Pre-use checks for existing flues: sweeping and visual inspection

Prior to bringing a flue back into use, it should be checked by – (a) Sweeping the flue. This is intended to clean the flue to demonstrate that it is essentially free from obstructions and to enable better visual inspection and testing of the flue. Tar deposits caused by burning wood may be especially hard to dislodge and must be removed. The debris that comes down the chimney when sweeping should be examined for excessive quantities of lining or brick that are signs that further repairs are necessary. (b) Carrying out a visual inspection of the accessible parts to identify – (i) deterioration in the structure, connections or linings which could affect the flue's gas-tightness and safe performance with the proposed combustion appliance. Examine the interior of the flue and the exterior of the chimney, including in the roof space. The presence of smoke or tar stains on the exterior of a chimney are signs of leaks that indicate damage; (ii) modifications made whilst the flue was out of service, such as the fitting of a ventilator terminal, which would be incompatible with using the flue with the intended appliance; and (iii) correct lining and lining sizes for the proposed new application.