Results 1 to 12 of 12
  1. #1
    Join Date
    Dec 2005
    Posts
    2
    Dear Friends,

    Last year, we had problems with our gas furnace. A technician came in to fix the problem. While he was troubleshooting, he put a small hole in the flue pipe and inserted a small rod to read the flue temperature. After that, he put a small button like cover to close the hole.

    Recently, last week I found out that the button cover was on the floor. I don't know when it fell. I put it back to cover the hole.

    Can the harmful flue products like CO escape through such a small hole?

    The small cover keeps on falling. Every day, I have to check this out. can this small hole be open for some hours without causing any harm to us?

    Any idea? thank you.

  2. #2
    Join Date
    Nov 2000
    Location
    Eastern PA
    Posts
    68,981
    It depends on what type of furnace you have. If you have a furnace that has induced draft (a small fan that starts up before anything else happens when the thermostat calls for heat) then you may be getting a small amount of flue gas out of that hole before the chimney's natural draft takes over.

    Even at that, there should be no CO entering your home. After all, there is no vent whatsoever for your gas stove or oven.
    Government is a disease...
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  3. #3
    Join Date
    Mar 2004
    Location
    SE Michigan
    Posts
    18,223
    How big of a hole? if its the size of a screw, then put a screw in it or just replace that section of pipe or put some high temperature silicone on it or some UL approved foil tape.

    You should always have a carbon monoxide detector in your home and replace it every couple of years.

    Even with a brand new shiny furnace.
    To put the world in order, we must first put the nation in order; to put the nation in order, we must put the family in order; to put the family in order, we must cultivate our personal life; and to cultivate our personal life, we must first set our hearts right.
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  4. #4
    Join Date
    Nov 2001
    Posts
    1,874
    Is this an oil furnace ?
    If so he was trying measure the draft.

    If it is oil, you should call them back out every year.
    Then while they are there ask them to seal it.

    [Edited by Toolpusher on 12-12-2005 at 04:48 PM]
    If you try to fail, and succeed.
    Which have you done ?



  5. #5
    Join Date
    Dec 2005
    Posts
    2

    My furnace is induced draft. If I am getting small amount of flue gas out of the hole, does it mean that I am also getting CO? I thought that the flue gas has CO in it.
    Please, correct me If I am wrong.

    My furnace is natural gas.

  6. #6
    Join Date
    Feb 2005
    Location
    Richmond
    Posts
    480
    Im no pro, but I would think that if the furnace is burning cleanly, it should not produce CO or maybe only a small amount. In any case, you should get the hole fixed, just to be safe.

  7. #7
    Join Date
    Jun 2003
    Location
    Chicago, IL
    Posts
    4,568
    a properly tuned furnace should produce a minimum amount of CO, but why risk it.

    if the hole is fairly small, get a stainless steel screw from the hardware store to plug the hole. the stainlenss steel screw will be easy to remove in the future in case another test is necessary. a regular screw will rust and could break off and fall into the inducer fan and damage it. untill you get the screw wrap some duct tape around the pipe as a tempory fix

  8. #8
    Join Date
    Mar 2005
    Location
    burlington county n.j.
    Posts
    9,765
    do NOT put duct tape on a furnace flue. use a rated foil tape or high temp caulk to seal hole.

  9. #9
    Originally posted by geetha

    My furnace is induced draft. If I am getting small amount of flue gas out of the hole, does it mean that I am also getting CO? I thought that the flue gas has CO in it.
    Please, correct me If I am wrong.

    My furnace is natural gas.
    Yes, with an induced draft furnace it will put out some CO.

    Seal the hole with either a SS screw or high temp silicone.

    FYI... Everything that burns creates CO no matter how clean it burns.

  10. #10
    Join Date
    Apr 2003
    Location
    California
    Posts
    634
    jultzya and some of the others are correct, seal that small hole up.. use a screw or some kind of hi-temp caulk. you can never be to careful....

  11. #11
    Join Date
    Jun 2003
    Location
    Chicago, IL
    Posts
    4,568
    Originally posted by t527ed
    do NOT put duct tape on a furnace flue. use a rated foil tape or high temp caulk to seal hole.
    when i posted the suggestion about duct tape as a temporary fix, i was thinking that this was a condensing furnace with a PVC vent. however i now see the type of furnace is not stated other than that it has a draft inducer. so, if the vent is metal don't use duct tape or it will burn up

  12. #12
    Join Date
    Aug 2002
    Location
    Westlake, Ohio
    Posts
    2,535
    If you have a metal flue the hole has no affect on CO getting in the house. None of the joints on the flue pipe are air tight and would leak just as much. You flue should be sucking in and up. If it was a plastic flue you would see lots of water coming out and that would be the worst problem. If flue gases or CO coming out of these holes is a problem then there is a much bigger problem that needs to be fixed. Usually any mechanic that drills a hole in the flue to test is of the highest skills and knows this is the only way to truly service your equipment properly. Those that don't are just winging it.
    captain CO

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