1083286-UIM-F-1116
Johnson Controls Unitary Products
11
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.
HIGH ALTITUDE MANIFOLD PRESSURE SETTINGS
This furnace is constructed at the factory for natural gas-fired operation
at 0 – 7,999 feet (0 – 2,438 m) above sea level.
The manifold pressure 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 7,999 feet (2,438 m) above sea level. Refer to
Tables 5 and 6 for proper manifold pressure settings.
HIGH ALTITUDE PRESSURE SWITCH CONVERSION
For installation where the altitude is less than 5,000 feet (1,524m), it is
not required that the pressure switch be changed unless you are in an
area subject to low pressure inversions.
Table 5:
Nominal Manifold Pressure - High Fire
Second Stage Manifold Pressures
Second Stage Manifold Pressures
Gas Heating
Value
(BTU/cu ft.)
Altitude (feet)
Gas Heating Value
(MJ/cu m)
Altitude (m)
0-7999
8000-8999
9000-9999
0-2437
2438-2742
2743-3048
in. w.c.
in. w.c.
in. w.c.
kPa
kPa
kPa
800
3.5
3.5
3.5
29.8
0.87
0.87
0.87
850
3.5
3.5
3.5
31.7
0.87
0.87
0.87
900
3.5
3.5
3.5
33.5
0.87
0.87
0.87
950
3.5
3.5
3.3
35.4
0.87
0.87
0.81
1000
3.5
3.2
2.9
37.3
0.87
0.80
0.73
1050
3.5
2.9
2.7
39.1
0.87
0.73
0.67
1100
3.2
2.7
2.4
41.0
0.80
0.66
0.61
2500 (LP)
9.8
8.2
7.5
93.2 (LP)
2.44
2.03
1.86
TABLE 6:
Nominal Manifold Pressure - Low Fire
First Stage Manifold Pressures
First Stage Manifold Pressures
Gas Heating
Value
(BTU/cu ft.)
Altitude (feet)
Gas Heating Value
(MJ/cu m)
Altitude (m)
0-7999
8000-8999
9000-9999
0-2437
2438-2742
2743-3048
in. w.c.
in. w.c.
in. w.c.
kPa
kPa
kPa
800
1.7
1.7
1.7
29.8
0.42
0.42
0.42
850
1.7
1.7
1.7
31.7
0.42
0.42
0.42
900
1.7
1.7
1.7
33.5
0.42
0.42
0.42
950
1.7
1.7
1.5
35.4
0.42
0.42
0.38
1000
1.6
1.5
1.4
37.3
0.41
0.37
0.34
1050
1.5
1.4
1.3
39.1
0.37
0.34
0.31
1100
1.3
1.2
1.1
41.0
0.34
0.31
0.28
2500 (LP)
4.1
3.8
3.5
93.2 (LP)
1.03
0.95
0.87
DANGER
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, caus-
ing premature heat exchanger burnout, high levels of carbon monoxide, excessive sooting, a fire hazard, personal injury, property damage and/or
death.
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