What Are the Signs of a Carbon Monoxide Leak?

Carbon monoxide (CO) is known as the “silent killer” for a reason. It’s clear, scentless and tough to detect without the right tools. If it builds up in your home, it can quickly become a serious hazard for you and your family. So, how do you guard against something you can’t really notice naturally?

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

1. Condensation on Windows Closest to Appliances

If you spot lots of condensation on your windows, especially near a combustion-based system like a gas fireplace, this could mean that there’s an issue with ventilation. While humidity or condensation itself doesn’t always mean CO, this still should be checked out.

2. Yellow or Brown Stains

Fuel-powered appliances should always have unobstructed ventilation. If you see brownish-yellow or soot-like stains around a heating system, fireplace or boiler, it could mean something’s wrong with the combustion process. This can be a sign of a carbon monoxide leak.

3. Exhaust Fumes Appear Indoors

If you can notice exhaust inside the house, you are at risk of carbon monoxide exposure. Gas-burning items like cars, charcoal grills and generators should always be used outdoors to prevent an accumulation of exhaust fumes indoors.

4. Soot in or Around Your Fireplace

Your fireplace should vent smoke and other gases through the chimney. Seeing soot buildup around your fireplace is a red flag, especially if there’s an unusual amount. An obstructed flue in the chimney could be why carbon monoxide is leaking back indoors.

5. Weak or No Draft from Your Chimney

Staying on the topic of chimneys, a properly working one should have the solid updrafts to fully remove smoke and other fumes. If you detect weak airflow or even no draft at all, your chimney could be obstructed, sending carbon monoxide right back indoors.

6. Yellowish or Flickering Flames

All appliances that use gas should have a steady blue flame. Whenever the flame is weak and yellow (and it’s not a decorative gas fireplace), it means the gas has combustion issues and could be releasing carbon monoxide.

7. Solid Fuel Fires Aren’t Burning as Fast

When your wood- or coal-fired stove begins taking longer to burn or has trouble maintaining a flame, it could be dealing with a ventilation issue, heightening the possibility of CO buildup.

Common Health Symptoms of CO Poisoning

If you fail to notice the other signs of a carbon monoxide leak in time, the next warning may soon come from your health. Symptoms of CO poisoning include:

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 together with any of the previously mentioned clues, move outdoors immediately and contact emergency services.

Prevention and Safety Tips

It’s always better to prevent issues than respond to them, especially when it comes to CO gas exposure. To start, 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 appliances like a gas stove or water heater. For added security, it’s smart to use interconnected detectors so that whenever one detects CO, all of them will alarm you as well. Perform monthly testing and swap them out when necessary, usually every five to seven years.

In addition to using carbon monoxide detectors, follow these safety tips: