GC9S96 Service Manual
SYSTEM OPERATION
18
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.
Inlet gas supply pressures must be maintained within the
-
-
ances operating. The minimum gas supply pressure must
be maintained to prevent unreliable ignition. The maximum
Natural Gas Minimum: 4.5" w.c. Maximum: 10.0" w.c.
Propane Gas Minimum: 11.0" w.c. Maximum: 13.0" w.c.
When this furnace is installed at high altitude, the appropri-
due to the natural reduction in the density of both the gas
fuel and combustion air as altitude increases. The kit will
-
High altitude kits are purchased according to the installation
altitude and usage of either natural or propane gas. Refer
this Manual for a tabular listing of appropriate altitude rang-
es and corresponding manufacturer’s high altitude (Natural,
Propane gas, and/or Pressure Switch) kits.
Do not derate the furnace by adjusting the manifold pressure
The combination of the lower air density and a lower manifold
-
er amount of air into the burner. This may cause incomplete
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
regardless of the BTU/ft
3
content of the fuel used. Refer to
tabular listing of appropriate altitude ranges and correspond-
ing manufacturer’s pressure switch kits.
WARNING
-
ufacturer’s propane gas conversion kit, must be applied for
propane gas installations.
**9S9* 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.
the appropriate propane gas conversion kit. Taps for mea-
suring 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” position. Refer to the Lighting Instructions Label
or the “Putting the Furnace Into Operation” section of this
manual or the installation instructions for use of this control
during start up and shut down periods.