4
PRODUCT DESIGN
Notes:
1. Category I Venting is venting at a non-positive pressure.
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
products of combustion through a heat exchanger allowing,
in some instances, common venting with natural draft
appliances (i.e. water heaters).
All installations must be vented in accordance 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:
The vertical height of the Category I venting system
must be at least as great as the horizontal length of the
venting system.
2. Line voltage wiring can enter through the right or left side
of the furnace. Low voltage wiring can enter through the
right or left side of furnace.
3. Conversion kits for propane gas and high altitude natural
and propane gas operation are available. See High Alti-
tude Derate chart for details.
Accessibility Clearances (Minimum)
Unobstructed front clearance of 24"
for servicing
is recom-
mended.
Note:
In all cases accessibility clearance shall take prece-
dence over clearances from the enclosure where accessibil-
ity clearances are greater. All dimensions are given in inches.
General Operation
Models covered by this manual come with a new 4-wire com-
municating PCB. When paired with a compatible communi-
cating indoor unit and a CTK01AA communicating thermo-
stat, these models can support 4-wire communication pro-
tocol and provide more troubleshooting information. These
models are also backward compatible with the legacy ther-
mostat wiring.
The ADVC8, AMVC8, and GMVC8 furnaces are equipped
with an electronic ignition device to light the burners and an
induced draft blower to exhaust combustion products.
An interlock switch prevents furnace operation if the blower
door is not in place. Keep the blower access doors in place
except for inspection and maintenance.
These furnaces are also equipped with a self-diagnosing elec-
tronic control module. In the event a furnace component is
not operating properly, the control module's dual 7-segment
LED's will display an alpha-numeric code, depending upon
the problem encountered. These LED's may be viewed
through the observation window in the blower access door.
Refer to the
Troubleshooting Chart
for further explanation of
the LED codes and
Abnormal Operation - Integrated Igni-
tion Control
section in the Service Instructions for an expla-
nation of the possible problem.
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 Con-
tractors of America.
*Obtain from: American National Standards Institute 1430
Broadway New York, NY 10018
Location Considerations
•
The furnace should be as centralized as is practical
with respect to the air distribution system.
•
Do not install the furnace directly on carpeting, tile, or
combustible material other than wood flooring.
•
When suspending the furnace from rafters or joists,
use 3/8" threaded rod and 2” x 2” x 1/8” angle as
shown in the Installation and Service Instructions. The
length of the rod will depend on the application and
clearance necessary.
•
When installed in a residential garage, the furnace
must be positioned so the burners and ignition source
are located not less than 18 inches (457 mm) above
the floor and protected from physical damage by ve-
hicles.
WARNING
T
O PREVENT POSSIBLE PERSONAL INJURY OR DEATH DUE TO ASPHYXIATION,
THIS FURNACE MUST BE
C
ATEGORY
I
VENTED.
D
O NOT VENT USING
C
ATEGORY
III
VENTING.
SW
B
1
0
3
6
1
1
* 24" clearance for serviceability recommended.
MINIMUM CLEARANCE TO COMBUSTIBLE MATERIALS - INCHES
** Single Wall Vent (SW) to be used only as a conncetor.
Refer to the venting tables outlined in the Installation Manual for
additional venting requirements.
Vent
Sides
Top
Rear
Front*
