16
Installing the Water Heater
Table 2
From Sea Level through 2,000 ft. (609 m) Above Sea Level
Model
Vent &
Combustion
Air-Inlet System
Diameter
Min. Allowed
Equivalent Vent &
Combustion Air-Inlet
Lengths (Each Pipe
Run)
Max. Allowed Equivalent
Vent & Combustion Air-
Inlet Lengths (Each Pipe
Run)
Vent and Combustion Air-Inlet
System Termination(s)Inches Feet Meters Feet Meters
50 Gallon, 65,000 &
47,000 Btu/hr. Models
3 7 2 55 17 90° Elbows Concentric
4 7 2 100 30 90° Elbows
65 Gallon, 65,000 &
56,000 Btu/hr. Models
3 8 2.5 60 18 90° Elbows
3 8 2.5 50 15 Concentric
4 8 2.5 100 30 90° Elbows
75 Gallon, 75,100
&70,000 Btu/hr. Models
3 8 2.5 50 15 90° Elbows
3 8 2.5 40 12 Concentric
4 8 2.5 100 30 90° Elbows
From 2,000 Ft. (609 m) Above Sea Level through 5,999 Ft. (1,828 m) Above Sea Level
Model
Vent &
Combustion
Air-Inlet System
Diameter
Min. Allowed
Equivalent Vent &
Combustion Air-Inlet
Lengths (Each Pipe
Run)
Max. Allowed Equivalent
Vent & Combustion Air-
Inlet Lengths (Each Pipe
Run)
Vent and Combustion Air-Inlet
System Termination(s)Inches Feet Meters Feet Meters
50 Gallon, 65,000 &
47,000 Btu/hr. Models
3 7 2 55 17 90° Elbows Concentric
4 7 2 100 30 90° Elbows
65 Gallon, 65,000 &
56,000 Btu/hr. Models
3 8 3 40 12 90° Elbows
3 8 3 30 9 Concentric
4 8 3 100 30 90° Elbows
75 Gallon, 75,100 &
70,000 Btu/hr. Models
3 8 3 25 8 90° Elbows
3 8 3 20 6 Concentric
4 8 3 100 30 90° Elbows