Results 1 to 11 of 11
  1. #1
    Join Date
    Jul 2004
    Location
    NJ
    Posts
    56
    Hello everyone and thank you in advance.

    Here goes.
    Do you need to install a chimney liner IF you are replacing an old unit with an 80%+ induced draft unit?

  2. #2
    Join Date
    Jul 2002
    Location
    Zelienople, Pa
    Posts
    2,965
    yes
    How tall are you Private???!!!!

  3. #3
    Join Date
    Jan 2004
    Location
    Lancaster PA
    Posts
    67,876
    Unless its a clay liner, or other approved liner in the chimney already. And the chimney isn't too big for the new smaller 80% furnace.
    Contractor locator map

    How-to-apply-for-Professional

    How many times must one fix something before it is fixed?

  4. #4
    Join Date
    Jul 2004
    Location
    NJ
    Posts
    56
    Thank you (beenthere) yes it does have clay liner, It did not make sense to run another liner down there.
    Thank you

  5. #5
    Join Date
    Dec 2003
    Posts
    2,390
    you need a liner

  6. #6
    Join Date
    Jul 2004
    Location
    NJ
    Posts
    56
    I thought ( INDUCED DRAFT) took care of the slow moving gases( only mid-efficiency) going up before they condensate? or no?

  7. #7
    Join Date
    May 2000
    Location
    Indianapolis, IN, USA
    Posts
    34,052
    If 1 or more sides is exposed, line it.
    If furnace is alone and no WH, line it.

    Inside chimney with water heater, gas code sez: the flow area of the chimney cannot be more than 7 times the outlet area of the smallest draft hood appliance.

    Well, that would be your water heaters with likely a 3" (7 sq inch) outlet. So if the internal dimensions of your tile liner are more than 49 sq inches, code says line it.

    Of course if you don't want to take any chances, line it. Liners are cheap, chimney repairs aren't!

  8. #8
    Join Date
    Feb 2004
    Posts
    2,597
    flue gasses are lower temps. with an 80 furnace as opposed to an older 65-70.

    therefore condensation will occur at colder temps.

    the flue gasses are acidic and will eat through any mortar joints in the clay liner.

    new chimney= $$$$$

    LINER=$$$

    it's up to you i guess.

  9. #9
    Join Date
    Dec 2003
    Posts
    287
    Hmmm, my chimney has long since been orphaned to just WH duty but is on an inside wall, so I guess that's why it still drafts properly.

  10. #10
    Join Date
    Jul 2004
    Location
    NJ
    Posts
    56
    THANK YOU ALL

    Direct vent it is then. lol


  11. #11
    Join Date
    Jan 2004
    Location
    Lancaster PA
    Posts
    67,876
    Originally posted by billva
    flue gasses are lower temps. with an 80 furnace as opposed to an older 65-70.

    therefore condensation will occur at colder temps.

    the flue gasses are acidic and will eat through any mortar joints in the clay liner.

    There is no motar joint on clay liners.

    Teracotta, yes there is.
    Contractor locator map

    How-to-apply-for-Professional

    How many times must one fix something before it is fixed?

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •  
Comfortech Show Promo Image

Related Forums

Plumbing Talks | Contractor Magazine
Forums | Electrical Construction & Maintenance (EC&M) Magazine
Comfortech365 Virtual Event