Yes, a furnace can produce carbon monoxide (CO) if it’s malfunctioning, poorly vented, or has a damaged heat exchanger. CO has no smell, no color, and no taste, so you can’t rely on your nose. The best protection is working CO detectors near every sleeping area, a yearly furnace tune up, and knowing the warning signs. If your alarm goes off, leave the house right away and call 911. Here’s what every Michigan homeowner should know before the heating season starts.
How a Furnace Can Produce Carbon Monoxide
Any appliance that burns fuel can produce carbon monoxide, and gas and oil furnaces are on that list. According to the Centers for Disease Control and Prevention, CO comes from burning fuel, and gas or oil burning furnaces, portable generators, and grills are all common sources. When everything works properly, the exhaust leaves your home through the vent. When something goes wrong, CO can end up inside.
The most common furnace related causes are:
A cracked heat exchanger. This is the metal part that separates the burning gas from the air you breathe. Over time, heating and cooling can cause cracks, and a crack can let combustion gases mix into your home’s air.
A blocked or damaged vent. If the exhaust can’t leave the house, it can back up. In Michigan, that can mean snow or ice blocking the outside vent, or a bird nest or debris in the pipe.
Poor combustion. A dirty burner or an out of adjustment system can burn less cleanly and produce more CO.
Poor maintenance. The CDC recommends having fuel burning appliances like furnaces serviced by a qualified technician every year, because small problems are caught before they become dangerous.
Warning Signs of Carbon Monoxide
The tricky part is that CO poisoning feels like the flu. The CDC lists headache, dizziness, and weakness as the most common signs, along with upset stomach, vomiting, chest pain, and confusion. It also warns that people who are sleeping can die from CO before they ever have symptoms.
A few clues that point toward CO instead of a bug:
Several people feel sick at once. If everyone in the house has a headache or feels dizzy at the same time, take it seriously.
Symptoms improve when you leave. If you feel better when you’re away from home, and worse when you get back, that’s a red flag.
Pets are acting off. Pets can show signs before people do.
Symptoms show up when the furnace is running. Pay attention if they started right after the heat came on for the season.
You might also notice signs on the furnace itself, like soot or dark staining around it, a burner flame that looks yellow or orange instead of mostly blue, or excess moisture on windows. None of these prove CO is present, but they’re reasons to have a technician look at the system.
Where to Put Carbon Monoxide Detectors
Detectors are your only reliable early warning, since you can’t smell CO.
The CDC says to install battery operated or battery backup CO detectors near every sleeping area. Consumers Energy suggests going a step further and placing one on every floor of your home. We agree with both. A basement furnace room, a main floor hallway, and the area outside each bedroom is a good starting point.
Two maintenance habits matter as much as placement:
Check the batteries twice a year. The CDC suggests doing it when you change your clocks in spring and fall.
Replace the detector on schedule. Follow the manufacturer’s instructions, and the CDC says no later than every 5 years. An old detector can quit working without telling you.
What to Do If Your CO Alarm Goes Off
Don’t assume it’s a false alarm. Consumers Energy’s guidance is clear on this. If a CO alarm sounds, leave the home immediately and call 911. Move everyone, including pets, outside into fresh air, and don’t go back in until help has arrived and the problem has been found and fixed.
If anyone has symptoms like dizziness, nausea, headache, or confusion, tell the 911 dispatcher so they can get medical help to you.
After the all clear, don’t use the furnace again until a technician has inspected it. That’s the call you make to us.
Michigan Winter Habits That Help
Keep outdoor vents clear. After heavy snow, walk around the house and check the furnace exhaust and intake vents, along with the dryer and water heater vents. Clear snow and ice away from them.
Never heat your home with a gas oven. The CDC specifically warns against it.
Keep generators outside. If you use a portable generator during an outage, it must be well away from the house. Never run it in the garage.
Schedule your fall inspection early. A technician can check the heat exchanger, venting, burners, and safety controls before the first deep freeze.
How Aspen One Hour Heating & Air Conditioning Can Help
At Aspen One Hour Heating & Air Conditioning, we’ve been keeping Jackson County homes safe and comfortable since 1981. Our fall furnace visit covers the parts of your system that affect safety, and Comfort Clubhouse plans include a carbon monoxide and smoke detector inspection along with the furnace tune up. Plans start at $20 a month, with priority scheduling and no standard diagnostic fees.
If your furnace is old, noisy, or hasn’t been checked in over a year, now is a good time to call. Reach us at (517) 879-2049. We serve Jackson County plus Ingham, Eaton, Calhoun, Hillsdale, Lenawee, and Washtenaw counties, and we’re available 24/7.
Frequently Asked Questions
Can a furnace cause carbon monoxide poisoning?
Yes, if it’s malfunctioning or poorly vented. Gas and oil furnaces burn fuel, and problems like a cracked heat exchanger or a blocked vent can let carbon monoxide into your home. That’s why a yearly tune up and working detectors matter.
Can you smell carbon monoxide from a furnace?
No. Carbon monoxide is colorless and odorless. If you smell rotten eggs, that’s added to natural gas to warn you about a gas leak, and it’s a separate emergency. Leave the house and call 911 and your gas utility from outside.
What are the first signs of carbon monoxide poisoning?
Headache, dizziness, and weakness are the most common. You might also feel nauseated or confused, or have chest pain. It’s easy to mistake for the flu, so pay attention if several people feel sick at once or feel better when they leave the house.
Where should I put carbon monoxide detectors in my house?
Near every sleeping area, at a minimum. We also recommend one on every floor, including near the basement or utility room where your furnace is. Test them and check the batteries twice a year.
How often should I replace a carbon monoxide detector?
Follow the manufacturer’s instructions, and no later than every 5 years. Many detectors have a replacement date printed on the back. If you can’t find a date, replacing it is the safe move.
What should I do if my carbon monoxide alarm goes off?
Leave the house immediately and call 911. Take everyone, including pets, outside, and don’t go back in until help says it’s safe. Don’t use the furnace again until a technician has checked it.
Does the Comfort Clubhouse include a carbon monoxide inspection?
Yes, Comfort Clubhouse plans include a carbon monoxide and smoke detector inspection along with a furnace tune up. Members also get priority scheduling and no standard diagnostic fees. Plans start at $20 a month.
Aspen One Hour Heating & Air Conditioning provides HVAC services in Jackson County and the surrounding areas, including Marshall, Holt, and Clarklake. If you have any questions about our services or want to see if we service your area, give us a call at (517) 879-2049.
