[John Rogers]

I am not sure what hardwired units we have (3) in out alarm system but they have all been replaced once in 26 years. They detect everything and once we had a gas fitting under our old cook top crack and the gas build up tripped the one near the kitchen and by the time we got home the fire dept had the front door open, gas shut off and the house ventilating. Our neighbor has the combination to our front door and opened it so they would not have to break in. Once a year we get the house fumigated and we seal the units up very well with large zip bags and have never had that affect them.