Because carbon monoxide has no taste, smell or colour. Gas Safe Register strongly recommends you fit an audible carbon monoxide alarm in your home.
A carbon monoxide alarm looks similar to a smoke alarm and is very easy to fit by following the manufacturer’s instructions. You can purchase a carbon monoxide alarm for under £20 at your local DIY store, supermarket or from your energy supplier.
Before purchasing a carbon monoxide alarm, always make sure it is officially approved to EN 50291. It must have a British or European approval mark on it, such as a Kitemark.
You are particularly at risk from carbon monoxide poisoning while sleeping, as you may not be aware of early carbon monoxide symptoms until it’s too late. Do not use the ‘black spot’ detectors that change colour when carbon monoxide is present. These will not make a sound to wake you up if the poisonous gas is present while you are sleeping.