are considered expired and need to be replaced. This is true for all MD home owners.
I just recently hired an electrician
to get my home up to code. I had smoke alarms installed in all of my bedrooms and added another one on my main level (previously there was only one in the house and it was on the second level). These are hardwired into the house and if one is set off it will set off all of the other alarms. They also detect carbon monoxide. These updates are an important safety upgrade for your home.