INSTALLATION CONSIDERATIONS
22
Insert flange. Cut 2 ½” long.
R 000142
F
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 con
-
version kits required for alternate fuels and/or high altitude.
CAUTION
T
O 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.
Inlet gas supply pressures must be maintained within the
ranges specified below. The supply pressure must be constant
and available with all other household gas fired appliances
operating. The minimum gas supply pressure must be main
-
tained to prevent unreliable ignition. The maximum must not
be exceeded to prevent unit overfiring.
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
HIGH ALTITUDE DERATE
When this furnace is installed at high altitude, the appropriate
High Altitude orifice kit must be applied. This is required due
to the natural reduction in the density of both the gas fuel and
combustion air as altitude increases. The kit will provide the
proper design certified input rate within the specified altitude
range.
High altitude kits are purchased according to the installation
altitude and usage of either natural or propane gas. Refer
to the product Specification Sheet or Technical Manual for a
tabular listing of appropriate altitude ranges and corresponding
manufacturer’s high altitude (Natural, Propane gas, and/or
Pressure Switch) kits.
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 prop
-
er 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, and information provided by the gas supplier
to determine the proper orifice size.
A different pressure switch may be required at high altitude
regardless of the BTU/ft
3
content of the fuel used. Refer to the
product Specification Sheet or Technical Manual for a tabular
listing of appropriate altitude ranges and corresponding man
-
ufacturer’s pressure switch kits.
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 INSURE 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 man
-
ufacturer’s propane gas conversion kit, must be applied for
propane gas installations.
DM92SE models using a White-Rodgers 36J22 single stage
valve use LPM-07 LP Conversion Kit.
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 convertible for use with propane gas by using the
appropriate propane gas conversion kit. Taps for measuring
the gas supply pressure and manifold pressure are provided
on the valve.
NOTE: The gas supply pressure on White-Rodgers "J"
model gas valve, used on single stage furnaces, can be
checked with a gas pressure test kit (Part #0151K00000S)
available through our authorized distributors.
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”
position. Refer to the
Lighting Instructions Label
or the
“Put-
ting the Furnace Into Operation”
section of this manual or the
installation instructions for use of this control during start up
and shut down periods.
GAS PIPING CONNECTIONS
CAUTION
T
O AVOID POSSIBLE UNSATISFACTORY OPERATION OR EQUIPMENT DAMAGE
DUE TO UNDERFIRING OF EQUIPMENT, USE THE PROPER SIZE OF
NATURAL/PROPANE GAS PIPING NEEDED WHEN RUNNING PIPE FROM THE
METER/TANK TO THE FURNACE.
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.