Carbon Monoxide Detector Followup

I clearly survived the night, though when I checked and saw that it was supposed to get down to freezing or at least near it last night I only left the windows open by a crack. I did sleep next to the balcony door though. That makes 12 hours and no headache yet, and from the labels on the detector it sounds like it’s supposed to be quiet when you hit the reset button so you can call emergency services. Guess I’ll take it over to the apartment office and see what they have to say about it.

Actually, reading more closely it says specifically that it’s supposed to beep 4 times then pause for 5 seconds, not whine constantly for 12 hours. I got a replacement one from the apartment office, and it chirped upon being plugged in and has been silent since.