Operating instructions

IV Vent System Installation

Figure 3 shows a typical BWF Category I vent system. The major components of this system are the adapter box, the

vent connector, and the chimney.

1) Acceptable Chimneys - The following chimneys may be used to vent BWF series boilers:

• Listed Type B or L gas vent - Install in accordance with the manufacturer’s instructions, the terms of its listing,

and applicable codes.

• Masonry Chimney (lined with a listed metal lining system) - Install in accordance with the liner manufacturer’s

instructions, the terms of the liner’s listing, and applicable codes.

• Masonry Chimney (lined with a ceramic liner) - In many cases, the National Fuel Gas Code does not permit

installation of fan assisted appliances such as the BWF into clay lined masonry chimneys. Consult the National Fuel

Gas Code before attempting to connect a BWF series boiler into a ceramic lined masonry chimney.

2) Acceptable Vent Connectors - The following may be used for vent connectors:

• Listed type B or L Gas Vent

• Single Wall Galvanized Pipe - Use 0.018” (26 gauge or heavier). The size and location of the chimney may not

permit the use of a single wall connector in some cases. See Chapter 10 of the National Fuel Gas Code. Do not use

single wall pipe for vent connectors in attics.

• Other Vent Connectors Permitted by the National Fuel Gas Code.

3) Chimney and Vent Connector Sizing - Size the chimney and vent connector in accordance with the National Fuel Gas

Code.

4) Exterior Chimneys - An exterior chimney has one or more sides exposed to the outdoors below the roof line. There

are two conditions under which an exterior chimney may be used:

• In some very restrictive cases, the BWF series boiler may be vented into an exterior ceramic lined masonry

chimney. See the National Fuel Gas Code for information on when exterior ceramic lined 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) Do not connect the vent of this appliance into any portion of a mechanical vent system operating under positive

pressure.

6) Do not connect the boiler into a chimney flue serving an open fireplace or other solid fuel appliance.

7) Prior to boiler installation, inspect chimney for obstructions or other defects and correct as required. Clean chimney as

necessary.

8) Vent connector should slope upward from the vent adapter box not less than 1/4 inch per foot. No portion of the vent

connector should run downward or have sags. All vent piping must be securely supported.

9) The vertical section of the 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.

10) Vent connector should be installed above the bottom of the chimney to prevent blockage.

11) Vent connector must be inserted flush with inside face of the chimney liner and the space between vent pipe and

chimney sealed tight.