15
!
WARNING:
FIRE OR EXPLOSION HAZARD
Failure to follow the safety warnings exactly
could result in serious injury, death or
property damage.
Never test for gas leaks with an open
flame. Use a commercially available soap
solution made specifically for the detection
of leaks to check all connections. A fire or
explosion may result causing property
damage, personal injury or loss of life.
Conversion
Conversion of this furnace to use LP/propane
gas must be made by qualified service
personnel, using only approved parts.
!
WARNING:
This furnace was equipped at the factory
for use with natural gas only. A special
kit, supplied by the manufacturer, is
required to convert the furnace to operate
on LP/propane gas. Failure to use the
proper conversion kit can cause fire,
explosion, property damage, carbon
monoxide poisoning, personal injury, or
death.
HIGH ALTITUDE CONVERSION
High Altitude Application
Conversion of this furnace to replace the pressure
switch or to utilize LP/propane gas must be made
by qualified service personnel, using factory
authorized or approved parts. High altitude
application with this furnace can be field performed
by a simple adjustment of manifold pressure, and
if necessary changing the orifices and the pressure
switch. The changes required depend on the
installation altitude and the heating value of the
gas. The gas heating value based on sea level can
be obtained from your local gas utility. The heating
value of gas at high altitude is always lower than
the sea level heating value. The heating values
used in Tables 5 & 6 are based on sea level values.
Pressure Switch Conversion for High
Altitude Applications
The pressure switch is factory equipped to oper-
ate between zero and 5000 feet above sea level.
For higher altitude applications, you may need to
replace the pressure switch. The approved high
altitude pressure switch kit is 903853. The
directions to convert the furnace are given below:
1. READ ALL INSTRUCTIONS BEFORE
PROCEEDING WITH THE CONVERSION.
2. Disconnect all electrical power to the
furnace.
3. Remove the access door(s) from the front
of the unit.
4. Turn the gas valve knob to the OFF position.
5. Shut off the gas to the unit.
6. Disconnect the electrical leads to the
pressure switch (see Figure 14). It is not
necessary to mark the leads as polarity
does not matter across the switch.
7. Remove the hose from the pressure switch
and remove the fasteners that secure the
pressure switch to the burner box.
8. Discard the old pressure switch.
9. From the kit, install the new high altitude
pressure switch using the same fasteners
that were removed above.
10. Reattach the hose to the pressure switch
port in the same manner as it was removed.
11. Reattach the electrical leads to the
pressure switch.
12. Turn on the electrical power to the furnace.
13. Turn the gas valve knob to the ON position.
14. Follow the start-up procedure outlined later
in these installation instructions. Verify that
the furnace is operating properly after the
conversion.
Natural Gas High Altitude Conversion
All factory shipped furnaces are ready to operate
up to 4999 ft. above sea level. For higher
altitudes (between 5000 and 10,000 ft. above
sea level), conversion can be achieved simply
by adjusting the furnace manifold pressure as
shown in Table 5.
LP/Propane Gas Sea Level and High
Altitude Conversion
IMPORTANT NOTE:
When converting a low NOx Furnace from
Natural gas to LP/Propane gas, it is necessary
to remove the NOx Baffles.
Conversion to LP/propane gas can be
accomplished by first replacing the natural gas
orifices with the appropriate LP/propane orifices
shown in Table 7 or 8. Note: for installations
between zero and 5000 ft., refer to Table 7. For
installations above 5000 ft. above sea level,
refer to Table 8. After changing the orifices, use
Table 6 to determine the appropriate manifold
pressure for your installation.
