Coleman UGAA075BUA, UGAA075BUH, UGAB100BUG, UGAB100BUA, UGAB075BUH Installation Guide
HIGH EFFICIENCY
CLAM TUBE HEAT EXCHANGER SERIES
MODELS: UGAA & UGAB
(Single Stage Upflow/Horizontal)
75 - 100 MBH INPUT
(21.98 - 29.31 KW) INPUT
TABLE OF CONTENTS
SAFETY ................................................ 1 TWINNING AND STAGING ................................ 12
DUCTWORK ............................................ 4 VENT/COMBUSTION AIR SYSTEM ......................... 14
FILTERS ............................................... 8 SAFETY CONTROLS .................................... 20
GAS PIPING ............................................ 9 START-UP AND ADJUSTMENTS ........................... 20
ELECTRICAL POWER ................................... 11 WIRING DIAGRAM ...................................... 26
LIST OF FIGURES
Dimensions ............................................. 6
Floor Installation .......................................... 6
Platform Installation ....................................... 7
Typical Attic Installation .................................... 7
Typical Suspended Furnace / Crawl Space Installation ............ 8
Side Return Cutout Markings ................................ 8
Horizontal Mount and Filter ................................. 8
Gas Valve ............................................... 9
Upflow Configuration ...................................... 9
Horizontal Gas Piping ..................................... 9
Burner Assembly ........................................ 10
Line Wiring Connections .................................. 11
Heating and cooling Thermostat Connections .................. 12
Two-Stage Heating and Cooling Thermostat Connections ........ 12
Accessory Connections ................................... 12
Typical Twinned Furnace Application ........................ 13
Single Stage Twinning Wiring Diagram ....................... 13
Two-Stage Twinning Wiring Diagram ......................... !4
Vent Termination ........................................ !4
Vent Termination ........................................ !4
Alternate Air Intake, Air Outlet and Chimney Connections ......... 15
Air Inlet, Outlet and Chimney Connections ..................... 15
Typical Sidewall Vent Application ............................ !6
Typical Sidewall Vent and Termination Configuration ............ 16
Typical Chimney Connections .............................. !6
Horizontal Air Inlet, Outlet and Chimney Connections ............ 16
Home Layout ........................................... !7
Combustion Airflow Path Through The Furnace Casing
to the Burner Box ........................................ !8
Outside and Ambient Combustion Air ......................... 19
Pressure Switch Tubing Routing ............................ 20
Gas Valve .............................................. 23
Reading Gas Pressure .................................... 23
Typical Heat/Cool Speed Tap Connections .................... 24
Wiring Diagram .......................................... 26
LIST OF TABLES
Unit Clearances to Combustibles ............................. 4
Minimum Duct Sizing For Proper Airflow ....................... 5
External Static Pressure Range .............................. 5
Cabinet and Duct Dimensions ............................... 6
Filter Sizes - Upflow ....................................... 8
Inlet Gas Pressure Range .................................. 9
High Altitude Conversion .................................. 1!
Ratings & Physical / Electrical Data - Upflow Models ............ 11
Roof Pitch .............................................. 14
Horizontal Sidewall Venting Clearances ....................... 16
Estimated Free Area ...................................... !8
Free Area .............................................. 18
Unconfined Space Minimum Area in Square Feet ............... 18
Inlet Gas Pressure Range ................................. 23
Nominal Manifold Pressure ................................. 23
Filter Performance - Pressure Drop Inches W.C. and (kPa) ........ 24
Blower Performance - CFM ................................ 25
Field Installed Accessories - Non Electrical .................... 25
Field Installed Accessories - Electrical ........................ 25
SECTION h SAFETY
Q _ ]SO 9001
Certified Quality
Management System
_WARNING
[_ This is a safety alert symbol. When you see this symbol on
labels or in manuals, be alert to the potential for personal
injury,
Understand and pay particular attention to the signal words DANGER,
WARNING, or CAUTION.
DANGER indicates an imminently hazardous situation, which, if not
avoided will result in death or serious iniurv.
WARNING indicates a potentially hazardous situation, which, if not
avoided could result in death or serious injury.
CAUTION indicates a potentially hazardous situation, which, if not
avoided may result in minor or moderate iniurv. It is also used to
alert against unsafe practices and hazards involving only property dam-
age.
Improper installation may create a condition where the operation of
the product could cause personal injury or property damage.
Improper installation, adjustment, alteration, service or mainte-
nance can cause injury or property damage. Refer to this manual
for assistance or for additional information, consult a qualified con-
tractor, instafler or service agency.
A CAUTION
This product must be installed in strict compliance with the installa-
tion instructions and any applicable local state, and national codes
including, but not limited to building, electrical and mechanical
codes.
66840/035-20003-001 Rev. B (1205)
66840/035-20003-001Rev.B(1205)
SPECIFIC SAFETY RULES AND PRECAUTIONS
1. Only Natural gas or Propane (LP) gas are approved for use with
this furnace. Refer to the furnace rating plate or Section IV d
these instructions.
2. Install this furnace only in a location and position as specified in
SECTION I of these instructions.
3. A gas-fired furnace for installation in a residential garage must be
installed as specified in SECTION I of these instructions.
4. Provide adequate combustion and ventilation air to the furnace
space as specified in SECTION VI! of these instructions.
5. Combustion products must be discharged outdoors. Connect this
furnace to an approved vent system only, as specified in SEC-
TION VII of these instructions.
FIRE OR EXPLOSION HAZARD
Failure to follow the safety warnings exactly could result in serious
injury, death or property damage.
Never test for gas leaks with an open flame. Use a commercially
available soap solution made specifically for detection of leaks to
check all connections. A fire or explosion may result causing prop-
erty damage, personal injury or loss of life.
6. Test for gas leaks as specified in SECTION IX of these instruc-
tions.
7. Always install the furnace to operate within the furnace's intended
temperature rise range. Only connect the furnace to a duct system
which has an external static pressure within the allowable range,
as specified on the furnace rating plate.
8. When a furnace is installed so that supply ducts carry air circulated
by the furnace to areas outside the space containing the furnace,
the return air may also be handled by duct(s) sealed to the furnace
casing and terminating outside the space containing the furnace.
The return air duct system is required by the furnace manufacturer
provided the combustion air and vent system have been installed
and maintained as a Two Pipe Sealed Combustion Air System and
provided a return air duct system and return air plenum are not
required by state, local, or regional codes.
9. It is permitted to be use the furnace for heating of buildings or
structures under construction. Installation must comply with all
manufacturer's installation instructions including:
• Proper vent installation;
• Furnace operating under thermostatic control;
• Return air duct sealed to the furnace;
• Air filters in place;
• Set furnace input rate and temperature rise per rating plate
marking;
• Means for providing outdoor air required for combustion;
• Return air temperature maintained between 55°F (13°C) and
80°F (27°C);
• The air filter must be replaced upon substantial completion of
the construction process;
• Clean furnace, duct work and components upon substantial
completion of the construction process, and verify furnace-
operating conditions including ignition, input rate, temperature
rise and venting, according to the manufacturer's instructions.
The following requirements to be met:
a. Clean, outside combustion air is provided to the furnace to
minimize the impact of corrosive adhesives, sealants, and
other construction materials. Drywall dust is a major concern
during construction, which can be pulled into the combustion
air path, leading to plugged gas valves, burners, and inducer
assemblies.
b. Filter must be installed in the furnace as specified in the
installation instructions, and must be replaced or thoroughly
cleaned prior to occupancy of the home. Again, drywall dust
is the key issue, as that dust can be pulled into the circulating
blower motor, plugging the motor vents, coating the rotors
and stators, etc. which can lead to a potential fire hazard.
c. The temperature of the return air to the furnace must not be
less than 55 degrees F (13 deg C), with no evening setback
or furnace shutdown, to prevent condensation in the primary
heat exchangers.
d. The air temperature rise must be within the stated rise range
as indicated on the furnace rating plate, and the firing input
rate must be set to the unit nameplate value.
e. The external static pressure of the air distribution system
ductwork must at set for heating operation to be at least 0.!0
to 0.20 inches water column, based on the input rate of the
furnace, with the lower value for input rates less than 55,000
btu/hr and the upper value for units with input rates above
100,000 btu/hr.
f. A return air duct must be used, sealed to the furnace cabinet,
and terminated outside the space where the furnace is
installed. This prevents any recirculation of supply air, which
can generate a negative pressure condition at the furnace for
non-direct vent furnaces, leading to possible flame rolIout or
combustion problems.
g. The furnace and ductwork should be thoroughly and com-
pletely cleaned prior to occupancy of the dwelling to insure
the proper operation of the furnace and to avoid potential
health concerns.
10. When installed in a Manufactured (Mobile) Home, Modular Home,
or building constructed on-site, combustion air must never be sup-
plied from occupied spaces.
11. The size of the unit should be based on an acceptable heat loss
calculation for the structure. ACCA, Manual J or other approved
methods may be used.
12. Mobile Home Installations:
This appliance must be installed with a vent terminate in the same
atmospheric zone, external to the building.
13. Modular and Manufactured (Mobile) Home Installations:
This appliance must be installed so that the vent pipe from the
vent connection on the furnace can be easily connected to a B
type vent that terminates outdoors. This appliance cannot be con-
nected to a vent that is serving another appliance. This appliance
shall be installed in an area where there is an adequate supply of
combustion air available to assure proper combustion and ambient
air temperatures are maintained within safe operating limits.
If an adequate supply of combustion air is not available to assure
proper combustion and ventilation air, outside air shall be intro-
duced to the space in which the appliance is located. An outside
combustion air duct may be used to provide the outside air to the
space. Refer to ANSI Z223.1 National Fuel Gas Code or in Can-
ada B149-00 National Gas and Propane Installation Code for
proper duct sizing and installation.
NOTE: Air for combustion must never be taken from occupied spaces.
Appliance combustion air must be provided from outdoors.
14. Modular Home Definition:
Factory-built home constructed to the state, local, or regional code
where the house will be located. The home is transported in one or
more modules and joined at the home site.
15. Mobile Home Definition:
Factory-built home constructed, transported, and installed under
the federal building code administered by the U.S. Department of
Housing and Urban Development (HUD Code), rather than to
building codes at their destination. The house is built, transported,
and installed on a non-removable chassis.
16. This furnace is not approved for installation in trailers or recre-
ational vehicles.
2 Unitary Products Group
66840/035-20003-001Rev.B(1205)
SAFETY REQUIREMENTS
• A manufactured (mobile) home installation must conform with the
Manufactured Home Construction and Safety Standard, Title 24
CFR, Part 3280, or when such standard is not applicable, the
standard for Manufactured Home Installations (Manufactured
Home Sites, Communities, and Set-ups)ANSI/NCS A225.1, and/
or the Canadian Standard for CANICSA Z240 MH, Series M92
Mobile Homes. Furnaces have been certified to the latest edition
of standard ANSI Z21-47 • CSA 2.3.
• Refer to the unit rating plate for the furnace model number, and
then see the dimensions page of this instruction for return air ple-
num dimensions in Figure 1. The plenum must be installed
according to the instructions.
• Provide clearances from combustible materials as listed under
Clearances to Combustibles.
• Provide clearances for servicing ensuring that service access is
allowed for both the burners and blower.
• These models are CSA listed or approved for installation into a
Modular Home or a Manufactured (Mobile) Home.
• Failure to carefully read and follow all instructions in this
manual can result in furnace malfunction, death, personal
injury and/or property damage.
• Furnaces for installation on combustible flooring shall not be
installed directly on carpeting, tile or other combustible material
other than wood flooring.
• Check the rating plate and power supply to be sure that the elec-
trical characteristics match. All models use nominal !15 VAC, 1
Phase, 60-Hertz power supply. DO NOT CONNECT THIS APPLI-
ANCE TO A 50 HZ POWER SUPPLY OR A VOLTAGE ABOVE
130 VOLTS.
• Furnace shall be installed so the electrical components are pro-
tected from water.
• Installing and servicing heating equipment can be hazardous due
to the electrical components and the gas fired components. Only
trained and qualified personnel should install, repair, or service
gas heating equipment. Untrained service personnel can perform
basic maintenance functions such as cleaning and replacing the
air filters. When working on heating equipment, observe precau-
tions in the manuals and on the labels attached to the unit and
other safety precautions that may apply.
• 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 who have not kept up with changing manufac-
tured (mobile) home and modular home construction practices.
These instructions are required as a minimum for a safe installa-
tion.
COMBUSTION AIR QUALITY
(LIST OF CONTAMINANTS)
The furnace will require OUTDOOR AIR for combustion when the fur-
nace is located in any of the following environments.
• Restricted Environments
Commercial buildings
Buildings with indoor pools
Furnaces installed in laundry rooms
Furnaces installed in hobby or craft rooms
Furnaces installed near chemical storage areas
Chemical Exposure
The furnace will require OUTDOOR AIR for combustion when the fur-
nace is located in an area where the furnace is being exposed to the fol-
lowing substances and / or chemicals.
• Permanent wave solutions
• Chlorinated waxes and cleaners
• Chlorine based swimming pool chemicals
• Water softening chemicals
De-icing salts or chemicals
Carbon tetrachloride
Halogen type refrigerants
Cleaning solvents (such as perchloroethylene)
Printing inks, paint removers, varnishes, etc.
Hydrochloric acid
Cements and glues
Antistatic fabric softeners for clothes dryers
Masonry acid washing materials
If outdoor air is used for combustion, the combustion air intake duct sys-
tem termination must be located external to the building and in an area
where there will be no exposure to the substances listed above.
_WARNING
The furnace area must not be used as a broom closet or for any
other storage purposes, as a fire hazard may be created. Never
store items such as the following on, near or in contact with the fur-
Race.
1. Spray or aerosol cans, rags, brooms, dust mops, vacuum
cleaners or other cleaning tools.
2. Soap powders, bleaches, waxes or other cleaning com-
pounds; plastic items or containers; gasoline, kerosene, ciga-
rette lighter fluid, dry cleaning fluids or other volatile fluid.
3. Paint thinners and other painting compounds.
4. Paper bags, boxes or other paper products
Never operate the furnace with the blower door removed. To
do so could result in serious personal injury and/or equipment
damage.
INSPECTION
As soon as a unit is received, it should be inspected for possible dam-
age during transit. If damage is evident, the extent of the damage
should be noted on the carrier's freight bill. A separate request for
inspection by the carrieCs agent should be made in writing. Also, before
installation, the unit should be checked for screws or bolts, which may
have loosened in transit, and have shipping or spacer brackets which
need to be removed.
FURNACE LOCATION AND CLEARANCES
The furnace shall be located usina the followina auidelines:
1. Where a minimum amount of vent piping and elbows will be
required.
2. As centralized with the air distribution as possible.
3. Where it will not interfere with proper air circulation in the confined
space.
4. Where the outdoor vent terminal will not be blocked or restricted.
Refer to "VENT CLEARANCES" located in SECTION VII of these
instructions. These minimum clearances must be maintained in
the installation.
5. Where the unit will be installed in a level position with no more
than 1/4" (0.64 cm) slope side-to-side and front-to-back to provide
proper condensate drainage.
Installation in freezina temoeratures:
1. Furnace shall be installed in an area where ventilation facilities
provide for safe limits of ambient temperature under normal oper-
ating conditions. Ambient temperatures falling below 32 ° F (0 ° C)
may result in the flue temperature falling below 260° F (!27 ° C) at
any point in the flue pipe. The flue products will condense in the
vent pipe if the flue temperature fails below 260 ° F (127 ° C) caus-
ing the vent pipe to deteriorate rapidly.
2. Do not allow return air temperature to be below 55° F (13 ° C) for
extended periods. To do so may cause condensation to occur in
the main heat exchanger, leading to premature heat exchanger
failure.
Unitary Products Group 3
66840/035-20003-001Rev.B(1205)
Improper installation in an ambient below 32°t: (0.0 ° C) could create
a hazard, resulting in damage, injury or death.
3. If this furnace is installed in an unconditioned space and an
extended power failure occurs, there will be potential damage to
the internal components. Following a power failure situation, do
not operate the unit until inspection and repairs are performed.
Clearances for access:
Ample clearances should be provided to permit easy access to the unit.
The following minimum clearances are recommended:
TABLE 1: Unit Clearances to Combustibles
1. Twenty-four (24) inches (61 cm) between the front d the furnace
and an adjacent wall or another appliance, when access is
required for servicing and cleaning.
2. Eighteen (18) inches (46 cm) at the side where access is required
for passage to the front when servicing or for inspection or replace-
ment of flue/vent connections.
In all cases, accessibility clearances shall take precedence over clear-
ances for combustible materials where accessibility clearances are
greater.
Installation in a residential aaraoe:
3. A gas-fired furnace for installation in a residential garage must be
installed so the burner(s) and the ignition source are located not
less than 18 inches (46 cm) above the floor, and the furnace must
be located or protected to avoid physical damage by vehicles.
APPLICATION
TOP FRONT REAR SIDES SINGLE WALL VENT
In. (cm) In, (cm) In. (cm) In. (cm) In. (cm)
UPFLOW 1 (254) 2 (5.08) 0 (0.0) 0 (00) 6 (1524)
UPFLOW B-VENT 1 (254) 1 (2.54) 0 (0.0) 0 (00) N/A
HORIZONTAL 1 (254) 2 (5.08) 0 (0.0) 1 (5.08) 6 (1524)
HORIZONTAL B-VENT 1 (2.54)) 1 (254) 0 (0.0) 0 (00) N/A
1. Line contact only permitted between lines formed by the intersection of the rear paneI and side paneI (top in horizontal position) of the furnace jacket and buitding
joists, studs or framing
FLOOR/ LINE
BOTTOM CONTACT
COMBUSTIBLE YES YES YES NO
COMBUSTIBLE YES YES YES NO
COMBUSTIBLE NO YES YES YES 1
COMBUSTIBLE NO YES YES YES 1
CLOSET ALCOVE ATTIC
SECTION Ih DUCTWORK
DUCTWORK GENERAL INFORMATION
The duct system's design and installation must:
1. Handle an air volume appropriate for the served space and within
the operating parameters of the furnace specifications.
2. Be installed in accordance with standards of NFPA (National Fire
Protection Association) as outlined in NFPA pamphlets 90A and
90B (latest editions) or applicable national, provincial, or state, and
local fire and safety codes. In Canada refer to the National Gas
and Propane Installation Code B149.!-00, Provincial, Local Fire
and Safety Codes.
3. For manufactured (mobile) home and modular home return
duct system installation: The return air duct and the return air
plenum are required by the furnace manufacturer.
4. Complete a path for heated or cooled air to circulate through the
air conditioning and heating equipment. Air must circulate to and
from the conditioned space.
A CAUTION
The cooling coil must be installed in the supply air duct, down-
stream of the furnace. Cooled air may not be passed over the heat
exchanger.
When the furnace is used in conjunction with a cooling coil, the coil
must be installed parallel with, or in the supply air side of the furnace to
avoid condensation in the primary heat exchanger. When a parallel flow
arrangement is used, dampers or other means used to control airflow
must be adequate to prevent chilled air from entering the furnace. If
manually operated, the damper must be equipped with means to pre-
vent the furnace or the air conditioner from operating unless the damper
is in full heat or cool position.
The duct system must be properly sized to obtain the correct airflow
for the furnace size that is being installed.
Refer to Table 8 and the furnace rating plate for the correct rise
range and static pressures
If the ducts are undersized, the result will be high duct static pres-
sures and/or high temperature rises which can result in a heat
exchanger OVERHEATING CONDITION. This condition can result
in premature heat exchanger failure, which can result in personal
injury, property damage, or death.
DUCTWORK INSTALLATION
Upflow Instructions
When replacing an existing furnace, if the existing plenum is not the
same size as the new furnace then the existing plenum must be
removed and a new plenum installed that is the proper size for the new
furnace. If the plenum is shorter than 12" (30.5 cm) the turbulent air flow
may cause the limit controls not to operate as designed, or the limit con-
trois may not operate at all.
The duct system is a very important part of the installation. If the duct
system is improperly sized the furnace will not operate properly.
The ducts attached to the furnace plenum, should be of sufficient size
so that the furnace operates at the specified external static pressure
and within the air temperature rise specified on the nameplate.
Table 2 is a guide for determining whether the rectangular duct system
that the furnace is being connected to be of sufficient size for proper fur-
nace operation.
Use the Example below to help you in calculating the duct area to deter-
mine whether the ducts have sufficient area so that the furnace oper-
ates at the specified external static pressure and within the air
temperature rise specified on the nameplate.
kWARNING
Attach the supply plenum to the furnace outlet duct
S cleat material when a metal plenum is used. The use
of an approved flexible duct connector is recom-
mended on all installations. This connection should be
connection flanges. This is typically through the use of
sealed to prevent air leakage. The sheet metal should
be crosshatched to eliminate any popping of the sheet
metal when the indoor fan is energized.
4 Unitary Products Group
66840/035-20003-001 Rev. B (1205)
Example:Thefurnaceinputis80,000BTUH,1,200CFM.Therecom-
mendedductareais280sq.in,therearetwo8x14rectangularducts
attachedtotheplenumandtherearetwo7inchroundductsattachedto
thefurnace.
1. Take8x14,whichequals112sq.in.X2,whichequals224square
inchthengotoroundductsizelocatedinTable2.
2. Thesquareinchareafor7inchroundpipeis38.4,multiplyby2for
tworoundductswhichequals76.8squareinch.
3. Thentakethe224squareinchfromtherectangularductandaddit
tothe76.8sq.in,ofroundduct.Thetotalsquareinchofduct
attachedtothefurnaceplenumis300.8squareinch.Thisexceeds
therecommended280squareinchofduct.
Inthisexample,theductsystemattachedtotheplenumhasasufficient
areasothatthefurnaceoperatesatthespecifiedexternalstaticpres-
sureandwithintheairtemperaturerisespecifiedonthenameplate.
Considerationshouldbegiventotheheatingcapacityrequiredandalso
totheairquantity(CFM)required.Thesefactorscanbedeterminedby
calculatingtheheatlossandheatgainofthehomeorstructure.Ifthese
calculationsarenotperformedandthefurnaceisover-sized,thefollow-
ingmayresult:
1. Shortcyclingofthefurnace.
2. Widetemperaturefluctuationsfromthethermostatsetting.
3. Reducedoveralloperatingefficiencyofthefurnace.
Thesupplyandreturnductsystemmustbeofadequatesizeand
designedsuchthatthefurnacewilloperatewithinthedesignedairtem-
peratureriserangeandnotexceedthemaximumdesignedstaticpres-
sure.Thesevaluesarelistedinthetablebelow.
TABLE2:MinimumDuctSizingForProperAirflow
TABLE 3: External Static Pressure Range
Input Output
MBH kW MBH kW
75 22.0 60 17.6
75 22.0 60 17.6
100 29.3 80- 23.4
TABLES 2 and 3 are to be used as a guide only to help the installer
determine if the duct sizes are large enough to obtain the proper air flow
(CFM) through the furnace. TABLES 2 and 3 ARE NOT to be used to
design ductwork for the building where the furnace is being installed.
There are several variables associated with proper duct sizing that are
not included in the tables. To properly design the ductwork for the build-
ing, Refer to the ASHRAE Fundamentals Handbook, Chapter on
"DUCT DESIGN" or a company that specializes in Residential and Mod-
ular Home duct designs.
IMPORTANT: The minimum plenum height is 12" (30.5). The furnace
will not operate properly on a shorter plenum height. The minimum rec-
ommended rectangular duct height is 4 inches (10 cm) attached to the
plenum.
IMPORTANT: The air temperature rise should be taken only after the
furnace has been operating for at least 15 minutes. Temperatures and
external static pressures should be taken 6" (15 cm) past the first bend
from the furnace in the supply duct and the return duct. If an external fil-
ter box or an electronic air cleaner is installed, take the return air read-
ings before the filter box or air cleaner.
Nominal
Air Flow
CFM cmm
1200 34.0
1600 45.3
1600 45.3
Ext. Static Pressure
Minimum Maximum
In.W.C kPa In.W.C kPa
0.12 0.0299 0.50 0.!245
0.12 0.0299 0.50 0.1245
0.15 0.0374 0.50 0.!245
Input
BTU/H
(kW)
75000
(2198)
75000
(2198)
100000
(2931)
NOTE: This chart does not replace proper duct sizing calculations or take into
account static pressure drop for run length and fittings. Watch out for the temper-
ature rise and static pressures.
1 Maximum return air velocity in rigid duct @ 700 feet per minute (19.82 m3/
minute)
2 Example return main trunk duct minimum dimensions
3 Maximum supply air velocity in rigid duct @ 900 feet per minute (25.49 m3 /
minute)
Airflow Return I Rectangular 2 Round 2 Supply 3
CFM Ins in. x in in Ins
(m 3) (cm _) (cm x cm) (cm) dia. (cm _)
1,200 280 14 x 20 18 216
(3398) (711) (356 x 508) (457) (549)
1,600 360 18 x 20 22 280
(4531) (914) (457 x 508)) (558) (711)
1,600 360 18 x 20 22 280
(4531) (914) (45.7 x 50.8) (558) (711)
The supply air temperature MUST NEVER exceed the Maximum
Supply Air Temperature, specified on the nameplate.
Operating the furnace above the maximum supply air temperature
will cause the heat exchanger to overheat, causing premature heat
exchanger failure. Improper duct sizing, dirty air filters, incorrect
manifold pressure, incorrect gas orifice and/or a faulty limit switch
can cause the furnace to operate above the maximum supply air
temperature. Refer to sections II, III and IX for additional informa-
tion on correcting the problem.
If a matching cooling coil is used, it may be place directly on the furnace
outlet and sealed to prevent leakage. Follow the coil instructions for
installing the supply plenum. On all installations without a coil, a remov-
able access panel is recommended in the outlet duct such that smoke
or reflected light would be observable inside the casing to indicate the
presence of leaks in the heat exchanger. This access cover shall be
attached in such a manner as to prevent leaks.
Unitary Products Group 5
66840/035-20003-001Rev.B(1205)
29-3/4
,7 cm) (75,6 cm_.
31-1/2
(80.0 cm)
13-15/16
(85A cm)
(58A cm)
FIGURE 1: Dimensions
TABLE 4: Cabinet and Duct Dimensions
BTUH (kW) Cabinet Cabinet Dimension
Input/Output CFM (m3/min) Size A(in.) A(cm) B(in.)* B(cm)*
/b/6U (22.0/1/.6) 1200 (33.98) B 1 / 1/2 44.b 16 1/2 41.9
/bt6U (22.0/1/.6) !600 (46.31) C 21 53.3 20 50.8
100/80 (29.3/23A) 1600 (45.31) C 21 53.3 20 50.8
* Dimensions "B", "C', "D', and "E" arewith duct flangesturned up "F', "G","H", and "J" are with flanges flat
MOBILE HOME AND MODULAR HOME UPFLOW
RETURN PLENUM CONNECTION
Return air may enter the furnace through the side(s) or bottom depend-
ing on the type of application. Return air may not be connected into the
rear panel of the unit. For single return application, see data and notes
on blower performance data tables in this manual.
BOTTOM RETURN AND ATTIC INSTALLATIONS
Bottom return applications normally pull return air through a base plat-
form or return air plenum. Be sure the return platform structure or return
air plenum is suitable to support the weight of the furnace.
The return air ducts to the furnace must have a total cross sectional
area of not less than two square inches per 1000 BTU H of furnace input
rating for heating operation. If air conditioning is to be installed with the
furnace, larger return air ducts may be required, depending on the
capacity of the air conditioner and the airflow required. The return air
opening in the top of the furnace is large enough for the largest capacity
air conditioner for which the furnace blower is rated. The return air duct
or plenum can be connected to the furnace by performing the following
steps:
1. Bend the 3/4" (1.905 cm) flanges that will be used to attach the
return air plenum using the scribe marks in the furnace base.
Refer to Figure 1 for flange locations.
2. Be sure to seal the furnace to plenum connections to prevent air
leakage. Refer to Figure 1 for unit and plenum dimensions.
Attic installations must meet all minimum clearances to combustibles
and have floor support with required service accessibility.
INSTALLATION RECOMMENDATIONS
FLOOR INSTALLATIONS
As shown below in Figure 2, the furnace may be installed directly on the
floor of the home, using a side return air connection. A short duct
should be connected to the side cutout in the furnace casing. The other
end of the return air duct should be connected to a minimum 25" x 16"
filter grille. If a Blend Air ventilation system is to be installed, the return
air duct must be long enough so that the Blend Air damper can be
mounted in the top of the duct.
1 I I J ( fZZCOIL
[ [l rd CAO'NET
F--_ ( /. H_ BLENDAIR
_I_ FLEX DUCT
_I I # [_ BLEND AIR
_-GRILLrT=._ E
FIGURE 2: Floor Installation
PLATFORM INSTALLATIONS
As shown below in Figure 3, the furnace may be installed on a raised
platform. The platform must be a minimum of 20" in height and a filter
grille with a minimum area of 25" x 16" must be mounted in the front,
back or side of the platform. If a Blend Air ventilation system is to be
installed, the platform must be wide enough so that the Blend Air
damper can be mounted in the top of the platform
C(in.)* C(cm)*
20 3/8 t1.8
20 3/8 51 .U
20 3/8 51.8
PLENOM
/DAMPER
I _[ 25"x 18"
I H _ FILTER
6 Unitary Products Group
25" x 16"
FILTER
GRILLE
FIGURE 3: Platform Installation
HORIZONTAL MODELS
Horizontal Installations With a Cooling Coil Cabinet
The furnace should be installed with coil cabinet part number specifi-
cally intended for Horizontal application. If a matching cooling coil is
used, it may be placed directly on the furnace outlet and sealed to pre-
vent leakage. Fellow the ceiI instructions for installing the supply ple-
num. For details of the coiI cabinet dimensions and installation
requirements, refer to the installation instructions supplied with the coil
cabinet
The perforations in the wrapper flanges must be bent away from the
heat exchanger to create duct flanges so the air conditioning ceil can be
properly seated on the furnace.
Attach the supply plenum to the air conditioning coiI cabinet outlet duct
flanges through the use of S cleat material when a metal plenum is
used. The use of an approved flexible duct connector is recommended
on all installations. The connection to the furnace, air conditioning coil
cabinet and the supply plenum should be sealed to prevent air leakage.
The sheet metal should be crosshatched to eliminate any popping of
the sheet metal when the indoor fan is energized.
The minimum plenum height is 12" (30.5 cm). If the plenum is shorter
than 12" (30.5 cm) the turbulent air flow may cause the limit controls not
to operate as designed, or the limit controls may not operate at all. Also
the plastic drain pan in the air conditioning coil can overheat and melt.
Refer to the installation instructions supplied with the air conditioning
coil for additional information.
Horizontal Installations Without a Cooling Coil Cabinet
When installing this appliance, the furnace must be installed so as to
create a closed duct system, the supply duct system must be con-
nected to the furnace outlet and the supply duct system must terminate
outside the space containing the furnace. When replacing an existing
furnace, if the existing plenum is not the same size as the new furnace
then the existing plenum must be removed and a new plenum installed
that is the proper size for the new furnace.
Attach the supply plenum to the furnace outlet duct flanges through the
use of S cleat material when a metal plenum is used. The use of an
approved flexible duct connector is recommended on all installations.
This connection should be sealed to prevent air leakage. The sheet
metal should be crosshatched to eliminate any popping of the sheet
metal when the indoor fan is energized. On all installations without a
66840/035-20003-001 Rev. B (1205)
coil, a removable access panel is recommended in the outlet duct such
that smoke or reflected light would be observable inside the casing to
indicate the presence of leaks in the heat exchanger. This access cover
shall be attached in such a manner as to prevent leaks.
Mobile Home and Modular Home Upflow/Horizontal Return
Plenum Connections
The return air duct and the return air plenum is required by the furnace
manufacturer.
If a upflow return air duct system and return plenum are required by
state, local, or regional codes then the return plenum may be connected
to the furnace inlet and must terminate outside the space containing the
furnace. The external air filter accessory shown in Figure 7 is designed
and recommended for use inside the return plenum.
Attach the return plenum to the furnace inlet duct flanges. This is typi-
cally through the use of S cleat material when a metal plenum is used
for installations where a return air duct system is utilized, the use of a
listed flexible duct connector is recommended. The connection of the
plenum to the furnace and all the ducts connecting to the plenum must
be sealed to prevent air leakage. The sheet metal should be cross-
hatched to eliminate any popping of the sheet metal when the indoor
fan is energized.
The duct system is a very important part of the installation. If the duct
system is improperly sized the furnace will not operate properly. The
ducts attached to the furnace must be of sufficient size so that the fur-
nace operates at the specified external static pressure and within the air
temperature rise specified on the nameplate and in Table 8.
An upflow return air duct and plenum can be attached to the bottom,
side, both sides, or bottom and side of the furnace as shown in Figure
4.
Attic and crawl space installations must meet all minimum clearances to
combustibles and have floor support with required service accessibility
Refer to Figures 4 and 5. All attic and crawl space installations must
have a return air duct system and return plenum. Horizontal installa-
tions require a single return duct as shown in Figure 4. A side return is
not required in a horizontal application.
IMPORTANT: When replacing an existing furnace, if a return air plenum
is used and the existing plenum is not the same size as the new furnace
then the existing plenum must be removed and a new plenum installed
that is the proper size for the new furnace. If a return duct mounted filter
rack or filter grille is being used see the instructions provided with that
accessory for proper hole cut size.
ATTIC INSTALLATION
LINE CONNECT ONLY PERMISSIBLE BETWEEN
LINES FORMED BY THE INTERSECTION OF
FURNACE TOP AND TWO SIDES AND BUILDING
JOISTS, STUDS, OR FRAMING
FILTER RACK MUST
BE A MI NIMUM DISTANCE
OF 18" (45.7 CM) F!
THE FURNACE
SUPPLY
AIR
TRAP
SHEET METAL IN FRONT OF FURNACE COMBUSTION
AIR OPENINGS IS RECOMMENDED
FIGURE 4: Typical Attic Installation
This appliance is design certified for line contact when the furnace is
installed in the horizontal left or right position. The line contact is only
permissible between lines that are formed by the intersection of the top
and two sides of the furnace and the building joists, studs or framing.
This line may be in contact with combustible material.
PLYWOOD
FLOOR
Unitary Products Group 7
66840/035-20003-001Rev.B(1205)
When a furnace is installed in an attic or other insulated space,
keep all insulating materials at least 12 inches (30.5 Cm) away from
furnace and burner combustion air openings.
SUSPENDED FURNACE / CRAWL SPACE
INSTALLATION
The furnace can be hung from floor joists or installed on suitable blocks
or pad. Blocks or pad installations shall provide adequate height to
ensure the unit will not be subject to water damage. Units may also be
suspended from rafters or floor joists using rods, pipe angle supports or
straps. Angle supports should be placed at the supply air end and near
the blower deck. Do not support at return air end of unit. All four sus-
pension points must be level to ensure quiet furnace operation. When
suspending the furnace, use a secure platform constructed of plywood
or other building material secured to the floor joists. Refer to Figure 5
for typical crawl space installation.
ANGLE IRON
BRACKET
SUPPORT
ROD
1"MAX, BETWEEN 6"MtN BETWEEN
ROD & FURNACE ROD & FURNACE
FIGURE 5: Typical Suspended Furnace / Crawl Space Installation
SECTION IIh FILTERS
FILTER INSTALLATION
All applications require the use of a filter. Models must have a field-sup-
plied filter and mounting hardware. Replacement filter size is shown in
Table 5.
TABLE 5: Filter Sizes - Upflow
UPFLOW Side
Input Output Air Flow Size
MBH kW MBH kW CFM cmrn in. crn
75 220 60 17.6 1200 34.0 B 25x16 64x41
75 220 60 17.6 1600 45.3 C 25x16 64x41
100 293 80 23.4 1600 45.3 C 25x16 64x41
SIDE RETURN/BOTTOM EXTERNAL INSTALLATION
Locate and knock out the square corner Iocators. These indicate the
size of the cutout to be made in the furnace side panel. Refer to Figures
1 and 6.
r
I I _ CORNER
Iq FJ J_ MARKINGS
FIGURE 6: Side Return Cutout Markings
Cabinet Return
1"MAX, BETWEEN
ROD & FURNACE
Bottom/End
in. cm
24x 15 61 x38
24x 18 61 x46
24x 18 61 x46
_ FRONT OF
Return
Install the side filter rack following the instructions provided with that
accessory. If a filter(s) is provided at another location in the return air
system, the ductwork may be directly attached to the furnace side
panel. An accessory filter rack is available for mounting the filter exter-
nal to the cabinet.
Some accessories such as electronic air cleaners and pleated media
may require a larger side opening. Follow the instructions supplied with
that accessory for side opening requirements. Do not cut the opening
larger than the dimensions shown in Figure 1.
EXTERNAL FILTER INSTALLATION FOR
UPFLOW/HORIZONTAL CONFIGURATIONS
1. Select desired filter position for upfiow/horizontal (left/right side,
bottom). Remove the corresponding cabinet cut-outs per instruc-
tions provided.
2. Install the external filter box to the side of the cabinet and secure to
the cabinet as specified in the instructions provided with the air fil-
ter kit. If a side return is to be used, cut out the side of the casing
14" high by 16 1/4" wide using the lances in the casing side as a
guide. DO NOT CUT THE OPENING LARGER THAN 14" X 16 1/
4". It is not permissible to cut out the back of the furnace. For bot-
tom returns, place the external filter box between the return air ple-
num and the base of the furnace. The casing bottom is embossed
to indicate where to bend the flanges. Refer to Figure ! for the
maximum return air opening sizes. Seal this connection to prevent
leaks.
3. Install the return air duct to the air filter box and secure with
screws. Seal this connection to prevent leaks.
4. Install the field provided filter. Refer to Table 5 for the recom-
mended filter size for your furnace.
NOTE: Air velocity must not exceed 300 feet per minute through low
velocity disposable filters. Air velocity must not exceed 650 feet
per minute through high velocity cIeanable permanent filters.
Use d a filter that is too small will cause static pressure in the
duct system to be too high, which will have an adverse effect on
heating and cooling operation.
RETURN
DUCT
AIR__ _F
FILTER
FIGURE 7: Horizontal Mount and Filter
If the accessory electronic air cleaner is installed, be sure the air
cleaner is designed to accommodate the furnace CFM (cm/m) and the
air cleaner is installed so it does not obstruct the return airfow. Consid-
eration should be given when locating the air cleaner for maintenance
and temperatures should the indoor fan motor fail to operate. The use
of straps and / or supports is required to support the weight of the elec-
tronic air cleaner. It is recommended that the air cleaner not be located
within 12 inches (2.5 cm) from the top of the return air opening on the
furnace. Refer to the instructions supplied with the electronic air
cleaner.
If pleated media air filters or any filter that has a large pressure drop is
installed in the return air duct system be sure that the pressure drop
caused by the air filter will not prevent the furnace from operating within
the rise range specified on the rating plate. If the furnace does not oper-
ate within the specified rise range then a larger air filter or an air filter
that has a lower pressure drop must be installed. Refer to Table 16 and
the furnace accessories for accessory external filter kit options.
IMPORTANT: Air velocity through throwaway type filters must not
exceed 300 feet per minute (1.52 m/m). All velocities over this require
the use of high velocity filters. Refer to Table 16.
[] []
[] FURNACE []
[]
[]
[] D
[]
[]
[]
MN I
[]
[]
8 Unitary Products Group
SECTION IV: GAS PIPING
GAS SAFETY
kDANGER
This furnace is designed to operate on NATURAL GAS or PRO-
PANE GAS ONLX Do not burn any other fuel in this furnace. Bum-
ing any fuel except NATURAL GAS or PROPANE GAS can cause
premature heat exchanger burnout, high levels of carbon monox-
ide, excessive sooting, a fire hazard, personal injury, property dam-
age and/or death.
An overpressure protection device, such as a pressure regulator,
must be installed in the gas piping system upstream of the furnace
and must act to limit the downstream pressure to the gas valve so it
does not exceed 0.5 PSI (14" w.c. (3.48 kPa)). Pressures exceed-
ing 0.5 PSI (14" w.c. (3.48 kPa)) at the gas valve will cause damage
to the gas valve, resulting in a fire or explosion or cause damage to
the furnace or some of its components that wil! result in property
damage and loss of life.
OUTLET
PRESSURE r! I_] I'_
PORT L_ I I
WRENCH _ _
BOSS __
INLET/
PRESSURE
PORT
ON/OFF SWITCH
(Shown in OFF position)
FIGURE 8: Gas Valve
VENT PORT
OUTLET
N REGULATOR
ADJUSTMENT
66840/035-20003-001Rev.B(1205)
GAS _ PIPE
SHUT-OFF
VALVE
VENT --
BLOWER
DRIP
LEG --_
ROLL-OUT _
SWITCH
FIGURE 9: Upflow Configuration
GAS PIPING INSTALLATION
Properly sized wrought iron, approved flexible or steel pipe must be
used when making gas connections to the unit. If local codes allow the
use of a flexible gas appliance connection, always use a new listed con-
nector. Do not use a connector that has previously serviced another gas
appliance.
Some utility companies or local codes require pipe sizes larger than the
minimum sizes listed in these instructions and in the codes. The furnace
rating plate and the instructions in this section specify the type of gas
approved for this furnace - only use those approved gases. The instal-
lation of a drip leg and ground union is required. Refer to Figure 10.
GAS
MAN UAL
SHUT-OFF
VALVE
PRESSURE
GAS
VALVE
HOT
IGNITOR
ROLL-OUT
SWITCHES
BLOWER
DOOR
SWITCH
FURNACE
CONTROL
CHECKING THE GAS PRESSURES
1. The pressure ports on the gas valve are marked OUT P and IN
R
2. The manifold pressure must be taken at the port marked OUT R
3. The inlet gas supply pressure must be taken at the port marked
INP.
4. Using a 3/32" (0.2 cm) Allen wrench, loosen the set screw by
turning it 1 turn counter clockwise. DO NOT REMOVE THE
SET SCREW FROM THE PRESSURE PORT.
5. Push one end the 3/8" (0.9 cm) ID flexible tubing over the pres-
sure port so that the body of the port is inside the tubing.
6. Use a reducer connector to connect the 3/8" (0.9 cm) ID flexible
tube to a 1/4" (0.9 cm) ID flexible tube that is connected to a "U"
tube manometer or digital pressure measuring equipment.
TABLE 6: Inlet Gas Pressure Range
INLET GAS PRESSURE RANGE
Natural Gas Propane (LP)
Minimum 45" W.C (1 12 kPa) 80" W.C (1 99 kPa)
Maximum 105" W.C. (261 kPa) 130" (3.24 kPa) WC.
IMPORTANT: The inlet gas pressure operating range table specifies
the minimum and maximum gas line pressures required for safe fur-
nace operation.
The minimum inlet gas pressure required to obtain the BTU input
specified on the rating plate and in these instructions is shown below:
• 4.5" W.C. (1.12 kPA) for Natural Gas
• 11.0" W.C. (2.74 kPA) for Propane (LP) Gas
--GAS BURNERS
-- GAS VALVE
HI....................................................................3
DRIP MANLJAL
LEG SHUT-OFF VALVE
FIGURE 10: Horizontal Gas Piping
IMPORTANT: An accessible manual shut-off valve must be installed
upstream of the furnace gas controls and within 6 feet (! .8 m) of the fur-
nace. Refer to Figures 9 and 10.
The furnace must be isolated from the gas supply piping system by
closing its individual external manual shutoff valve during any pressure
testing of the gas supply piping system at pressures equal to or less
than 1/2 psig (3.5 kPa).
CAUTION]
The gas valve body is a very thin casting that cannot take any
external pressure. Never apply a pipe wrench to the body of the gas
valve when installing piping. A wrench must be placed on the octa-
gon hub located on the gas inlet side of the valve. Placing a wrench
to the body of the gas valve wil! damage the valve causing improper
operation and/or the valve to leak.
Gas piping may be connected from either side of the furnace using any
of the gas pipe entry knockouts on both sides of the furnace. Refer to
Figure ! dimensions.
Unitary Products Group 9
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