(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 style ones.
I’d call the fire department to ask them to come out and make sure that there’s not anything slow burning that’s hidden in the walls. Be sure to mention two separate smoke detectors have been going off. Even if that’s not what it is they’ll be fine with coming out to check.
Anecdotally, when I was a kid, we had an electrical issue wherein a short or something was causing wires to slowly melt through their jacket, inside the wall. It was triggering smoke detectors, but we couldn’t see or smell anything. Fire department came out and found it, but if we’d ignored it, it almost definitely would have been a huge house fire eventually. Definitely second this advice. It doesn’t cost anything to have them come look.
In my first apartment, I had a smoke detector that was mains powered. The wire metals weren’t compatible and eventually the wirenuts burned and cut off power to half the room. The smoke detector’s wires were all burnt up. It never alarmed unfortunately so I only learned about it when half the room just went dark. That could absolutely have turned into an electrical fire.
Definitely worth getting it checked.