Install Instructions

25
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 indi-
cated kits must be used to insure safe and proper furnace op-
eration. All conversions must be performed by a qualified in-
staller, or service agency.
The high altitude,kit will provide the proper design certified in-
put 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 pres-
sure will prohibit the burner orifice from drawing the proper
amount of air into the burner. This may cause incomplete com-
bustion, 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 deter-
mined 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
P OSSIBLE PROPERTY DAMAGE , PERSONAL INJURY OR DEATH MAY
OCCUR IF THE CORRECT CONVERSION KITS ARE NOT INSTALLED . T HE
APPROPRIATE KITS MUST BE APPLIED TO ENSURE SAFE AND PROPER
FURNACE OPERATION . A LL 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 ap-
propriate 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.
GAS VALVE
This unit is equipped with a 24 volt gas valve controlled during
furnace operation by the integrated control module. As shipped,
the valve is configured for natural gas. The valve is field con-
vertible for use with propane gas by replacing the regulator spring
with a propane gas spring from an appropriate manufacturer’s
propane gas conversion kit. Taps for measuring the gas supply
pressure and manifold pressure are provided on the valve.
The gas valve has a manual ON/OFF control located on the valve
itself. This control may be set only to the “ON” or “OFF” posi-
tion. Refer to the lighting instructions label or Startup Procedure
& Adjustment for use of this control during start up and shut
down periods.
T O AVOID POSSIBLE UNSATISFACTORY OPERATION OF EQUIPMENT
DAMAGE DUE TO UNDERFIRING OR EQUIPMENT , USE THE PROPER SIZE
OF NATURAL / PROPANE GAS PIPING NEEDED WHEN RUNNING PIPE FROM
THE METER / TANK TO THE FURNACE .
WARNING
GAS PIPING CONNECTIONS
½
”
¾
”
1
”
1¼” 1 ½”
10 132 278 520 1050 1600
20 92 190 350 730 1100
30 73 152 285 590 980
40 63 130 245 500 760
50 56 115 215 440 670
60 50 105 195 400 610
70 46 96 180 370 560
80 43 90 170 350 530
90 40 84 160 320 490
100 38 79 150 305 460
CFH = BTUH Furnace Input _______
_
_________
Heating Value of Gas (BTU/Cubic Foot)
Natural Gas Capacity of Pipe
In Cubic Feet of Gas Per Hour (CFH)
Nominal Black Pipe Size
Length of
Pipe in Feet
(Pressure 0.5 psig or less and pressure drop of 0.3" W.C.; Based on
0.60 Specific gravity Gas)
The gas piping supplying the furnace must be properly sized based
on the gas flow required, specific gravity of the gas, and length
of the run. The gas line installation must comply with local codes,
or in their absence, with the latest edition of the National Fuel
Gas Code, NFPA 54/ANSI Z223.1 or CAN/CSA B149.1-15.
To connect the furnace to the building’s gas piping, the installer
must supply a ground joint union, drip leg, manual shutoff valve,
and line and fittings to connect to gas valve. In some cases, the
installer may also need to supply a transition piece from 1/2"
pipe to a larger pipe size.
The following stipulations apply when connecting gas piping. Re-
fer to Gas Piping Connections figure for typical gas line connec-
tions to the furnace.
• Gas piping must be supported external to the furnace
cabinet so that the weight of the gas line does not
distort the burner rack, manifold or gas valve.
• Use black iron or steel pipe and fittings for building
piping. Where possible, use new pipe that is properly
chamfered, reamed, and free of burrs and chips. If old
pipe is used, be sure it is clean and free of rust, scale,
burrs, chips, and old pipe joint compound.