State SBL85 390NE A - Manual (Page 15)

13 Servicing should only be performed by a Qualified Service Technician
EXTERIOR CLEARANCES
The illustration below shows the required clearances for venting units using natural draft venting.
The vent must extend at least 3 feet above the highest point where it passes through a roof of a building
and at least 2 feet higher than any portion of a building within a horizontal distance of 10 feet (for vents of 12
inches in diameter or less).
References: NFPA 54/ ANSI Z223.1 may allow reduction to 8 feet with a “listed vent cap.”