What Are the Warning Signs of a Carbon Monoxide Leak?

Carbon monoxide (CO) is referred to as the “silent killer” for a reason. It’s invisible, scentless and hard to recognize without the right tools. If it accumulates 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 find with your senses?

The key is to use carbon monoxide detectors. These alarms are your first line of defense, notifying you of the presence of CO gas before the situation gets dangerous. But other than a detector going off, how can you tell if there’s a carbon monoxide leak in your home? These are 10 signs to watch out for.

1. Condensation on Windows Closest to Appliances

If you see heavy condensation on your windows, namely near a combustion-based system like a gas fireplace, this could suggest that ventilation isn’t working properly. While condensation by itself may not mean CO, this still warrants investigation.

2. Yellow or Brown Stains

Appliances that run on combusting fuel should have clean, clear exhaust. If you see brownish-yellow or soot-like stains around a heater or gas fireplace, there may be combustion issues. This can signal a carbon monoxide issue.

3. Exhaust Fumes Appear Indoors

If you can smell or see exhaust fumes 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 reduce the risk of exhaust fumes indoors.

4. Soot in or Around a Gas Fireplace

Your fireplace should vent smoke and other gases up and out the chimney. Finding soot inside or around the fireplace is a red flag, especially if there’s an unusual amount. A clogged chimney could be why carbon monoxide is leaking back into your home.

5. Weaker or No Draft from Your Chimney

On the topic of chimneys, a properly working one needs the strong airflow to fully remove smoke and other fumes. If you notice weak airflow or even no draft at all, your chimney may be clogged, pushing carbon monoxide back into your home.

6. Yellowish or Inconsistent Flames

All appliances that use gas should produce a distinct blue flame. If the flame is weaker and yellow (and it’s not a decorative gas fireplace), it can mean the gas is burning inefficiently and could be releasing carbon monoxide.

7. Solid Fuel Fires Burning Slowly

When your wood or coal stove starts burning slower than usual or has trouble even staying on, it could be dealing with a problem with airflow, heightening the possibility of CO buildup.

Symptoms of CO Poisoning

If you fail to notice the initial warning signs of a carbon monoxide leak in time, the next clue may soon come from your body. 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 family starts getting sick, especially combined with any of the above signs, leave the house right away for fresh air before you dial 911.

Prevention and Safety Tips

Prevention is always better than a cure, especially when it comes to carbon monoxide. First, check that there are carbon monoxide detectors in appropriate places. Building codes require them close to any bedrooms, on each level of your home and in rooms with gas-powered equipment. For extra safety, it’s smart to use interconnected detectors so that whenever one detects CO, all of them will sound. Test these detectors monthly and swap them out when necessary, about every five to seven years.

In addition to having enough carbon monoxide detectors, keep these safety precautions in mind: