Bests & Worsts Reviews from Amazon

These things are apparently programmed from the factory to go off only in the middle of the night. The beeping is just loud enough that you can't just sleep through it. And the darn beeping occurs with too much of a delay so that when you do get up to find it, it takes way too long in the middle of the night to triangulate and figure out which one you have to take down so that you can go back to sleep and deal with it in the morning. It's like some torture game of hide and seek. By the time you figure out which one is malfunctioning, you've been awake and annoyed long enough that you're pretty much now wide awake. Is it some kind of North Korean/Russian plot to destroy the lives of normal mundane US citizens through intermittent sleep deprivation? First the election, now this. One chirp every 3-4 minutes means that the 9V back up battery is dead. Three chirps that go off every 3-4 minutes indicates that the detector as a whole is malfunctioning. Replacing the battery doesn't do anything. I've tried dusting them out with an air gun but usually doesn't work. Most authorities recommend replacing these things about ever 5-10 yrs or so. So far, about 5 years is about how long these have lasted in my house, and over the past several months I've been replacing one after the other. I've lost enough sleep on random nights over the past several weeks that I'm just going to replace all the rest of the ones in my house and just move on with my life. As a bonus annoying factor, the 9V battery lasts about 4 yrs. I just went through and replaced all the batteries less than 9 months ago, and now I'm going around replacing the whole darn thing. So that was a nice waste of money, especially since the new detectors come with new 9V batteries and now I have a small stockpile of partially used 9V batteries. The only good thing is that they are easy to replace, and much cheaper on Amazon than the local brick and mortar stores. And thankfully, I haven't had one go off because of a house fire or carbon monoxide buildup, so I can't comment on their effectiveness, but I guess it's one of those things you just have to assume will work when it needs to... like the airbag in your car.