Page 1 of 2 12 LastLast
Results 1 to 13 of 14
  1. #1
    Join Date
    Nov 2004
    Posts
    10
    A month or so ago I had a carbon monoxide problem in my house, picked-up by my Nighthawk detector (registered from 10-45 depending on where you were in the house). I had two different certified serviceman come out to check my natural gas 1989 Carrier Weathermaker SX . Each came to a different conclusion. One believed it was solely a venting problem, the other said I also had a bad/plugged secondary heat exchanger.

    The exhaust flue was in a corner directly above a basement window and directly below the an opening to the kitchen stove exhaust fan on the side of the house.. The Nighthawk detector registered as has a 45? when placed in kitchen. The first serviceman said move exhaust flu and you will be fine. What concerns me is the second serviceman said my secondary heat exchanger is bad or plugged because the exhaust outside smelled bad. He thought the carbon monoxide in the house may also be caused by a bad seal which must be leaking and also distributing carbon monoxide throughout the house. It's true if you standout side when the heat is on and running there is a very very distinct smell I can't describe, but it is definitely there. He says because the fresh air intake to the system is right next to the dryer vent, it sucked in lint from the dryer and has plugged the secondary heat exchanger. I extended the exhaust flu up above the facia of the house and have had carbon monoxide problem again (no reading on the Nighthawk device). However, here are my questions

    1) Is it a problem that the exhaust from my heating system smells really funny and would that indicate the secondary heat exchanger is plugged?
    2) If yes, would that produce a higher concentration of carbon monoxide which might have contributed to my problem and should I still be concerned?
    3) If yes, is a secondary heat exchanger serviceable? This serviceman said, let just replace the system because it is 15yrs old.
    4) What other signs might confirm my secondary heat exchange is plugged? For example, if I cover the fresh air intake pipe it doesn’t seem to be sucking much air. It barely holds big leaf to it, if placed in front. Is that an indicator?

    Simple I don’t want to have to replace the system unless I have must.

    Your advice is very much appreciated

    Matthew

  2. #2
    "I extended the exhaust flu up above the facia of the house and have had carbon monoxide problem again (no reading on the Nighthawk device). However, here are my questions"

    Are you saying you still have the problem ?

    Did it get better after moving the flue pipe ?

    Does your house have an attached garage ?

    Does the exhaust in your stove have a damper that is stuck open ?

  3. #3
    Join Date
    Feb 2004
    Posts
    175
    if its a 58sxc furnace get rid of it.

  4. #4
    Join Date
    Jul 2004
    Location
    midwest
    Posts
    2,868
    You need to get another opinion and ASAP. They should be able to tell you without a doubt what is causing your problem and we would just be guessing from here.

  5. #5
    Join Date
    Apr 2004
    Posts
    7,680
    jkelly there was nothing wrong with the SXC.

    The original vent was against code if it was directly above and/or below a window and I suspect it is single pipe vented rather than two pipes. Over the years what changed in the house? Maybe the basement was remodeled? Just asking because it sounds as though the furnace at one time was starved of combustion air and created some soot. The HX can be serviced and the vent should be corrected, hopefully to include an intake pipe.

  6. #6
    Join Date
    Nov 2004
    Posts
    10

    owner response; secondary heat exchanger ?

    Qwner answers: It is a two pipe system (one on top of another). Since moving the exhaust flu pipe to the roof the carbon monoxide problem in the house is fixed, no readings on the Nighthawk. I'm still concerned with the funky smell of the exhaust that the second serviceman said meant my secondary heat exchanger is bad/plugged. He recommended I replace the whole system. Should I be concerned with the funk smell? And should there be a lot of suction on the intake pipe which I notice did not have alot of?

    Thanks again to all.

    mb

  7. #7
    Join Date
    Mar 2004
    Location
    SE Michigan
    Posts
    17,940
    I have replaced these secondary heat exchangers in the past. Have a tech pull it for inspection. Or it may be cost effective to just replace the furnace.
    Behind the ostensible government sits enthroned an invisible government owing no allegiance and acknowledging no responsibility to the people.

    Theodore Roosevelt

  8. #8
    Join Date
    Nov 2004
    Posts
    10
    So you agree that because the exhaust should not smell funny and because it does it may be an indication that the secondary heat exchange is bad/plugged?

  9. #9
    Join Date
    Apr 2004
    Posts
    7,680
    Until someone actually checkes the negative pressure and the exhaust temperature its just a guess. Odds are, it isnt plugged if its still running.

    Pulling, and flushing the secondary if needed is a couple hour job maybe 3 tops on an SXC.

    [Edited by docholiday on 02-21-2005 at 09:57 AM]

  10. #10
    Join Date
    Nov 2004
    Posts
    10
    Last question; The 30 min service call cost me $70. Should he have checked the negative pressure and exhaust tempeture for that price? All he did was turn on the system check a few registers with the Carbon Monoxide device and walkout side to see the vent.

    Thanks again

  11. #11
    Join Date
    Apr 2004
    Posts
    7,680
    That's really an unfair question but I say No. He should have stayed and hour and charged you more. Those tests take some time to do and coulnt be done in a half an hour when added to the other stuff he did.

    Many companies dont even offer 1/2 hour rates until after the first hour. And we cannot comment on the rates. In all fairness, he did fix your complaint of high CO. Now, after the fact, you have learned some things you would like tested, you can call him back and pay him to test them if you wish.

  12. #12
    Join Date
    Nov 2004
    Posts
    10
    That makes sense. Thanks for comment.

    mb

  13. #13
    Join Date
    Feb 2004
    Posts
    175
    I have seen countless problems with the sxc. Usually the install is within spec but still can't handle long vent pipe lengths. Not to mention the secondary HX problems with those boat anchors.

Page 1 of 2 12 LastLast

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