16
INSPECT CHIMNEY
to verify it is constructed according
to latest revision of the NFPA 211. Local codes may differ
from this code and should be checked. Where there is a
conflict, local code will prevail.
• Boiler must be installed into chimney which has
masonry or metallic chimney liner.
•
Unlined chimney will have leaks that will cause poor
chimney performance (NO DRAFT), and could result in
positive pressure in combustion chamber.
•
Horizontal portions of venting system should not
exceed 10 feet in length. Horizontal lengths over 10
feet will have negative effect on chimney performance.
•
Chimney should extend at least 2 feet above any
portion of building within 10 feet. See
Figure #15
. It
should produce negative draft of .06 to .08 inches of
water column, (W.C.), as measured with draft gauge
between boiler and barometric draft control while
maintaining .02 inch W.C. negative draft in combustion
chamber. See chart “Chimney or Vent Sizes” for
recommended chimney or vent sizes.
• Inadequate draft will cause improper combustion,
resulting in dirty flue ways and high fuel bills.
CONNECT FLUE PIPE
same size as boiler outlet to
chimney, sloping upward continuously toward chimney
approximately ¼” per foot. Bolt or screw joints together to
avoid sag.
If oil fired water heater is vented into same flue as
boiler, provide separate hole into chimney whenever
possible. When not possible, use “Y” connection in
flue pipe, using separate draft regulator for each unit.
When chimney will not provide adequate draft
to handle input from water heater and boiler
simultaneously, wire units so that only one will
operate at a time, favoring water heater.
VENTING SYSTEM INSPECTION & INSTALLATION
Figure #15
