Where is the best place to put a carbon monoxide detector?

He says the best place to put your carbon monoxide detector is either near your bed or your most dodgy gas appliance. This is because when carbon monoxide is in air, it won't rise up to the ceiling but will stay mixed in with everything else. Putting the detector near the most likely source or where you are most likely to suffer from carbon monoxide poisoning is the best plan of action. However, you do need to put smoke detectors near the ceiling because unlike carbon monoxide, smoke does rise.