A chimney is the flue, vent or passage through which the products of combustion from a burning fire pass. This may be constructed from a variety of materials, and depending on when the house was built, in varying sizes as well. A chimney plays a vital role for most domestic heating appliances and experts must be consulted when changing appliances or opening up a chimney that has not been in use for some time. Anglia | CICO | Pennine Systems