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.

Direct Vent in Chimney

Dale Member Posts: 1,317
If the nameplate says cat. 1 then yes you can if the chimney/common vent is able to take it, if not catagory 1 then the mfg. must supply venting instructions. If the chimney is big enough you can have plastic and b-vent in the chimney which is now the chase as long as the b vent clearance is maintained.


  • Big Ed
    Big Ed Member Posts: 1,117
    Direct Vent in Chimney

    This was asked of me and I don't know. Could a gas direct vent boiler be used in a chinmey.The only problem I can see is low stack temperature... Chimney liner needed ??

    I asked the question too,"why ?" . Seems like he is getting a deal on a boiler .. : )
  • Dirk Wright
    Dirk Wright Member Posts: 142

    My understanding is no, they cannot be installed in a chimney. Consult the manufacturer for their instructions.
  • Joe Brix
    Joe Brix Member Posts: 626
    most will tell you

    they've run the PVC up the Chimney as a chase. But then you can't be using the chimney for any other appliance.
  • J.C.A._3
    J.C.A._3 Member Posts: 2,981
    Dale gave the right answer.

    Look at the IMO book. The ones I've been reading lately have more pages concerning venting than they have "warning" pages. (quite a switch from the old days!)

    The manufacturer has tried and ruled out all the "hairbrained schemes" that Joe Homeowner could come up with, and printed the preferred methods. Follow them and the inspectors will rarely have a problem with your install.
    They have all made things pretty clear, and any deviation from the manual will leave you holding the bag.... Chris
  • Big Ed
    Big Ed Member Posts: 1,117
    thank you all

    As always I learn a lot from you guys. Thanks for sharing
  • supersonicus
    supersonicus Member Posts: 3
    direct vent boiler

    Read the Mfg. installation requirements very carefully. All the info you need is there.
  • JackFre
    JackFre Member Posts: 225
    You can, but...

    yes, read the manuf installation instructions. As noted running a vent system up the masonry chimney converts it from a chimney to a chase. No other use. The max length spec vent length both height and vert rise come into play. Also, does the appliance require a special vertical termination? Does the applianbce have to terminate in a horiz fashion?
This discussion has been closed.