Carbon Monoxide is a highly poisonous gas that has no smell, colour or taste. Any appliance that burns oil, solid fuel, wood or gas, including boilers, if they are not properly installed and maintained, can release it.

Do not ignore these symptoms:

• Other people in your home or building are having similar symptoms.
• You've recently moved into your home.
• Symptoms disappear when you go out or go on holiday but return when you return.
• Symptoms tend to be seasonal, e.g. headaches during the winter when the central heating is used more often.

Other danger signs include:

• Sooting or staining on or around the appliance.
• Excessive condensation in the room where the appliance is installed.
• Lazy yellow/orange coloured gas flames on cookers or boilers, rather than a sharp blue one.