105561-UIM-B-0605
Unitary Products Group
7
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.
The inlet to the gas valve lines up directly with the opening in the left
side of the furnace casing. To line up with the opening in the right side
of the casing, two street ells should be used.
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 5 or 6 or the instructions in the propane (LP)
conversion 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 5 or 6 or the instructions in
the high altitude conversion kit or ANSI Z223.1 NFPA 54 National Fuel
Gas Code or in Canada CAN/CGA-B149.1-00 Natural Gas and Pro-
pane Installation Code for proper orifice size.
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, pro-
vided the maximum vent/intake pipe lengths are adjusted as shown in
the notes to Table 9. For altitudes above 4,500 feet (137 m), refer to
Instructions in the Accessory High Altitude Kit.
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 octag-
onal 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.
TABLE 5: High Altitude Conversion (40-120 MBTUH Models)
Type
Of Gas
Orifice at
Sea Level
2,000 ft.
(610 m)
3,000 ft.
(914 m)
4,000 ft.
(1219 m)
Natural
#45
#46
#47
#47
Propane
#55
#55
#55
#55
Type
Of Gas
5,000 ft.
(1524 m)
6,000 ft.
(1829 m)
7,000 ft.
(2134 m)
8,000 ft.
(2438 m)
Natural
#47
#48
#48
#49
Propane
#56
#56
#56
#56
Type
Of Gas
9,000 ft.
(2743 m)
10,000 ft.
(3048 m)
Natural
#49
#50
Propane
#56
#57
TABLE 6: High Altitude Conversion (135 MBTUH Models)
Type
Of Gas
Orifice at
Sea Level
2,000 ft.
(610 m)
3,000 ft.
(914 m)
4,000 ft.
(1219 m)
Natural
#44
#45
#44
#45
Propane
#54
#54
#55
#55
Type
Of Gas
5,000 ft.
(1524 m)
6,000 ft.
(1829 m)
7,000 ft.
(2134 m)
8,000 ft.
(2438 m)
Natural
#46
#47
#47
#48
Propane
#55
#55
#55
#56
Type
Of Gas
9,000 ft.
(2743 m)
10,000 ft.
(3048 m)
Natural
#48
#49
Propane
#56
#56
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 propane (LP) gas. Do not use this furnace with butane gas.
Incorrect gas orifices or a furnace that has been improperly con-
verted will create an extremely dangerous condition resulting in pre-
mature 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.
