......................................... 14 ', H', ,'1.-¢" 'l.I
HIGH EFFICIENCY
CLAM TUBE HEAT EXCHANGER SERIES
MODEL: UGAE
(Single Stage Upflow Only)
75 MBH INPUT
(21.98 KW)INPUT
! I
TABLE OF CONTENTS
SAFETY ................................................ 1 TWINNING AND STAGING ................................ 11
DUCTWORK ............................................ 4 VENT/COMBUSTION AIR SYSTEM ......................... 12
FILTERS ............................................... 6 SAFETY CONTROLS .................................... 16
GAS PIPING ............................................ 7 START-UP AND ADJUSTMENTS ........................... 17
ELECTRICAL POWER ................................... 10 WIRING DIAGRAM ...................................... 22
LIST OF FIGURES
Dimensions ............................................. 5
Floor Installation .......................................... 6
Platform Installation ....................................... 6
Side Return Cutout Markings ................................ 6
External Air Filter Rack - Left & Right Side Position .............. 7
External Air Filter Rack - Bottom Position ...................... 7
Gas Valve ............................................... 7
Gas Piping Configuration ................................... 8
Burner Assembly ......................................... 8
Line Wiring Connections .................................. 10
Heating and Cooling Thermostat Connections ................. 10
Accessory Connections ................................... 11
Typical Twinned Furnace Application ........................ 11
Single Stage Twinning Wiring Diagram ....................... 12
Two-Stage Twinning Wiring Diagram ......................... 12
Roof Jack .............................................. 13
Roof Jack Assembly ...................................... 14
Roof Jack Installation ..................................... 14
Ceiling Ring ............................................ 14
Home Layout ........................................... 15
Pressure Switch Tubing Routing ............................ 16
Gas Valve .............................................. 19
Reading Gas Pressure .................................... 19
Typical Heat/Cool Speed Tap Connections .................... 20
Wiring Diagram .......................................... 22
ISO 9001
Certified Quality
Management System
LIST OF TABLES
Unit Clearances to Combustibles ............................. 4
Minimum Duct Sizing For Proper Airflow ....................... 5
External Static Pressure Range .............................. 5
Cabinet and Duct Dimensions ............................... 5
Filter Sizes - Upflow ....................................... 7
Inlet Gas Pressure Range .................................. 8
High Altitude Conversion ................................... 9
SECTION h SAFETY
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 injury.
WARNING indicates a potentially hazardous situation, which, if not
avoided, could result in death or serious iniurv.
CAUTION indicates a potentially hazardous situation, which, if not
avoided mav result in minor or moderate iniurv. It is also used to
alert against unsafe practices and hazards involving only property dam-
age.
Ratings & Physical/Electrical Data - Upflow Models ............. 10
Roof Jack Options ....................................... 14
Inlet Gas Pressure Range ................................. 19
Nominal Manifold Pressure ................................. 19
Filter Performance - Pressure Drop Inches W.C. and (kPa) ........ 20
Blower Performance CFM ................................. 21
Field Installed Accessories - Non Electrical .................... 21
Field Installed Accessories - Electrical ........................ 21
AWARNING
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, installer or service agency.
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.
98618/035-20009-001 Rev. B (1205)
98618/035-20009-001Rev.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 of
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 VII 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.
AWARNING
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 not required by the furnace manufac-
turer 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 ple-
num 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 or air filter rack must be 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 or thoroughly cleaned upon sub-
stantial 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 heat exchangers, 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° F (13 ° 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 0.10
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 for non-direct vent installations
in a modular home or building constructed on site. The return
duct must be sealed to the furnace cabinet, and terminated
outside the space where the furnace is installed. This pre-
vents any recirculation of supply air, which can generate a
negative pressure condition for non-direct vent furnaces lead-
ing to possible flame rollout 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.
In Canada refer to the Natural Gas and Propane Installation code,
section on Central Furnaces. When installed in a Manufactured
(Mobile) Home, combustion air shall not be supplied from occu-
pied 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.
Manufactured (Mobile) Home and Modular Home Installation:
This appliance must be installed in a (sealed combustion) configu-
ration using a roof jack vent system. A roof jack is the only
approved vent system that can be used to vent this appliance.
13.
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.
14.
Manufactured (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.
15.
This furnace is not approved for installation in trailers or recre-
ational vehicles.
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 CAN/CSA 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 and!or filter rack must
be installed according to the instructions.
2 Unitary Products Group
Provide clearances from combustible materials as listed under
Furnace Locations and Clearances.
Provide clearances for servicing ensuring that service access is
allowed for both the burners and blower.
These models are CSA listed and 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 115 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 Modular
Home and Manufactured (Mobile) Home home construction prac-
tices. These instructions are required as a minimum for a safe
installation.
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
Laundry rooms
Hobby or craft rooms
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.
98618/035-20009-001Rev.B(1205)
AWARNING
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-
nace.
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
3. Containers; gasoline, kerosene, cigarette lighter fluid, dry
cleaning fluids or other volatile fluid.
4. Paint thinners and other painting compounds.
5. 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 the furnace and/or accessories are received, it should be
inspected for damage 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 carrier's agent should be made in writing.
Also, before installation, the furnace and/or accessories should be
checked for screws or bolts which have loosened in transit or shipping
and any spacer brackets that need to be removed.
FURNACE LOCATION AND CLEARANCES
The furnace shall be located usina the followina auidelines:
1. The furnace should be located where the roof jack can be installed
with out major modifications to the roof of the structure.
2. As centralized with the air distribution as possible.
3. Where there is access to fresh air particularly when the blend air
accessory will be installed.
4. Where it will not interfere with proper air circulation in the confined
space.
5. Where the outdoor roof jack terminal will not be blocked or
restricted. Refer to "VENT CLEARANCES" located in SECTION
VII of these instructions. These minimum clearances must be
maintained through out the installation.
6. 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
a proper roof jack connection and seal.
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 (127 ° C) at
any point in the flue pipe. If the flue temperature falls below 260 ° F
(127 ° C) the flue products will condense in the vent pipe causing
the vent pipe to deteriorate rapidly.
_WARNING
Installation in an ambient below 32°F (0.0 ° C) could create a haz-
ard, resulting in damage, injury or death.
2.
Do not allow return air temperature to be below 550 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.
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.
Unitary Products Group 3
98618/035-20009-001Rev.B(1205)
Clearances for access:
Ample clearances should be provided to permit easy access to the unit.
The following minimum clearances are recommended:
1. Twenty-four (24) inches (61 cm) between the front of 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.
TABLE 1: Unit Clearances to Combustibles
APPLICATION
UPFLOW
ROOF JACK
TOP
In, (cm)
1 (2.54)
0 (0.0
FRONT
In. (cm)
2 (5.08)
0 (0.0)
REAR
In. (cm)
0 (0.0)
0 (0.0)
SIDES
In. (cm)
0 (0.0)
0 (0.0)
In all cases, accessibility clearances shall take precedence over clear-
ances for combustible materials where accessibility clearances are
greater.
Installation in a residential aaraae:
1. 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.
FLOOR/
BOTTOM
COMBUSTIBLE
COMBUSTIBLE
CLOSET
YES
YES
ALCOVE
YES
YES
ATTIC
YES
YES
LINE
CONTACT
NO
NO
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), in Canada CAN/CGA-B149.1-00 Natural Gas
and Propane Installation Code. or applicable national, provincial,
or state, and local fire and safety codes.
3. For Manufactured (Mobile) Home and Modular Home Return
Duct System Installations:
The return air duct and the return air plenum are not required by
the furnace manufacturer, provided a return air duct and plenum
are not required by state, local, or regional codes. The only vent
system that is approved for use on this furnace is a Roof Jack
which is a Sealed Combustion Direct Vent System.
4. Complete a path for heated or cooled air to circulate through the
air conditioning and heating equipment and to and from the condi-
tioned space.
CAUTION1
The coolingcoilmust be installedin the supply airduct,down-
stream ofthefurnace.Cooled airmay notbe passed over theheat
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.
_WARNING
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 Table 3 for 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
connection flanges. This is typically through the use of
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
Attach the supply plenum to the furnace outlet duct
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.
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-
trols 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.
Example: The furnace input is 80,000 BTUH, 1,200 CFM. The recom-
mended duct area is 280 sq.in, there are two 8 x 14 rectangular ducts
attached to the plenum and there are two 7 inch round ducts attached to
the furnace.
1. Take 8 x 14, which equals 112 sq.in. X 2, which equals 224 square
inch then go to round duct size located in Table 2.
2. The square inch area for 7 inch round pipe is 38.4, multiply by 2 for
two round ducts which equals 76.8 square inch.
3. Then take the 224 square inch from the rectangular duct and add it
to the 76.8 sq.in, of round duct. The total square inch of duct
attached to the furnace plenum is 300.8 square inch. This exceeds
the recommended 280 square inch of duct.
In this example, the duct system attached to the plenum has a sufficient
area so that the furnace operates at the specified external static pres-
sure and within the air temperature rise specified on the nameplate.
4 Unitary Products Group
98618/035-20009-001Rev.B(1205)
Consideration should be given to the heating capacity required and also
to the air quantity (CFM) required. These factors can be determined by
calculating the heat loss and heat gain of the home or structure. If these
calculations are not performed and the furnace is over-sized, the follow-
ing may result:
1. Short cycling of the furnace.
2. Wide temperature fluctuations from the thermostat setting.
3. Reduced overall operating efficiency of the furnace.
The supply and return duct system must be of adequate size and
designed such that the furnace will operate within the designed air tem-
perature rise range and not exceed the maximum designed static pres-
sure. These values are listed in the table below.
TABLE 2: Minimum Duct Sizing For Proper Airflow
Input Airflow Return 1 Rectangular 2 Round 2 Supply 3
BTU/H CFM In2 in. x in. in. In2
(kW) (m3) (cm 2) (cm x cm) (cm) dia. (cm 2)
75000 1,600 360 18 x 20 22 280
(21.98) (45.31) (914) (45.7 x 50.8)) (55.8) (711)
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).
TABLE 3: External Static Pressure Range
Input
Output
Nominal
Air Flow
Ext. Static Pressure
Minimum Maximum
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.
kWARNING
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.
20 "19-1/2
MBH kW
75 22.0
MBH kW
60 17.6
CFM cmm
1600 45.3
In.W.C kPa In.W.C kPa
0.12 0.0299 0.50 0.1245
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-
TABLE 4: Cabinet and Duct Dimensions
BTUH (kW)
Input/Output
75/60 (22.0/17.6) 1
BTUH (kW)
Input/Output
75/60 (22.0/17.6) 1
1. 4-position models ma
CFM
" " ="tm31mm/ Size A(in.) A(cm) B(in.)
1600 (45.31) C 21 53.3 20
CFM
" " ""(m3/mm) Size F(in.) F(cm) G(in.)
1600 (45.31) C 18 1/4 46.35 18 3/4
be factory configured as upflow (MU) or downfiow (MD).
Cabinet
Cabinet
14
I
21
FIGURE 1: Dimensions
Cabinet Dimension
B(cm) C(in.) C(cm) D(in.) D(cm) E(in.) E(cm)
50.8 20 3/8 51.8 20.0 50.8 19 1/2 49.5
KVent KVent
G(cm) H(in.) H(cm) J(in.) J(cm) (in.) (cm)
47.62 18 5/8 47.3 19.0 48.2 42 10.162
Unitary Products Group 5
98618/035-20009-001Rev.B(1205)
MANUFATURED (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 BTUH (12.9 cm 2 per
0.29 kW) 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 air-
flow 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" flanges that will be used to attach the return air ple-
num using the scribe marks in the furnace base.
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 furnace 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.
PLATFORM INSTALLATIONS
As shown 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 plat-
form must be wide enough so that the Blend Air damper can be
mounted in the top of the platform.
FIGURE 3: Platform Installation
SECTION IIh FILTERS
FILTER INSTALLATION
All applications require the use of a filter. All models must have a field-
supplied filter and mounting hardware. Replacement filter size is shown
in Table 5.
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 Figure 4.
I , PLENUM
__ FRONT OF
FURNACE
/ , ITHOAB'NET
_1 I t [A BLENDAIR
FIGURE 2: Floor Installation
/DAMPER
I 14: 25"x16"
I b_" FILTER
-- GRILLE
FIGURE 4: Side Return Cutout Markings
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.
' ' ' ' Iv// MARKINGS
6 Unitary Products Group
ER
98618/035-20009-001 Rev. B (1205)
EXTERNAL INSTALLATION FOR
UPFLOW CONFIGURATIONS
1. Select desired filter position for upflow (left/right side, side and bot-
tom). Remove the corresponding cabinet cutouts per instructions
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 filter
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 bottom returns,
place the external filter box between the return air plenum and the
base of the furnace. The casing bottom is embossed to indicate
where to bend the flanges. Refer to Figure 1 for the maximum return
air opening sizes. Seal this connection to prevent leaks.
Do not cut the opening larger than the dimensions shown in Figure 1.
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 cleanable permanent filters.
Use of 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.
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 12 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 12.
[ CAUTION
All installations must have a filter installed.
AIR FLOW
AIR FILTER
RACK
ACCESS
DOORF___ FURNACE
r---q
AIR FILTER
RACK
ACCESS
DOOR
DUCT
FLOW
-=
[][][][][][][][]
r---q
FURNACE
AIR FI_ER RACK
//ACCESSDOOR
AIR FLOW _ t DUCT
FIGURE 6: External Air Filter Rack - Bottom Position
TABLE 5: Filter Sizes - Upflow
UPFLOW Side
Input Output Air Flow Cabinet Return
MBH kW MBH kW CFM cmm 25x1664x41
75 22.0 60 17.6 1600 45.3 C
Size
in. cm
Bottom/End
Return
24i_'18 6 lcxm46
SECTION IV: GAS PIPING
GAS SAFETY
,DANGER
This furnace is designed to operate on NATURAL GAS or PRO-
PANE GAS ONLY. Do not bum any other fuel in this furnace. Burn-
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.
ADANGER
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 exceeding
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 will result in property
damage and loss of life.
OUTLET ..........
PRESSURE
PORT
"VENT PORT
BOSS
LEFT SIDE
FILTER RACK
FIGURE 5: External Air Filter Rack - Left & Right Side Position
RIGHTSIDE
FILTERRACK
FIGURE 7: Gas Valve
INLET / MAIN REGULATOR
PRESSURE ADJUSTMENT
PORT ON/OFF SWITCH
(Shown in OFF position)
Unitary Products Group 7
98618/035-20009-001Rev.B(1205)
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
IN R
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
Minimum 4.5" W.C. (1.12 kPa) 8.0" W.C. (1.99 kPa)
Maximum 10.5" W.C. (2.61 kPa) 13.0" (3,24 kPa) W.C.
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 ROOF JACK
SHUT-OFF VENT CONNECTION
VALVE
BLOWER
DRIP
LEG
SWITCH
BURNER
SIGHT GLASS
Natural Gas Propane (LP)
j GAS VALVE
HOT
I SURFACE
IGNITOR
GROUND
UNION
BURNERS
_ LOWER
DOOR
SWITCH
_FURNACE
CONTROL
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 will 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 8 Gas Piping Configuration.
GAS ORIFICE CONVERSION FOR PROPANE (LP)
,&WARNING
The conversion shaft be installed by a qualified service agency in
accordance with the manufacturer's instructions and all applicable
codes and requirements of the authority having jurisdiction. If the
information in these instructions is not followed exactly, a fire, an
explosion or production of carbon monoxide may result causing
property damage, personal injury or loss of life. The qualified ser-
vice agency is responsible for the proper installation. The installa-
tion is not proper and complete until the operation of the converted
appliance is checked as specified in the manufacturer's instruc-
tions.
,&WARNING
Improper installation may damage equipment, can create a shock
hazard, and will void the warranty.
IMPORTANT: These instructions are for the use of qualified individuals
specially trained, experienced and certified in the installation of this type
of equipment and related system components. Installation and service
personnel are required by some states to be licensed. Persons not
qualified shall not install this equipment nor interpret these instructions.
NOTE: The words "Shall" or "Must" indicate a requirement, which is
essential to satisfactory and safe product performance.
NOTE: The words "Should" or "May" indicate a recommendation or
advice which is not essential and not required but which may be
useful or helpful.
CONTENTS
1. Burner orifices for LP (propane) gas are located in bag attached to
the gas valve.
2. Conversion plate.
FIGURE 8: Gas Piping 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 8.
IMPORTANT: An accessible manual shutoff valve must be installed
upstream of the furnace gas controls and within 6 feet (1.8 m) of the fur-
Race.
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).
FIGURE 9: Burner Assembly
BURNER GASVALVE
GAS
ORIFICE GAS
MANIFOLD
8 Unitary Products Group