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Subscribe to our RSS Feed Know What Can Trigger a Carbon Monoxide Detector Before It Sounds

Monday, December 16, 2013

If your home uses any combustion appliances or has an attached garage, you may want to install carbon monoxide detectors to protect you and your family. The only way to know it's present is with a detector. The threshold at which the alarm sounds varies by detector, and a few types show periodic read-outs of the level, which is helpful if you have aging gas appliances. Here's some insight into where CO leaks can occur to trigger your detector:


A gas furnace has the potential to bring CO into your home when:

  • It has a crack in the heat exchanger. This part gets hot during the combustion process and air flows over it when the furnace runs. The heat exchanger is made from metal that's subject to cracking due to aging and metal fatigue. It can also crack if the furnace isn't routinely maintained.
  • The flue or chimney has an obstruction or a crack. These need to be checked periodically to make sure they're clear and intact. 
  • The ductwork has a leak. Leaks in the ductwork can pull carbon monoxide into your home if you have any vented gas appliances. If your ducts run through the attic and your garage is attached, the leaks can also pull CO, along with other fumes, into your home's air. If the carbon monoxide detectors go off during or just after the furnace runs, you should have a HVAC contractor inspect your heating system for leaks or other problems.


  • A gas water heater can also have a blocked vent pipe that will emit CO into your home.
  • Gas stoves and ovens can emit CO into the air, which is why you should never use them for heating your home during a power outage. 
  • Ventless combustion heaters can emit CO into your home. They shouldn't be used without fresh air ventilation over a prolonged period.


Running your car in an attached garage or using a barbecue inside it, even with the door open, can bring carbon monoxide into your home.

To learn more about the importance of carbon monoxide detectors in your Chicago, southwestern Michigan or northwestern Indiana home, contact today.

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