User Guide

507716-01 Page 47 of 58Issue 1717
High Altitude Information
NOTE: In Canada, certication for installations at elevations over 4500 feet (1371 m) is the jurisdiction of local authorities.
Units may be installed at altitudes up to 10,000 ft. above sea level. See Table 11 for de-rate manifold values. Units installed
at altitude of 7501 - 10,000 feet require an orice change. Units installed at altitudes of 4,501 - 10,000 feet (1371 -3048 m)
may require a pressure switch change which can be ordered separately.
Table 12 lists required pressure switch changes and orice conversion kits at varying altitudes.
The combustion air pressure switches are factory set and require no adjustment.
Table 12.
Burner Orice Conversion Kits at Varying Altitudes
Capacity
0-7,500 ft
(0-2,286m)
7,501 - 10,000 ft
(2,286 - 3,048 m)
Natural to LP/
Propane
LP/Propane to
Natural
High Altitude
Natural Burner
Orice Kit
High Altitude LP/
Propane Burner
Orice Kit
045
11K50+ 73W80* 51W01 11K45+
070
090
110
135
* Conversion requires installation of a gas valve regulator spring which is provided with the gas conversion
kit.
+ LP Kits include low line pressure switch.
GUH95C Pressure Switch Requirements at Varying Altitudes
Capacity
0 - 4500 ft
(0 - 1,371m)
4501 - 7500 ft
(1371 - 2286m)
7501 - 10000 ft
(2286 - 3048m)
045 No Change No Change 11J09
070 No Change 11J12 10U93
090 No Change 11J11 10U93
110 No Change 11J12 10U93
135 No Change 11J11 10U93
Pressure switch is factory set. No adjustment necessary. All models use the factory-installed pressure switch
from 0-4500 feet (0-1371 m).