Smoke Alarms Won't Shut Off

My friend had that problem and had to call fire dept hers just went off in middle of the night it turned out it was the wiring, it did take the fireman quite a bit of time to figure that out and they said they learned from coming out to her home.
Good luck to you.

Happened with me. It had battery, replaced it, still beeping. disconnected it from wiring, took it down.On the back,that peticuilar model only lasted 2 years. It had to be replaced. No more beeping.

Perhaps your batteries are bad, even though they are new. Have you tried a different package of batteries just in case?

Are they older than 12 years? Most manufacturers say replace them after 10-12 years. Are the vents clean of all dust and bugs? If they are hardwired, you may need to reset your breaker (off and back on) or hit the reset button on the alarm. If all else fails, replace them. I am a firefighter, and too many times have heard people say they disconnected them instead of replacing them, sadly, they tell us as we are fighting their house fire.

Depending on the model, if the "test" button hasn't been used in 6 months to a year it will continually beep until you do the monthly test. I had this same problem a while back, and it worked like a charm!