User Guide

8
110118-01 12/19
CG-F
Installation, Operating & Service Manual
5 Venting (continued)
E. Install Vent Piping
1. Install vent piping from vent damper outlet
to chimney.
2. Vent pipes serving appliances vented by
natural draft shall not be connected into
any portion of mechanical draft systems
operating under positive pressure.
DANGER
Inspect existing chimney before installing
boiler. Look for corrosion holes. Failure to clean
chimney or replace corroded pipe or tile lining
will cause severe injury or death.
3. Do not connect into same flue of chimney
serving an open fireplace.
Figure 5-2: Vent Damper Position Indicator
4. Vent pipe to chimney must not be smaller
than outlet on draft hood or vent damper.
Arrange venting system so boiler is
served by vent damper device.
Exception: National Fuel Gas Code,
ANSI Z223.1/NFPA 54, and allow vent
downsizing when vent size
determined by their Vent Sizing
Tables is smaller than draft hood
outlet/vent damper. These codes
require all of following:
a. Total vent height (H) is at least
10 ft;
b. Vent not reduced more than one
table size;
and
c. Draft hood outlet/vent damper is
greater than 4 in. in diameter.
5. Vent pipe should have greatest possible
initial rise above draft hood consistent
with head room available and required
clearance from adjacent combustible
building structure. Vent pipe should be
installed above bottom of chimney to prevent
blockage.
6. Slope vent pipe upward from draft hood to
vent terminal not less than 1/4" per foot.
7. Support horizontal portions of venting
system to prevent sagging. Use pipe
straps, brackets or hangers spaced 4 ft. or
less.
8. Vent pipe must be inserted into but not
beyond inside wall of chimney liner. Seal tight
between vent pipe and chimney.
!