25
INSTALLATION EXAMPLE
Elevation:
................................................... 5,000 feet
Type of Gas:
............................................Natural Gas
Local Heating Value of Gas:
...............................750
Determine which natural gas table to use. From Table
11, fi nd 750 and follow down the column, stop at the
5,000 feet row. The heating value listed is LOW. Table
13 will be used to determine orifi ce size and manifold
pressure.
pressure and orifi ce sizes to use at various altitudes. Table
13 (HIGH) is for natural gas installations with a heating
value of more than 1,000 Btu per cubic foot and Table
14 (LOW) is for less than 1,000 Btu per cubic foot. To
determine which table to use:
1. Consult the local utility for the local heating value at
your installation site.
2. From Table 12 (page 41), fi nd your local heating value
as supplied by the utility company. Follow down the
column and stop at your altitude level.
3. If your sea level heating value is HIGH, use Table 13
or if it’s LOW, use Table 14. See example.
After changing the regulator pressure or the orifi ces, it is
required that you measure the gas input rate. This may be
accomplished in the usual way, by clocking the gas meter
and using the local gas heating value. See Verifying and
Adjusting the Input Rate (page 31).
IMPORTANT NOTE: Observe the action of the burners
to make sure there is no yellowing, lifting or fl ashback
of the fl ame.
Conversion to LP/Propane
WARNING:
This furnace was shipped from the factory
equipped to operate on natural gas. Conversion
to LP/propane gas must be performed by
qualified service personnel using factory
supplied conversion parts. Failure to use the
proper conversion kit can cause fi re, explosion,
property damage, carbon monoxide poisoning,
personal injury, or death.
This furnace can be converted from factory-equipped
natural gas to Liquid Propane gas. Conversion of this
valve requires replacement of the burner orifi ces on the
manifold assembly. The orifi ces required for conversion
are supplied with the furnace.
For altitudes between 0 and 1,999 feet, only the orifi ce is
changed. Altitudes between 2,000 and 10,000 feet require
both the orifi ce and regulator pressure to be changed.
See Table 11 (page 41) to determine the correct orifi ce
size and manifold pressure to use at different altitudes.
WARNING:
Shut off the gas supply at the manual gas shutoff
valve, before disconnecting the electrical power.
A fi re or explosion may result causing property
damage, personal injury or loss of life. Failure to
follow the safety warnings exactly could result
in serious injury, death or property damage.
WARNING:
To avoid electric shock, personal injury, or death,
turn off the electric power at the disconnect
or the main service panel before making any
electrical connections.
1. Remove the burner orifi ces (Figure 34):
a. Adjust the thermostat to the “OFF” position, or its
lowest temperature setting.
b. Turn the main gas supply valve (on the outside of
the unit) to the OFF position.
c. Turn off all electrical power to the furnace.
d. Remove the door from the burner compartment.
e. Turn the gas valve ON/OFF knob (1) to the OFF
position.
Figure 34. Burner and Manifold Assembly
3
2
1
7
5
4
6
CAUTION:
It is good practice to label all wires prior
to disconnection. Wiring errors can cause
improper and dangerous operation.
f. Disconnect the wires from the terminals (2).
g. Remove the supply gas piping from the gas valve
inlet (3).
