Dunkirk PVWB, Installation Instructions Manual

Page: 7 / 24

7
CHECK YOUR CHIMNEY
This is a very important part of your heating system. It must be
clean, the right size, properly constructed and in GOOD
CONDITION. No boiler can function properly with a bad
chimney. Fig. 7 gives typical chimney sizes. Fig. 8 gives you
an idea how a boiler might be vented to a chimney. Note that
the height (HT) is measured from the vent pipe to the top.
CHIMNEY SIZING
Chimney sizing, and all other aspects of the vent installation
must be in accordance with Part 7 of the National Fuel Gas
Code, ANSI Z223.1 latest revision, and applicable provisions
of the local building codes.
In Canada, follow CAN/CGA B149.1 and B149.2, Installation
Codes for Gas Burning Appliances and Equipment.
CONNECTING THE VENT DAMPER AND VENT
CONNECTOR
Refer to Fig. 1 flue diagram for the size and location of the vent
(flue opening). Use a 28 gauge (minimum) galvanized pipe to
connect to the chimney.
IMPORTANT - The damper blade on the furnished vent damper
has a 1/2 square inch hole (approximately3/4 diameter). On
boilers equipped with standing pilot, the hole must be left open.
On boilers equipped with intermittent ignition, the hole should
be plugged by using the plug supplied with the vent damper.
1. Position furnished vent damper on top of flue outlet collar.
Fasten damper securely to flue outlet collar with sheet
metal screws. Make sure damper blade has clearance to
operate inside of diverter.
On 2 section boilers equipped with vent damper, the
supplied 4-inch vent damper is equipped with a 3- to 4-
inch adapter so that the 4-inch vent damper may be
installed on the boiler’s 3-inch flue outlet collar. Fasten all
fittings securely.
As An Option (U.S.A. Only)
The damper may be installed in any horizontal or vertical
position, closer to the flue outlet collar preferred. Follow
the diagrams - Figures 9, 10 and 11.
2. Install the vent damper to service only the single boiler for
which it is intended. The damper position indicator shall
be in a visible location following installation. Locate the
damper so that it is accessible for servicing.
3. The damper must be in the open position when appliance
main burners are operating.
4. The boiler is equipped with a factory wired harness that
plugs into the vent damper.
5. Vent pipe must be same size as the flue outlet collar, except
2 section boilers with vent damper as noted above.
6. Slope pipe up from boiler to chimney not less than 1/4” per foot.
Chimney and Vent Pipe Connection
For boilers for connection to gas vents or chimneys, vent installations shall be in
accordance with Part 7, Venting of Equipment, of the National Fuel Gas Code, ANSI
Z223.1-latest revision and applicable provisions of the local building codes.
7. Run pipe as directly as possible with as few elbows as
possible.
8. Do not connect to fireplace flue.
9. End of vent pipe must be flush with inside face of chimney
flue. Use a sealed-in thimble for the chimney connection.
10. Horizontal run should not be longer than
3
/4 the
chimney height (HT) (Fig, 8).
The sections of vent pipe should be fastened with sheet metal
screws to make the piping rigid. Horizontal portions of the vent
system must be supported to prevent sagging. Use stovepipe
wires every 5' to support the pipe from above If the vent pipe
must go through a crawl space, double wall vent pipe should
be used Where vent pipe passes through a combustible wall
or partition, use a ventilated metal thimble. The thimble should
be 4 inches larger in diameter than the vent pipe.
Boiler Input *HT. *HT. *HT.
Btuh 10-15 Ft. 10-25 Ft. 25 Ft. UP
Up to 100,000 6 x 6 6 x 5 5 x 5
Up to 155,000 6 x 7 6 x 6 6 x 5
Up to 230,000 7 x 8 7 x 7 6 x 7
Up to 350,000 9 x 9 8 x 9 8 x 8
FLUE AREA IN INCHES
* HT = top of thimble to top of flue. See Fig. 8
For boiler input refer to table, page 2.
For information only - not meant to imply minimum sizes.
MINIMUM VENT PIPE CLEARANCE
Wood and other combustible materials must not be closer than
6" from any surface of single wall metal vent pipe. Listed Type
B vent pipe or other listed venting systems shall be installed in
accordance with their listing.
REMOVING EXISTING BOILER FROM
COMMON VENTING SYSTEM
When an existing boiler is removed from a common venting
system, the common venting system is likely to be too large
for proper venting of the appliances remaining connected to it.
At the time of removal of an existing boiler, the following steps
shall be followed with each appliance remaining connected to
the common venting system placed in operation, while the other
appliances remaining connected to the common venting system
are not in operation.
1. Seal any unused openings in the common venting system.
2. Visually inspect the venting system for proper size and
horizontal pitch and determine there is no blockage or
restriction, leakage, corrosion and other deficiencies which
could cause an unsafe condition.
FIG. 7 - TYPICAL CHIMNEY SIZES