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  1. #1
    Join Date
    Oct 2008
    Posts
    6

    Rusted through heat exchanger? pics....

    Hello experts....

    I have a Lennox 023Q3-105/120-2A oil furnace.... the tech guy will be coming soon to service it and replace the nozzles (it has .65 70B in there now, even though the spec calls for an 80deg nozzle?) and replace fuel filters and such..

    Last year, the tech was unable to remove a couple of the caps on the inspection ports, and so was unable to see/clean the whole thing. I decided to remove the caps myself ahead of time, so he could get all the stuff done.

    There's a lot of corrosion in there, and on the left side the curved wall that is visible at the end of the pipe is perforated.

    Is this the heat exchanger? Does that perforation and corrosion mean the entire furnace needs to be replaced? There are actually two furnaces... identical pair, upstairs/downstairs.

    There is a lot of corrosion/drippings on the burner unit, as you can see in the photo, and it appears this is coming from condensation inside the flue pipe. Is this normal, and/or is there a way to prevent it?

    I'm not looking to DIY this, but i'm aware enough of things mechanical that i want to understand the situation and issues fully.

    THANKS!

    ;-)
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  2. #2
    Join Date
    Jun 2004
    Location
    Howell, Michigan
    Posts
    16,173
    Well from here it looks like the rear of the heat exchanger is rusted out. What's the serial number. I can't remember, but older O23's have a 20 year warranty and newer ones have a lifetime to original owner.

  3. #3
    Join Date
    Feb 2008
    Location
    Waffleville
    Posts
    10,339
    looks to me as an opportunity to make the switch to a gas furnace
    If Guns Kill People, Do Pencils Misspell Words?

    http://www.youtube.com/watch?v=An2a1...eature=related

    Before we work on artificial intelligence why don't we do something about natural stupidity?

  4. #4
    Join Date
    Dec 2007
    Location
    Ohio
    Posts
    2,875
    Quote Originally Posted by beachtech View Post
    looks to me as an opportunity to make the switch to a gas furnace
    Amen.....
    I need a new signature.....

  5. #5
    Join Date
    Oct 2008
    Posts
    6
    Thanks for the quick responses!

    I'd love to switch to gas, but i'm quite rural.....


    There are two of these furnaces (zoned), and they are:
    8496L36527 (the one in the pics)
    8496L36476 (the one i haven't opened yet)


    I note that there's a lot of foamy/crusty corrosion stuff that seems to be dripping out of the flue pipes, all over the burner and other stuff in the cabinet. It wasn't there last year.

    Any ideas what's causing that, and how to correct it? It looks like i'll be looking for a local contractor....

    again, thanks for helping!

  6. #6
    Join Date
    Oct 2002
    Location
    Yo.... Here!, I'm right here..
    Posts
    6,236
    Time to up grade to Hybrid...........cut your fuel cost and do your part to help the environment...........

    Reduce your fuel cost, by adding a Hybrid Heat Pump and a new Oil Furnace, or switch to a 2 stage gas and a high efficient heat pump...........check your utility companies web site for the best prices..........and fuel comparison...........

    check the Propane prices v/s your oil prices

  7. #7
    Join Date
    Mar 2005
    Location
    burlington county n.j.
    Posts
    9,708
    12 yr old heat exchangers should be under warranty.

  8. #8
    Join Date
    Oct 2008
    Posts
    6
    Hey, thanks for all the responses!


    First off, i'd LOVE to go with a geo-thermal (geo-coupled heat pump) system....

    But it would be a huge retrofit, i think. Ideally, i'd like to go hydronic/radiant on the first floor (joists accessible from the basement) at least, rather than the forced-air we have everywhere now.

    When the well fails (within ten years, i'm guessing) i suppose there's the option of using the old borehole for the geo-heatsink.


    Anyhow, right here, right now.... upgrading two hvac systems to my dream setup is not in the cards.

    So... warranty sounds good! These systems were installed by a previous owner of the house.

    Does a warranty still apply? How would i go about exercising it?

    Thanks again!

    ;-)
    Last edited by scirocco; 10-19-2008 at 10:59 PM.

  9. #9
    Join Date
    Jun 2004
    Location
    Howell, Michigan
    Posts
    16,173
    Call a Lennox dealer and he will get you warranty. Also, that equipment may not be running properly, it needs to be set up right after the heat exchangers are installed.

  10. #10
    Join Date
    Jun 2005
    Location
    The Gray Northwest
    Posts
    661
    The furnace may be under-fired which causes condensation to occur. Your stack temp should be at least 400* gross. When your tech comes out he should do a combustion test and make sure the stack temp is high enough so you don't get all that moisture you're seeing.

  11. #11
    Join Date
    Oct 2008
    Posts
    6
    .
    Last edited by scirocco; 10-27-2008 at 06:21 PM. Reason: doublepost, sorry!

  12. #12
    Join Date
    Oct 2008
    Posts
    6
    Hey everyone... First off, thanks for the great advice.

    Here's the follow-up. The heat exchanger is fine. What i saw (and freaked out about) was the usual thin, flaky rust-stuff that comes down. It just happened to be piled up in a way that looked like the HE was rusted through, and i was scared to poke it for fear of damaging the exchanger even worse.

    Once i vacuumed it out, heat-exchanger is pretty darn solid.

    The upshot is that:

    1) I have identified my local Lennox dealer

    2) I have learned that maybe the furnaces (both of them) are not running correctly, hence the condensation in the flue pipes, and the rusty dripping all over everything

    3) I have decided that i will have the Lennox dealer out to service them this year, rather than my oil supplier (i buy oil on the open market, no contract), hoping to have them adjusted correctly.



    There was one other bit of fun involved.... The whole reason this was so bad is that the service guy couldn't get one of the caps off last year. It was stuck. I started out with this by taking the cap off myself, before he arrives, so that it gets clean this year.

    In doing so, i destroyed a cap. It's a flimsy stamped piece of steel, as you-all surely know. When i went to buy a new one, i found that the price for the kit (two caps and a third one with the bolt in it "inspection port") was $65!

    Well, i would have been pleased with $15 (for $5 worth of parts, even all three, at most), and would have been fine with $20 or even $25.... but $65?!??

    No way.

    So, i fixed the one cap i messed up. Having an anvil, hammers, oxy-acetylene torch and some brazing rod comes in handy. I would have felt seriously ripped off to have to pay that much for a flimsy stamped cap.


    Pics related, one of the fixed cap, the other of them installed.

    Again, THANKS to everyone here!

    ;-)
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  13. #13
    Join Date
    Aug 2007
    Location
    MN
    Posts
    2,677
    Quote Originally Posted by scirocco View Post
    Hey, thanks for all the responses!


    First off, i'd LOVE to go with a geo-thermal (geo-coupled heat pump) system....

    But it would be a huge retrofit, i think. Ideally, i'd like to go hydronic/radiant on the first floor (joists accessible from the basement) at least, rather than the forced-air we have everywhere now.

    When the well fails (within ten years, i'm guessing) i suppose there's the option of using the old borehole for the geo-heatsink.


    Anyhow, right here, right now.... upgrading two hvac systems to my dream setup is not in the cards.

    So... warranty sounds good! These systems were installed by a previous owner of the house.

    Does a warranty still apply? How would i go about exercising it?

    Thanks again!

    ;-)
    Install air source HP's, if oil prices stay as high as they are now, it won't take long to recoup the costs of the install. Geo is nice, but its not the only type of HP to save you some ching in oil! Just keep in mind you won't have 200 degree air coming out of the registers when in HP mode
    You can't fix stupid

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