Install Instructions

31
Installation & Service Manual
4 Vertical direct venting (continued)
Vent/air termination – vertical
Prepare roof penetrations
1. Air pipe penetration:
a. Cut a hole for the air pipe. Size the air pipe hole as
close as desired to the air pipe outside diameter.
2. Vent pipe penetration:
a. Cut a hole for the vent pipe. For either
combustible or noncombustible construction, size
the vent pipe hole with at least a 1/2 inch clearance
around the vent pipe outer diameter:
• 4½ inch hole for 3 inch vent pipe
• 5½ inch hole for 4 inch vent pipe
b. Insert a galvanized metal thimble in the vent pipe
hole.
3. Space the air and vent holes to provide the minimum
spacing shown in FIG. 4-1A, page 30.
4. Follow all local codes for isolation of vent pipe when passing
through floors, ceilings, and roofs.
5. Provide flashing and sealing boots sized for the vent pipe
and air pipe.
Multiple vent/air terminations
1. When terminating multiple Shield water heaters, terminate
each vent/air connection as described in this manual (FIG.
4-2).
Terminate all vent pipes at the same height
and all air pipes at the same height to avoid
possibility of severe personal injury, death,
or substantial property damage.
 WARNING
2. Place roof penetrations to obtain minimum clearance of
12 inches between edge of air intake elbow and adjacent
vent pipe of another water heater for U.S. installations (see
FIG. 4-2). For Canadian installations, provide clearances
required by CSA B149.1 Installation Code.
3. The air inlet of a Shield water heater is part of a direct
vent connection. It is not classified as a forced air intake
with regard to spacing from adjacent water heater vents.
Figure 4-2 Vertical Terminations with Multiple Water
Heaters
Figure 4-3 Alternate Vertical Terminations with Multiple
Water Heaters