SYSTEM OPERATION
20
For sizing of flexible liners, see Note 22 and the tables in the
National Fuel Gas Code NFPA 54/ANSI Z223.1 - latest edition
and in the National Standard of Canada, CAN/CGA B149.1
and CAN/CGA B149.2 - latest editions and amendments.
To install the liner, read and follow the liner manufacturer’s
instructions and your local codes. Excess liner length should
be pulled out of the chimney and cut off. Use caution when
doing this, as the cut edges of flexible liners may be sharp.
Do not spiral excess liner inside of the chimney. Support the
liner as recommended by the liner manufacturer.
Some manufacturers of flexible liners offer an insulation
sleeve designed to be added to the liner before it is installed
in the chimney. (Poured insulation, either vermiculite or
other materials, is no longer recommended.) Insulation will
need to be added to the flexible liner if:
•
It is required by the liner manufacturer’s instructions.
•
The previous liner was properly sized and installed,
and suffered from condensation damage.
•
It is required by your local building codes.
Even if none of those three conditions exist which require ad
-
ditional liner insulation, the installer may wish to consider it if:
•
The local climate is very cold.
•
The chimney is very tall.
•
The vent connectors used are very long or have a large
number of elbows.
•
Local experience indicates that flexible liners installed
without insulation are likely to have condensation
problems.
Insulation must be selected and installed in accordance with
the liner manufacturer’s instructions.
Finally, cap the chimney and terminate the liner in accor-
dance with the liner manufacturer’s instructions.
Horizontal Applications and Considerations
Horizontal applications, in particular, may dictate many of
the installation’s specifics such as airflow direction, ductwork
connections, and flue pipe connections.
Alternate Electrical and Gas Line Connections
Furnaces have provisions allowing for electrical and gas line
connections through either side panel. In horizontal applica-
tions the connections can be made either through the “top”
or “bottom” of the furnace.
Propane Gas and/or High Altitude Installations
WARNING
Possible property damage, personal injury or death may occur
if the correct conversion kits are not installed. The appro
-
priate kits must be applied to ensure safe and proper furnace
operation. All conversions must be performed by a qualified
installer or service agency.
This furnace is shipped from the factory configured for nat
-
ural gas at standard altitude. Propane gas installations re-
quire an orifice change to compensate for the energy con
-
tent difference between natural and propane gas.
High altitude installations may require both a pressure
switch and an orifice change. These changes are neces
-
sary to compensate for the natural reduction in the density
of both the gas fuel and the combustion air at higher altitude.
Refer to the
Accessories Charts
in this manual or prod-
uct Specification Sheet for a tabular listing of appropriate
manufacturer’s kits for propane gas and/or high altitude in-
stallations. The indicated kits must be used to insure safe
and proper furnace operation. All conversions must be per-
formed by a qualified installer, or service agency.
WARNING
Failure to follow these instructions can result in bodily injury
or death. Carefully read and follow all instructions given in
this section.
WARNING
Upon completion of the furnace installation, carefully inspect
the entire flue system both inside and outside the furnace
to assure it is properly sealed. Leaks in the flue system can
result in serious personal injury or death due to exposure to
flue products including carbon monoxide.
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
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.
Inlet gas supply pressures must be maintained within the
ranges specified below. The supply pressure must be con
-
stant and available with all other household gas fired appli
-
ances operating. The minimum gas supply pressure must
be maintained 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 appropri-
ate 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
