Earlier this evening I was using my oven for about 3, 4 hours. I've never had trouble using it that long before. Anyway, my carbon monoxide detector starts to go off. So I turn off my oven open all my windows, all my doors and it keeps going off. What I'm asking is, can ovens cause the CO detector to go off? If not the oven, then what? How long should the alarm continuously go off? Was opening the doors and windows a good idea or useless? And what are signs of CO poisoning?