What Are the Warning Signs of a Carbon Monoxide Gas Leak?

Carbon monoxide (CO) is referred to as the “silent killer” for a reason. It’s clear, odorless and hard to detect without the right tools. If it builds up in your home, it can quickly become a danger for you and your family. So, how do you stay safe against something you can’t find with your senses?

The key is to install carbon monoxide detectors. These small alarm systems are your first 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 signs to watch out for.

1. Condensation on Windows Near Appliances

If you see heavy condensation on your windows, especially near a fuel-burning appliance like a gas fireplace, this could suggest that ventilation isn’t working properly. While humidity or condensation itself doesn’t always mean CO, this still deserves a closer look.

2. Discoloration or Soot-Like Stains

Combustion-based appliances should always have clear exhaust. If you find brownish-yellow or sooty stains around a heating system, fireplace or boiler, there may be combustion issues. This can signal a carbon monoxide issue.

3. Exhaust Fumes Indoors

If you start to smell or see exhaust fumes indoors, you are in danger of carbon monoxide symptoms. Gas-burning items like cars, charcoal grills and generators should only be operated outside to avoid the buildup of exhaust fumes indoors.

4. Soot in or Around a Natural Gas-Burning Fireplace

Your fireplace should vent smoke and other gases through the chimney. Seeing soot buildup around your fireplace is cause for concern, especially if there’s an unusual amount. A blocked chimney vent could be the reason carbon monoxide is coming back indoors.

5. Increasingly Weak or No Draft from Your 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, your chimney may be blocked, sending carbon monoxide back into your home.

6. Yellowish or Flickering Flames

Gas-powered appliances should have a steady blue flame. If the flame is weaker and yellow (and you don’t have a decorative gas fireplace), it means the gas isn’t burning properly and might be emitting carbon monoxide.

7. Solid Fuel Fires Aren’t Burning as Fast

In situations where your wood- or coal-fired stove begins burning slower than usual or has trouble even staying on, it could be dealing with a ventilation issue, raising the risk of CO buildup.

Common Health Symptoms of CO Poisoning

If you miss the first red flags of a carbon monoxide leak in time, the next one may soon come from your health and well-being. 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 combined with any of the previously mentioned clues, move outdoors immediately and contact emergency services.

Prevention and Safety Tips

Prevention is always better than a cure, especially when it comes to CO gas exposure. For the most basic safety, ensure you’ve installed carbon monoxide detectors in all the right places. Building codes require them in hallways near all bedrooms, on each floor of your home and in rooms with fuel-burning appliances. For an additional safety measure, it’s smart to install interconnected detectors so that when one goes off, all of them will raise the alarm. Check your alarms monthly and replace them as needed, about every five to seven years.

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