Vent Requirements
The GF 300 BV Allagash is specifically designed to operate using 4” Type B vent pipe components or a Listed Flexible gas liner.
•All venting components must be installed in accor- dance with the terms of their listing and manufacturer’s instructions.
•The minimum height of a vertically terminated system shall be no less than 7', and the maximum height shall be no more than 35'. See diagrams page 9.
•With steep roofs, nearby trees, and in predominant windy conditions, poor draft or down draft conditions can occur. In these cases, increasing the height of the vent or high wind termination caps may improve the situation.
•ELBOWS: If an offset or elbow is necessary in the vertical rise, it is important to support the vent pipe every three feet, to avoid excessive stress on the offsets.
•Whenever possible use 45° elbows opposed to 90° elbows. This offers less restrictions for the flow of flue gases.
Maximum number of 90° elbows: three
Maximum number of 45° elbows: four
•TOTAL MAXIMUM HORIZONTAL RUN ANYWHERE IN THE VENTING CONFIGURATION IS 4 FEET. The distance between any 45° elbows is considered a horizontal run. See diagrams, page 10.
•Any Type B vent passing through a roof must have a flashing, storm collar, thimble and a Type B cap is required. See diagrams, page 10.
•Venting on the Allagash CANNOT be less than 4” in diameter or greater than 4” in diameter.
•Any unused flue or masonry enclosure can be used as a passage way for venting, but the flue must be relined using Type B 4” vent or Listed Flexible Gas Liner.
•The remaining space around the liner in a masonry or
Figure 5. Termination Height Requirements.
•When terminating through the roof refer to the Gas Vent Rule for proper vent termination height.
See fig. 5.
•NO venting may terminate horizontally or below roof eaves.
•Passage through combustibles (walls, ceilings) must be with Type B venting and must maintain listed clearances.
•Any horizontal run should have an upward slope of 1/4” per foot toward the termination cap.
•When venting through a thimble into a masonry flue, any venting exposed in the room must be Type B venting, or a flexible liner sleeve within 24 ga. 6” stove pipe.
•Listed Flexible Gas Liners may not be exposed in any living space.
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