Some Carbon Monoxide Hazards are Unique to Winter

Written by Anita Alvarez
Updated January 20, 2015
Icicles hanging from a roof
When your furnace’s sidewall vents are blocked with snow or ice, they can push poisonous carbon monoxide into your house. (Angie's List/Eldon Lindsay)

Homeowners must be vigilant about carbon monoxide hazards throughout the year. But winter brings a unique safety concern tied to high-efficiency furnaces.

Get quotes from up to 3 pros!
Enter a zip below and get matched to top-rated pros near you.

Carbon monoxide hazards are a year-round concern, but you also should know about the one danger that happens only in winter.

High-efficiency furnaces

Very efficient furnaces pose a specific CO threat in winter. Their manufacturers use a unique venting and sealed combustion system that has a sidewall vent not seen with standard furnaces. If you make sure such sidewall venting is clear of snow or ice, it will continue to provide a secure way for CO to escape the house. That means you and your family should remain safe.

What can go wrong

When it snows or ice forms on the vents, they can become clogged. When the CO is blocked from getting out, it can be pushed back into your home and could lead to carbon monoxide poisoning.

How to stay safe

After a snowstorm or ice storm, or when the temperatures are extremely low, you should go out and visually inspect the vents. Keeping them clear will help avoid CO poisoning.

If there's a lot of snow, clear a path of 2 to 3 feet around each vent. If you see ice forming on the vents, gently knock it off without damaging the pipes.

Preventive step in the fall

In the late fall, take off the exhaust vent’s screen, which is designed to keep debris from entering or exiting the vent. The screen makes it easy for ice to hang on, which lets more ice and snow build up and create a larger blockage.

More you can do

Do not run a gas-powered stove to provide heat when the power goes out. That leads to a buildup of CO, which raises the risk of poisoning, according to the Centers for Disease Control and Prevention.Install CO detectors around the home, and check them monthly to ensure they're working.Schedule annual HVAC service for your furnace, including inspecting the venting system and combustion process.Set service appointments for all natural-gas appliances to prevent CO hazards. Also have a wood-burning stove or fireplace looked at, as they can pose a CO threat.To learn more tips, read this. If you have an attached garage, learn what you can do to keep your home safe.

Call a professional

With a few simple maintenance tasks and routine expert tune-ups, you can make your home as safe as possible and eliminate CO hazards. Don't wait to contact an HVAC provider or appliance repair person. Schedule a service appointment for the gas-powered appliances in your home to stay safe all year.

Need professional help with your project?
Get quotes from top-rated pros.