506305-01
Page 29 of 36
Issue 0938
High Altitude
In both the United States and Canada, this furnace is approved
for operation at altitudes from 0 to 4500 feet above sea level
without any required modifications. From 4500 to 7500 feet,
the gas manifold pressure needs to be adjusted according to
the information shown in Table 4 on page 29.
To adjust the manifold pressure, refer to previous section
Checking and Adjusting Gas Input.
For installations above
7500 feet, refer to the latest issue of the National Fuel Gas
Code and/or contact Technical Service at 1-800-448-5872.
For installations above 4500 feet, fill in the appropiate
information on the furnace label that has the words
“This
furnace was converted on.......”.
For installation above 4,000 ft refer to section
Vent Pipe
Size and Length
on page 7 and Figure 4 on page 8 vent
pipe sizing.
Manifold Pressure vs. Altitude
* Consult local utility for actual heating value.
Furnace Input = Input Factor x Nameplate Input
Above 7500 feet, refer to the National Fuel Gas Code and/or
contact Technical Service at 1-800-448-5872.
Table 4
