4
PRODUCT DESIGN
Notes:
1.CategoryIVentingisventingatanon-positivepressure.
A furnace vented as Category I is considered a fan-as-
sisted appliance and the vent system does not have to
be “gas tight.”
NOTE: Gas furnaces with induced draft blowers draw
productsof combustion throughaheat exchanger allowing,
in some instances, common venting with natural draft
appliances(i.e. water heaters).
Allinstallations must beventedinaccordance with National
Fuel Gas Code NFPA 54/ANSI Z223.1 - latest edition. In
Canada, the furnaces must be vented in accordance with
the National Standard of Canada, CAN/CSA B149.1 and
CAN/CSA B149.2 - latest editions and amendments.
NOTE: Thevertical height of the Category Iventingsystem
must be at least as great as the horizontal length of the
ventingsystem.
WARNING
TO PREVENT POSSIBLE PERSONAL INJURY OR DEATH DUE TO ASPHYXIATION,
COMMON VENTING WITH OTHER MANUFACTURER'S INDUCED DRAFT APPLIANCS
IS NOT ALLOWED.
2. Linevoltage wiringcan enterthroughtherightor leftside
ofthe furnace. Low voltagewiringcan enter through the
rightorleftsideoffurnace.
3. Conversionkits forhigh altitude natural or propane gas
operation are available. See High Altitude Derate chart
fordetails.
4. Installer must supply the following gas line fittings, de-
pendingonwhichentranceisused:
Left -- Two 90º Elbows, one close nipple, straight pipe.
Right --Straight pipe to reach gas valve.
GeneralOperation
GMV8furnaces are equippedwithan electronic ignition de-
viceused to lighttheburners and aninduceddraft blower to
exhaustcombustionproducts.
Aninterlock switch prevents furnace operation iftheblower
door is not in place. Keep the blower access door in place
exceptfor inspection and maintenance. (See illustration on
page6.)
This furnace is also equipped with a self-diagnosing elec-
tronic control module. In the event a furnace component is
notoperating properly,the controlmoduleLED will flash on
and off in a factory-programmed sequence, depending on
theproblem encountered. This light can be viewed through
theobservation window in the blower accessdoor.Refer to
theTroubleshootingChart forfurther explanationof theLED
codesand AbnormalOperation- Integrated IgnitionControl
section in the Service Instructions for an explanation of the
possibleproblem.
Therated heating capacity ofthefurnaceshould be greater
thanorequaltothetotalheatlossoftheareatobeheated.
The total heat loss should be calculated by an approved
methodor in accordance with “ASHRAEGuide”or “Manual
J-LoadCalculations” publishedby theAirConditioningCon-
tractors of America.
*Obtain from: American National Standards Institute 1430
BroadwayNew York, NY 10018
LocationConsiderations
• The furnace should be as centralized as is practical
with respect to the air distribution system.
• Donot install the furnacedirectlyon carpeting, tile, or
combustiblematerial other than woodflooring.
• When suspending the furnace from rafters or joists,
use 3/8" threaded rod and 2” x 2” x 3/8” angle as
showninthe Installationand ServiceInstructions. The
length of the rod will depend on the application and
clearancenecessary.
• When installed in a residential garage, the furnace
mustbe positionedso theburnersand ignitionsource
are located not less than 18 inches (457 mm) above
the floor and protected from physical damage by ve-
hicles.
WARNING
TO PREVENT POSSIBLE PERSONAL INJURY OR DEATH DUE TO ASPHYXIATION,
THIS FURNACE MUST BE CATEGORY IVENTED. DO NOT VENT USING
CATEGORY III VENTING.
