23
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.
For installations above 7000 feet, please refer to the
furnace Specification Sheets for required kit(s).
High altitude kits are purchased according to the
installation altitude and usage of either natural or propane
gas. The indicated kits must be used to insure safe
and proper furnace operation. All conversions must be
performed by a qualified installer, or service agency.
The high altitude,kit will provide the proper design certified
input rate within the specified altitude range.
Do
not
derate the furnace by adjusting the manifold
pressure to a lower pressure than specified on the furnace
rating plate. The combination of the lower air density and a
lower manifold pressure will prohibit the burner orifice from
drawing the proper amount of air into the burner. This may
cause incomplete combustion, flashback, and possible
yellow tipping.
In some areas the gas supplier may artificially derate the
gas in an effort to compensate for the effects of altitude. If
the gas is artificially derated, the appropriate orifice size
must be determined based upon the BTU/ft
3
content of the
derated gas and the altitude. Refer to the National Fuel
Gas Code, NFPA 54/ANSI Z223.1 or CAN/CSA B149.1-15
in Canada, and information provided by the gas supplier to
determine the proper orifice size.
Propane Gas Conversion
WARNING
Possible property damage, personal injury or
death may occur if the correct conversion kits
are not installed. The appropriate kits must
be applied to ensure safe and proper furnace
opearation. All conversions must be performed
by a qualified installer or service agency.
This unit is configured for natural gas. The appropriate
manufacturer’s propane gas conversion kit, must be
applied for propane gas installations. Refer to the
Propane
Gas and/or High Altitude Installations
for details.
Consult the furnace Specification Sheet for a listing of
appropriate kits. The indicated kits must be used to insure
safe and proper furnace operation. All conversions must
be performed by a qualified installer, or service agency.
original bottom of the furnace.
16.
Using the two sheet metal screws provided in the
cabinet, secure the trap to the furnace.
17.
Refer to Field Supplied Drain section for instructions
on field supplied / installed drain on outlet of furnace
trap.
CAUTION
To prevent unreliable operation or equipment
damage, the inlet gas supply pressure must
be as specified on the unit rating plate with
all other household gas fired appliances
operating.
Natural Gas
Minimum: 4.5" w.c. Maximum: 10.0" w.c.
Propane Gas
Minimum: 11.0" w.c. Maximum: 13.0" w.c.
INLET GAS SUPPLY PRESSURE
GAS SUPPLY AND PIPING
The furnace rating plate includes the approved furnace gas
input rating and gas types. The furnace must be equipped
to operate on the type of gas applied. This includes any
conversion kits required for alternate fuels and/or high
altitude.
Inlet gas supply pressures must be maintained within
the ranges specified in the following table. The supply
pressure must be constant and available with all other
household gas fired appliances operating. The minimum
gas supply pressure must be maintained to prevent
unreliable ignition. The maximum must not be exceeded to
prevent unit overfiring.
Propane Gas/High Altitude Installations
High
Stage
Low
Stage
Natural
None
#45
3.5" w.c.
1.9" w.c.
None
Propane
LPM-08*
1
1.25mm
10.0" w.c. 6.0" w.c.
None
Gas
Altitude
Kit
Orifice
Manifold Pressure
Pressure
Switch
Change
0-7000
1
LPM-08* supports both Honeywell and White-Rodgers 2-stage valves
NOTE:
In Canada, gas furnaces are only certified to 4500 feet.
This furnace is shipped from the factory configured for
natural gas at standard altitude. Propane gas installations
require an orifice change to compensate for the energy
content difference between natural and propane gas.
For furnaces being converted to LP gas, it is strongly
recommended that a LPLP03 kit also be installed. The
use of this kit will prevent the furnace from firing when
the LP gas supply pressure is too low to support proper
combustion.
