theappli-
cable national codes.
Fieldwiringconnectionsmustbemadeinsidethefurnaceconnec-
tion box. A suitable strain relief should be used at the point the
wires exit the furnace casing.
Copper conductors shall be used. Line voltage wires should be
sized for the input amps stated on the rating plate. Furnace must
be connected to its own separate circuit.
Thermostat
Thermostat location has an important effect on the operation of
the unit. Follow instructions included with thermostat for correct
mounting and wiring.
Low voltage connections to furnace must be made on terminal
board to fan control. (See Figure 9)
Ifcoolingisused,theYfromthethermostatmustbeconnectedto
the control board Yto energize cooling blower speed.
Set thermostat heat anticipator in accordance with the Technical
Support Manual.
Optional Equipment
AllwiringfromfurnacetooptionalequipmentMUSTconformtolo-
calcodesor,intheabsenceoflocalcodes,theapplicablenational
codes. Install wiring in accordance with manufacturer’s instruc-
tions.
Humidifier/Electronic Air Cleaner
The furnace is wired for humidifier and/or electronic air cleaner
connection.
CAUTION
Do NOT exceed 220V/0.4 amp. maximum current load
for both the EAC terminal and the HUM terminal com-
bined.
NOTE: The humidifier will be powered when the furnace is fired
andthecirculatingairblowercomeson.Theelectronicaircleaner
will be powered anytime the thermostat calls for air movement.
However, theelectronic aircleaner is NOT energized duringcon-
tinuous fan operation controlled by the electronic fan control.
Figure 9 Electrical Connections
25--24--33
NOTE: 220 VAC/50Hz/single--phase
Operating voltage range*: 242 max, 198 min.
* Permissible limits of voltage at which unit will operate satisfactorily
220V/50Hz.

14 44101261000
Control Center Fuse
The 24V circuit contains a 5--amp, automotive--type fuse located
oncontrolcenter.(SeeFigure 10)Anyelectricalshortsof24Vwir-
ingduringinstallation,service,ormaintenancemaycausefuseto
blow. If fuse replacement is required, use only a fuse of identical
size (5 amp.)
Fan Timer Connections
Figure 10
25--23--41
DIP Switch
FUSE
8. Ductwork and Filter (Upflow/Horizontal)
CARBON MONOXIDE POISONING HAZARD.
Failure to properly seal duct can result in death
and/or personal injury.
Do NOT draw return air from inside a closet or
utility room where furnace is located. Return air
duct MUST be sealed to furnace casing.
!
Duct Connections
This furnace may be installed in only a bottom or side return ap-
plication. Return air through the back of the unit is NOT allowed.
Side connections canbe made by cutting outthe embossed area
shown in Figure 11.
Cutting Side Return Air Opening
Starting
Hole
Figure 11
Bottom returns can be made by removing the knockout panel in
the furnace base. Do NOT removeknock-out exceptfora bottom
return.
Duct Design
DesignandinstallairdistributionsystemtocomplywithAirCondi-
tioning Contractors of America manuals or other approved meth-
ods that conform to local codes and good trade practices.
When the furnace is locatedin anarea near or adjacentto the liv-
ing area, the system should be carefully designed with returns to
minimize noise transmission through the return air grille. Any
blower moving a high volume of air will produce audible noise
whichcouldbeobjectionablewhentheunitislocatedverycloseto
alivingarea.Itisoftenadvisabletoroutethereturnairductsunder
the floor or through the attic.
·Refer to furnace Technical Support Manual (Blower Data)
for air flow information.
·Sizeductworktohandleairflowforheatingandaircondition-
ing if used.
Duct Installation Requirements
·When furnace supply ducts carry air outside furnace area,
seal return air ductto furnace casing andterminate duct out-
side furnace space.
·Whenarefrigerationcoilisusedinconjunctionwiththisunit,it
must be installed on the discharge side of the unit to avoid
condensation on the heat exchanger.
·If separate evaporator and blower unit is used, install good
sealingdampersforairflowcontrol.Chilledairgoingthrough
the furnace could cause condensation and shorten furnace
life. Dampers (purchased locally) can be either automatic or
manual. Manually operated dampers MUST be equipped
withameanstopreventfurnaceorairconditioningoperation
unless damper is in the full heat or cool position.
!
CARBON MONOXIDE POISONING HAZARD.
This could result in personal injury and/or death.
Cool air passing over heat exchanger can cause
condensatetoformresultinginheatexchangerfailure.
·Installation of locking-type dampers are recommended in all
branches, or in individual ducts to balance system’s air flow.
·Ifairreturngrilleislocatedclosetothefaninlet,installatleast
one,90°air turn between fan and inlet grille to reduce noise.
·Ductwork installed in attic, or exposed to outside tempera-
turesrequiresaminimumof2²ofinsulationwithoutdoortype
vapor barrier.
·Ductworkinstalledinanindoorunconditionedspacerequires
a minimum of 1²of insulation with indoor type vapor barrier.

15
44101500100
Inspection Panel on some models
A removal access panel should be provided in the outlet duct
when thefurnace isinstalled without acooling coil. This willallow
smokeorreflectedlighttobeobservableinsidethecasingtoindi-
catethepresenceofleaksintheheatexchanger.Thisaccesscov-
er shall be attached in such a manner as to prevent air leaks.
Filters
A filter MUST be used:
Filtersarenotsuppliedwiththesefurnaces,butcanbepurchased
from your dealer.
Use either filter type:
·Washable,highvelocity filtersarebased ona maximumair
flow rating of 600 FPM.
·Disposable,lowvelocityfiltersarebasedonamaximumair
flow of 300 FPM when used with filter grille.
·The furnaces, with 1600or less CFM ratinguse a 16²x25²
high velocity filter. On these models the filter may be
mounted internally for bottom return using factory kit or ex-
ternally for side return.
·Thefurnaceswithgreaterthan1600CFMrequiresthatboth
left and right side returns are used in side return applica-
tions. Two 16²x25²high velocity filters and racks are pro-
videdwithfurnace.Filterracksmustbemountedexternally.
If return air must be on one side only, an optional 20²x25²
filter standoff rack kits can be used. (See Figure 12) For
bottom return, an optional 20²x25²filter rack kit can be
mounted internally.
NOTE: The20x25²standoff filter rack gives more filter area but
does not provide more air. To achieve 2000 CFM a bottomreturn
or 2 side returns are still needed.
NOTE: Disposable, low velocity filters may be replaced with
washable, high velocity filter providing they meet the minimum
size areas. Washable, high velocity filters canbe replaced ONLY
with same type and size.
25-20-31
Figure 12 Optional Duct Standoff
20x25Optional
Filter Rack
Filter Installation using Optional Filter Rack
Wheninstallingorremovingabottommountedfilter,slidethetwo
sidefilterclipstothebackofthefurnaceBEFOREinstallingorre-
moving.Thiswillallowthefiltertoclearthefrontraisededgeofthe
furnace.Insertfilterintosideclipsfirstandpushfilterbackuntilitis
fullyengagedintobackclip.Whenfilterisinplace,slideclipsback
into place midway on filter as shown in Figure 13.
Figure 13 Bottom Mounted Filter Rack
Slide filter clips towards back before removing
25--24--18
9. Checks and Adjustments
Startup
NOTE: Refer to startup procedures in the Users Information
Manual.
CAUTION
If any sparks, odors or unusual noises occur, immedi-
ately shut OFF power to furnace. Check for wiring er-
rors or obstruction to blower.
Gas Supply Pressure
Gas supply pressure should be within minimum and maximum
valueslistedonratingplate.Pressuresareusuallysetbygassup-
pliers.
(SeeL.P.KitinstructionmanualforfurnacesconvertedtoL.P.gas)
Manifold Gas Pressure Adjustment
NOTE: Makeadjustmenttomanifold pressurewithburnersoper-
ating.
!
Fire or explosion hazard.
Turn OFF gas at shut off before connecting
manometer.
Failure to turn OFF gas at shut off before
connecting manometer can result in death and/or
personal injury.
1. With gas OFF, Connect manometer to gas valve or maniflod
tap.Usemanometerwitha0tomin.12²watercolumnrange.
2. Turn gas ON and remove adjustment screw cover on gas
valve. Turn counterclockwise to decrease pressure and
clockwise to increase.

16 44101261000
NOTE:AdjustmentscrewcoverMUSTbeplacedongasvalvebe-
fore reading manifold pressure and operating furnace.
3. For altitudes up to 2000¢, set pressure to value shown in
Table 2. For altitudes between 2000¢to 8000¢,seeSection
6. ”Gas Supply and Piping” for correct pressure value.
Adjust Pilot Burner
The furnace has a pilot flame to light the main burner. The flame
shouldsurround3/8²to1/2²oftheflamerod.SeeFigure 14.To ad-
just, remove cap from pilot adjusting screw on gas valve. Turn
screw counterclockwise to increase or clockwise to decrease
flame as required. Replace cap after adjusting screw.
Pilot Burner
Figure 14
Proper Flame
Adjustment
Flame Rod
Hot Surface
Igniter
1 0 -- 11 -- 6 5
Main Burner Flame Check
Allow the furnace to run approximately 10 minutes then inspect
the main burner and pilot flames. See Figure 15.
Check for the following (Figure 15):
·Stable and blue flames. Dust may cause orange tips or
wisps of yellow, but flames MUST NOT have solid, yellow
tips.
·Flamesextendingdirectlyfromburnerintoheatexchanger.
·Flames do NOT touch sides of heat exchanger
Ifanyproblemswithmainburnerflamesarenoted, itmay benec-
essary to adjust gas pressures, or check for drafts.
Main Burner
Burner Face
10--10--78
Figure 15
Temperature Rise Check
TheblowerspeedMUSTbesettogivethecorrectairtemperature
rise through the furnace as marked on therating plate. Tempera-
ture rise is the difference between supply and return airtempera-
tures.
To check temperature rise,use the following procedure:
1. Place thermometers in supply and return air registers as
closetofurnaceaspossible,avoidingdirectradiantheatfrom
heat exchangers.
2. Take readings and compare with range specified on rating
plate.
3. If the temperature rise isnot in the correct range, the blower
speedmustbechanged.Ahigherblowerspeedwilllowerthe
temperaturerise.Alowerblowerspeedwillincreasethetem-
perature rise.
Changing Blower Speed
ELECTRICAL SHOCK HAZARD.
Failure to do so can result in death, personal injury
and/or property damage.
Turn OFF power to furnace before changing speed
taps.
!
NOTE:Thespeedtapsthatthemanufacturesetsfromthefactory
for this product are based on a nominal 400 CFM per ton cooling
and the basic mid range on the temperature rise for heating.
Since the manufacturer cannot establish the static pressure
that will be applied to the unit, it is the responsibility of the
installerdealer/contractortoselecttheproperspeedtapsfor
the application when the unit is installed.
If it is necessary to change speeds, refer to steps below.
1. Refer to Furnace Wiring Diagram for location of the heating
and cooling speed taps located on the electronic fan control
aswellas locationofunusedblower motorspeedleads.Use
thechart(Table 6 )todeterminetheblowermotorspeedset-
tings.
Table 6 Blower Speed Chart
Wire Color Motor Speed
Black High
Orange*Med--High
Blue Medium
Red Low
*Med--High speed may not be provided on all models.
2. Changetheheatorcoolblowermotorspeedbyremovingthe
motor lead from the “Heat”or“Cool” terminal and replace it
with the desired motor speed lead fromthe “Unused Motor
Lead” location. Connect the wire previously removed from
the “Heat”or“Cool” terminal to thevacated “Unused Motor
Lead” terminal.
3. Ifthesamespeedmustbeusedforbothheatingandcooling,
remove the undesired motor speed lead from the “Heat”or
“Cool”terminalandconnectthatleadtotheopenterminalat
“Unused Motor Lead” location or tape off. Attach a jumper
between the “Heat” and “Cool” terminals and the remaining
motor speed lead.
Note: When using the same speed on motorswith (4) speed
leads,itwillbenecessarytotapeofftheterminalofthemotor
speed lead removed from the “Heat”or“Cool”terminalwith
electrical tape since an open terminalwill not be availableat
the “Unused Motor Lead” location.
Continuous Fan Operation
A terminal is provided on the electronic fan control located in the
circulating blower compartment for operation of the continuous
fan option. This connection is intended for the low speed motor

17
44101500100
tap,andhasalowercontactrating(8amps)thantheheatandcool
taps. When the low speed blower lead is connected to this termi-
nal,thiswillprovidelowspeedbloweroperationwhenevertheoth-
er two speeds (Heat or Cool) are not energized.
Thoroughly check the system after modification to ensure the
properoperationofthecirculatingairblowerinallmodesofopera-
tion.
Separate speed selections for Heat, Cool, and
Continuous Fan
Connectlowspeedleadfromcirculatingmotortothe“Cont”termi-
nal at the electronic fan control. The appropriate motor leads
should already be connected to the “Heat”and“Cool” terminals.
Heating and Continuous Blower Speed the Same
If it is necessary to operate the heating speed and continuous
blowerspeedusingthesameblowerspeed,connectajumperbe-
tween the “Heat” and “Cont” terminals on the electronic fan con-
trol.
Note: There should be only ONE motor lead going to the “Heat”
and “Cont” terminals.
10. Furnace Maintenance
CAUTION
It is recommended that the furnace be inspected and
serviced on an annual basis (before the heating sea-
son) by a qualified service technician.
See “User’s Information Manual”.
11. Sequence of Operation & Diagnostics
The following is the normal operating sequence.
Cooling (Y) Request:
24 VAC signals applied to Y & G terminals of EFT (electronic fan timer) control.
·Cool motor speed energized after 5 second Cool Fan On Delay time.
Y & G signals removed from EFT.
·Cool motor speed de--energized after 90 second Cool Fan Off Delay time.
Circulating Fan (G) Request:
24 VAC signals applied to G terminals of EFT control.
·Heat motor speed energized without delay.
G signal removed from EFT.
·Heat motor speed de--energized without delay.
NOTE 1) Furnaces with PSC blower motors de--energize the Low Heat fan speed during the heat exchanger warm--up period on a
call for Heating that occurs during a G request.
NOTE 2) Heating orCooling requests received duringa Fan request cause the fan speed tochange to the appropriateheat or cool
speedaftertheselectedFanOnDelaytimeexpires.ThefanreturnstocirculatingspeedaftertheselectedFanOffDelaytimeexpires
following loss of the Heating or Cooling request.
Heating (W) Request:
24 VAC signals applied to W terminal of EFT control.
·Inducer motor turns on at high speed.
·Followinga3secondprepurge delay, the pilot valve opens and the ignitor begins to warm up.
·After the pilot lights, the main burners energize and light (burners).
·Timed from the opening of the main gas valve, the control will delay the selected Heat Fan On Delay time.
W signal removed from EFT.
·The gas valve de--energizes and the main burners go out.
·The inducer runs for a 30 second postpurge period.
·The fan stays at Heat speed.
·Timed from the gas valve de--energizing, the Heat fan speed
de--energizes after the selected Heat Fan Delay time expires.
Heating Request with Gas Supply Line Shut Off:
24 VAC signals applied to W1 terminal of EFT control.
·Inducer motor turns on.
·Followinga3secondprepurge delay, the pilot valve opens and

Typical Gas Valve Honeywell
Figure 16
INLET
OUTLET
Diagnostic Light
(on some models)
25--22--25a
On/Off
Switch Pilot
Adjustment
Manifold
Adjustment
(Hidden)
18 44101261000
the ignitor begins to warm up.
·The ignitor glows red--hot for 30 seconds, then turns off.
·The igniter stays off for 25 seconds, then begins to
warm--up again.
·The igniter glows red--hot for 30 seconds, then turns off.
·The pilot valve closes 3 seconds after the igniter de--energizes.
·The inducer de--energizes 30 seconds after the pilot valve closes.
·The SmartValve proceeds to soft lockout and flashes error
code 6.
·The control exits soft lockout after 5 minutes and begins another
ignition sequence.
Gas Valve Diagnostic Codes (See Figure 16)
OFF = Control not powered
Heartbeat = Normal Operation (Standby or call for heat)
1 Flash = Not used
2 Flashes = Low Pressure switch closed when should be open
3 Flashes = Low Pressure switchcircuit was still sensedas open 30seconds after the inducerwas energized.System
is in 5 minute delay mode, with inducer off. After 5--minute delay, a new ignition sequence will be initiated.
(Note: SV9541Q On/Off switch in off position during a call for heat will generate this diagnostic code)
4 Flashes = Limit switch string open
5 Flashes = Flame sensed out of sequence -- Flame signal still present.
6 Flashes + 1 Note 1 = Soft Lockout --Maximum retry count exceeded (failed to light within 4 trials for ignition)
6 Flashes + 2 Notes 1,2 = SoftLockout--Maximumrecyclecountexceeded --LastfailurewasFlameSenseLostDuringRun,Cycling
Pressure Switch or Blocked Condensate.
6 Flashes + 3 Notes 1,2 = Soft Lockout --Maximum recycle count exceeded -- Last failure was Airflow Proving Circuit Opened
During Run
6 Flashes + 4 Notes 1,2 = Soft Lockout --Maximum recycle count exceeded -- Last failure was Limit Circuit Opened During Run
7 Flashes = Soft Lockout Due to Limit Trips Taking Longer than 2 minutes to Reset; Auto Reset After 1 Hour if
Call for Heat Still Present. Reset by Cycling Call for Heat at Any Time.
8 Flashes = High Pressure Switch closed when sould be open.
9 Flashes = High Pressure Switch open when sould be closed.
NOTE1:The6+Xdesignationindicatesacombinationofflashcodes:6flashesshowsthecontrolisinsoftlockout,followedbyXflashes
toindicatethereasonthecontrolwentintosoftlockout.Whenthe6+Xcodeisflashing,theSV9541willattemptanewignitionsequence
afterafiveminutedelayperiod,ifthecallforheatisstillpresent.Resetofthethermostatwillinitiateanewignitionsequenceimmediately.
NOTE 2: Any combination of 5 ‘abnormal’ events during a single call for heat will result in soft lockout. An ‘abnormal’ event is aFlame
SenseFailureDuringRun,AirflowProvingCircuitOpenDuringRun,orLimitCircuitOpenDuringRun.Theflashcodewillindicatewhich
was the last ‘abnormal’ event that put the system into the soft lockout state based on the table above.