506528-01
Page 12 of 37
Issue 1035
These series units are classified as fan assisted Category I
furnaces when vertically vented according to the latest edition
of National Fuel Gas Code (NFPA 54 / ANSI Z223.1) in the
USA. A fan assisted Category I furnace is an appliance
equipped with an integral mechanical means to either draw
or force combustion products through the combustion
chamber and/or heat exchanger. This unit is not approved
for use with horizontal venting.
NOTE:
Use these instructions as a guide. They do not
supersede local codes. This furnace must be vented
according to all local codes these installation instructions,
and the provided venting tables in these instructions.
The venting tables in this manual were extracted from the
National Fuel Gas Code (NFPA 54 / ANSI Z223.1) and are
provided as a guide for proper vent installation. Proper
application, termination, construction and location of vents
must conform to local codes having jurisdiction. In the
absence of local codes, the NFGC serves as the defining
document.
Refer to the tables and the venting information contained in
these instructions to properly size and install the venting
system.
Venting
A 4 inch diameter flue transition is factory installed on the
combustion air inducer outlet of all models.
The unit will not vent properly with the flue transition pointed
down in the 6 o’clock position.
The combustion air inducer may be rotated clockwise or
counterclockwise by 90° to allow for top or side vent
discharge in all applications. When the unit is installed,
the flue transition must be in the 9 o’clock, 12 o’clock or 6
o’clock position.
IMPORTANT
Filters
This unit is not equipped with a filter or rack. A field provided
high velocity filter is required for the unit to operate properly.
A filter must be in place any time the unit is operating.
Duct System
Use industry approved standards (such as those published
by Air Conditioning Contractors of America or American
Society of Heating, Refrigerating and Air Conditioning
Engineers) to size and install the supply and return air duct
system. This will result in a quiet and low static system that
has uniform air distribution.
NOTE:
Do not operate the furnace in the heating mode
with an external static pressure that exceeds 0.8 inches w.c.
Higher external static pressures may cause erratic limit
operation.
Supply Air Plenum
If the furnace is installed without a cooling coil, a removable
access panel must be installed in the supply air duct. The
access panel should be large enough to permit inspection
(either by smoke or reflected light) of the heat exchanger
for leaks after the furnace is installed. The furnace access
panel must always be in place when the furnace is operating
and it must not allow leaks into the supply air duct system.
Return Air Plenum
NOTE:
Return air must not be drawn from a room where
this furnace, or any other gas fueled appliance (i.e., water
heater), or carbon monoxide producing device (i.e., wood
fireplace) is installed.
When return air is drawn from a room, a negative pressure
is created in the room. If a gas appliance is operating in a
room with negative pressure, the flue products can be pulled
back down the vent pipe and into the room. This reverse
flow of the flue gas may result in incomplete combustion
and the formation of carbon monoxide gas. This toxic gas
might then be distributed throughout the house by the furnace
duct system.
Once the venting system is installed, attach the
“Disconnected Vent” warning sticker to a visible area of
the plenum near the vent pipe. See Figure 15. The
warning sticker is provided in the bag assembly. Order
kit 66W04 for additional stickers.
IMPORTANT
