It's a common enquiry when new occupants move in and the find central heating not working. One of the most common plumbing enquiries usually occurs when new occupants move into a property and are unfamiliar with the central heating system.  During the cold months of the year, an enquiry like this is treated as an emergency.  A problem like this is not usually caused by a faulty component within the central heating system,  but just the new occupants being unfamiliar ...