Chimney & Vent Pipe Connection - Dunkirk XEB-2 Installation, Operation & Maintenance Manual

For boilers for connection to gas vents or chimneys, vent
installations shall be in accordance with the National Fuel
Gas Code, ANSI Z223.1- latest revision and applicable
provisions of the local building codes.
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 CONDI-
TION. No boiler can function properly with a bad chimney.
1. Use local codes for installation or National Fuel Gas Code
Z223.1-latest revision. In Canada, follow CSA B149.1 or .2
Installation Codes. It is very important to properly size the
venting system for induced draft appliances. Consult the Vent
Sizing Tables, in the National Fuel Gas Code ANSI Z223.1-
latest revision for correct sizing information. In Canada, consult
the Vent Sizing Tables, Amendment #1 to CSA-B149.1 and .2
Installation Codes.
2. The boiler's induced draft blower has a 3" outlet. A 3" X 4"
increaser fitting is included in the parts bag. Locate the in-
creaser fitting on the outlet of the induced draft blower, and
secure gastight with a bead of the furnished silicone sealant. The
increaser fitting is required on this boiler for Category I venting,
and 4" is the minimum permissible vent diameter. This does
not imply that the vent connector is intended to be 4" diam-
eter pipe. The vent connector shall be sized according to the
appropriate venting tables in the National Fuel Gas Code or the
Canadian Installation Codes, and may be required to be larger
than 4" diameter.
The boiler installation for chimney venting is not complete
unless the 3" x 4" increaser fitting is located and secured.
3. These are high efficiency boilers with a low stack or exhaust
temperature.
4. If venting into a masonry chimney without a liner, line the
chimney from top to bottom with either:
A. Listed Type B vent pipe
B. Listed flexible vent liner
C. Poured ceramic liner.
5. Outside chimneys should not be used unless they are (choose
one of the following):
A. Enclosed in a chase
B. Lined with Type B vent pipe
C. Use a listed flexible vent liner
D. Use a certified chimney lining system
6. The vent connector from the boiler to the chimney should run
as directly as possible with as few elbows as possible.
CHImNEy & VENT pIpE CONNECTION
NOTICE
NOTICE
7. Where possible, it is recommended to common vent the water
heater and boiler. Consult the appropriate Vent Sizing Tables in
either the National Fuel Gas Code, or the Canadian Installation
Codes for specific requirements of multiple appliance venting.
8. If the boiler is the only appliance connected to the vent, Type B
vent pipe is recommended for the vent connector.
9.
Slope pipe up from boiler to chimney not less than 1/4" per
foot.
10. End of vent pipe must be flush with the inside face of the chim-
ney flue. Use a sealed-in thimble for the chimney connection.
11. The sections of vent pipe should be fastened with sheet metal
screws to make the piping rigid. Use stovepipe wires to support
the pipe from above.
12. Do not connect to fireplace flue.
13. Do not install a damper on this boiler.
minimum Vent pipe Clearance
If the vent pipe must go through a crawl space, Type B 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.
If boiler is installed with single wall vent, it must have a 6" clear-
ance between its surface and any combustible material. A new Type
B gas vent or flexible liner must be installed in accordance with the
instructions furnished with the vent. Maintain clearances as speci-
fied for the vent pipe.
Check the vent pipe to see if it is fire-stopped where it goes through
the floor or ceiling. It should have an approved vent cap with clear-
ances from the roof as shown in Figure 9. If clearances are less
than shown in Figure 9, have the vent checked by local authorities.
For boilers for connection to gas vents or chimneys, vent installa-
tions shall be in accordance with the National Fuel Gas Code, ANSI
Z223.1-latest revision and applicable provisions of the local building
codes. In Canada, follow CSA B149.1 or .2 Installation Codes.
Vent connectors serving appliances vented by natural draft shall not
be connected into any portion of mechanical draft systems operating
under positive pressure.
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 vent-
ing 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 com-
mon venting system placed in operation, while the other appliance
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 hori-
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