Chemical odor from central heating's chimney

Discussion in 'HVAC Heating & Cooling' started by Bill Calley, Dec 21, 2008.

  1. Bill Calley

    Bill Calley New Member

    Dec 21, 2008
    Hi all,

    I have an outdoor natural gas central heating unit (which also has a built-in AC). On the side of this large box-like unit is a small vent that outputs hot air/gasses. The odor of these gasses has a VERY strong "chemically" smell. Is this normal, or might there be excessive unburnt natural gas mixing with the normal heater vent exhaust? And can this be dangerous?

    Thank you!

  2. Bill Calley

    Bill Calley New Member

    Dec 21, 2008
    Answer to furnace vent odor...

    To save anyone who may read this thread in the future: the smell from the vent was caused by poisonous gasses due to a cracked combustion chamber in the gas furnace.
    There are only two solutions to this problem (that is, if you lived through the carbon monoxide poisoning that this issue causes): replace the combustion chamber (>$1500), or get a new central heating unit (>$4200).
    PS: I'm really somewhat surprised that this HVAC forum didn't know the answer to this critical life and death problem...

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  4. Verdeboy

    Verdeboy In the Trades

    Jun 12, 2006
    Thanks for posting that.

    BTW, this is first and foremost a plumbing forum. HVAC questions that are are more serious than just replacing the thermostat are often given the standard answer, "Call your HVAC professional."

    PS: Didn't your CO detector go off, alerting you to a hazardous situation?
    Last edited: Dec 26, 2008
  5. burleymike

    burleymike New Member

    Nov 4, 2008
    If that smell is coming out of the exhaust what would that have to do with a cracked exchanger? If that smell is coming out of the supply ducts then it makes sense.
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