If your CO alarm goes off
Get everyone, pets included, outside into fresh air right away and call 911. Don't stay inside to look for the cause, and don't go back in until responders say it's safe.
Once it's safe, call us. We'll check the furnace, water heater and venting to find where the CO came from. Don't run the furnace again until it's been checked.
Warning signs of CO poisoning
The CDC lists headache, dizziness, weakness, upset stomach, vomiting, chest pain and confusion as the most common symptoms, often described as flu-like. Be suspicious if several people or pets in the home feel sick at the same time, and feel better after they leave the house.
Where to put CO alarms
- Install CO alarms on every level of the home and outside each sleeping area, as the U.S. Consumer Product Safety Commission recommends.
- Test them every month and replace the batteries at least once a year. The CDC suggests checking them when you change your clocks in spring and fall.
- Replace the alarm itself when its manufacturer says to, or at least every five years, per the CDC.
How a furnace can produce CO
A gas furnace burns natural gas or propane and sends the exhaust outside through a flue or vent pipe. CO becomes a risk when the fuel burns poorly or the exhaust doesn't get out:
- A blocked or disconnected vent pipe or chimney, including snow or ice over the plastic vent pipes of a high-efficiency furnace.
- A cracked heat exchanger, which can let combustion gases mix with the air the blower sends through your house.
- Dirty or poorly adjusted burners that don't burn cleanly.
- Exhaust being pulled back into the house instead of going up the flue, for example when a shared flue is blocked.
How to lower the risk
- Have your furnace and other gas appliances checked by a qualified technician every year, as the CDC recommends.
- Keep outdoor vent pipes clear of snow, leaves and debris.
- Never run a generator, grill or car in the house or an attached garage, even with the door open. Keep generators at least 20 feet from windows, doors and vents.
- Never use a gas oven or stove to heat the house.
What our heating tune-up checks
Our fall heating tune-up includes a carbon monoxide check on the venting, along with the flame sensor, burners, gas pressure, safety switches and blower. See tune-ups and maintenance.
The Comfort Club is $180 a year and includes a heating tune-up in the fall and a cooling tune-up in the spring, plus 20% off repairs and priority scheduling. Call or text (859) 684-3259 to book.
Common questions
Can a furnace leak carbon monoxide?
Yes. A gas furnace can release CO into the home if its vent is blocked or disconnected, its heat exchanger is cracked, or its burners aren't burning cleanly. Electric furnaces and heat pumps don't burn fuel, so they don't produce CO.
Where should carbon monoxide alarms go?
On every level of the home and outside each sleeping area, per the U.S. Consumer Product Safety Commission. Test them every month.
How often should CO alarms be replaced?
Follow the manufacturer's instructions; the CDC says to replace them at least every five years. Replace the batteries at least once a year.
What should I do if my CO alarm goes off?
Get everyone outside into fresh air and call 911. Don't go back in until responders say it's safe. Then have the furnace, water heater and other gas appliances checked before you use them again.
Does a furnace tune-up check for carbon monoxide?
Ours does. HVAC Doctor's heating tune-up includes a carbon monoxide check on the venting, along with the burners, flame sensor, gas pressure, safety switches and blower.