Welcome! Here are the website rules, as well as some tips for using this forum.
Need to contact us? Visit https://heatinghelp.com/contact-us/.
Click here to Find a Contractor in your area.

B-Vent that sweats

Scott383
Scott383 Member Posts: 4
The unit is draft induced so there is no draft hood.

Comments

  • Scott383
    Scott383 Member Posts: 4
    B-Vent

    I have a Boiler that is 80% ant the inside of the B-Vent is sweating. Any idea as to what it could be?
  • Brad White_203
    Brad White_203 Member Posts: 506
    Sweating, silly.... :)

    I would think that your flue pipe is simply below your apparatus dew point. What is the ambient temperature around the B-vent?

    Also, where is this relative to dilution (draft hood)?
  • Mark Eatherton
    Mark Eatherton Member Posts: 5,858
    Dilution is the solution to pollution...

    and producin condensation...

    When it happens to us, we block of the draft hood and install a barometric damper, and the problem goes away.

    ME

    There was an error rendering this rich post.

  • k
    k Member Posts: 38
    Condensation

    Also-you could be returning water to the boiler that is too cool and causing the flue products to condense-80% Boilers require return water temperatures 140 or above
  • Scott383
    Scott383 Member Posts: 4


    My return temp is only about 120. This must be the problem. Thank you to everyone for your help.
  • Joannie_15
    Joannie_15 Member Posts: 115
    Vent Size

    Your vent may be too big, as well. Vent tables for fan-assisted units show minimum BTU/hr requirements. If the vent pipe is too large, you will condense inside.
This discussion has been closed.