035-19670-003 Rev. A (1004)
8
Unitary Products Group
IMPORTANT:
An accessible manual shutoff valve must be installed
upstream of the furnace gas controls and within 6 feet (1.8 m) of the fur-
nace.
The furnace must be isolated from the gas supply piping system by
closing its individual external manual shutoff valve during any pressure
testing of the gas supply piping system at pressures equal to or less
than 1/2 psig (3.5 kPa).
Gas piping may be connected from either side of the furnace using any
of the gas pipe entry knockouts on both sides of the furnace. Refer to
Figure 1 dimensions.
GAS ORIFICE CONVERSION FOR PROPANE (LP)
This furnace is constructed at the factory for natural gas-fired operation,
but may be converted to operate on propane (LP) gas by using a fac-
tory-supplied LP conversion kit. Follow the instructions supplied with
the LP kit. Refer to Table 7 or the instructions in the propane (LP) con-
version kit for the proper gas orifice size.
HIGH ALTITUDE GAS ORIFICE CONVERSION
This furnace is constructed at the factory for natural gas-fired operation
at 0 – 2,000 ft. (0 m – 610 m) above sea level.
The gas orifices on this furnace must be changed in order to maintain
proper and safe operation, when the furnace is installed in a location
where the altitude is greater than 2,000 ft. (610 m) above sea level on
natural gas or the altitude is greater than 4,000 ft. (1219 m) above sea
level on propane (LP) gas. Refer to Table 7 or the instructions in the
high altitude conversion kit for the proper gas orifice size.
The unit may also be converted for altitudes up to 10,000 ft. (3048 m)
on natural and propane (LP) gas with additional derate as shown in
Table 7 or refer to ANSI Z223.1 NFPA 54 National Fuel Gas Code or in
Canada CAN/CGA-B149.1-00 Natural Gas and Propane Installation
Code.
HIGH ALTITUDE PRESSURE SWITCH CONVERSION
For installation in locations where the altitude is less than 4,500 feet
(1372 m), it is not required that the pressure switch be changed. For
altitudes above 4,500 feet (137 m), refer to Instructions in the Acces-
sory High Altitude Kit.
FIGURE 7:
Upflow Gas Piping
FIGURE 8:
Horizontal Gas Piping
The gas valve body is a very thin casting that cannot take any
external pressure. Never apply a pipe wrench to the body of the gas
valve when installing piping. A wrench must be placed on the octa-
gon hub located on the gas inlet side of the valve. Placing a wrench
to the body of the gas valve will damage the valve causing improper
operation and/or the valve to leak.
EXTERNAL MANUAL
SHUTOFF VALVE
TO GAS
SUPPLY
TO GAS
SUPPLY
GROUNDED JOINT UNION
MAY BE INSTALLED
INSIDE OR OUTSIDE UNIT.
DRIP
LEG
MANUAL
SHUT-OFF
VALVE
DRIP
LEG
GAS
PIPE
GAS BURNERS
GAS VALVE
GAS
PIPE
DRIP
LEG
MANUAL
SHUT-OFF VALVE
LoNOx furnaces requiring propane (LP) gas must have the LoNOx
screens removed prior to installation and operation. See propane
instructions 035-14445-000 or the start up procedure at the back of
these instructions on proper removal of the NOx screens.
TABLE 7:
High Altitude Conversion
Type
Of Gas
Orifice at
Sea Level
2,000 ft.
(610 m)
3,000 ft.
(914 m)
4,000 ft.
(1219 m)
5,000 ft.
(1524 m)
6,000 ft.
(1829 m)
7,000 ft.
(2134 m)
8,000 ft.
(2438 m)
9,000 ft.
(2743 m)
10,000 ft.
(3048 m)
Natural
#45
#46
#47
#47
#47
#48
#48
#49
#49
#50
Propane
#55
#55
#55
#55
#56
#56
#56
#56
#56
#57
PROPANE AND HIGH ALTITUDE CONVERSION KITS
It is very important to choose the correct kit and/or gas orifices for the altitude and the type of gas for which the furnace is being installed.
Only use natural gas in furnaces designed for natural gas. Only use propane (LP) gas for furnaces that have been properly converted to use pro-
pane (LP) gas. Do not use this furnace with butane gas.
Incorrect gas orifices or a furnace that has been improperly converted will create an extremely dangerous condition resulting in premature heat
exchanger failure, excessive sooting, high levels of carbon monoxide, personal injury, property damage, a fire hazard and/or death.
High altitude and propane (LP) conversions are required in order for the appliance to satisfactory meet the application.
An authorized distributor or dealer must make all gas conversions.
In Canada, a certified conversion station or other qualified agency, using factory specified and/or approved parts, must perform the conversion.
The installer must take every precaution to insure that the furnace has been converted to the proper gas orifice size when the furnace is installed.
Do not attempt to drill out any orifices to obtain the proper orifice size. Drilling out a gas orifice will cause misalignment of the burner flames,
causing premature heat exchanger burnout, high levels of carbon monoxide, excessive sooting, a fire hazard, personal injury, property damage
and/or death.
