(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.
Vapes don’t trigger traditional alarms
My partner’s vape triggers ours https://www.kidde.com/home-safety/en/us/products/fire-safety/combination-smoke-co-alarms/KN-COSM-IBA/
I resolved it by installing an air purifier in the bedroom where she vapes. But agreed, her vape isn’t invisible (though I think some e-liquids are) and OP didn’t mention so it’s low probability in this case.
They will trigger a laser alarm though. Depends what type of fire alarm you have. I have a laser alarm in my house and if I open the bathroom door too quick after a shower the steam can even trigger it.
They also don’t produce invisible results