New York state leads the nation in deadly house fires with more than 800 deaths since 2017, according to the Firefighters Association of the State of New York. Fire officials say that's why having smoke and carbon monoxide detectors is a must for the safety of every home and everyone in it.

The detectors come in various forms and fire safety experts say it's essential to understand how to use them and when to replace the batteries. Typically, smoke and carbon monoxide detectors are separate devices, however, they are also sold as one combined unit. It's important to know which type you have installed in your home.

The Gates Fire Department recommends changing the battery annually, regardless of your location in the state. Opting for detectors with a 10-year sealed battery minimizes the need for frequent battery replacements. Many detectors will emit a chirping sound to let you know when the battery needs to be changed. It's also recommended to replace the entire detector after 10 years.

Kalliopi Lang, a community risk reduction specialist, emphasizes the role of the detectors in saving lives.

"We've gone to many homes where they were alerted by their wireless smoke and carbon monoxide alarms, and many residents have been able to escape their homes prior to the fire getting worse because of those smoke and CO alarms," said Lang. "It is required and we recommend having at least one smoke and one carbon monoxide alarm on each level of your home, including your basement, but also, if you can in every room as well, especially bedrooms."

You can find an expiration date located on the back of most smoke and carbon monoxide alarms that will tell you when they need to be replaced. Safety experts say when it is time to buy a new detector, it's best to avoid Amazon and eBay because you may end up with a defective unit that would compromise your safety. Your best bet is to check with your local fire department or your local home improvement store for brand new, certified smoke and CO alarms.