Honeywell R200 CO Carbon Monoxide Detector Alarm, £37.49 The Honeywell CO monitor is perfect for any living space, be it a home, guest house or even a caravan.

NORTHFORD, Conn., Nov. 20, 2013 - Silent Knight by Honeywell today introduced a single detector that senses both fire and carbon monoxide (CO) and greatly reduces nuisance alarms.

But Honeywell's Lyric Wi-Fi Leak and Freeze Detector is just that. It can do more than its competitors, and it's easier to use, since it doesn't need a smart hub to function.