Crown Boiler AWR070 Installation Instructions Manual page 13

4) Exterior Chimneys - An exterior chimney has one or more sides exposed to the outdoors below the roof line. The
National Fuel Gas Code prescribes two conditions under which an exterior chimney may be used:
•
In some very restrictive cases, the AWR series boilers may be vented into an exterior ceramic lined masonry
chimney. See the National Fuel Gas Code for information on when exterior chimneys may be used.
•
An exterior masonry chimney may be used if it is lined with B vent or a listed chimney lining system.
FIGURE 6.1: TYPICAL VENT SYSTEM INSTALLATION AND COMPONENTS
5) This boiler may be vented using a listed power venter. The power venter must be in sized and installed in accordance
with the power venter manufacturer's instructions, the terms of the power venter listing, and applicable codes. The boiler
must be electrically interlocked with the power venter to prevent boiler operation if the power venter fails to operate.
Before deciding to use a power venter, make certain that the flue gas exiting the power venter will not damage adjacent
construction or other structures. Also make certain that the power venter terminal will not be subjected to winds which
could affect power venter operation.
6) Do not connect the vent of this appliance into any portion of a mechanical vent system operating under positive pressure.
7) Do not connect the boiler into a chimney flue serving an open fireplace or other solid fuel appliance.
8) Prior to boiler installation, inspect chimney for obstructions or other defects and correct as required. Clean chimney as
necessary.
9) Vent pipe should slope upward from draft diverter not less than one inch in four feet. No portion of vent pipe should run
downward or have sags. Vent pipe must be securely supported.
10) The vertical section of vent pipe coming off the boiler should be as tall as possible, while still maintaining the proper
clearance from the horizontal vent connector to combustibles and the proper pitch called for in (9) above.
11) Vent pipe should be installed above the bottom of the chimney to prevent blockage.
12) Vent pipe must be inserted flush with inside face of the chimney liner and the space between vent pipe and chimney
sealed tight.
13) Do not install the vent damper in any portion of the vent system which is used by appliances other than the boiler being
installed.
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