What Are the Signs of a Carbon Monoxide Leak?

Carbon monoxide (CO) is known as the “silent killer” for a reason. It’s colorless, scentless and difficult to recognize without the right tools. If it collects in your home, it can rapidly turn into a danger for you and your family. So, how do you stay safe against something you can’t see, smell or taste?

The key is to install carbon monoxide detectors. These small alarm systems are the first line of defense, alerting you to the presence of CO gas before the situation gets dangerous. But aside from a detector going off, how can you recognize if there’s a carbon monoxide leak in your home? Below are 10 clues to be aware of.

1. Condensation on Windows Near Appliances

If you see heavy condensation on your windows, especially near a combustion-based system like a gas fireplace, this could mean that something isn’t venting correctly. While condensation by itself may not mean CO, this clue should be checked out.

2. Discoloration or Soot-Like Stains

Combustion-based appliances should have clean, clear exhaust. If you notice brownish-yellow or soot-like stains around a heater or gas fireplace, combustion isn’t happening as it should. This may point to a carbon monoxide issue.

3. Exhaust Fumes Appear Indoors

If you can smell or see exhaust fumes inside the house, you are in danger of carbon monoxide leaks. Fuel-burning appliances like cars, charcoal grills and generators should exclusively be operated outside to avoid the buildup of exhaust fumes indoors.

4. Soot in or Around the Fireplace

Your fireplace vent should remove smoke and other gases through the chimney. Finding soot inside or around the fireplace is cause for concern, especially if there’s excessive amounts. A blocked chimney vent could be the culprit for why carbon monoxide is coming back indoors.

5. Increasingly Weak or No Draft in the Chimney

Speaking of chimneys, a properly working one needs the solid updrafts to fully remove smoke and other fumes. If you notice weak airflow or even no draft at all, the chimney might be blocked, pushing carbon monoxide backward.

6. Yellowish or Weak Flames

All appliances that use gas should produce a distinct blue flame. Whenever the flame is yellow or flickering (and you don’t have a decorative gas fireplace), it can mean the gas isn’t burning properly and might be emitting carbon monoxide.

7. Solid Fuel Fires Burning Slowly

When your wood-burning stove starts taking longer to burn or has trouble staying lit, it could be dealing with a ventilation issue, increasing the risk of CO buildup.

Signs You May Have CO Poisoning

If you fail to notice the first red flags of a carbon monoxide leak in time, the next warning might come from your health. 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 starts getting sick, especially combined with any of the previously mentioned clues, leave the house right away for fresh air before you dial 911.

Prevention and Safety Tips

Prevention is always better than a cure, especially regarding CO gas exposure. For the most basic safety, ensure you’ve installed carbon monoxide detectors in all the right places. Building codes require them close to any bedrooms, on each level of your home and in rooms with gas-powered equipment. For an additional safety measure, it’s wise to install interconnected detectors so that whenever one detects carbon monoxide, all of them will alarm you as well. Perform monthly testing and swap them out when necessary, about every five to seven years.

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