Carbon monoxide dangers you should be aware of

The winter months pose a deadly risk for many homeowners -- the danger of being exposed to carbon monoxide from furnaces and heaters that burn natural gas.

There's a major recall of smoke and carbon monoxide alarms that are supposed to warn people if there is a buildup of the gas in a home.

Channel 9 discovered another concern that often goes overlooked, and it’s one that will have you climbing a ladder to check every unit in your house.

Mary Anne White was suffering from terrible headaches, nausea and diarrhea, and she had no idea why.

"Why do I keep having these headaches every day? If I'm away from this house and gone more than two hours, I don’t have a headache,” she explained to Channel 9. “As soon as I come back in a have a headache."

Then a utility worker checked the wall-mounted heater in her Rock Hill home and found it was leaking carbon monoxide -- deadly gas that cannot be seen or smelled.

"I would have died in this house," White said.

She had no carbon monoxide detectors in her house, and Channel 9 has reported on several tragic results due to lack of protection.

A couple died inside a room at a Boone hotel in 2013, and weeks later, a young boy died in the same room. An investigation revealed that carbon monoxide was leaking into the room from a pool heater.

There were no alarms.

In November of last year, 31 people in North Carolina went to the emergency room due to carbon monoxide exposure. Among them, 16 people who became sick at a Salisbury home after running a portable generator inside.

Experts agree that a working CO detector is a must, but even that may not be foolproof.

Last fall, Kidde recalled more than 5 million of its Nighthawk smoke and carbon monoxide detectors because they might not chirp when their 7-year usable life is over, so homeowners wouldn't know they need to be replaced.

Channel 9 learned that the concern goes beyond just one recall though.

Charlotte Fire Safety educator Amy Rea helped Eyewitness News check the units inside one particular house, and found something disturbing -- all of them were made in 2002 and were well past their usable life span.

Smoke and smoke/carbon monoxide combination detectors only last 10 years, while CO detectors are only usable for 5-7 years.

Some of the units in the house we checked did appear to work properly when tested, but Rea said they were way too old.

"You want the manufacture date to be within the past 10 years," she said.

If your home is 7-10 years old and you still have the original ceiling mounted units, it’s time to take a look. Experts say you should already be changing the batteries every six months and testing each unit.

White recently had new heater installed in her Rock Hill home, and she feels better now that she had carbon monoxide detectors put in.

If your CO detectors goes off you should move to fresh air and call 911.

Channel 9 called and emailed Kidde several times to ask how many of those recalled alarms they've been able to replace, but they never returned any messages.

Click here to check if your alarm is under any recalls, and learn more about the Kidde recall here.

Cox Media Group