(I have carbon monoxide detectors that are not going off)
I have smoke detectors that are incorporated into my home alarm system. The other day, the one by my front door went off for no apparent reason, twice, and when I changed the batteries, it started alarming again immediately.
there was absolutely no reason for it, there were no open windows or doors nearby, it just went off. so, my alarm company replaced it. installed the new smoke detector yesterday and… it just went off again. completely different smoke detector.
there’s absolutely nothing in my house that could produce carbon monoxide, but I have separate CO detectors anyway that aren’t going off. there’s no smell, there’s nothing visible, and these are those electro optical photoelectric style ones.
Try replacing the batteries. That’s often the reason for this type of thing.
as stated, as soon as I replaced the battery it started alarming immediately so I replaced the entire detector and it’s still doing it
AFAIK in the USA you can’t have the main batteries be replaceable (I think an aux battery for wireless functions is allowed…).
EDIT: I seem to be thinking of California, maybe not all of US.