Goodman xMEC96 Series User manual

5151 San Felipe Suite 500
Houston, TX 77056
www.goodmanmfg.com • www.amana-hac.com
©2014 Goodman Manufacturing Company, L.P.
*MEC96
U
PFLOW / H ORIZONTAL T WO -S TAGE
G AS F URNACE
IOG-2011B
11/14
(Type FSP CATEGORY IV Direct
or Non Direct Vent Air Furnace)
These furnaces comply with requirements em-
bodied in the American National Standard / Na-
tional Standard of Canada ANSI Z21.47·CSA-2.3
Gas Fired Central Furnaces.
Installer:
Affix all manuals
adjacent to the unit.
As a professional installer you have an obligation to know
the product better than the customer. This includes all safety
precautions and related items.
Prior to actual installation, thoroughly familiarize yourself
with this Instruction Manual. Pay special attention to all
safety warnings. Often during installation or repair it is
possible to place yourself in a position which is more
hazardous than when the unit is in operation.
Remember, it is your responsibility to install the product
safely and to know it well enough to be able to instruct a
customer in its safe use.
Safety is a matter of common sense...a matter of thinking
before acting. Most dealers have a list of specific good
safety practices...follow them.
The precautions listed in this Installation Manual are intended
as supplemental to existing practices. However, if there is
a direct conflict between existing practices and the content
of this manual, the precautions listed here take precedence.
RECOGNIZE THIS SYMBOL
AS A SAFETY PRECAUTION.
*NOTE: Please contact your distributor or our website for
the applicable Specification Sheet referred to in this manual.
TABLE OF CONTENTS
is a registered trademark of Maytag Corporation or its related companies and is used under license to Goodman Company, L.P., Houston, TX, USA. All rights reserved.
SAFETY CONSIDERATIONS .................................... 3
SHIPPING INSPECTION ............................................ 4
ELECTROSTATIC DISCHARGE (ESD) PRECAUTIONS .................... 4
TOTHE INSTALLER ............................................. 5
PRODUCT DESCRIPTION ....................................... 5
FEATURES ...................................................... 5
PRODUCT APPLICATION ....................................... 5
LOCATION REQUIREMENTS & CONSIDERATIONS ........... 6
CLEARANCES AND A CCESSIBILITY ................................... 7
EXISTING FURNACE REMOVAL ..................................... 8
THERMOSTAT LOCATION .......................................... 8
COMBUSTION & VENTILATION A IR REQUIREMENTS ................... 9
INSTALLATION POSITIONS .................................... 9
HORIZONTAL APPLICATIONS & CONSIDERATIONS ......... 9
FURNACE SUSPENSION .......................................... 10
FRONT COVER PRESSURE SWITCH T UBE LOCATION ................ 10
DRAIN TRAP AND LINES ........................................ 10
HORIZONTAL FURNACE LEVELING ................................ 10
ALTERNATE ELECTRICAL AND GAS LINE CONNECTIONS .............. 10
DRAIN PAN ................................................... 10
FREEZE PROTECTION ........................................... 10
PROPANE GAS/HIGH ALTITUDE INSTALLATIONS .......... 10
VENT/FLUE PIPE & COMBUSTION AIR PIPE ................ 11
DUAL CERTIFICATION: NON-DIRECT/DIRECT VENT ................. 11
MATERIALS AND JOINING METHODS .............................. 11
PROPER VENT/FLUE AND COMBUSTION A IR PIPING PRACTICES ...... 12
TERMINATION LOCATIONS ........................................ 12
CANADIAN VENTING REQUIREMENTS .............................. 13
STANDARD FURNACE CONNECTIONS .............................. 13
VENT/FLUE PIPE .............................................. 13
NON-DIRECT VENT (SINGLE PIPE) PIPING ........................ 14
VENT/INTAKE TERMINATIONS FOR INSTALLATION
OF MULTIPLE DIRECT VENT FURNACES ......................... 18
CONCENTRIC VENT T ERMINATION ................................. 18
SIDE WALL VENT KIT .......................................... 18
CONDENSATE DRAIN LINES & DRAIN TRAP ................ 18
UPFLOW MODEL I NSTALLED VERTICALLY .......................... 19
DRAIN EXITING RIGHT SIDE ..................................... 19
GENERAL DRAIN INFORMATION ................................... 19
FIELD SUPPLIED DRAIN ......................................... 19
DRAIN EXITING LEFT SIDE ...................................... 20
UPFLOW MODEL INSTALLED HORIZONTALLY WITH RIGHT SIDE DOWN 20
UPFLOW MODEL INSTALLED HORIZONTALLY WITH LEFT SIDE DOWN .20

2
ELECTRICAL CONNECTIONS ................................. 21
WIRING HARNESS .............................................. 21
115 VOLT LINE CONNECTIONS .................................. 21
JUNCTION BOX RELOCATION ..................................... 21
24 VOLT THERMOSTAT WIRING .................................. 22
SINGLE-STA G E HEATING T HERMOSTAT A PPLICATION ................ 23
FOSSIL FUEL A PPLICATIONS ...................................... 23
TWINNING .................................................... 23
115 VOLT LINE CONNECTION OF A CCESSORIES
(HUMIDIFIER AND ELECTRONIC A IR CLEANER) .................. 23
GAS SUPPLY AND PIPING ...................................... 24
HIGH A LTITUDE DERATE ........................................ 24
PROPANE GAS CONVERSION ..................................... 24
GAS PIPING CONNECTIONS ...................................... 25
PROPANE GAS T ANKS AND PIPING ............................... 26
CIRCULATING AIR & FILTERS ................................ 27
DUCT WORK - AIR FLOW ....................................... 27
CHECKING DUCT STATIC ........................................ 27
BOTTOM RETURN A IR OPENING [UPFLOW MODELS] ............... 28
FILTERS - READ THIS SECTION BEFORE INSTALLING
THE RETURN A IR DUCT WORK ............................... 28
UPRIGHT INSTALLATIONS ......................................... 29
HORIZONTAL INSTALLATIONS ..................................... 29
STARTUP PROCEDURE & ADJUSTMENT ..................... 29
DRAIN TRAP PRIMING .......................................... 29
FURNACE OPERATION ........................................... 29
GAS SUPPLY P RESSURE MEASUREMENT ........................... 30
GAS MANIFOLD PRESSURE MEASUREMENT AND A DJUSTMENT ........ 31
GAS INPUT RATE MEASUREMENT (NATURAL GAS ONLY) ........... 32
TEMPERATURE RISE ............................................ 32
CIRCULATOR BLOWER SPEEDS ................................... 33
BLOWER HEAT OFF DELAY TIMINGS ............................. 37
NORMAL SEQUENCE OF OPERATION ........................ 37
POWER UP................................................... 37
HEATING MODE ............................................... 37
COOLING MODE ............................................... 38
FAN ONLY MODE ............................................. 38
OPERATIONAL CHECKS ....................................... 38
SAFETY CIRCUIT DESCRIPTION .............................. 38
INTEGRATED CONTROL MODULE ................................. 38
PRIMARY LIMIT ................................................. 38
AUXILIARY LIMIT ............................................... 38
ROLLOUT LIMIT ............................................... 39
PRESSURE SWITCHES ........................................... 39
FLAME SENSOR ................................................ 39
TROUBLESHOOTING ............................................. 39
ELECTROSTATIC DISCHARGE (ESD) PRECAUTIONS ................... 39
CHECKING FLAME SENSOR ...................................... 39
LIMIT FAULT CODES ........................................... 39
DIAGNOSTIC CHART ............................................ 40
FAULT RECALL ................................................ 40
RESETTING FROM LOCKOUT ..................................... 41
MAINTENANCE ................................................. 41
ANNUAL INSPECTION ........................................... 41
FILTERS ....................................................... 41
BURNERS ..................................................... 42
INDUCED DRAFT AND CIRCULATOR BLOWERS ...................... 42
CONDENSATE TRAP AND DRAIN SYSTEM (QUALIFIED SERVICER ONLY)42
FLAME SENSOR (QUALIFIED SERVICER ONLY) ..................... 42
FLUE PASSAGES (QUALIFIED SERVICER ONLY) ..................... 43
BEFORE LEAVING AN INSTALLATION ........................ 43
REPAIR AND REPLACEMENT PARTS .......................... 43
TROUBLESHOOTING CHART ................................. 44
WIRING DIAGRAM ............................................. 46
SPECIAL INSTRUCTIONS FOR PRODUCTS
INSTALLED IN THE STATE OF MASSACHUSETTS... 47
S AFETY C ONSIDERATIONS
Adhere to the following warnings and cautions when installing,
adjusting, altering, servicing, or operating the furnace. To
ensure proper installation and operation, thoroughly read this
manual for specifics pertaining to the installation and applica-
tion of this product.
This furnace is manufactured for use with natural gas. It may
be field converted to operate on L.P. gas by using the appro-
priate L.P. conversion kit listed in the PROPANE GAS/HIGH ALTITUDE INSTALLATIONS section of this manual
Install this furnace only in a location and position as specified in LOCATION REQUIREMENTS & CONSIDERATIONS section and
INSTALLATION POSITIONS section of this manual.
Provide adequate combustion and ventilation air to the furnace as specified in COMBUSTION & VENTILATION AIR REQUIRE-
MENTS section of this manual.
G OODMAN WILL NOT BE RESPONSIBLE FOR ANY INJURY OR PROPERTY
DAMAGE ARISING FROM IMPROPER SERVICE OR SERVICE PROCEDURES .
I
F YOU INSTALL OR PERFORM SERVICE ON THIS UNIT , YOU ASSUME
RESPONSIBILITY FOR ANY PERSONAL INJURY OR PROPERTY DAMAGE
WHICH MAY RESULT . M ANY JURISDICTIONS REQUIRE A LICENSE TO
INSTALL OR SERVICE HEATING AND AIR CONDITIONING EQUIPMENT .
WARNING

3
Combustion products must be discharged to the outdoors.
Connect this furnace to an approved vent system only, as
specified in VENT/FLUE PIPE & COMBUSTION AIR PIPE sec-
tion of this manual.
Never test for gas leaks with an open flame. Use a commer-
cially available soap solution made specifically for the detec-
tion of leaks to check all connections, as specified in GAS
SUPPLY AND PIPING section of this manual.
Always install a furnace to operate within the furnace’s in-
tended temperature-rise range with a duct system which has
external static pressure within the allowable range, as speci-
fied on the furnace rating plate and OPERATIONAL CHECKS
section of these instructions.
When a furnace is installed so that supply ducts carry air
circulated by the furnace to areas outside the space contain-
ing the furnace, the return air shall also be handled by duct(s)
sealed to the furnace casing and terminating outside the
space containing the furnace.
A gas-fired furnace for installation in a residential garage
must be installed as specified in the LOCATION REQUIRE-
MENTS AND CONSIDERATIONS section of this manual.
This furnace may be used as a construction site heater only
if certain conditions are met. These conditions are listed in
the PRODUCT APPLICATION section of this manual.
T O PREVENT PERSONAL INJURY OR DEATH DUE TO IMPROPER
INSTALLATION , ADJUSTMENT , ALTERATION , SERVICE OR MAINTENANCE ,
REFER TO THIS MANUAL . F OR ADDITIONAL ASSISTANCE OR
INFORMATION , CONSULT A QUALIFIED INSTALLER , SERVICER AGENCY OR
THE GAS SUPPLIER .
WARNING
FROZEN AND BURST WATER PIPE HAZARD
F
AILURE TO PROTECT AGAINST THE RISK OF FREEZING MAY RESULT IN
PROPERTY DAMAGE .
S
PECIAL PRECAUTIONS MUST BE MADE IF INSTALLING FURNACE IN AN
AREA WHICH MAY DROP BELOW FREEZING . T HIS CAN CAUSE IMPROPER
OPERATION OR DAMAGE TO EQUIPMENT . I F THE FURNACE
ENVIRONMENT HAS THE POTENTIAL OF FREEZING , THE DRAIN TRAP AND
DRAIN LINE MUST BE PROTECTED . T HE USE OF ACCESSORY DRAIN TRAP
HEATERS , ELECTRIC HEAT TAPE AND / OR RV ANTIFREEZE IS
RECOMMENDED FOR THESE INSTALLATIONS .
CAUTION
I F THE INFORMATION IN THESE INSTRUCTIONS IS NOT FOLLOWED
EXACTLY , A FIRE OR EXPLOSION MAY RESULT CAUSING PROPERTY
DAMAGE
, PERSONAL INJURY OR LOSS OF LIFE .
D O NOT STORE OR USE GASOLINE OR OTHER FLAMMABLE VAPORS AND
LIQUIDS IN THE VICINITY OF THIS OR ANY OTHER APPLIANCE .
D
O NOT TRY TO LIGHT ANY APPLIANCE .
D
O NOT TOUCH ANY ELECTRICAL SWITCH ; DO NOT USE ANY PHONE
IN YOUR BUILDING .
I
MMEDIATELY CALL YOUR GAS SUPPLIER FROM A NEIGHBOR ’ S
PHONE . F OLLOW THE GAS SUPPLIER ’ S INSTRUCTIONS .
I
F YOU CANNOT REACH YOUR GAS SUPPLIER , CALL THE FIRE
DEPARTMENT .
I
NSTALLATION AND SERVICE MUST BE PERFORMED BY A QUALIFIED
INSTALLER , SERVICE AGENCY OR THE GAS SUPPLIER .
WHAT TO DO IF YOU SMELL GAS:




WARNING
T HIS PRODUCT CONTAINS OR PRODUCES A CHEMICAL OR CHEMICALS
WHICH MAY CAUSE SERIOUS ILLNESS OR DEATH AND WHICH ARE
KNOWN TO THE S TATE OF C ALIFORNIA TO CAUSE CANCER , BIRTH
DEFECTS OR OTHER REPRODUCTIVE HARM .
WARNING
H EATING UNIT SHOULD NOT BE UTILIZED WITHOUT REASONABLE ,
ROUTINE , INSPECTION , MAINTENANCE AND SUPERVISION . I F THE
BUILDING IN WHICH ANY SUCH DEVICE IS LOCATED WILL BE VACANT ,
CARE SHOULD BE TAKEN THAT SUCH DEVICE IS ROUTINELY INSPECTED ,
MAINTAINED AND MONITORED . IN THE EVENT THAT THE BUILDING
MAYBE EXPOSED TO FREEZING TEMPERATURES AND WILL BE VACANT ,
ALL WATER - BEARING PIPES SHOULD BE DRAINED , THE BUILDING SHOULD
BE PROPERLY WINTERIZED , AND THE WATER SOURCE CLOSED . IN THE
EVENT THAT THE BUILDING MAY BE EXPOSED TO FREEZING
TEMPERATURES AND WILL BE VACANT , ANY HYDRONIC COIL UNITS
SHOULD BE DRAINED AS WELL AND , IN SUCH CASE , ALTERNATIVE HEAT
SOURCES SHOULD BE UTILIZED .
WARNING
T O PREVENT POSSIBLE PROPERTY DAMAGE , PERSONAL INJURY OR
DEATH DUE TO ELECTRICAL SHOCK , THE FURNACE MUST BE LOCATED TO
PROTECT THE ELECTRICAL COMPONENTS FROM WATER .
WARNING
Drain trap must be primed at time of installation. Trap is
internally partitioned; add water to both inlet ports until wa-
ter appears at both sides of the outlet opening. Failure to
prime trap at time of installation may have a negative ef-
fect on combustion quality and pressure switch action.

4
SHIPPING I NSPECTION
All units are securely packed in shipping containers tested accord-
ing to International Safe Transit Association specifications. The
carton must be checked upon arrival for external damage. If dam-
age is found, a request for inspection by carrier’s agent must be
made in writing immediately.
The furnace must be carefully inspected on arrival for damage and
bolts or screws which may have come loose in transit. In the event
of damage the consignee should:
1. Make a notation on delivery receipt of any visible damage to
shipment or container.
2. Notify carrier promptly and request an inspection.
3. With concealed damage, carrier must be notified as soon as
possible - preferably within five days.
4. File the claim with the following support documents within a nine month statute of limitations.
• Original or certified copy of the Bill of Lading, or indemnity bond.
• Original paid freight bill or indemnity in lieu thereof.
• Original or certified copy of the invoice, showing trade and other discounts or reductions.
• Copy of the inspection report issued by carrier’s representative at the time damage is reported to carrier.
The carrier is responsible for making prompt inspection of damage and for a thorough investigation of each claim. The distributor or
manufacturer will not accept claims from dealers for transportation damage.
ELECTROSTATIC DISCHARGE (ESD) PRECAUTIONS
NOTE: Discharge your body’s static electricity before touching unit. An electrostatic discharge can adversely affect electrical
components.
Use the following precautions during furnace installation and servicing to protect the integrated control module from damage. By
putting the furnace, the control, and the person at the same electrostatic potential, these steps will help avoid exposing the
integrated control module to electrostatic discharge. This procedure is applicable to both installed and non-installed (ungrounded)
furnaces.
1. Disconnect all power to the furnace. Do not touch the integrated control module or any wire connected to the control prior to
discharging your body’s electrostatic charge to ground.
S HOULD OVERHEATING OCCUR OR THE GAS SUPPLY FAIL TO SHUT OFF ,
TURN OFF THE MANUAL GAS SHUTOFF VALVE EXTERNAL TO THE
FURNACE BEFORE TURNING OFF THE ELECTRICAL SUPPLY .
WARNING
P OSSIBLE PROPERTY DAMAGE , PERSONAL INJURY OR DEATH DUE TO
FIRE , EXPLOSION , SMOKE , SOOT , CONDENSATION , ELECTRICAL SHOCK
OR CARBON MONOXIDE MAY RESULT FROM IMPROPER INSTALLATION ,
REPAIR OPERATION , OR MAINTENANCE OF THIS PRODUCT .
WARNING
B10259-216
CO can cause serious illness including permanent brain
damage or death.
Advertencia especial para la instalación de calentadores ó manejadoras
de aire en áreas cerradas como estacionamientos ó cuartos de servicio.
B10259-216
El monóxido de carbono puede causar enfermedades severas
como daño cerebra l permanente ó muerte.
Las em isiones de monóxido de carbono pue den circular a través
del aparato cuando se opera en cualquie r modo.
B10259-216
RISQUE D'EMPOISONNEMENT AU MONOXYDE DE CARBONE
Le monoxyde de
des
carbone peut causer des maladies graves telles que
dommages permanents au cerveau et meme la mort.
Cette ventilation est nécessaire pour éviter le danger d'intoxication
au CO pouvant survenir si un appareil produisant du monoxyde
de carbone continue de fonctionner au sein de la zone confinée.

5
2. Firmly touch a clean, unpainted, metal surface of the furnaces near the control. Any tools held in a person’s hand during
grounding will be discharged.
3. Service integrated control module or connecting wiring following the discharge process in step 2. Use caution not to recharge
your body with static electricity; (i.e., do not move or shuffle your feet, do not touch ungrounded objects, etc.). If you come
in contact with an ungrounded object, repeat step 2 before touching control or wires.
4. Discharge your body to ground before removing a new control from its container. Follow steps 1 through 3 if installing the
control on a furnace. Return any old or new controls to their containers before touching any ungrounded object.
TOTHE INSTALLER
Before installing this unit, please read this manual thoroughly to
familiarize yourself with specific items which must be adhered to,
including but not limited to: unit maximum external static pres-
sure, gas pressures, BTU input rating, proper electrical connec-
tions, circulating air temperature rise, minimum or maximum CFM,
and motor speed connections.
P RODUCT D ESCRIPTION
FEATURES
The *MEC96 furnace may be installed upflow or horizontally with left or right side down. The *MEC96 two-stage gas furnace
features a multi-speed ECM indoor fan motor, two heating inputs (W1 & W2), two cooling inputs (YLO & Y) and a two stage
gas valve. A single stage heating thermostat may also be used in conjunction with timed transition to high fire by the furnace
integrated control board.
P RODUCT A PPLICATION
This furnace is primarily designed for residential home-heating applications. It is NOT designed or certified for use in mobile homes,
trailers or recreational vehicles. Neither is it designed or certified for outdoor applications. The furnace must be installed indoors
(i.e., attic space, crawl space, or garage area provided the garage area is enclosed with an operating door).
This furnace can be used in the following non-industrial commercial applications:
Schools, Office buildings, Churches, Retail stores, Nursing homes, Hotels/motels, Common or office areas
In such applications, the furnace must be installed with the following stipulations:
• It must be installed per the installation instructions provided and per local and national codes.
• It must be installed indoors in a building constructed on site.
• It must be part of a ducted system and not used in a free air delivery application.
• It must not be used as a “make-up” air unit.
• It must be installed as a two-pipe system for combustion air.
• All other warranty exclusions and restrictions apply This furnace is an ETL dual-certified appliance and is appropriate for use
with natural or propane gas (NOTE: If using propane, a propane conversion kit is required).
Dual certification means that the combustion air inlet pipe is optional and the furnace can be vented as a:
Non-direct vent (single pipe) central forced air furnace in which combustion air is taken from the installation area or from air
ducted from the outside or,
Direct vent (dual pipe) central forced air furnace in which all combustion air supplied directly to the furnace burners through
a special air intake system outlined in these instructions.
This furnace may be used as a construction site heater ONLY if all of the following conditions are met:
• The vent system is permanently installed per these installation instructions.
• A room thermostat is used to control the furnace. Fixed jumpers that provide continuous heating CANNOT be used and can
cause long term equipment damage.
• Return air ducts are provided and sealed to the furnace.
• A return air temperature range between 60ºF (16ºC) and 80ºF (27ºC) is maintained.
• Air filters are installed in the system and maintained during construction replaced as appropriate during construction, and
upon completion of construction.
• The input rate and temperature rise are set per the furnace rating plate.
T O PREVENT PROPERTY DAMAGE , PERSONAL INJURY OR DEATH DUE TO
FIRE , DO NOT INSTALL THIS FURNACE IN A MOBILE HOME , TRAILER , OR
RECREATIONAL VEHICLE .
WARNING

6
• 100% outside air is provided for combustion air requirements during construction. Temporary ducting can be used.
NOTE: Do not connect the temporary duct directly to the furnace. The duct must be sized for adequate combustion and
ventilation in accordance with the latest edition of the National Fuel Gas Code NFPA 54/ANSI Z223.1 or CAN/CSA B149.1
Installation Codes.
•The furnace heat exchanger, components, duct system, air filters and evaporator coils are thoroughly cleaned following final
construction clean up.
• All furnace operating conditions (including ignition, input rate, temperature rise and venting) are verified according to
these installation instructions.
NOTE: The Commonwealth of Massachusetts requires that the following additional requirements must also be met:
• Gas furnaces must be installed by a licensed plumber or gas fitter.
• A T-handle gas cock must be used.
• If the unit is to be installed in an attic, the passageway to and the service area around the unit must have flooring.
To ensure proper furnace operation, install, operate and maintain the furnace in accordance with these installation and
operation instructions, all local building codes and ordinances. In their absence, follow the latest edition of the National Fuel Gas
Code (NFPA 54/ANSI Z223.1), and/or CAN/CSA B149 Installation Codes, local plumbing or waste water codes, and other applicable
codes.
A copy of the National Fuel Gas Code (NFPA 54/ANSI Z223.1) can be obtained from any of the following:
American National Standards Institute National Fire Protection Association CSA International
25 West 43rd Street, 4th Floor 1 Batterymarch Park 8501 East Pleasant Valley
New York, NY 10036 Quincy, MA 012169-7471 Independence, OH 44131
The rated heating capacity of the furnace should be greater than or equal to the total heat loss of the area to be heated. The total
heat loss should be calculated by an approved method or in accordance with “ASHRAE Guide” or “Manual J-Load Calculations”
published by the Air Conditioning Contractors of America.
A copy of the CAN/CSA B149 Installation Codes can also be obtained from:
CSA International
178 Rexdale Boulevard
Etobicoke, Ontario, Canada M9W 1R3
L OCATION R EQUIREMENTS & C ONSIDERATIONS
Follow the instructions listed below and the guidelines provided in the Combustion and Ventilation Air Requirements section when
selecting a furnace location.
T O PREVENT POSSIBLE EQUIPMENT DAMAGE , PROPERTY DAMAGE ,
PERSONAL INJURY OR DEATH , THE FOLLOWING BULLET POINTS MUST BE
OBSERVED WHEN INSTALLING THIS UNIT .
WARNING
P OSSIBLE PROPERTY DAMAGE , PERSONAL INJURY OR DEATH DUE TO
FIRE , EXPLOSION , SMOKE , SOOT , CONDENSATION , ELECTRICAL SHOCK
OR CARBON MONOXIDE MAY RESULT FROM IMPROPER INSTALLATION ,
REPAIR OPERATION , OR MAINTENANCE OF THIS PRODUCT .
WARNING
• Centrally locate the furnace with respect to the proposed or existing air distribution system.
• Ensure the temperature of the return air entering the furnace is between 55°F and 100°F when the furnace is heating.
• Provide provisions for venting combustion products outdoors through a proper venting system. Special consideration
should be given to vent/flue pipe routing and combustion air intake pipe when applicable. Refer to Vent/Flue Pipe and
Combustion Air Pipe -Termination Locations for appropriate termination locations and to determine if the piping system
from furnace to termination can be accomplished within the guidelines given. NOTE: The length of flue and/or combustion
air piping can be a limiting factor in the location of the furnace.
• Locate the furnace so condensate flows downwards to the drain. Do not locate the furnace or its condensate drainage
system in any area subject to below freezing temperatures without proper freeze protection. Refer to Condensate Drain
Lines and Trap for further details.
• Ensure adequate combustion air is available for the furnace. Improper or insufficient combustion air can expose building
occupants to gas combustion products that could include carbon monoxide. Refer to Combustion and Ventilation Air
Requirements.
• Set the furnace on a level floor to enable proper condensate drainage. If the floor becomes wet or damp at times, place the
furnace above the floor on a concrete base sized approximately 1-1/2" larger than the base of the furnace. Refer to the
Horizontal Applications and Considerations for leveling of horizontal furnaces.

7
• Ensure upflow or horizontal furnaces are not installed directly on carpeting, or any other combustible material. The only
combustible material allowed is wood.
• Exposure to contaminated combustion air will result in safety and performance-related problems. Do not install the furnace
where the combustion air is exposed to the following substances:
permanent wave solutions chlorinated waxes or cleaners chlorine-based
carbon tetrachloride water softening chemicals swimming pool chemicals
deicing salts or chemicals halogen type refrigerants
cleaning solutions (such as perchloroethylene) printing inks
paint removers varnishes hydrochloric acid
cements and glues antistatic fabric softeners for clothes dryers
• Seal off a non-direct vent furnace if it is installed near an area frequently contaminated by any of the above substances. This
protects the non-direct vent furnace from airborne contaminants. To ensure that the enclosed non-direct vent furnace has
an adequate supply of combustion air, vent from a nearby uncontaminated room or from outdoors. Refer to the Combustion
and Ventilation Air Requirements for details.
• If the furnace is used in connection with a cooling coil unit, install the furnace upstream or in parallel with the cooling coil
unit. Premature heat exchanger failure will result if the cooling unit is placed ahead of the furnace.
For vertical applications, the minimum cooling coil width shall not be less than furnace width minus 1”.
For upflow applications, the front of the coil and furnace must face the same direction.
• If the furnace is installed in a residential garage, position the furnace so that the burners and ignition source are located not
less than 18 inches (457 mm) above the floor. Protect the furnace from physical damage by vehicles.
• If the furnace is installed horizontally, ensure the access doors are not on the “up/top” or “down/bottom” side of the
furnace.
• Do not connect this furnace to a chimney flue that serves a separate appliance designed to burn solid fuel.
CLEARANCES AND ACCESSIBILITY
NOTES:
• For servicing or cleaning, a 24” front clearance is required.
• Unit connections (electrical, flue and drain) may necessitate greater clearances than the minimum clearances listed
above.
• In all cases, accessibility clearance must take
precedence over clearances from the enclosure where
accessibility clearances are greater.
Installations must adhere to the clearances to combustible mate-
rials to which this furnace has been design certified. The mini-
mum clearance information for this furnace is provided on the
unit’s clearance label. These clearances must be permanently main-
tained. Clearances must also accommodate an installation’s gas,
electrical, and drain trap and drain line connections. If the alter-
nate combustion air intake or vent/flue connections are used additional clearance must be provided to accommodate these connec-
tions. Refer to Vent/Flue Pipe and Combustion Air Pipe for details.
NOTE: In addition to the required clearances to combustible materials, a minimum of 24 inches service clearance must be available
in front of the unit.
TOP
BOTTOM
TOP
BOTTOM
Figure 1
A furnace installed in a confined space (i.e., a closet or utility room) must have two ventilation openings with a total minimum free
area of 0.25 square inches per 1,000 BTU/hr of furnace input rating. Refer to Specification Sheet applicable to your model for
minimum clearances to combustible surfaces. One of the ventilation openings must be within 12 inches of the top; the other opening
must be within 12 inches of the bottom of the confined space. In a typical construction, the clearance between the door and door
frame is usually adequate to satisfy this ventilation requirement.
POSITION* SIDES REAR FRONT BOTTOM FLUE TOP
Upflow 0" 0" 3" C 0" 1"
Horizontal 6" 0" 3" C 0" 6"
C = If placed on combustible floor, floor MUST be wood only.
*M EC96 M INIMUM CLEARANCES TO COM BUSTIBLE M ATERIALS
(INCHES)

8
EXISTING FURNACE REMOVAL
NOTE: When an existing furnace is removed from a venting system serving other appliances, the venting system may be too large to
properly vent the remaining attached appliances.
The following vent testing procedure is reproduced from the American National Standard/National Standard of Canada for Gas-
Fired Central Furnaces ANSI Z21.47, CSA-2.3 latest edition Section 1.23.1.
The following steps shall be followed with each appliance connected to the venting system placed in operation, while any 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 by the National Fuel Gas Code, ANSI Z223.1
or the Natural Gas and Propane Installation Code, CSA B149.1-05 and these instructions. Determine that there is no
blockage or restriction, leakage, corrosion and other deficiencies which could cause an unsafe condition.
3. As far as practical, close all building doors and windows and all doors between the space in which the appliance(s)
connected to the venting system are located and other spaces of the building.
4. Close fireplace dampers.
5. Turn on clothes dryers and any appliance not connected to the venting system. Turn on any exhaust fans, such as range
hoods and bathroom exhausts, so they shall operate at maximum speed. Do not operate a summer exhaust fan.
6. Follow the lighting instructions. Place the appliance being inspected in operation. Adjust thermostat so appliance shall
operate continuously.
7. Test for spillage from draft hood appliances at the draft hood relief opening after 5 minutes of main burner operation.
Use the flame of a match or candle.
8. If improper venting is observed during any of the above tests, the venting system must be corrected in accordance
with the National Fuel Gas Code ANSI Z223.1/NFPA 54 and/or National Gas and Propane Installation Code CSA B149.1-05.
9. After it has been determined that each appliance connected to the venting system properly vents when tested as
outlined above, return doors, windows, exhaust fans, fireplace dampers and any other gas burning appliance to their
previous conditions of use.
If resizing is required on any portion of the venting system, use the appropriate table in Appendix G in the latest edition of the
National Fuel Gas Code ANSI Z223.1 and/or CSA B149.1-05 Installation Codes.
THERMOSTAT LOCATION
The thermostat should be placed approximately five feet from the floor on a vibration-free, inside wall in an area having good air
circulation. Do not install the thermostat where it may be influenced by any of the following:
• Drafts, or dead spots behind doors, in corners, or under cabinets.
• Hot or cold air from registers.
• Radiant heat from the sun.
• Light fixtures or other appliances.
• Radiant heat from a fireplace.
• Concealed hot or cold water pipes, or chimneys.
• Unconditioned areas behind the thermostat, such as an outside wall.
Consult the instructions packaged with the thermostat for mounting instructions and further precautions.

9
C OMBUSTION & V ENTILATION A IR R EQUIREMENTS
Improved construction and additional insulation in buildings have
reduced heat loss by reducing air infiltration and escape around
doors and windows. These changes have helped in reducing heat-
ing/cooling costs but have created a problem supplying combus-
tion and ventilation air for gas fired and other fuel burning appli-
ances. Appliances that pull air out of the house (clothes dryers,
exhaust fans, fireplaces, etc.) increase the problem by starving appliances for air.
House depressurization can cause back drafting or improper combustion of gas-fired appliances, thereby exposing building occu-
pants to gas combustion products that could include carbon monoxide.
If this furnace is to be installed in the same space with other gas appliances, such as a water heater, ensure there is an adequate
supply of combustion and ventilation air for the other appliances. Refer to the latest edition of the National Fuel Gas Code NFPA
54/ANSI Z223.1 or CAN/CSA B149.1-05 Installation Codes or applicable provisions of the local building codes for determining the
combustion air requirements for the appliances.
Most homes will require outside air be supplied to the furnace area by means of ventilation grilles or ducts connecting directly to
the outdoors or spaces open to the outdoors such as attics or crawl spaces.
I NSTALLATION P OSITIONS
Figure 2A Figure 2B Figure 2C
Recommended Installation Positions
*MEC96 models may be installed upflow or horizontally with left or right side down. Do not install this furnace on its back. For
upright upflow furnaces, return air ductwork may be attached to the side panel(s) and/or basepan. For horizontal upflow
furnaces, return air ductwork must be attached to the basepan. NOTE: Ductwork must never be attached to the back of the
furnace. Contact your distributor for proper airflow requirements and number of required ductwork connections. Refer to
“Recommended Installation Positions” figure for appropriate installation positions, ductwork connections, and resulting airflow
arrangements.
H ORIZONTAL A PPLICATIONS & C ONSIDERATIONS
When installing a furnace horizontally, additional consideration must be given to the following:
T O AVOID PROPERTY DAMAGE , PERSONAL INJURY OR DEATH ,
SUFFICIENT FRESH AIR FOR PROPER COMBUSTION AND VENTILATION OF
FLUE GASES MUST BE SUPPLIED . M OST HOMES REQUIRE OUTSIDE AIR BE
SUPPLIED INTO THE FURNACE AREA .
WARNING

10
FURNACE S USPENSION
If suspending the furnace from rafters or joists, use 3/8" threaded
rod and 2”x2”x1/8” angle iron as shown in the following diagram.
The length of rod will depend on the application and the clearances
necessary.
If the furnace is installed in a crawl space it must be suspended
from the floor joist or supported by a concrete pad. Never install
the furnace on the ground or allow it to be exposed to water.
FRONT COVER PRESSURE SWITCH TUBE LOCATION
When an upflow model is installed horizontally with left side
down, the front cover pressure switch tube must be relocated
to the lower port of the collector box cover.
1. Remove tube from front cover pressure switch and collector
box cover.
2. Remove rubber plug from bottom collector box port and install on top collector box port.
3. Locate 24” x 1/4” tube in parts bag.
4. Install one end on front cover pressure switch.
5. Route tube to lower port on collector box cover and cut off excess tubing.
DRAIN TRAP AND LINES
In horizontal applications the condensate drain trap is secured to the furnace side panel, suspending it below the furnace. A minimum
clearance of 5.5” below the furnace must be provided for the drain trap. Additionally, the appropriate downward piping slope must be
maintained from the drain trap to the drain location. Refer to Condensate Drain Trap and Lines for further details. If the drain trap and
drain line will be exposed to temperatures near or below freezing, adequate measures must be taken to prevent condensate from
freezing.
HORIZONTAL FURNACE LEVELING
Leveling ensures proper condensate drainage from the heat exchanger and induced draft blower. For proper flue pipe drainage, the
furnace must be level lengthwise from end to end. The furnace should have a slight tilt from back to front with the access doors
downhill from the back panel approximately 1/2 to 3/4 inches. The slight tilt allows the heat exchanger condensate, generated in
the recuperator coil, to flow forward to the recuperator coil front cover.
ALTERNATE ELECTRICAL AND GAS LINE CONNECTIONS
This furnace has provisions allowing for electrical and gas line connections through either side panel. In horizontal applications the
connections can be made either through the “top” or “bottom” of the furnace.
DRAIN PAN
A drain pan must be provided if the furnace is installed above a conditioned area. The drain pan must cover the entire area under the
furnace (and air conditioning coil if applicable).
FREEZE PROTECTION
Refer to Horizontal Applications and Conditions - Drain Trap and
Lines.
P ROPANE G AS /H IGH A LTITUDE I NSTALLATIONS
This furnace is shipped from the factory configured for natural gas
at standard altitude. Propane gas installations require an orifice
and spring change to compensate for the energy content differ-
ence between natural and propane gas.
High altitude installations may require both a pressure switch and
an orifice/spring change. These changes are necessary to compensate for the natural reduction in the density of both the gas fuel and
the combustion air at higher altitude.
2" 2" 3/8" ANGLE IRON
(3 PLACES )
XX
Figure 2
WARNING
P OSSIBLE PROPERTY DAMAGE , PERSONAL INJURY OR DEATH MAY
OCCUR IF THE CORRECT CONVERSION KITS ARE NOT INSTALLED . T HE
APPROPRIATE KITS MUST BE APPLIED TO ENSURE SAFE AND PROPER
FURNACE OPERATION . A LL CONVERSIONS MUST BE PERFORMED BY A
QUALIFIED INSTALLER OR SERVICE AGENCY .

11
For installations above 7000 feet, please re-
fer to the furnace Specification Sheets for
required kit(s).
Contact the distributor for a tabular listing of
appropriate manufacturer’s kits for propane
gas and/or high altitude installations. The
indicated kits must be used to insure safe and
proper furnace operation. All conversions must
be performed by a qualified installer, or ser-
vice agency.
V ENT /F LUE P IPE & C OMBUSTION A IR P IPE
A condensing gas furnace achieves its high level of efficiency by
extracting almost all of the heat from the products of combustion
and cooling them to the point where condensation takes place.
Because of the relatively low flue gas temperature and water con-
densation requirements, PVC pipe is used as venting material.
In addition to PVC and ABS pipe and fittings, Innoflue®by
Centrotherm Eco Systems and PolyPro®by M&G Duravent are
also approved vent and combustion air materials for installa-
tions in the U.S.A. and Canada. Manufacturers Installation
instructions for these products must be followed. These products have specific instructions for installing, joining and termi-
nating. Do not mix materials or components of one manufacturer with materials or components of another manufacturer.
All furnaces are built with 2" vent / intake pipe and connectors. For furnaces requiring installation of 3" pipe, the transition
from 2" to 3" should be done as close to the furnace as practically possible.
This furnace must not be connected to Type B, BW, or L vent or vent connector, and must not be vented into any portion of a factory
built or masonry chimney except when used as a pathway for PVC as described later in this section. Never common vent this appliance
with another appliance or use a vent which is used by a solid fuel appliance. Do not use commercially available “no hub connectors”
other than those shipped with this product.
It is the responsibility of the installer to follow the manufacturers’ recommendations and to verify that all vent/flue piping and
connectors are compatible with furnace flue products. Additionally, it is the responsibility of the installer to ensure that all piping and
connections possess adequate structural integrity and support to prevent flue pipe separation, shifting, or sagging during furnace
operation.
DUAL CERTIFICATION: NON-DIRECT/DIRECT VENT
This furnace is dual certified and may be installed as a non-direct vent (single pipe) or direct vent (dual pipe) appliance. A non-direct
vent installation requires only a vent/flue pipe, while a direct vent installation requires both a vent/flue pipe and a combustion air
intake pipe. Refer to the appropriate section for details concerning piping size, length, number of elbows, furnace connections, and
terminations.
MATERIALS AND JOINING METHODS
Two-three-inch nominal diameter PVC Schedule 40 pipe meet-
ing ASTM D1785, PVC primer meeting ASTM F656, and PVC
solvent cement meeting ASTM D2564 specifications must be
used. Fittings must be DWV type fittings meeting ASTM D2665
and ASTM D3311. Carefully follow the manufacturer’s instruc-
tions for cutting, cleaning, and solvent cementing of PVC.
The use of Schedule 40 PVC or ABS cellular core (Foam Core) plastic pipe is also acceptable as a flue/vent and intake pipe
material. PVC primer meeting ASTM F656 and PVC solvent cement meeting ASTM D2564 specifications must be used. Fittings
must be DWV type fittings meeting ASTM D2665 and ASTM D3311. Carefully follow the manufactures instructions for cutting,
cleaning and solvent cementing of PVC.
For Canadian installations; all PVC pipe, fittings and joining materials must be UL S636 listed.
U PON COMPLETION OF THE FURNACE INSTALLATION , CAREFULLY
INSPECT THE ENTIRE FLUE SYSTEM BOTH INSIDE AND OUTSIDE OF THE
FURNACE TO ASSURE IT IS PROPERLY SEALED . L EAKS IN THE FLUE
SYSTEM CAN RESULT IN SERIOUS PERSONAL INJURY OR DEATH DUE TO
EXPOSURE TO FLUE PRODUCTS , INCLUDING CARBON MONOXIDE .
WARNING
F AILURE TO FOLLOW THESE INSTRUCTIONS CAN RESULT IN BODILY
INJURY OR DEATH . C AREFULLY READ AND FOLLOW ALL INSTRUCTIONS
GIVEN IN THIS SECTION .
WARNING
T O AVOID BODILY INJURY , FIRE OR EXPLOSION , SOLVENT CEMENTS
MUST BE KEPT AWAY FROM ALL IGNITION SOURCES ( I . E ., SPARKS , OPEN
FLAMES , AND EXCESSIVE HEAT ) AS THEY ARE COMBUSTIBLE LIQUIDS .
A
VOID BREATHING CEMENT VAPORS OR CONTACT WITH SKIN AND / OR
EYES .
WARNING
HIGH STAGE LOW STAGE
#45 (1)
#50 (2)
LPM-08* (1) 1.25MM (1)
LPM-30* (2) #57 (2)
*supports both Honeywell and White-Rodgers 2-stage valves
(1) FOR USE WITH ALL MODELS EXCEPT*MEC960302BN**
(2) FOR USEWITH ONLY *MEC960302BN**MODEL
MANIFOLD PRESSURE PRESSSURE
SWITCH CHANGE
NATURAL
PROPANE
0 - 7000
NONE
GAS ALTITUDE KIT ORIFICE
3.5" w.c. 1.9" w.c. NONE
NONE10.0" w.c. 6.0" w.c.

12
As an alternative to PVC pipe, primer, solvent cement, and fittings, ABS materials which are in compliance with the following
specifications may be used. Two-or-three-inch ABS Schedule 40 pipe must meet ASTM D1527 and, if used in Canada, must be CSA
listed. Solvent cement for ABS to ABS joints must meet ASTM D2235 and, if used in Canada, must be CSA listed. The solvent cement
for the PVC to ABS transition joint must meet ASTM D3138. Fittings must be DWV type fittings meeting ASTM D2661 and ASTM D3311
and, if used in Canada, must be CSA listed. Carefully follow the manufacturers’ instructions for cutting, cleaning, and solvent
cementing PVC and/or ABS.
All 90° elbows must be medium radius (1/4 bend DWV) or long radius (Long sweep 1/4 bend DWV) types conforming to ASTM D3311.
A medium radius (1/4 bend DWV) elbow measures 3 1/16” minimum from the plane of one opening to the center line of the other
opening for 2” diameter pipe, and 4 9/16” minimum for 3” pipe.
PROPER VENT/FLUE AND COMBUSTION AIR PIPING PRACTICES
Adhere to these instructions to ensure safe and proper furnace performance. The length, diameter, and number of elbows of the vent/
flue pipe and combustion air pipe (when applicable) affects the performance of the furnace and must be carefully sized. All piping
must be installed in accordance with local codes and these instructions.
Some models require the use of 3” pipe. Do not transition from a 2” to 3” pipe in a horizontal section of pipe as this may
create a water trap.
PREFERRED
TRANSITION NO LESS
THAN 45 DEGREES TO
HORIZONTAL PLANE TO
AVOID CREATING A WATER
TRAP IN VENT PIPING.
ACCEPTABLE
NO TRANSITION ON
HORIZONTAL PLANE,
THIS CREATES A
WATER TRAP AND
RESTRICTS FLUE
GASES
Figure 4 Figure 5 Figure 6
Piping must be adequately secured and supported to prohibit sagging, joint separation, and/or detachment from the furnace.
Horizontal runs of vent/flue piping must be supported every three to five feet and must maintain a 1/4 inch per foot downward slope,
back towards the furnace, to properly return condensate to the furnace’s drain system. Allowances should be made for minor
expansion and contraction due to temperature variations. For this reason, particular care must be taken to secure piping when a long
run is followed by a short offset of less than 40 inches.
Precautions should be taken to prevent condensate from freezing inside the vent/flue pipe and/or at the vent/flue pipe termination.
All vent/flue piping exposed to freezing temperatures below 35°F for extended periods of time must be insulated with 1/2” thick
closed cell foam. Also all vent/flue piping exposed outdoors in ex-
cess of the terminations shown in this manual (or in unheated ar-
eas) must be insulated with 1/2” thick closed cell foam. Inspect
piping for leaks prior to installing insulation.
TERMINATION LOCATIONS
NOTE: Refer to Location Requirements and Considerations for
combustion air contaminant restrictions.
The following bullets and diagram describe the restrictions con-
cerning the appropriate location of vent/flue pipe and combustion
air intake pipe (when applicable) terminations. Refer to Non-Direct
Vent (Single Pipe) Piping and Direct Vent (Dual Pipe) Piping located
in this section for specific details on termination construction.
• All terminations (flue and/or intake) must be located at least
12 inches above ground level or the anticipated snow level.
• Vent terminations (non-direct and direct vent) must terminate
at least 3 feet above any forced air inlet located within 10
feet.
NOTE: This provision does not apply to the combustion air
intake termination of a direct vent application.
12"
Non-Direct Vent
Vent/Flue Termination
No Terminations
Above Walkway
12"
min.
4'
min.
Non-Direct Vent
Vent/Flue Termination
Direct Vent
Vent/Flue Termination
<10'
Forced Air
Inlet
Non-Direct Vent
&
Direct Vent
Vent/Flue Terminations
Grade or Highest
Anticipated
Snow Level
3' min.
12" min.
4' min.
12" min.
Vent Termination Clearances
Figure 7

13
• The vent termination of a non-direct vent application must terminate at least 4 feet below, 4 feet horizontally from, or 1 foot
above any door, window, or gravity air inlet into any building.
• The vent termination of a direct vent application must terminate at least 12 inches from any opening through which flue
gases may enter a building (door, window, or gravity air inlet).
• The vent termination of vent pipe run vertically through a roof must terminate at least 12 inches above the roof line (or the
anticipated snow level) and be at least 12 inches from any vertical wall (including any anticipated snow build up).
• A vent termination shall not terminate over public walkways or over an area where condensate or vapor could create a
nuisance or hazard or could be detrimental to the operation of regulators, relief valves, or other equipment.
• The combustion air intake termination of a direct vent application should not terminate in an area which is frequently dusty
or dirty.
NOTE: In Canada, the Canadian Fuel Gas Code takes precedence over the preceding termination restrictions.
CANADIAN VENTING REQUIREMENTS
In Canada, venting must conform to the requirements of the current CAN/CSA-B149.1-05 Installation Code. Use only CSA-listed, ULC-
S636 compliant two- or three-inch diameter PVC or ABS pipe, solvent cement, and fittings throughout. The certified piping should be
clearly marked with the ULC Std “S636” on the pipe and fittings. Carefully follow the pipe manufacturers’ instructions for cutting,
cleaning, and solvent cementing PVC and/or ABS.
The vent can be run through an existing unused chimney provided the space between the vent pipe and the chimney is insulated and
closed with a weather-tight, corrosion-resistant flashing.
STANDARD FURNACE CONNECTIONS
It is the responsibility of the installer to ensure that the piping connections to the furnace are secure, airtight, and adequately
supported.
VENT/FLUE P IPE
The vent pipe outlet is sized to accept 2” pipe. Secure vent/flue pipe directly into the
furnace fitting with the appropriate glue. Alternately, a small section of 2" pipe may be
glued in the furnace socket and a rubber coupling installed to allow removal for future
service. Combustion Air and Vent piping should be routed in a manner to avoid contact
with refrigerant lines, metering devices, condensate drain lines, etc. If necessary,
clearances may be increased by creating an offset using two 45 degree elbows. This
joint can be rotated on the fitting to establish maximum clearance between refrigerant
lines, metering devices, and condensate drain lines, etc. This joint is the equivalent of
one 90 deg. elbow when considering elbow count. (Figure 8A)
NOTE: For non-direct vent installations, a minimum of one 90° elbow should be in-
stalled on the combustion air intake coupling to guard against inadvertent blockage.
DIRECT V ENT I NSTALLATIONS
On upflow units secure the combustion air intake pipe to the air intake coupling by
using a take apart rubber coupling supplied with the furnace or a plastic cou-
pling. Also, the intake coupling may be inverted to allow the intake pipe to be
glued directly to it. After inverting the coupling, secure it to the furnace top
with screws. On counterflow units secure the combustion air intake pipe to the air
intake coupling using the rubber coupling and worm gear hose clamps provided with
the unit. The counterflow rubber coupling allows service removal of air intake piping
internal to the furnace blower compartment. The combustion air intake pipe can
also be secured directly to the counterflow unit air intake pipe coupling.
COMBUSTION AIR INTAKE OPTION: The RF000142 coupling can be secured
directly to the furnace intake coupling if condensation is a concern. If the
RF000142 is used on the combustion air inlet, it must be installed with the
arrow pointing up. It should be noted, the combustion air will actually be moving in a direction opposite of the arrow on the
RF000142 coupling. It must have a field supplied, trapped drain tube free-draining to proper condensate disposal location. A
loop in the drain tube can serve as a trap. The unused RF000142 drain fitting should be capped. (Figure 8B)
45 DEGREE
LONG-SWEEP
ELBOWS
V
E
N
T
Increased Clearance Configuration
Figure 8A
VENT-DRAIN
The RF000142 Coupling
Figure 8B

14
NON-DIRECT V ENT I NSTALLATIONS
A minimum of one 90° elbow should be installed on the combustion
air intake “coupling” to guard against inadvertent blockage.
ALTERNATE VENT/FLUE LOCATION
The alternate vent/flue location is the large hole directly in line with the induced draft blower outlet. To use the alternate vent/flue
location refer to the following steps and the “Alternate Vent/Flue Location” figure.
NOTE: In the horizontal left installation position, a means of
condensate collection must be provided to keep vent pipe con-
densate from entering the draft inducer housing. If the vent
drain elbow is eliminated from the installation, an RF000142
kit must be used.
1. Remove the four screws from the vent pipe flange on top
the furnace.
2. Remove the internal elbow and vent pipe
3. Cut 2 1/2" from the flange .
4. Remove plastic plug in line with the inducer outlet
5. Install cut end of the flanged section and connect to inducer
with rubber coupling supplied with furnace.
6. Install screws removed in step 1 securing flange to cabinet.
T HE RUBBER ELBOW IS NOT DESIGNED TO SUPPORT A LOAD . W HEN THE
RUBBER ELBOW IS MOUNTED EXTERNALLY TO THE FURNACE CABINET ,
EXTREME CARE MUST BE TAKEN TO ADEQUATELY SUPPORT FIELD -
SUPPLIED VENT / FLUE PIPING , AS DAMAGE CAN RESULT IN LEAKS
CAUSING BODILY INJURY OR DEATH DUE TO EXPOSURE TO FLUE GASES ,
INCLUDING CARBON MONOXIDE
WARNING
ALTERNATE COMBUSTION AIR PROVISION
(Upflow / Horizontal models only)
When using the alternate venting location, either in a horizontal left side down installation or a vertical installation using
down – venting, an alternate combustion air opening can be used. A locating dimple is located on the right side of the
furnace cabinet. The locating dimple is 1 7/8" measured from the front edge of the cabinet in line with the knock out. To
use the alternate combustion air location:
1. Remove screws and combustion air flange from cabinet.
2. Insert cabinet plug in unused combustion air hole.
3. Drill a pilot hole at the cabinet dimple (size dictated by
knockout tool used).
4. Use a knockout tool to create a 3" diameter hole
5. Install combustion air flange and secure with screws
removed in step one.
Insert flange. Cut 2 ½” long.
R 000142F
Figure 9
CUTHERE
Vent/Flue Pipe Cuts
Figure 10
B E SURE NOT TO DAMAGE INTERNAL WIRING OR OTHER COMPONENTS
WHEN REINSTALLING COUPLING AND SCREWS .
CAUTION
E DGES OF SHEET METAL HOLES MAY BE SHARP . U SE GLOVES AS A
PRECAUTION WHEN REMOVING HOLE PLUGS .
WARNING

15
NON-DIRECT VENT (SINGLE PIPE) PIPING
Non-direct vent installations require only a vent/flue pipe. The vent pipe can be run horizontally with an exit through the side of the
building or run vertically with an exit through the roof of the building. The vent can also be run through an existing unused chimney;
however, it must extend a minimum of 12 inches above the top of the chimney. The space between the vent pipe and the chimney
must be closed with a weather-tight, corrosion-resistant flashing.
Although non-direct vent installations do not require a combustion air intake pipe, a minimum of one 90° elbow should be attached to
the furnace’s combustion air intake if: an upright installation uses the standard intake location, or a horizontal installation uses the
alternate air intake location. This elbow will guard against inadvertent blockage of the air intake.
VENT/FLUE PIPE LENGTHS AND DIAMETERS
Refer to the following table for applicable length, elbows, and pipe diameter for construction of the vent/flue pipe system of a non-
direct vent installation. In addition to the vent/flue pipe, a single 90° elbow should be secured to the combustion air intake to prevent
inadvertent blockage. The tee used in the vent/flue termination must be included when determining the number of elbows in the
piping system.
VENT/FLUE PIPE TERMINATIONS
NOTE: If either a 90 degree or 45 degree elbow is used for termination, it must be pointed downward.
The vent/flue pipe may terminate vertically, as through a roof, or horizontally, as through an outside wall.
Vertical vent/flue pipe terminations should be as shown in the following figure. Refer to Vent/Flue Pipe and Combustion Air Pipe -
Termination Locations for details concerning location restrictions. The penetration of the vent through the roof must be sealed tight
with proper flashing such as is used with a plastic plumbing vent.
Horizontal vent/flue pipe terminations should be as shown in the following figure. Refer to Vent/Flue Pipe and Combustion Air Pipe.
To secure the pipe passing through the wall and prohibit damage to piping connections, a coupling should be installed on either side
of the wall and solvent cemented to a length of pipe connecting the two couplings. The length of pipe should be the wall thickness plus
the depth of the socket fittings to be installed on the inside and outside of the wall. The wall penetration should be sealed with
silicone caulking material.
NOTE: Terminate both pipes in the same pressure zone (same side of roof, no major obstacles between pipes, etc.).
12345678
30,000
40,000
2
or 2 1/2 100 95 90 85 80 75 70 65
30,000
40,000 3 168 161 154 147 140 133 126 119
60,000 2
or 2 1/2 50 45 40 35 30 25 20 15
60,000 3 143 136 129 122 115 108 101 94
80,0002or21/26055504540353025
80,0003113106999285787164
100,0002or21/24540353025201510
100,000 3 103 96 89 82 75 67 60 53
120,000 3 185 178 171 164 157 150 143 136
Maximum Allow able Length of Vent/Flue Pipe
Unit Input
(Btu)
Pipe Size
(4) (in.)
Number of Elbows (3) (5)
*M EC96 Direct Vent (2 - Pipe) and Non-Direct Vent (1- Pipe) (6)

16
COMBUSTION AIR INTAKE
(OPTIONAL)
*Not required for
single pipe installation
TEE (OPTIONAL)
96”MAX.-3”MIN.
ROOFLINE
12” MIN
HEIGHT DIFFERENCE
BETWEEN
INTAKE AND VENT
12” MIN TO ROOF OR HIGHEST
ANTICIPATED SNOW LEVEL
Figure 11
Figure 12
STRAIGHT
ELBOWS
Figure 13
VENT/FLUE TEE (
or
45° ELBOW
TURNED DOWN or
90° ELBOW TURNED
DOWN
OPTIONAL)
12" MIN. ABOVE
HIGHEST ANTICIPATED
SNOW LEVEL
12" MIN.
Horizontal Termination (Single Pipe)
Above Highest Anticipated Snow Level
Figure 14
Floor
Use alternate vent
& combination air locations
DOWN VENTING UPFLOW MODEL FURNACES ONLY
Basement/Crawlspace
Condensate trapped
to prevent flue gas from escaping
and routed to field supplied
condensate disposal
Combustion Air Pipe
Vent Pipe
A
ll piping and fittings must be joined per material manufacturer’s specifications
to prevent separation and flue gas leaks.
Both Pipes Terminated
Outside Structure
1/4” per foot min. slope
6’ MAX.
Field Supplied
Drain Tee on Vent Pipe

17
DIRECT VENT (DUAL PIPE) PIPING
Direct vent installations require both a combustion air intake and a vent/flue pipe. The pipes may be run horizontally and exit
through the side of the building or run vertically and exit through the roof of the building. The pipes may be run through an existing
unused chimney; however, they must extend a minimum of 12 inches above the top of the chimney. The space between the pipes
and the chimney must be closed with a weather tight, corrosion resistant flashing. Both the combustion air intake and a vent/flue
pipe terminations must be in the same atmospheric pressure zone. Refer to Vent/Flue and Combustion Air Pipe - Termination
Locations or Concentric Vent Termination for specific details on termination construction. For details concerning connection of pipes
to the furnace, refer to the Vent/Flue Pipe and Combustion Pipe - Standard Furnace Connections or Alternate Furnace Connections.
The number of elbows tabulated represents the number of elbows
and/or tees in each (Vent/Flue & Combustion Air Intake) pipe.
Elbows and/or tees used in the terminations must be included when
determining the number of elbows in the piping systems.
If the combustion air intake pipe is to be installed above a finished
ceiling or other area where dripping of condensate will be objec-
tionable, insulation of the combustion air pipe may be required.
Use 1/2” thick closed cell foam insulation such as Armaflex™ or
Insultube™ where required.
VENT/FLUE AND COMBUSTION AIR PIPE TERMINATIONS
The vent/flue and combustion air pipes may terminate vertically,
as through a roof, or horizontally, as through an outside wall.
Vertical pipe terminations should be as shown in the following fig-
ure. Refer to Vent/Flue Pipe and Combustion Pipe - Termination
Locations for details concerning location restrictions. The pen-
etrations through the roof must be sealed tight with proper flash-
ing such as is used with a plastic plumbing vent.
Vent & Combustion Air Intake Measurements for Standard
Horizontal Terminations (Dual Pipe)
Center to center = 10” min / 24” max. Vertical separation: 0” - 24”
Vent termination from wall = 8” min / 12” max.
Combustion air intake from wall = 6” max.
Vent and intake clearance to ground
or anticipated snow level = 12” min.
Alternate Horizontal Vent Termination (Dual Pipe)
Figure 16
90°
ELBOWS
12" MIN. ABOVE
HIGHEST ANTICIPATED
SNOW LEVEL
3” - 24”
Standard Horizontal Terminations (Dual Pipe)
Figure 15
90º OR 45°
ELBOW
12" MIN. TO GRADE OR
HIGHEST ANTICIPATED
SNOW LEVEL
6” MAX
10”- 24”
4” MIN
Combustion Air Intake may also be snorkeled to obtain 12” min ground
clearance.
Alternate Vent Termination Above Anticipated Snow Level
(Dual Pipe)
Figure 17
90°
ELBOWS
12" MIN. ABOVE
HIGHEST ANTICIPATED
SNOW LEVEL
3”-24” BETWEEN PIPES

18
VENT/INTAKE TERMINATIONS FOR INSTALLATION OF MULTIPLE
DIRECT VENT FURNACES
If more than one direct vent furnace is to be installed vertically
through a common roof top, maintain the same minimum clear-
ances between the exhaust vent and air intake terminations of
adjacent units as with the exhaust vent and air intake terminations
of a single unit.
If more than one direct vent furnace is to be installed horizontally
through a common side wall, maintain the clearances as in the
following figure. Always terminate all exhaust vent outlets at the
same elevation and always terminate all air intakes at the same
elevation.
CONCENTRIC VENT TERMINATION
Refer to the directions provided with the Concentric Vent Kit (CVENT)
for installation specifications.
SIDE WALL VENT KIT
This kit is to be used with 2” or 3” direct vent systems. The vent kit
must terminate outside the structure and may be installed with the in-
take and exhaust pipes located side-by-side or with one pipe above the
other. These kits are NOT intended for use with single pipe (non-direct
vent) installations.
Refer to the directions furnished with the Side Wall Vent Kit (p/n
0170K00000S or 0170K000001S) for installation specifications.
C ONDENSATE D RAIN L INES & D RAIN T RAP
A condensing gas furnace achieves its high level of efficiency by extract-
ing heat from the products of combustion to the point where condensation takes place. The condensate must be collected in the
furnace drain trap and routed to an appropriate drain location in compliance with local and national codes.
Follow the bullets listed below when installing the drain system. Refer to the following sections for specific details concerning furnace
drain trap installation and drain hose hook ups.
• The drain trap supplied with the furnace must be used.
• The drain trap must be primed at time of installation.
• The drain line between furnace and drain location must meet local and national codes.
• The drain line between furnace and drain location must maintain a 1/4 inch per foot downward slope toward the drain.
• Do not trap the drain line in any other location than at the drain trap supplied with the furnace.
• If the drain line is routed through an area which may see temperatures near or below freezing, precautions must be
taken to prevent condensate from freezing within the drain line.
• If an air conditioning coil is installed with the furnace, a common drain may be used. An open tee must be installed in
the drain line, to relieve positive air pressure from the coil’s plenum. This is necessary to prohibit any interference with
the function of the furnace’s drain trap.
Vertical Installation
Horizontal Installation
Side Wall Vent Kit
Figure 19
3” MIN
12” MIN TO GRADE OR HIGHEST
ANTICIPATED SNOW LEVEL
12” MIN SEPARATION
3”MIN
24”MAX
Termination of Multiple Direct Vent Furnaces
Figure 18

19
GENERAL DRAIN INFORMATION
All furnace models come with a factory installed drain trap. For
vertical installations, the trap will remain in the factory posi-
tion. All furnace models installed horizontally require the trap to
be relocated. Many drain hoses have a built–in grommet which
will provide a cabinet seal when installed. See instructions below
for your model and installation position. NOTE: Both sides of
the drain trap must be primed prior to initial furnace start
up
FIELD SUPPLIED D RAIN
Drain the furnace and air conditioning coil if applicable, in com-
pliance with code requirements. In horizontal installations, a field
installed rubber coupling will allow the drain trap to be removed
for cleaning. The drain trap must be primed before initial fur-
nace start up. When an air conditioning coil drain is connected
to the field supplied furnace drain, it must be vented with an
open tee installed at a height no higher than the bottom of the
furnace collector box to prevent air conditioning condensate from
backing up into the furnace if the common drain became blocked.
#3
#1 #2
#4 #5
#6
#7 #8
#9
#10
#11
100 Degree
Elbow
Coupling
Figure 20
NOTE: Hoses are model specific
and not all hoses will be shipped with all models.
Installer selects right or left side drain
and installs this hose accordingly.
Hose #1
Hose #2
45 degree
barb-pipe
adapter
45 degree
barb-pipe
adapter
Figure 21
UPFLOW MODEL INSTALLED VERTICALLY
The trap and factory installed hoses remain as shipped. The
furnace drain may exit either the right or left side of the fur-
nace cabinet.
DRAIN EXITING RIGHT SIDE
1. Locate and Install the 45º pipe / hose drain coupling from
the outside of the cabinet (barbed end goes in the cabinet)
through hole in the right side of the cabinet and secure
with two field supplied #8 self-tapping screws (see Figure
21).
2. Locate the long drain hose #3 and cut at line “A” .
3. Install large end of hose #3 to trap outlet and secure with
1.25" clamp.
4. Install smaller end of hose #3 on 45º elbow and secure with
1" clamp.
5. Refer to Field Supplied Drain section for instructions on
field supplied / installed drain on outlet of furnace trap.

20
DRAIN EXITING LEFT SIDE
1. Install the 45 degree pipe / hose drain coupling from the outside of the cabinet (barbed end goes in the cabinet)
through the hole in the left side of the cabinet and secure with two field supplied #8 self-tapping screws (see Figure
21).
2. Locate the long drain hose #3 and cut at “B” line for a 17.5" cabinet; cut at line “C” for a 21" cabinet; do not cut for
a “D” width cabinet.
3. Install large end of hose #3 to trap outlet and secure with 1.25" clamp.
4. Install smaller end of hose #3 on 45º elbow and secure with 1" clamp.
5. Refer to Field Supplied Drain section for instructions on field supplied / installed drain on outlet of furnace trap.
UPFLOW MODEL INSTALLED HORIZONTALLY WITH RIGHT SIDE
DOWN
Minimum 5 1/2" clearance is required for the drain trap be-
neath the furnace.
1. Remove the clamps from both ends of the drain hoses.
2. Remove the two screws holding the drain trap to the blower
deck.
3. Remove the trap and two hoses from the blower deck
4. Remove the two plugs from the right side of the cabinet
and install them in the blower deck.
5. (Draining the Vent Elbow ) Locate hose #5 and cut it at line
“C”. Install the cut end of hose #5 from outside the cabinet
through the cabinet drain hole nearest the top. Secure it
to the barbed fitting in the elbow with a red clamp.
6. (Draining the Collector Box) Install the non-grommet end
of hose #11 from outside the cabinet in the bottom drain
hole. Install on collector box and secure with a silver clamp.
7. Use two silver clamps and secure the hoses to drain trap. The trap outlet faces the front of the furnace. Secure the
trap to the cabinet using two screws removed in step 2 by inserting the two screws through the large set of holes in the
top mounting tabs of the trap into the two predrilled holes in the side of the cabinet.
8. Refer to Field Supplied Drain section for instructions on field supplied / installed drain on outlet of furnace trap.
UPFLOW MODEL INSTALLED HORIZONTALLY WITH LEFT SIDE
DOWN
Minimum 5 1/2" clearance is required for the drain trap be-
neath the furnace.
*Also see Front Cover Pressure Switch Tube Location on page
10.
1. Remove the clamps from the two drain tubes on the trap.
2. Remove the two screws holding the drain trap to the blower
deck.
3. Remove the trap and hoses from the blower deck .
4. Remove the two plugs from the left side of the cabinet
and install them in the blower deck.
5. (Draining the Vent Elbow) Locate hose #6. Measuring from
the non-grommet end; cut off and discard 1 ½” for a “D”
width cabinet, 5” for a “C” width cabinet, 8 ½” for a “B”
width cabinet.
6. Remove the rubber plug from vent – drain elbow side port.
Place hose #6 on the vent – drain elbow side port and secure with a silver clamp .
7. Place cap on vent – drain elbow barb fitting and secure with red clamp
8. Locate hose #5 and cut 3” from the non-grommet end. Discard the section without the grommet.
9. Insert the cut end of tube #5 through the lower cabinet drain hole.
Hose #11
Hose #5-Cut at “C”
Figure 22
Hose #6
Hose #5 Hose #11
Figure 23