American Water Heater American Water Heaters Residential Gas Water Heater Manuale Utente

23

With the route of the venting system and selection of materials completed, 

as discussed in the section of this manual titled PLANNING THE VENT 

SYSTEM, the through the wall vent terminal in place and the first section

of piping, up to first elbow, installed at the blower it is time to complete the

installation of the venting system for the sidewall installation.

It is recommended that the completion of the venting system start 

at the blower assembly and run to the coupling on the inside wall 

of the vent terminal, Figure18.
The vent system piping should be supported every 5 feet (1.5 m) 

of vertical run and every 3 feet (91 cm) of horizontal run. Follow vent

pipe manufacturer’s instructions for proper joining procedures.
If  necessary  to  achieve  the  12”  minimum  clearance  above

the highest anticipated snow level, install a snorkel as shown 

in bottom portion of Figure 20.
note:  With the installation of a snorkel it is necessary to 

use two 90° elbows that shall be considered along with the

additional vent pipe when calculating maximum equivalent 

feet of venting.

A  proper  flashing  or  “BOOT”  should  be  used  to  seal  the

pipe where it exits the roof. The total vent system should 

not exceed the  equivalent feet of pipe as listed in Table 2.

Provide support for all pipe protruding through the roof. All piping should 

be properly secured. The vent system piping should be supported  

every 5 feet (1.5 m) of vertical run and every 3 feet (91 cm) of

horizontal run. Follow vent pipe manufacturer’s instructions for proper  

joining procedures.

The vent system must terminate so that proper clearances 

are maintained as cited in local codes or the current edition 

of the National Fuel Gas Code (ANSI Z223.1) or the Natural

Gas and Propane Installation Code (CAN/CSA-B149.1) and as  

listed below:

1.  Vent Termination must extend a minimum of 12 inches (30 cm)

above roof or 12 inches (30 cm) above the anticipated snow level

to prevent blockage of the vent termination, as shown in Figures 

20 and 21.