Installation Guide

15
At all altitudes, the manifold pressure must be within 0.3 inches
w.c. of that listed in the Specifi cation Sheet applicable to your
model for the fuel used. At all altitudes and with either fuel,
the air tempera ture rise must be within the range listed on the
furnace nameplate. Should this appliance be converted to
LP, refer to the instructions included in the factory authorized
LP conversion kit.
HIGH ALTITUDE DERATE
High altitude installations may require both a pressure switch
and an orifi ce change. These changes are necessary to com-
pensate for the natural reduction in the density of both the gas
fuel and the combustion air at higher altitude.
Clearance in accordance with local installation codes, the
requirements of the gas supplier and the manufacturer’s
installation instructions.
Dégaugement conforme aux dodes d’installation locaux, aux
exigences du fournisseur de gaz et aux instructions d’instal-
lation du fabricant.
High Stage Low Stage
Natural None
#45 3.5" w.c. 1.9" w.c. None
Propane
LPM-06 H/W
GAS VALVE
#55 10.0" w.c. 6.0" w.c. None
Propane 0-7000
LPM-08 W-R
VALVE
#55 10.0" w.c. 6.0" w.c. None
NOTE: In Canada, gas furnaces are only certified to 4500 feet.
Gas
0-7000
Manifold Pressure
Pre ssure
Switch Change
Altitude
Kit
Orifice
Consult the furnace Specifi cation Sheet for appropriate manu-
facturer’s kits for propane gas and/or high altitude installations.
The indicated kits must be used to insure safe and proper
furnace operation. All conversions must be performed by a
qualifi ed installer, or service agency.
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 confi gured for natural gas. The appropriate man-
ufacturer’s propane gas conversion kit must be applied for
propane gas installations.
If converting to LP gas, it is recommended that an LPLP0* kit
also be installed. The use of this kit will prevent the furnace
from fi ring when the LP gas supply pressure is too low to
support proper combustion.
GAS PIPING CONNECTIONS
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
When sizing gas lines, be sure to include all appliances which
will operate simultaneously.
The gas piping supplying the furnace must be properly sized
based on the gas fl ow required, specifi c 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.
Natural Gas Capacity of Pipe
In Cubic Feet of Gas Per Hour (CFH)
Length of Nominal Black Pipe Size
Pipe in Feet 1/2" 3/4" 1" 1 1/4" 1 1/2"
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
(Pressure 0.5 psig or less and pressure drop of 0.3" W.C.; Based on
0.60 Specific Gravity Gas)
CFH =
BTUH Furnace Input
Heating Value of Gas (BTU/Cubic Foot)
To connect the furnace to the building’s gas piping, the install-
er must supply a ground joint union, drip leg, manual shutoff
valve, and line and fi ttings 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.
• 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 fi ttings for the building
piping.
• Use pipe joint compound on male threads only. Pipe
joint compound must be resistant to the action of the
fuel used.
• Use ground joint unions.
• Install a drip leg to trap dirt and moisture before it can
enter the gas valve. The drip leg must be a minimum
of three inches long.
• Use two pipe wrenches when making connection to
the gas valve to keep it from turning. The orientation
of the gas valve on the manifold must be maintained
as shipped from the factory.
• Install a manual shutoff valve between the gas
meter and unit within six feet of the unit. If a union
is installed, the union must be downstream of the
manual shutoff valve, between the shutoff valve and
the furnace.
• Tighten all joints securely.
• Connect the furnace to the building piping by one of
the following methods: