Bosch 660 EF User Manual page 12

Installation instructions
Horizontal Vent Termination
Fig. 6
• Terminate at least 12" (300mm) above grade or
above snow line.
• Terminate at least 7' (2.1m) above a public walkway,
6' (1.8m) from the combustion air intake of any appli-
ance, and 3' (0.9m) from any other building opening,
gas utility meter, service regulator etc.
• Terminate at least 3' (0.9m) above any forced air inlet
within 10' (3m), 4' (1.2m) below, 4' (1.2m) horizon-
tally from or 1' (0.3m) above any door, window, or
gravity air inlet into any building per National Fuel
Gas Code ANSI Z223.1/NFPA 54.
• Slope the horizontal vent 1/4" downwards for every
12" (300mm) toward the termination.
• In the Commonwealth of Massachusetts a carbon
monoxide detector is required for all side wall hori-
zontally vented gas fuel equipment.
12
Vertical Vent Termination
Fig. 7
• Terminate at least 6' (1.8m) from the combustion air
intake of any appliance, and 3' (0.9m) from any other
building opening, gas utility meter, service regulator
etc.
• Enclose exterior vent systems below the roofline to
limit condensation and protect against mechanical
failure.
• When the vent penetrates a floor or ceiling and is not
running in a fire rated shaft, a firestop and support is
required.
• When the vent termination is located not less than 8'
(2.4m) from a vertical wall or similar obstruction, ter-
minate above the roof at least 2' (0.6m), but not more
than 6' (1.8m), in accordance with the National Fuel
Gas Code ANSI Z223.1/NFPA 54.
• Provide vertical support every 12' (3.6m) or as
required by the vent pipe manufacturer's instructions.
• Slope the horizontal vent 1/4" for every 12" (300mm)
towards the drain tee.
• A short horizontal section is recommended to pre-
vent debris from falling into the water heater.
• Install a condensation drain in the horizontal section
of the venting. For installations in tight spaces where
there is not enough room to install two elbows and a
horizontal drain tee, a vertical drain tee may be sub-
stituted.
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