Carbon Monoxide Detector, 10 Years Battery Carbon Monoxide Alarm, CO Alarm with LCD Display and Test/Silence Button Conforms to EN50291 Standard : Amazon.co.uk: DIY & Tools
If your CO alarm chirps every 30 seconds, it's not an emergency but you should replace the CO alarm a.s.a.p. - Fire Line
How to Easily Stop Smoke Detector Beeping or Chirping | Inspired Housewife