I heat with a wood stove in my 1,000 q ft house for several years, but this year if I close the door to the spare bedroom the CO detector goes off in the room. Any ideas as to why? The detector in the livingroom just 10 ft from the wood stove, and every other detector dosen't go off. I've even tried swapping detectors, and it still goes off..only in the closed off, empty room. I'm stumped. Never did this until this year. :shrug: Mike.