Goodman GMNTE Manual

All information contained herein is subject to change without notice.
Goodman Manufacturing Company, L.P.
I0-231 2550 North Loop West, Suite 400, Houston, TX 77092 6/03
www.goodmanmfg.com
©2003 Goodman Manufacturing Company, L.P.
WARNING
DO NOT USE THIS FURNACE IF ANY PART HAS
BEEN UNDERWATER. IMMEDIATELY CALL A
QUALIFIED SERVICE TECHNICIAN TO INSPECT
THE FURNACE AND TO REPLACE ANY PART OF
THE CONTROL SYSTEM AND ANY GAS CON-
TROL THAT HAS BEEN UNDERWATER.
WARNING
THIS FURNACE IS DESIGN CERTIFIED FOR IN-
STALLATION IN BUILDINGS CONSTRUCTED ON
SITE ONLY.
CUS
®
INSTALLATION & OPERATING
INSTRUCTIONS
for GMNTE
CONDENSING GAS FURNACE
(CATEGORY IV)
ama
EFFICIENCY
RATING
CERTIFIED

IO-231 6/03
2
INDEX
Warnings & General Information ............................ 2
Clearances, Location .............................................. 4
Combustion Air ....................................................... 4
Venting .................................................................... 6
Condensate Drains ................................................ 9
Gas Piping ............................................................ 11
Circulating Air ........................................................ 11
Electrical ............................................................... 12
Features ................................................................ 12
Rating the Furnace ............................................... 13
Timing the Gas Meter ........................................... 13
Safety Control ....................................................... 14
Circulating Air Filters ............................................ 15
Temperature Rise, Maintenance .......................... 15
Circulator Blower Speed Adjustment .................... 16
Service Instructions, Sequence of Operation ...... 18
Removing an Existing Appliance .......................... 18
Inspecting and Cleaning ....................................... 19
The Heat Exchanger
Lighting Instructions ............................................. 20
Wiring Diagram ..................................................... 21
REPLACEMENT PARTS
Replacement parts for this appliance are available through
your contractor or local distributor. For the location of your
nearest distributor consult the white business pages, the
yellow page section of the local telephone book or contact:
SERVICE PARTS DEPARTMENT
GOODMAN MANUFACTURING CO., L.P.
2550 NORTH LOOP WEST, SUITE 400
HOUSTON, TEXAS 77092
(713) 861 – 2500
The major parts groups are as follows:
BLOWER ASSEMBLY
Motor
Blower Housing
Blower wheel
Misc. sheetmetal items
Inductor
HEAT EXCHANGER
Heat exchanger sections
Secondary coil
Collector Box
ELECTRICAL CONTROLS
Control board
Auxiliary / main limit switch
Roll-out switch
Transformer
Door interlock switch
Air pressure switch
Induced draft blower
BURNER ASSEMBLY
Burners
Manifold
Orifices
Gas Valve
Igniter
Flame sensor
MISCELLANEOUS
Wrapper
Access doors
Drain hoses/Drain trap
Gaskets and seals
Wiring assemblies
In order to effectively process the parts requirement the
distributor / contractor will need the entire model number
and serial number found on the series and rating plate.
THIS FURNACE CONTAINS ELECTRONIC COMPONENTS,
WHICH REQUIRE A DEFINITE GROUND. PROVISIONS ARE
MADE FOR CONNECTION OF THE GROUND. A DEDICATED
GROUND FROM THE MAIN POWER SUPPLY OR AN EARTH
GROUND MUST BE PROVIDED.
WARNING
THE CIRCULATING AIR DUCTS MUST BE COMPLETELY
AND POSITIVELY SEALED TO PREVENT THE COMBUS-
TION PRODUCTS, INCLUDING CARBON MONOXIDE,
FROM ENTERING THE LIVING SPACE.
WARNING
WHILE CARBON MONOXIDE DETECTORS DO PROVIDE AD-
DITIONAL PROTECTION, CURRENT LIMITATIONS TO THEIR
EFFECTIVENESS REQUIRES THAT YOU OTHERWISE CON-
TINUE TO FOLLOW APPROPRIATE INSTRUCTIONS LO-
CATED IN THE “INSTALLATION & OPERATING INSTRUC-
TIONS” AND USERS INFORMATION” MANUALS RELATING
TO PROTECTING PERSONS FROM THE RISKS OF CARBON
MONOXIDE. REVIEW EACH CO DETECTORS MANUFAC-
TURERS’ EXPLANATION OF THEIR UNIT’S CAPABILITIES
AND FOLLOW THE INSTALLATION AND OPERATING MANUAL
WHEN INSTALLING AND OPERATING SUCH UNITS.

IO-231 6/03
3
CARBON MONOXIDE POISONING HAZARD
B10259-216
Carbon monoxide producing devices (such as an automobile, space
heater, gas water heater, etc.) should not be operated in enclosed areas
such as unventilated garages, utility rooms or parking areas because of
the danger of
carbon monoxide (CO) poisoning resulting from the exhaust
emissions. If a furnace or air handler is installed in an enclosed area such
as a garage, utility room or parking area
and a carbon monoxide producing
device is operated therein, there must be adequate, direct outside
ventilation.
This ventilation is necessary to avoid the danger of CO poisoning which
can occur if a carbon monoxide producing device continues to operate in
the enclosed area. Carbon monoxid
e emissions can be (re)circulated
throughout the structure if the furnace or air handler is operating in any
mode.
CO can cause serious illness including permanent brain damage or
d
eath.
Special Warning for Installation of Furnaces or Air Handling Units in
Enclosed Areas such as Garages, Utility Rooms or Parking Areas
GENERAL INFORMATION
The GMNTE series furnace can be installed as an upflow,
downflow or horizontal furnace. It can also be installed as a
direct vent or a non-direct vent furnace.
These Installation and Operating Instructions are intended
for use by fully qualified installation technicians. Some lo-
calities require the installer/sevicer to be licensed. If in doubt,
check with local authorities.
INSTALLATION: In the USA this furnace MUST be installed
in accordance with the latest edition of the ANSI Z223.1
booklet entitled “National Fuel Gas Code” (NFPA 54), and
the requirements or codes of the local utility or other au-
thority having jurisdiction. In Canada this furnace must be
installed in accordance with the current CAN/CGA-B149.1
& 2 Gas Installation Codes, local plumbing or waste water
codes and other applicable codes.
Additional helpful publications available from the NFPA are,
NFPA 90A - Installation of Air Conditioning and Ventilating
System and NFPA 90B - Warm Air Heating and Air Condi-
tioning System.
All venting shall be in accordance with PART 7, Venting of
Equipment, of the National Fuel Gas Code, ANSI Z223.1,
or applicable local building and/or air conditioning codes.
These publications are available from:
National Fire Protection Association, Inc.
Batterymarch Park
Quincy, MA 02269
WARNING
TO ENSURE PROPER INSTALLATION AND OPERATION OF
THIS PRODUCT, COMPLETELY READ AND UNDERSTAND
THESE INSTRUCTIONS PRIOR TO ATTEMPTING TO AS-
SEMBLE, INSTALL, MAINTAIN, OR REPAIR. IF THESE IN-
STRUCTIONS ARE NOT FOLLOWED PRECISELY THERE
IS A POTENTIAL OF CARBON MONOXIDE POISONING,
WHICH CAN RESULT IN SERIOUS ILLNESS OR DEATH.
WARNING
THIS FURNACE WAS EQUIPPED AT THE FACTORY FOR USE
WITH NATURAL GAS ONLY. LIQUID PETROLEUM (L.P.)
CONVERSION, IF REQUIRED, MUST BE PERFORMED BY A
QUALIFIED TECHNICIAN FAMILIAR WITH PERFORMING
THIS TYPE OF CONVERSION. IF L.P. CONVERSION IS RE-
QUIRED, ALL INSTRUCTIONS INCLUDED WITH THE FAC-
TORY AUTHORIZED KIT MUST BE FOLLOWED. THE ONLY
KIT THAT MUST BE USED FOR THIS CONVERSION IS THE
FACTORY AUTHORIZED LPT-01. FAILURE TO FOLLOW
THOSE INSTRUCTIONS EXPLICITLY MAY CAUSE FIRE,
EXPLOSION, PROPERTY DAMAGE, PERSONAL INJURY OR
DEATH.
WARNING
UNLESS ALLOWED BY LOCAL CODE, DO NOT INSTALL A
LIQUID PETROLEUM GAS BURNING APPLIANCE IN A PIT,
BASEMENT, OR SIMILAR LOCATION. L.P., A HEAVIER THAN
AIR GAS, CAN COLLECT IN LOW AREAS AND MAY NOT DIS-
PERSE NATURALLY. APPLIANCES SO FUELED SHALL NOT
BE INSTALLED IN AN ABOVE GRADE UNDER FLOOR SPACE
OR BASEMENT UNLESS SUCH LOCATION IS PROVIDED
WITH APPROVED MEANS FOR REMOVAL OF UNBURNED
GAS.
WARNING
THE GAS SUPPLY PIPE MUST NEVER BE USED FOR
GROUNDING PURPOSES.
WARNING
NEVER LAY THIS FURNACE ON ITS FRONT OR REAR.

IO-231 6/03
4
The GMNTE series of furnaces meet the California NOx
emission standards and California seasonal efficiency stan-
dards. ANNUAL inspections of the furnace and its vent sys-
tem is strongly recommended. It is the installer’s responsi-
bility to inform the user of this importance. Any installation,
alteration or repair of this equipment must not be in viola-
tion of local code or the information contained in this manual.
This furnace shall be securely fastened in place when in-
stalled in the vertical position. This furnace must be in-
stalled in such a manner as to allow for service, inspection,
repair or replacement without removing permanent con-
struction. A platform is recommended to allow for service.
LOCATION
DO NOT install this furnace in a mobile home. This furnace
is designed only for installation in buildings constructed on
site and connected to ductwork. When installed in a utility
room or closet, the door should be wide enough to allow
the largest part of the furnace to enter, or to permit the
replacement of another appliance, such as a water heater.
This furnace is designed to be installed indoors only. DO
NOT install outdoors. This furnace should be installed in
such a manner so that it is protected from water. If any
components should become wetted or submerged under
water, replace those parts before returning the furnace to
operation. DO NOT use as a construction heater. DO
NOT use in an area where freezing may occur without
properly protecting the vent and drain system. The drain
may crack and leak if subjected to freezing temperatures.
DO NOT install in a room used or designed to be used as
a bedroom, bathroom or storage closet, or in any enclosed
space with access only through such a room or space.
A return air filter grille or means of inserting a filter into the
return air duct is recommended. The opening in the duct
used for filter access must be capable of being sealed air
tight if located in the same pressure zone as the furnace.
The furnace and it’s individual shut-off must be
disconnected from the gas supply piping system during
any pressure testing of that system at test pressures in
excess of 1/2 psig (3.5kPa)
The furnace must be isolated from the gas supply piping
system by closing it’s individual manual shut-off valve during
any pressure testing of the gas supply piping system at
pressures equal to or less than 1/2 psig (3.5 kPa).
MIN. CLEARANCES TO COMBUSTIBLE SURFACES
Unobstructed front clearance of 24" for servicing is
recommended.
RIGHT SIDE - 1" VENT - 0"
REAR - 0" LEFT SIDE - 1"
TOP OF PLENUM - 1" FRONT - 3"
Line contact is permitted in the horizontal position.
ACCESSIBILITY CLEARANCE, WHERE GREATER,
SHOULD TAKE PRECEDENCE OVER MINIMUM FIRE
PROTECTION CLEARANCE.
A gas-fired furnace for installation in a residential garage
must be installed so that the ignition source and burners
are located not less than eighteen inches (18") above the
floor and is protected or located to prevent physical damage
by vehicles.
A gas furnace must not be installed directly on carpeting,
tile, or other combustible materials other than wood
flooring.
Before proceeding with this installation check the following;
•Correct clearance from combustible materials
•Adequate accessibility for servicing
•Flooring is not carpet or any other combustible
material, except wood
•Adequate combustion / ventilation air is supplied
•Metal base plate is in place when using side(s) for
return air
•In a garage, the furnace has been adequately elevated
and protected from vehicle damage
•Furnace area is free of flammable materials and vapors
such as gasoline
COMBUSTION AIR
The GMNTE furnace can be installed either as a Direct
Vent (2 pipe) or a Non-Direct Vent (1 pipe) appliance. If
installed as direct vent appliance the combustion air is to
be taken from the outdoors via 3” schedule 40 PVC pipe
and terminate at the furnace cabinet. As a non-direct vent
furnace the combustion air is taken from the area which
the furnace is installed. Avoid combustion air sources
which contain flammable fumes and vapors, and gasses
such as carbon monoxide, hydrogen sulfide, ammonia,
chlorine, and halogenated hydrocarbons.
WARNING
A SOLID METAL BASEPLATE IS SUPPLIED WITH THIS
FURNACE. THIS BASEPLATE MUST BE IN PLACE AND
SEALED AIR TIGHT WHEN THE FURNACE IS INSTALLED
WITH SIDE RETURN AIR DUCTS. FAILURE TO DO SO MAY
PERMIT COMBUSTION PRODUCTS, INCLUDING CABON
MONOXIDE, TO ENTER THE LIVING SPACE AND CREATE
POTENTIALLY HAZARDOUS CONDITIONS SUCH ASCARBON
MONOXIDE POISONING OR DEATH. FULL SIZE RETURN AIR
DUCT OPENINGS MUST BE UTILIZED. EMBOSSES ARE
PROVIDED FOR THIS PURPOSE.
WARNING
COMBUSTIBLE MATERIAL MUST NOT BE PLACED ON OR
AGAINST THE FURNACE CABINET. THE AREA AROUND
THE FURNACE MUST BE KEPT CLEAR AND FREE OF ALL
COMBUSTIBLE MATERIAL INCLUDING GASOLINE AND
OTHER FLAMMABLE VAPORS AND LIQUIDS. THE USER
MUST BE CAUTIONED THAT THE FURNACE AREA MUST NOT
BE USED AS A BROOM CLOSET OR FOR ANY OTHER STOR-
AGE PURPOSE.

IO-231 6/03
5
Direct Vent Combustion Air. As shown in the following
illustration, the combustion air pipe is to originate at the
furnace’s cabinet and terminate outside of the building.
The diameter of the PVC combustion air pipe depends
upon the furnace size, the length of pipe, and the quantity
of fittings employed. The table found in the “Combustion/
Vent Pipe Size” section of this manual outlines these sizing
requirements. As a direct vent installation, the “Air for
Combustion and Ventilation Air” requirements found in
ANSI Z223.1, section 5.3 is not required for the furnace to
operate correctly. However, other fuel burning appliances
located in the same space as the furnace may still require
that the area be serviced with Combustion and Ventilation
Air consistent with ANSI Z223.1, section 5.3.
Attaching Combustion Air Intake Fitting – A coupling for
attaching the combustion air fitting to the furnace cabinet
is included in a plastic bag packaged with the furnace.
The fitting is sized to accept a 3" diameter PVC pipe. In
certain situation, a 2" diameter pipe can be used for this
application. Refer to the combustion/ vent table for sizing
requirements. Attach the fitting to the cabinet using (4)
#10 x 1/2" sheet metal screws (field supplied). If a right
hand entrance is preferred, the plug installed on this side
is to be removed and reinstalled in the left side opening.
When installed as a direct vent furnace and NOT using
the concentric vent kit CVK-00 option, the combustion air
is to be terminated in the following manner;
OPTIONAL
INLET
SCREEN
COMBUSTION
AIR INTAKE
If the optional concentric vent kit (CVK-00) is used follow
the instructions provided with this accessory.
Non-Direct Vent Combustion Air. If the furnace is to be
installed as a non-direct vent appliance, the combustion
air pipe outlined previously is not used.
As a non-direct vent furnace, this must be installed in
accordance with the combustion and ventilation air
requirements found in ANSI Z221.3, section 5.3. When
installed as a non-direct vent furnace in an area, which is
deemed as a confined area, see (ANSI Z223.1, section
1.7, “Space, Confined”) the requirements are as follows:
All Combustion Air Taken From The Inside Of The
Building. When installed as a non-direct vent furnace
and indoor air is used as the combustion air source,
the space is to be provided with (2) permanent
openings communicating directly with an additional
room(s) of sufficient volume so that the combined
volume of all spaces meets the criteria of an
unconfined area. The total input of all gas burning
equipment shall be used to determine the minimum
size of each opening. Each opening shall be sized to
be a minimum of 1 square inch of free area per 1,000
Btu/hr of combined input of gas utilization equipment
in the area. The minimum area for each opening shall
not be less than 100 square inches, and the minimum
dimension of these openings shall not be less than 3
inches. One opening shall be commence within 12
inches of the top of the area, while the other opening
shall commence within 12 inches of the bottom of the
area.
All Combustion Air Taken From Outdoors. If
installed as a non-direct furnace and outdoor air is
selected as the combustion air source, then area shall
be serviced with an opening(s) communicating directly
with the outdoors by either of the following two
methods. When calculating the minimum area for each
opening the combined input of all gas utilization
equipment is to be considered. Also, the minimum
dimension for any opening shall not be less than 3
inches.
Method 1..... Two permanent openings communicating
directly with the outdoors via. horizontal ducts shall be
sized to be a minimum of 1 square inch per 2,000 Btu/
hr or, Two permanent openings communicating directly
with the outdoors via. vertical ducts shall be sized to
be a minimum of 1 square inch per 4,000 Btu /hr.
Method 2..... One permanent opening communicating
directly with the outdoors via. a horizontal duct. This
opening/duct shall be sized to be equal to 1 square
inch per 3,000 Btu / hr, but not less than the sum of
the areas all of the vent connectors in the confined
space.

IO-231 6/03
6
SOURCE OF COMBUSTION AIR
The recommended source of combustion air is to use the
outdoor air supply. However, the use of indoor air in most
applications is acceptable except as follows;
1. If the furnace is installed in a confined space the
necessary combustion must come from outdoors by
way of the attic, crawl space, or direct opening to the
outside.
2. If indoor combustion is used, there must be no
exposure to the substances listed in #3 below.
3. The following installations may require OUTDOOR AIR
for combustion, due to chemical exposures;
•Commercial buildings
•Buildings with indoor pools
•Furnaces installed in laundry rooms
•Furnaces installed in hobby or craft rooms
•Furnaces installed near chemical storage
areas
Exposures to the following substances in the
combustion air supply may also require OUTDOOR
AIR for combustion;
•Permanent wave solutions
•Chlorinated waxes and cleaners
•Chlorine based swimming pool 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
VENTING
ANNUAL inspections of the furnace and it’s vent /
combustion air supply is strongly recommended. It is the
contractor’s responsibility to inform the user of this
importance.
All venting shall be in accordance with Part 7; Venting of
Equipment, of the National Fuel Gas Code, ANSI Z223.1,
or applicable local building and/ or air conditioning codes.
PROPER INSTALLATION OF THE VENT / COMBUSTION
AIR SYSTEMS IS CRITICAL TO SAFE OPERATION OF
THIS APPLIANCE. CAREFULLY READ AND
UNDERSTAND THE INSTRUCTIONS IN THIS SECTION.
EACH VENT AND COMBUSTION AIR SUPPLY PIPE
MUST SERVE ONLY ONE APPLIANCE. DO NOT
CONNECT TO AN EXISTING VENT OR CHIMNEY
UNLESS IT CONFORMS TO ALL PROVISIONS IN THIS
INSTRUCTION BOOKLET. THE VENT MUST
TERMINATE OUTDOORS.
VENT/COMBUSTION AIR SUPPLY PIPE
LENGTHS
Elbows must be long radius types. (Quarter bends or DWV).
The maximum length of the vent pipe and the combustion
air supply pipe is 100 feet each.
Chart assumes a maximum of 4 - 90°elbows. For excess
of 4 elbows decrease length by 7.5 ft. per elbow. A
maximum of 6 elbows is acceptable. The use of two 45°
over one 90°is preferred. Do not count the termination as
an elbow.
Model
Vent Pipe
Comb. Air
GMNTE Diameter Pipe Diameter
060-3
3"
3"
080-4 3" 3"
100-4
3"
3"
120-5 3" 3"
Minimum vent length is 6 ft. for vertical and horizontal runs.
There is no minimum combustion air supply pipe length.
These furnaces are a condensing type appliance. The
products of combustion are recirculated through a
secondary coil. During this process the flue products are
brought to a point below dew point. Thus the moisture
present in the flue products condenses leaving a liquid
by-product. This by-product must be removed from the
furnace and it’s collection system.
In addition, the vent temperatures are also considerably
lower than conventional furnaces. This allows the use of
low temperature plastic as the vent system. The
recommended plastic is schedule 40 PVC, ABS, DWV (or
equivalent if allowed by local code). See the previous
chart for proper sizing. The use of two 45° elbows is
suggested over the use of a single 90° elbow. The vent
pipe must slope toward the furnace to properly drain the
condensate. The drain trap and related parts must be
installed as shown in the illustrations. Failure to follow these
instructions can cause products of combustion including
CARBON MONOXIDE entering the dwelling.
IF THIS FURNACE IS INSTALLED IN AN ATTIC OR
SIMILAR AREA WHERE CONDENSATE OVERFLOW
MAY BE A PROBLEM, AN AUXILIARY DRAIN PAN MUST
BE INSTALLED UNDER THE FURNACE WITH THE
AUXILIARY DRAIN LINES ROUTED TO THE
OUTDOORS TO PREVENT WATER DAMAGE CAUSED
BY LEAKS.
THE COMBUSTION PRODUCTS AND MOISTURE IN
THE FLUE GASES WILL CONDENSE. THE
CONDENSATE MAY FREEZE ON THE EXTERIOR WALL
AND SURROUNDING SURFACES. SOME
DISCOLORATION OR ETCHING IS TO BE EXPECTED.

IO-231 6/03
7
THE VENT AND COMBUSTION AIR SUPPLY PIPES
MUST BE INSPECTED ANNUALLY.
Visually check the vent terminal and combustion air supply
pipe screens, clean if necessary. Visually check for
blockage of the condensate disposal system. Hoses may
be disconnected to determine that proper flow is
maintained. Should an obstruction be observed, it can be
dislodged by forcing a stream of water through it using a
device such as a garden hose.
Materials and procedures must conform to the ASTM
Standards.
Pipe and Fittings ASTM 1785, D2465 and D2266
PVC Primer and Solvent Cement ASTM D2564
Procedure for Cementing Joints ASTM D2855 (ref.) This
appliance may be vertically or horizontally vented.
HORIZONTAL THROUGH THE WALL
VENTING
This appliance may be horizontally vented through an
exterior wall following the applicable instructions in the
“VENTING” section in conjunction with these additional
requirements.
ALL HORIZONTAL VENT INSTALLATIONS MUST BE
MADE IN ACCORDANCE WITH THESE
INSTRUCTIONS.
When selecting which exterior wall to penetrate, the
following items should be taken into consideration:
1. Layout the combustion air and vent system to avoid
the possibility of interference with beams, poles, posts,
electrical wiring, plumbing, etc.
2. When possible the combustion air and vent
termination should not be subjected to prevailing
winds.
3. The combustion air intake and vent termination must
be located at least twelve (12) inches above expected
snowfall. Consideration should be made to past
unusual snowfalls.
•DO NOT locate the terminal less than seven (7)
feet above public walkways. This applies to steps
and stairwells.
•DO NOT locate the termination areas where
condensate may present a problem such as
flowerbeds, patios, etc.
•DO NOT locate within four (4) feet of a gas meter,
electric meter, or gas regulator; (3) feet in Canada
•DO NOT locate the vent terminal within four (4)
feet of an adjacent building.
•DIRECT VENT INSTALLATION - DO NOT locate
the vent terminal within twelve (12) inches of an
operable window or door.
•NON-DIRECT VENT INSTALLATION - DO NOT
locate the vent terminal less than (12) inches
above a door or operable window.
•NON-DIRECT VENT INSTALLATION - DO NOT
locate the vent terminal less than (4) feet below or
(4) feet horizontally from any door, window or gravity
air inlet into any building.
•DO NOT locate the vent terminal less than three
(3) feet above, or (10) feet horizontally from, a
forced air inlet into any building, other than the
combustion air supply pipe.
•DO NOT locate the vent terminal within three (3)
feet of an inside corner of a building or structure.
Minor corners created by fireplace chimneys are
excluded from this requirement.
To protect the exterior surface from staining due to the
condensate, an aluminum plate or similar material may be
nstalled surrounding the termination. This plate should
extend approximately two (2) feet from the termination.
SUPPORTING AND PITCHING THE VENT AND
COMBUSTION AIR SUPPLY PIPE.
All horizontal runs must be supported at least every five (5)
feet and at joints with straps or hangers. No sags or dips
are permitted. The pipes must be saddles supported only.
Do not secure the hangers or straps tightly to the pipes to
allow for expansion and contraction of the vent pipe. Maintain
a 1/4 “ per foot minimum pitch upward on the horizontal
vent pipe from the drain to the terminal. This will allow the
condensate to flow into the drain system and not out the
terminal. Vertical runs must be supported minimum of every
six- (6) feet.
The combustion air supply pipe should be pitched slightly
downward at the inlet to prevent water from entering the
pipe.
VENT
COMB.
AIR
12"
MIN
12"/2" DIA.
14"/3" DIA.
GAS
WATER
HEATER
ALTERNATE
INSTALLATION COMB. AIR
VENT
WARNING
THE AREA SURROUNDING THE VENT TERMINAL AND
COMBUSTION AIR SUPPLY PIPE MUST BE KEPT FREE OF
SNOW, TRASH, BUSHES OR ANY OTHER OBSTACLE WHICH
COULD CAUSE CARBON MONOXIDE TO ENTER THE
BUILDING.

IO-231 6/03
8
VENT TERMINATION
When the horizontal vent option is used the vent pipe is to
be terminated with a “Tee” fitting. A debris screen (packaged
with the furnace) may be installed on each open end of the
termination tee.
When vertically vented no termination fitting is required.
However, if a debris screen is used a coupling is to be
attached to the end of the vent pipe. The debris screen is
to be glued into the coupling.
JOINING PIPE AND FITTINGS
Proper installation of the vent/combustion air system is
critical to safe operation of this product. Carefully read and
understand the instructions in this section. Do not connect
to an existing vent or chimney.
Provisions are made for the connection of outside
combustion air to the furnace casing. This connector may
be moved to the opposite side of the furnace by removing
the screws securing the collar, removing the large plug on
the side of the furnace and reconnecting both.
The plastic plugs must be in place when installed as a
direct vent unit.
When utilizing indoor air for combustion in unconfined
spaces, it is not necessary to connect any pipe to the collar.
It is recommended that the plug is removed and both sides
used for supplying combustion air.
When installed in the horizontal position in unconfined
spaces, a short length of pipe, a coupling and the screen
must be in place, facing up or the air may be obtained
from the bottom of the unit providing there is at least 4" of
unobstructed space. It is recommended that the plug is
removed and the combustion air supply is obtained from
both openings.
A pitch of 1/4" per foot toward the drain assembly is
recommended for proper drainage.
The GMNTE series of gas furnace is a condensing type
appliance. The products of combustion are recirculated
through a secondary coil. During this process the flue
products are brought to a temperature below dew point.
Thus the moisture present in the flue products condense,
leaving a liquid by-product. This by-product must be
removed from the furnace and it’s collection system. In
addition, the vent temperatures are also considerably lower
than conventional furnaces. This allows the use of low
temperature plastic as the vent system. The recommended
material is schedule 40 PVC, DWV, ABS (or equivalent if
allowed by local code).
See previous chart for proper sizing. The drain trap and
related parts must be installed as shown in the illustrations
located elsewhere in these instructions. Failure to follow
these instructions can cause products of combustion
including CARBON MONOXIDE to enter the building. This
appliance may be horizontally vented through an exterior
wall. See the illustrations located elsewhere in this manual.
IF THIS FURNACE IS INSTALLED ABOVE AN OCCUPIED
OR SIMILAR AREA WHERE CONDENSATE OVERFLOW
MAY BE A PROBLEM AN AUXILIARY DRAIN PAN MUST
BE INSTALLED UNDER THE FURNACE WITH THE
AUXILIARY DRAIN LINES ROUTED TO THE
OUTDOORS TO PREVENT WATER DAMAGE CAUSED
BY LEAKS.
This appliance may be vertically or horizontally vented.
Horizontal venting requires a Tee fitting be installed as the
vent terminal. This tee must be located no less than 12"
above grade or expected snow levels. To prevent damage
to the vent pipe and its terminal the distance from the
terminal to the exiting wall is to be the minimum practical
distance (within 12" would be acceptable). Vertical venting
does not require a terminal. If desired, the vent may be
faced downward to prevent water or other foreign objects
from entering the vent pipe. In that case two long radius
elbows may be employed, facing downward and
terminating no less than one foot (1’) from the roof surface
or expected snow level.
Protection From Freezing
The vent pipe and drain assembly must be properly
protected from freezing particularly if it is installed in an
UNHEATED SPACE. Low wattage tape heaters should be
employed on the drain system. The vent pipe should be
insulated using a one (1) inch thick closed foam insulation
if exposed to the outdoors. For pipes located indoors or
protected from the elements such as a garage, basement,
etc. fiberglass with an R value of 7 or greater is acceptable.
CONSULT LOCAL CODES FOR SPECIAL ADDITIONAL
REQUIREMENT.
THE COMBUSTION PRODUCTS IN THE FLUE GASES
WILL CONDENSE. THE CONDENSATE MAY FREEZE
ON THE EXTERIOR WALL AND SURROUNDING
SURFACES.
SOME DISCOLORATION OR ETCHING IS TO BE
EXPECTED.
CAUTION
DO NOT install the vent pipe in the same chase with the vent
from another fuel burning appliance, except with a GMN,
GMPN, GSUS, GSU, GSM, GSMS or another GMNT furnace
manufactured by GOODMAN.
DO NOT install the vent pipe within six (6) inches of another
fuel burning appliance.
The drain trap must be easily accessible for checking and/or
cleaning. It must be mounted as shown elsewhere in these
instructions.
DO NOT install the trap higher than the venter blower outlet.
DO NOT install this appliance in any area where freezing
may occur without properly protecting the drain assembly.
DO NOT terminate the vent under a deck, overhang or in a
positive pressure area. The recirculation of vent products
may occur.

IO-231 6/03
9
CONDENSATE DRAIN
This furnace is designed to remove both sensible and latent
heat from the combustion products. As a result water vapor
is condensed in the secondary heat exchanger. This
condensate must be drained either to the outdoors or, where
local code permits, to a sewage system.
In areas where floor level drains are not available a
condensate pump may be employed. This condensate
pump must be constructed of corrosion resistant materials.
It must also have an auxiliary switch that will shut down the
furnace in the event of a pump failure or drain tube
blockage.
DRAIN CONNECTIONS
HORIZONTAL
RIGHT SIDE
AIR
FLOW
HORIZONTAL
LEFT SIDE
AIR
FLOW
DO NOT run the condensate drain to an outdoor drain or to
an unheated area where the possibility of freezing may
occur.
Note: Some locals require the condensate to be
neutralized. Check local codes.

IO-231 6/03
10
DRAIN CONNECTIONS
UPFLOW
LEFT
DOWNFLOW
LEFT SIDE
DOWNFLOW
RIGHT SIDE
UPFLOW
RIGHT SIDE