What Are the Signs of a Carbon Monoxide Leak?

Carbon monoxide (CO) is called the “silent killer” for a reason. It’s invisible, odorless and difficult to notice without proper tools. If it collects in your home, it can rapidly turn into a danger for you and your family. So, how do you protect yourself against something you can’t find with your senses?

The key is to have carbon monoxide detectors. These alarms are your initial line of defense, warning you about the presence of CO gas before the situation gets dangerous. But besides a detector going off, how can you tell if there’s a carbon monoxide leak in your home? These are 10 clues to watch out for.

1. Condensation on Windows Closest to Appliances

If you spot lots of condensation on your windows, especially near a fuel-burning appliance like a gas fireplace, this could indicate that there’s an issue with ventilation. While condensation alone isn’t always CO-related, this clue should be checked out.

2. Brown, Sooty Stains

Appliances that run on combusting fuel should have clear exhaust. If you notice brownish-yellow or sooty stains around a heater or gas fireplace, there may be combustion issues. This may point to a carbon monoxide risk.

3. Exhaust Fumes Are in the House

If you start to notice exhaust inside the house, you are at risk of carbon monoxide leaks. Fuel-burning appliances like cars, charcoal grills and generators should exclusively be operated outside to reduce the risk of exhaust fumes indoors.

4. Soot in or Around a Gas Fireplace

Your fireplace should vent smoke and other gases up through and out the chimney. Finding soot inside or around the fireplace is a warning sign, especially if there’s more than usual. A clogged chimney could be the culprit for why carbon monoxide is coming back into your home.

5. Weaker or No Draft from the Chimney

Staying on the topic of chimneys, a properly working one should have the solid updrafts to fully pull out smoke and other fumes. If you notice reduced ventilation or even no draft at all, the chimney could be clogged, forcing carbon monoxide backward.

6. Discolored or Weak Flames

All appliances that use gas should produce a distinct blue flame. If the flame is weaker and yellow (and you don’t have a decorative gas fireplace), it means the gas has combustion issues and could be producing carbon monoxide.

7. Solid Fuel Fires Burning Slowly

If your wood or coal stove begins burning slower than usual or has trouble staying lit, it could have a ventilation issue, increasing the risk of CO buildup.

Signs You May Have CO Poisoning

If you miss the first red flags of a carbon monoxide leak in time, the next one could come from your body. Symptoms of CO poisoning may involve:

Flu-like symptoms
Headaches
Dizziness
Nausea or vomiting
Shortness of breath
Confusion
And fatigue

If you or anyone in your home experiences these symptoms, especially together with any of the warning signs listed above, move outdoors immediately and contact emergency services.

Prevent CO Poisoning and Gas Leaks with These Safety Tips

Taking all the proper precautions is key, especially regarding carbon monoxide. First, check that there are carbon monoxide detectors in appropriate places. Building codes require them outside every bedroom, on each floor of your home and in rooms with appliances like a gas stove or water heater. For an additional safety measure, it’s smart to set up interconnected detectors so that when one goes off, all of them will alarm you as well. Perform monthly testing and change them when required, approximately every five to seven years.

Besides installing and maintaining carbon monoxide detectors, keep these safety precautions in mind: