(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.
Does it get hot by your front door or in direct sunlight? We have a few in my house that go off if our kitchen gets too hot. We had to move them down the hall slightly and they stopped. A really old one we have upstairs, hardwired into the house electric (built in 86) trips if too much steam builds up in the bathroom and let’s loose into the hall.