Carbon Monoxide and Your Fireplace: Detectors, Venting, and Warning Signs
Yes, a fireplace can produce carbon monoxide (CO), the same as any appliance that burns fuel. The U.S. Consumer Product Safety Commission lists fireplaces among the consumer products linked to CO deaths. CO has no smell, so the best protection is a yearly inspection of your fireplace and chimney, a clear and working vent, and CO alarms on every level of your home. If an alarm sounds, get everyone outside and call 911. Here's what causes problems, what to watch for, and how to protect your family.
How a Fireplace Can Produce Carbon Monoxide
CO is produced by the incomplete burning of fuel. With wood, gas, or pellets, a fireplace or stove should send its exhaust up and out through the flue or vent. When that doesn't happen, CO can end up inside your home.
Common causes include:
A blocked chimney or flue. Creosote buildup, a bird nest, debris, or a failing liner can keep exhaust from leaving.
A damaged or disconnected vent. Cracks, corrosion, or loose connections can let exhaust escape into the house.
A closed damper. For a wood burning fireplace, running a fire with the damper closed sends smoke and gases into the room.
Poor combustion. A dirty or malfunctioning gas unit, or a fire that isn't getting enough air, can produce more CO.
Downdrafts. In some homes, a tightly sealed house or wind conditions can push exhaust back down the chimney.
Warning Signs to Watch For
CO can't be seen or smelled, so you rely on symptoms and on your alarms. The CPSC says low to moderate exposure looks like the flu, but without a fever. Watch for headache, fatigue, shortness of breath, nausea, and dizziness. High exposure can cause confusion, vomiting, loss of muscle coordination, unconsciousness, and death.
Clues that your fireplace may be involved:
Symptoms that show up when the fireplace is in use. Pay attention to headaches or dizziness that start once you've been near a fire.
Several people feel sick at once. Or pets seem unwell.
Smoke or fumes in the room. A fireplace should draw smoke up and out.
Soot stains or discoloration. Dark marks around the opening or on the wall can point to exhaust escaping.
A pilot light or ignition that keeps going out (gas units). It can signal a venting or airflow issue.
A CO alarm sounding. Never assume it's false.
Where to Put Carbon Monoxide Alarms
According to the CPSC, battery operated or battery backup CO alarms should go on every level of your home and outside sleeping areas. Interconnected alarms are best, because when one sounds, they all sound. The CPSC also says to avoid spots near heating vents or where furniture or draperies can cover them, and that it doesn't recommend installing CO alarms in kitchens or above fuel burning appliances.
Two habits matter just as much as placement:
Test and maintain them. Follow the manufacturer's instructions. The CPSC notes that a test button checks the circuitry, but not the accuracy of the sensor.
Replace them on schedule. The CDC says to replace detectors per the manufacturer's instructions, and no later than every 5 years. You can read more in the CPSC's carbon monoxide fact sheet.
Get a Yearly Inspection
The CPSC recommends having your heating system inspected and serviced yearly, including checking chimneys and flues for blockages, corrosion, and partial or complete disconnections. That's the most important thing you can do to prevent CO problems.
At The Grate Haus, we offer annual maintenance for all makes and models of fireplaces, stoves, and inserts, plus diagnostics and repair for units that aren't running right. On the chimney side, we do annual cleaning, masonry repair, flue cap installation, crown repair, and flashing.
Safe Habits for Every Fireplace Type
Wood burning. Open the damper fully before you light a fire, and keep it open until the ashes are completely cool. Burn only seasoned firewood, and keep the flue clean.
Gas. Have it serviced yearly, and don't ignore a pilot light that keeps going out or a unit that isn't operating normally.
Pellet. Keep the vent and exhaust pipe clear and clean, and follow the manufacturer's maintenance schedule.
All types. Never use a fireplace or stove that you suspect isn't venting properly, and never use a gas oven to heat your home.
What to Do If Your CO Alarm Goes Off
Don't assume it's a false alarm. Get everyone out of the house, including pets, into fresh air, and call 911. Don't go back inside until help says it's safe. Once the problem has been found, don't use your fireplace again until it's been inspected by a professional.
How The Grate Haus Can Help
The Grate Haus has served Jackson and the surrounding area for over 20 years. We sell and install gas, wood, pellet, and electric fireplaces, stoves, and inserts, and we maintain and repair them too. Our chimney services cover cleaning and repair, so we can look at your whole system.
If it's been a year since your last inspection, or you've noticed any warning signs, call us at (517) 750-0300 or fill out our form online to schedule an inspection.
Frequently Asked Questions
Can a fireplace cause carbon monoxide poisoning?
Yes. Fireplaces burn fuel, and if the exhaust doesn't leave through the flue or vent, carbon monoxide can build up in your home. The U.S. Consumer Product Safety Commission lists fireplaces among the products linked to CO deaths.
Can you smell carbon monoxide from a fireplace?
No. Carbon monoxide is odorless and colorless. That's why working CO alarms and a yearly inspection are so important.
Where should I put carbon monoxide alarms?
On every level of your home and outside sleeping areas. Interconnected alarms are best. Avoid kitchens, heating vents, and spots above fuel burning appliances, and don't let furniture or drapes cover them.
How often should I replace a CO alarm?
Follow the manufacturer's instructions, and no later than every 5 years, according to the CDC. Many alarms have a replacement date printed on them.
What are the symptoms of carbon monoxide poisoning?
Low to moderate exposure feels like the flu without a fever, with headache, fatigue, shortness of breath, nausea, and dizziness. High exposure can cause confusion, vomiting, and loss of consciousness. If you suspect it, get outside and call 911.
Should I have my fireplace inspected every year?
Yes. The CPSC recommends yearly inspection of heating systems, including checking chimneys and flues for blockages, corrosion, and disconnections. We offer annual maintenance for all makes and models of fireplaces, stoves, and inserts.
What should I do if my CO alarm goes off?
Get everyone outside, including pets, and call 911. Don't go back in until help says it's safe. Don't use the fireplace again until a professional has inspected it.
The Grate Haus is Jackson, Michigan’s premier fireplace store and home living specialists. From fireplace sales, to hot tubs, to outdoor kitchens and grills, we are your one-stop-shop for home upgrades and living. We serve Jackson County and the surrounding areas, including Hillsdale County, Lenawee County, and Washtenaw County.