Crown Boiler AWR Series Installation Instructions Manual page 15

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, this boiler 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.
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.
14) Installation of the vent damper supplied with this boiler is mandatory. Install vent damper (see Figure 6.2) as follows:
a) Open vent damper carton and remove installation instructions. Read the instructions thoroughly before proceeding.
Verify that vent damper is same size as draft diverter outlet (Figure 2.1). Unpack vent damper carefully. Do not
force closed damper blade. Forcing vent damper closed may result in damaged gear train and void warranty.
b) Vent damper is factory shipped having approximately ¾" diameter hole in the vent damper blade, which must be
plugged. Use the plug supplied with the damper.
c) Mount the vent damper on the flue collar without modification to either and secure with sheet metal screws. Make
sure screws do not interfere with damper blade operation. Vent damper blade position indicator must be visible to
users.
d) The damper wire harness is shipped pre-wired into the boiler. Plug the loose end of this harness into the damper and
secure the flexible conduit to the damper using a connector nut provided.
Provide adequate clearance to combustible construction and servicing.
e) Install vent connector pipe and vent fittings from vent damper outlet to chimney or gas vent. Secure with sheet metal
screws and support as required.
FIGURE 6.2: VENT DAMPER INSTALLATION DETAILS
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