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.

Concentric Termination extension

McNamara Member Posts: 1
I just had a new High efficiency gas boiler installed. They used a single pipe for venting fresh air in and exhaust out with a concentric terminator kit. But they also added a "periscope" type pipe to the end of the terminator - to get clear of mounting snow I suppose. I was under the impression a concentric termination was carefully engineered to maximize the exhaust and intake air currents. My question is this - now that the concentric terminator is no longer technically the termination - is it still able to do it's job with two elbow joints and 30 inches of pipe in front of it?


  • nicholas bonham-carter
    nicholas bonham-carter Member Posts: 8,578
    If the installer was worried about the highest snow level, then all the piping termination should have been raised.
    I think he was just trying to take an extra precaution against exhaust-intake contamination. Maybe the exhaust extension should point down so as to prevent condensate from building up in the pipe.
    Your owner/installation manual will have the final say on that setup.—NBC
  • kcopp
    kcopp Member Posts: 4,450
    Generally speaking I am not a fan of concentric set ups. Reason being is cross contamination of the exhaust and intake gases.
    His solution will minimize that.
    j a_2HomerJSmith
    JUGHNE Member Posts: 11,110
    How high above snow level is the air inlet cone at the bottom?
  • DZoro
    DZoro Member Posts: 1,048
    As long as he didn't exceed his piping lengths limits, it should be good.
    I'm actually thinking he is more concerned with the re ingestion of exhaust gas.
    Is the intake hood above anticipated snow depth?
  • lchmb
    lchmb Member Posts: 2,997
    What kind of system?
  • j a_2
    j a_2 Member Posts: 1,801
    What’s the boiler manufactures manual say, and are there any local codes in your area ? That’s not a concentric