When a carbon monoxide detector beeps, it’s crucial to reset it after changing the battery. Neglecting to reset the detector can leave you vulnerable to carbon monoxide poisoning. Follow these steps: press the reset button, usually located on the back or side of the device; hold the button for a few seconds until the beeping stops; wait for the detector to reinitialize, which may take a minute or two; and ensure the detector is properly mounted and has fresh batteries. Regularly testing and maintaining carbon monoxide detectors is essential for your safety.