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venting high efficiency boiler

Thank you very much for summarizing the rules: I knew there were such rules, but didn't know the specifics. You don't want to wait to find these things out AFTER you've bought the boiler! Tough to do a layout in a new space unless you know these things in advance.

Thanks again- this is a top-notch forum populated by very friendly and helpful people!


  • moltenmetal
    moltenmetal Member Posts: 5
    Venting high efficiency boiler


    Are there any guidelines for minimum separation distances between a high efficiency boiler vent and potential points of impingement: windows, doors or other potential points for leakage of the exhaust back into a home?
  • Perry_2
    Perry_2 Member Posts: 381

    Some items are driven by national fire codes such as the distance from a natural gas meter.

    Other distances are driven by other factors (and possibly local codes).

    Direct Vent boiler Mfr's typically have a chart with minimum distances for their boiler with their recomended venting distances. As such, there is some variation for differnt boilers.

  • Most Certainly!

    Following are US national codes--local codes may be effective as well:

    A vent must NOT terminate:

    1) ...less than 7' above a paved sidewalk or a paved driveway located on public property.

    2) ...within 4' horizontally from service regulator vents, electric and gas meters as well as relief equipment.

    3) least 3' above any forced air inlet within 10'.

    4) ...less than 1' above grade level or anticipated snow level. Locate the vent termination in such a way that it cannot be blocked by snow.

    5) ...within 1' of a window or door which may be opened in any building, any non-mechanical air supply inlet to any building or the combustion inlet of any other appliance

    6) areas where condensation may cause problems, such as above planters, patios or adjacent to windows where flue gases may cause fogging.

    7) ...within 3' to the property line (advisable, not mandatory--check with local authorities!)

    8) a location where ice formation on the ground can present a hazard.

    9) that the flu gasses are directed towards brickwork, siding, or other construction in such a manner that may cause damage from heat or condensate from the flue gasses.

    10) ...where discharging hot flue gasses may cause property damage or personal injury.

    11) ...within 3' from an inside corner of outside walls.
  • Empire_2
    Empire_2 Member Posts: 2,343
    Venting guid lines.

    The boiler should have come with an instruction manual giving you a complete list of do's and dont's. If not, you can usually down load them off the Internet.

    Mike T.
  • Jim Farrell
    Jim Farrell Member Posts: 46

    Refer to manufactures venting instructions...
    Also consult NFPA & Local Codes...
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